81 GTK Consortium Geological Surveys in Mozambique 2002–2007, edited by Yrjö Pekkala, Tapio Lehto & Hannu Mäkitie Geological Survey of Finland, Special Paper 48, 81–119, 2008 MESOARCHAEAN TO LOWER JURASSIC U-Pb AND Sm-Nd AGES FROM NW MOZAMBIQUE by Irmeli Mänttäri Mänttäri, I. 2008. Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique. Geological Survey of Finland, Special Paper 48, 81–119, five figures, two tables and three appendices. This paper exclusively presents isotopic ages for 35 rock samples from NW Mozam- bique sampled during the geological mapping of the LOT2 area. Dating methods in- clude SHRIMP and TIMS zircon U-Pb dating and the mafic rocks were dated using Sm-Nd mineral isochrones. The age range of felsic to mafic magmatic rocks varies from 2.91 Ga to 0.18 Ga. Several samples have ~500 Ma low Th/U zircon phases evi- dencing Pan-African metamorphism. Additional thermal event at ~0.8 Ga is indicated by anomalously high lower intercept ages. An indication of the existence of a ~3.1 Ga protolith was found from two samples. The oldest dated rock sampled from the eastern extension of the Archaean Zim- babwe craton to Mozambique is a tonalite with a zircon U-Pb age of 2907 ± 16 Ma. Four apparently Archaean ages of 2.71–2.50 Ga were dated from other TTG gneisses located in southern to northern parts of the Archaean domain. Additionally, these show Pan-African metamorphism at 520 ± 16 Ma. A ~1.8 Ga dolerite intrudes the Manica greenstones. Within the Archaean domain, Palaeoproterozoic Gairezi Group garnet gneiss cut by a ~1.0 Ga dolerite and Rushinga Group garnet-sillimanite gneiss indicate a maximum sedimentation age of ~2.0 Ga and supplementary Archaean provenanc- es. These sedimentary units suffered metamorphism at 518 ± 6 Ma. The tectonically emplaced Mesoproterozoic Báruè Complex in the core of the southern LOT2 area encloses ~1.1 (-1.3) Ga felsic igneous rocks with ~520 Ma metamorphic monazite. Crystalline rocks in the northern part of the LOT2 area covering the northern part of the Tete Province mainly have Mesoproterozoic ages. A felsic/intermediate volcanic rock from Fíngoè Supergroup yields a zircon U-Pb age of 1327 ± 16 Ma and all the dated granitic rocks are younger than this with ages between 1.2 Ga and 1.04 Ga. A gabbro from the Chipera Massif equivalent to the Tete Suite was dated at 1047 ± 29 Ma (Є Nd of +1.4). The few dated detrital zircon cores from Zámbuè Supergroup metas- andstone indicate a 1.3–1.2 Ga maximum sedimentation age and additional 2.7 Ga, 2.52 Ga, and 2.1 Ga sedimentary provinces. Late Mesoproterozoic Grenville ages were also dated from the Chacocoma granite (~1.05 Ga) located S of the coeval Tete Suite mafic plutonic rocks and from the Mashonaland dolerite (1.1 Ga; Є Nd = -7.3) intruding Umkondo metasediments further to the south from the LOT2 area. Neoproterozoic rocks comprise the ~0.86 Ga aplite granites belonging to Guro Bimodal Igneous Suite close to the northern part of the Archaean terrain. Moreover, Atchiza Suite gabbro, NW of the lake Cahora Bassa and the Matunda Suite gneiss located west of the Atchiza gabbro have ages of ~ 0.86–0.80 Ga. Pan-African metamorphism is evidenced by low Th/U metamorphic zircon domains. Palaeozoic Suites include the ~0.5 Ga Pan-African felsic rocks intruding the Mesoproterozoic rocks of the northern parts of the Tete prov- ince. Mesozoic Jurassic ~180 Ma Karoo event magmatism is evidenced by a syenite from the Gorongosa Intrusive Suite intruding the Mesoproterozoic Báruè Complex, Rukore Suite granite next to Zimbabwe border, and the Moeza dyke north of Tete.
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81
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
GTK Consortium Geological Surveys in Mozambique 2002–2007,edited by Yrjö Pekkala, Tapio Lehto & Hannu MäkitieGeological Survey of Finland, Special Paper 48, 81–119, 2008
MESOARCHAEAN TO LOWER JURASSIC U-Pb AND Sm-Nd AGES FROM NW MOZAMBIQUE
byIrmeli Mänttäri
Mänttäri, I. 2008. Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique. Geological Survey of Finland, Special Paper 48, 81–119, five figures, two tables and three appendices.
This paper exclusively presents isotopic ages for 35 rock samples from NW Mozam-bique sampled during the geological mapping of the LOT2 area. Dating methods in-clude SHRIMP and TIMS zircon U-Pb dating and the mafic rocks were dated using Sm-Nd mineral isochrones. The age range of felsic to mafic magmatic rocks varies from 2.91 Ga to 0.18 Ga. Several samples have ~500 Ma low Th/U zircon phases evi-dencing Pan-African metamorphism. Additional thermal event at ~0.8 Ga is indicated by anomalously high lower intercept ages. An indication of the existence of a ~3.1 Ga protolith was found from two samples.
The oldest dated rock sampled from the eastern extension of the Archaean Zim-babwe craton to Mozambique is a tonalite with a zircon U-Pb age of 2907 ± 16 Ma. Four apparently Archaean ages of 2.71–2.50 Ga were dated from other TTG gneisses located in southern to northern parts of the Archaean domain. Additionally, these show Pan-African metamorphism at 520 ± 16 Ma. A ~1.8 Ga dolerite intrudes the Manica greenstones. Within the Archaean domain, Palaeoproterozoic Gairezi Group garnet gneiss cut by a ~1.0 Ga dolerite and Rushinga Group garnet-sillimanite gneiss indicate a maximum sedimentation age of ~2.0 Ga and supplementary Archaean provenanc-es. These sedimentary units suffered metamorphism at 518 ± 6 Ma. The tectonically emplaced Mesoproterozoic Báruè Complex in the core of the southern LOT2 area encloses ~1.1 (-1.3) Ga felsic igneous rocks with ~520 Ma metamorphic monazite. Crystalline rocks in the northern part of the LOT2 area covering the northern part of the Tete Province mainly have Mesoproterozoic ages. A felsic/intermediate volcanic rock from Fíngoè Supergroup yields a zircon U-Pb age of 1327 ± 16 Ma and all the dated granitic rocks are younger than this with ages between 1.2 Ga and 1.04 Ga. A gabbro from the Chipera Massif equivalent to the Tete Suite was dated at 1047 ± 29 Ma (ЄNd of +1.4). The few dated detrital zircon cores from Zámbuè Supergroup metas-andstone indicate a 1.3–1.2 Ga maximum sedimentation age and additional 2.7 Ga, 2.52 Ga, and 2.1 Ga sedimentary provinces. Late Mesoproterozoic Grenville ages were also dated from the Chacocoma granite (~1.05 Ga) located S of the coeval Tete Suite mafic plutonic rocks and from the Mashonaland dolerite (1.1 Ga; ЄNd= -7.3) intruding Umkondo metasediments further to the south from the LOT2 area. Neoproterozoic rocks comprise the ~0.86 Ga aplite granites belonging to Guro Bimodal Igneous Suite close to the northern part of the Archaean terrain. Moreover, Atchiza Suite gabbro, NW of the lake Cahora Bassa and the Matunda Suite gneiss located west of the Atchiza gabbro have ages of ~ 0.86–0.80 Ga. Pan-African metamorphism is evidenced by low Th/U metamorphic zircon domains. Palaeozoic Suites include the ~0.5 Ga Pan-African felsic rocks intruding the Mesoproterozoic rocks of the northern parts of the Tete prov-ince. Mesozoic Jurassic ~180 Ma Karoo event magmatism is evidenced by a syenite from the Gorongosa Intrusive Suite intruding the Mesoproterozoic Báruè Complex, Rukore Suite granite next to Zimbabwe border, and the Moeza dyke north of Tete.
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Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
The “Mineral Resource Management Capacity Building Project, Republic of Mozambique, Compo-nent 2: Geological Infrastructure Development Pro-gramme, Geological Mapping LOT 2, 2002–2006” produced updated geological maps at the scale 1: 250 000 with explanations, covering the Provinces of Tete, Manica, and Sofala in NW Mozambique. During the bedrock mapping of the LOT 2 area, 37 rock samples were collected for radiometric dat-ing (Table 1) by geologists of a consortium lead by GTK (Geological Survey of Finland). The zir-con TIMS U-Pb and Nd-Sm mineral isochron ages were processed at GTK and the secondary ion mi-croprobe (SHRIMP) zircon U-Pb isotopic data were measured at VSEGEI, St. Petersburg.
For SHRIMP dating, only a limited number of analyses were performed. Therefore, especially in the case of sedimentary rocks, the age results may only be considered as preliminary. Therefore, further U-Pb analyses would be needed for comprehensive understanding of sedimentary provinces and the
INTRODUCTION
maximum sedimentation ages. In general, the zir-con in many Archaean rock samples was strongly altered and therefore TIMS dating yielded highly discordant U-Pb isotopic data. In addition, the very strong effect of the Pan-African metamorphism at ~0.5 Ga and sometimes the Early Pan-African proc-esses at ~0.8 Ga either disturbed the zircon U-Pb system, preferably in metamict grains, or crystal-lized a new zircon phase.
This paper exclusively presents the radiometric age results for 35 rock samples from the LOT 2 area, NW Mozambique. Further geological connec-tions and sample information must be obtained from the original map explanations (GTK Consortium, 2006a-d), from the other papers in this volume (e.g. Koistinen et al. 2008, Mäkitie et al. 2008, West-erhof et al. 2008), and from previous publications (Hunting team 1984, Koistinen et al. 2006, Mäkitie et al. 2006, Mänttäri et al. 2006, Westerhof 2006, and references therein).
ANALYTICAL METHODS
For ID-TIMS U-Pb dating, heavy minerals were separated using heavy liquids (methylenediiodide and Clerici’s solution) and a Frantz magnetic sepa-rator. The final selection of the minerals for U-Pb analysis was carried out by hand picking. The de-composition of selected zircon and monazite and extraction of U and Pb for multigrain ID-TIMS isotopic age determinations mainly followed the procedure described by Krogh (1973, 1982). 235U-208Pb (zircon) and 235U-206Pb (monazite) spiked and unspiked isotopic ratios were measured using a VG Sector 54 thermal ionization multicollector mass spectrometer (TIMS) in the static mode. According to repeated measurements of Pb standard SRM981,
TIMS U-Pb
the measured isotope ratios were corrected for 0.12–0.10 ± 0.05% / a.m.u. mass discrimination. Pb/U ratios were calculated using the PbDAT pro-gram (Ludwig, 1993). Plotting of the U-Pb isotopic data and age calculations were performed using the ISOPLOT/EX 3.00 program (Ludwig 2003). Com-mon lead corrections were carried out using the age-related Stacey’s and Kramers’s (1975) lead isotope compositions (206Pb/204Pb ± 0.2, 208Pb/204Pb ± 0.2, and 207Pb/204Pb ± 0.1). The total procedural blank level was 20–50 pg. All the ages were calculated with 2σ errors and without decay constant errors. In the figures, the data-point error ellipses are at the 2σ level.
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Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Selected zircon grains were mounted in epoxy resin together with chips of the TEMORA (Mid-dledale Gabbroic Diorite, New South Wales, Aus-tralia) and 91500 (Geostandard zircon; Wieden-beck et al. 1995) reference zircons. The grains were sectioned approximately in half and polished. Back-scattered electron images (BSE) and cathodo luminescence (CL) images were prepared for all zircons. The zircon U-Pb analyses were performed using a SHRIMP-II ion microprobe at Center of Isotopic Research, VSEGEI, St.Petersburg, Russia. Each analysis consisted of 5 scans through the mass range. The spot diameter was ~20 μm, and primary beam current was ~4 nA. The raw data reduction using the SQUID Excel Macro of Ludwig (2000) was done in a similar manner to that described by Williams (1998, and references therein). The Pb/U ratios were normalized relative to a value of 0.0668 for the 206Pb/238U ratio of the TEMORA reference
SHRIMP U-Pb dating
zircon, equivalent to an age of 416.75 Ma (Black et al. 2003). The common lead correction was car-ried out using the measured 204Pb and modern lead isotope composition (Stacey and Kramers 1975). Uncertainties given for individual analyses (App.1) are at the one σ level. The concordia plots and age calculations were performed using ISOPLOT/EX 3 (Ludwig 2003). In a few cases, the concordia ages were calculated using SQUID (Ludwig 2000). All the results are calculated at the 2σ level with the ig-nored decay constant errors. The uncertainties of the means of the Pb/U standard calibrations (see App. 1) are not included in table errors but are included in final concordia age errors: either added to the age calculated by Isoplot, or when calculated using SQUID, they are automatically taken into account in the final ages. In figures, the data-point error el-lipses as well as the error bars are at the 2σ level.
Sm-Nd mineral dating
For Sm-Nd analyses, handpicked mineral concen-trates were washed ultrasonically in warm 6 N HCl for 30 min, and rinsed several times in ultra clean water. The samples (150–200 mg) were dissolved in HF-HNO3 using Savillex® screw cap teflon beakers for 48h. A mixed 149Sm-150Nd spike was added to the sample prior to dissolution. After evaporation of flu-orides the residue was dissolved in 6N HCl. Sm and Nd were separated in two stages using a conventional cation-exchange procedure (7 ml of AG50Wx8 ion exchange resin in a bed of 12 cm length) and a modi-fied version of the Teflon-HDEHP (hydrogen di-ethylhexyl phosphate) method developed by Richard et al. (1976). The measurements were performed in a dynamic mode on a VG SECTOR 54 mass-spec-trometer using Ta-Re triple filaments. The 143Nd/144Nd ratio is normalized to 146Nd/144Nd = 0.7219. The aver-
age value for the La Jolla standard was 143Nd/144Nd = 0.511850 ± 10 (std, 50 measurements since 2002). The Sm/Nd ratio of the spike was calibrated against the Caltech-mixed Sm/Nd standard (Wasserburg et al. 1981). Based on duplicated analyses the er-ror in 147Sm/144Nd was estimated to be 0.4%. Initial 143Nd/144Nd and ε were calculated with the follow-ing parameters: λ147Sm = 6.54x10-12a-1, 147Sm/144Nd = 0.1966 and 143Nd/144Nd = 0.51264 for present CHUR (Jacobsen and Wasserburg 1980). T-DM was calcu-lated according to DePaolo (1981). Measurement on the rock standard BCR-1 provided the following val-ues: Sm = 6.58 ppm, Nd = 28.8 ppm, 147Sm/144Nd = 0.1380, 143Nd/144Nd = 0.51264 ± 0.00002. The blank measured during the analyses was 30–100 pg for Sm and 100–300 pg for Nd. Programs by Ludwig (2003) were used for age calculations.
AGE RESULTS
General information
The sample locations of the 35 dated rock sam-ples are presented in Figure 1. The rock types, cor-responding Suite and Group names, and related coordinates are collected in Table 1. The analyti-cal data are presented in three appendices, namely Appendix 1, Appendix 2, and Appendix 3 for U-Pb SHRIMP, U-Pb TIMS, and Sm-Nd TIMS isotopic
data, respectively. Some selected zircon CL images as well as the U-Pb concordia diagrams and Sm-Nd plots are collected in Figures 2 and 3, 4, respective-ly. For further geological information, please refer to the original map explanations (GTK Consortium 2006a–d).
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Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
Fig. 1. Simplified geological map of the LOT 2 area, NW Mozambique (simplified and modified after the work by the GTK Consortium). Sample numbers and sites of the dated rock samples are marked on map. See Table 1 for further sample information.
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Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Table 1. Sample information and dating methods.
Zircon separated from Rio Capoche granite is either short to long prismatic with clear crystal faces or the grains are ellipsoidal to quite tabular with smooth crystal faces. Within these transparent and reddish crystals, there are also translucent and more brownish grains. In all, although the shape of the crystals may vary, the population looks quite homogeneous. In CL images (Fig. 2), many grains show CL-paler zoned core domains surrounded by
Mos-1 / 1055-02 Rio Capoche Granite gneiss
CL-darker zones. However, as the magmatic zon-ing continues similarly through the whole crystal these do not show structurally separate core and rim domains. There are also longer zoned zircon grains without CL-pale centre domains and a few are completely CL-black.
A total of 18 zircon domains were dated using SHRIMP (App. 1). Seven of the analyses were rejected due to high common lead proportions.
LAB ID
FIELDNUMBER EASTING NORTHING ROCK-TYPE SUITE/GROUP DATING METHOD
Mos-1 1055-02 468284 8326745 Granite gneiss Rio Capoche granite U/Pb on Zr, SHRIMPMos-2 2253-03 432370 8416395 Monte Dombe granite Cassacatiza Suite U/Pb on Zr, TIMSMos-3 1024-02 527931 8134434 Aplite granite Guro Bimodal Suite U/Pb on Zr, SHRIMPMos-4 1072-02 494386 8126625 Aplite granite Guro Bimodal Suite U/Pb on Zr, TIMSMos-5 1097-03 541966 8202648 Granite Chacocoma granite U/Pb on Zr, SHRIMPMos-6 1170-03 513559 8099375 Massanga gneiss Mudzi Metamorphic Complex U/Pb on Zr, TIMSMos-7 1284-03 5037824 8119250 Gneiss Mudzi Metamorphic Complex U/Pb on Zr, SHRIMPMos-8 2450-03 463512 8369001 Granite Macanga Granite U/Pb on Zr, SHRIMPMos-9 2007-03 431180 8414421 Granite Cassacatiza Suite U/Pb on Zr, TIMSMos-10 2001-02 376147 8323791 Granite Monte Sanja Suite U/Pb on Zr, TIMSMos-11 2297-03 571952 8338810 Desaranhama granite Furancungo Suite U/Pb on Zr,TIMSMos-12 4493-03 316890 8371137 Granite Sinda Suite U/Pb on Zr, SHRIMPMos-13 6034-03 489885 8326199 Granite Castanho Granite U/Pb on Zr,TIMSMos-14 2395-03 279324 8287732 Gabbro Atchiza Suite Sm/Nd mineral isochronMos-15 4241-03 365684 8364734 Granite Cassacatiza Suite U/Pb on Zr, SHRIMPMos-16 13016-03 247659 8287248 Granite gneiss Matunda Suite U/Pb on Zr, SHRIMPMos-17 13014-03 433666 8286298 Gabbro Chipera Massif Sm/Nd mineral isochronMos-18 13032-03 384685 8304453 Granite Monte Capirimpica granite U/Pb on Zr, TIMSMos-19 2638-04 497125 8124948 Aplite granite Guro Bimodal Suite U/Pb on Zr, SHRIMPMos-20 2943-04 491312 8124697 Garnet-sillimanite
gneissRushinga Group U/Pb on Zr, SHRIMP
Mos-21 1519-04 527153 8040960 Fudeze orthogneiss Mudzi Metamorphic Complex U/Pb on Zr, SHRIMPMos-22 2893-04 472183 8158374 Granite Rukore Suite U/Pb on Zr,TIMSMos-23 13625-04 491095 7904308 Tonalite Mavonde Complex U/Pb on Zr, SHRIMPMos-24 15273-04 624078 7964477 Syenite Gorongosa Intrusive Suite U/Pb on Zr, TIMSMos-25 25416-04 481495 7908114 Dolerite Archaean terrain Sm/Nd mineral isochronMos-26 1011-02 512044 8008145 Garnet gneiss Gairezi Group U/Pb on Zr, SHRIMPMos-27 14410-03 503380 8325794 Moeza Dike Rukore Suite Sm/Nd mineral isochronMos-28 19313-04 594472 7857362 Granite Báruè Complex U/Pb on Zr, SHRIMPMos-29 19290-04 599246 7875441 Inchapa granodiorite Báruè Complex U/Pb on Mon and Zr, TIMS
and SHRIMPMos-30 19140-04 509199 7898986 Messeca granodiorite Mavonde Complex U/Pb on Zr, TIMSMos-31 6845-04 547097 7882708 Monte Chissui tonalite Báruè Complex U/Pb on Zr, TIMSMos-32 13888-04 491576 7758265 Dolerite Mashonaland dolerite (post-
metavolcanic rockFíngoè Supregroup U/Pb on Zr, SHRIMP
Mos-37 1714-05 515362 7896822 Dolerite Post-Gairezi Sm/Nd mineral isochronZr=zircon; Mon=monazite
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Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
Fig 2
Fig. 2. Selected CL images for SHRIMP U-Pb dated samples. The analysis spot sites and corresponding analysis numbers are indicated (see Table 3). Mos-1 granite gneiss: 2.1 and 3.1 belong to the 1.20 Ga age group; 4.1 has a high common lead content, and 15.1 shows post-crystallization lead loss. MOS-3 aplite granite: Magmatic ~850 Ma zircon. MOS-5 granite: Magmatic ~1.05 Ga zircon (3.1 and 5.1) and a supposedly inherited zircon with a CL-dark, disturbed core and a CL-bright metamorphic rim with a metamorphic age of ~1.05 Ga. Mos-7 gneiss: 6.1 and 9.1 are ~2.7 Ga magmatic zircon; younger and possibly metamorphic CL-dark zircon domains (7.1 and 13.1); CL-pale, low Th/U metamorphic rim 5.1 is ~520 Ma. Mos-8 granite: CL-dark ~470 Ma zircon with visible zoning (1.1 and 2.1); zircon showing a blurry internal structure (no analysis). Mos-12 granite: Zoned and homogeneous ~500 Ma zircon domains. Mos-15 granite: All analysed zircon domains are ~1.1 Ga. Mos-16 granite gneiss: ~800 Ma ages from 8.1, 6.1, 1.2, and 4.2; ~500 Ma from low Th/U domains 5.1, 6.2, 4.1, and 1.1; rounded, completely metamict zircon 4 enclosing a ~750 Ma zoned zircon (recrystallized?). Mos-19 aplite granite: Magmatic 850 Ma zircons (4, 5, and 6); metamorphic 850 Ma ages from rounded metamict zircon (3.2), its CL-pale rim (3.1), and from the CL-dark rim domain of zircon 9, which has a ~500 Ma core. Mos-20 garnet-sillimanite
Mos-3
14.1
4.1
12.1
Mos-1
2.1
15.1
4.1
3.1
6.16.2
3.1
5.1
6.1
Mos-5
Mos-7
13.1
7.1
6.1
9.1
5.1
1.1
Mos-8
2.1
2.22.1
10.2
10.1
1.1
Mos-15
2.1
5.1
3.1
3.2
Mos-16
Mos-121.1
1.2
5.1
4.1
6.1
6.2
8.1
4.2
Mos-19
3.1
3.2
6.1
5.1
4.1
9.1
9.2
9.1
9.21.1
1.2
3.1
12.1
Mos-21
1.1
1.2
2.13.1
12.1
3.1
Mos-23
4.1
5.11.1
Mos-20
Mos-26
12.1
9.1
10.1
15.1
Mos-28
11.1
8.1
12.1
13.1
5.2
5.1
6.1
7.1
Mos-29
10.1
6.1
6.2
8.1
8.2
9.1
3.1
2.1
5.1
Mos-33
1.1
11.1
2.1
Mos-34
100 m
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Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
gneiss: 2.8 Ga zoned zircon (1.2) enveloped by a CL-bright, low Th/U ~500 Ma rim (1.1); zircon core 9.2 plotting on a 1.98 Ga reference line is surrounded by a ~500 Ma CL-dark, low Th/U zircon phase (9.1); zoned core 12.1 plots on the ~2.5 Ga reference line and 3.1 is a ~500 Ma phase. Mos-21 orthogneiss: A > 3 Ga core (1.1) and ~2.60 Ga magmatic zircon phases (1.2, 2.1, and 3.1). Mos-23 tonalite: ~2.9 Ga magmatic zircon grains (1.1, 4.1, and 5.1). Mos-26 garnet gneiss: ~3.1 Ga rounded zircon (9.1); 15.1 is ~2.7 Ga; 10.1 and 12.1 plot on a 2.04 Ga cluster. Mos-28 granite: Zircon 8 is magmatic zircon in the 1119 ± 21 Ma zircon group and 13 and 12 are examples of inherited grains. MOS-29 granodiorite: 5.1, 6.1, and 7.1 magmatic ~1.08 Ga zircon domains; analysis from the CL-dark, low Th/U rim is highly discordant, indicating metamorphism at ~500 Ma. MOS-33 metasandstone: The youngest zoned zircon domain is ~0.83 Ga (2.1); detrital cores give ages of 2.7 Ga (6.2), 2.1 Ga (8.2), and 1.3-1.2 Ga (3.1, 10.1); CL-dark metamorphic rim zircon phases are 1.2 Ga (5.1) and 0.4 Ga (8.1) (analysis 6.1 was rejected due to a high common lead proportion). MOS-34 felsic/intermediate metavolcanic rock: Typical magmatic 1.3 Ga zircon (1.1 and 2.1); younger zircon domain 11.1 must have suffered lead loss.
On the concordia diagram (Fig. 3A), five analyses from zoned zircon domains plot in a cluster yielding a concordia age of 1201 ± 10 Ma. The remaining six concordant analyses plot roughly between 1050 Ma
Mos-2 / 2253-03 Monte Dombe granite, Cassacatiza Suite
Mos-3 / 1024-02 aplogranite gneiss, Guro Suite
and 1150 Ma. The younger data analysed mostly on CL-dark zoned domains probably show minor lead loss and therefore 1201 ± 10 Ma is interpreted as the age for the Rio Capoche granite.
Monte Dombe granite has a rather heterogene-ous zircon population. Zircon can be transparent to translucent, brownish to yellowish and short pris-matic or colourless and tabular with pyramidal edg-es, and the turbid, brownish grains exhibit mostly larger grain sizes.
Four zircon fractions were analysed for their Pb/U ratios using TIMS (App. 2). In general, the 206Pb/204Pb ratios are low and the analyses show a
high degree of discordance. As is normal, the most abraded fraction shows the lowest U content and the highest 206Pb/204Pb ratio. The analysed fractions plot roughly on the same line intercepting the concordia curve at 1102 ± 24 Ma (Fig. 3B). However, as the zircon population of the Monte Dombe granite is fairly heterogeneous and the analyses very discord-ant, it is difficult to judge the factual meaning of the 1102 ± 24 Ma age.
Mos-4 / 1072-02 aplogranite gneiss, Guro Suite
Sample Mos-3 contains abundant zircon with quite a homogeneous outlook. Grains are princi-pally long prismatic (l:w ~3–4), fairly colourless to yellowish-brownish, and transparent to translucent and contain occasional inclusions. Large, turbid, dark, and more formless grains are in the minority. In CL images (Fig. 3), the zircon shows clear mag-matic zoning and only a few show a dark, spotty CL indicating metamictization. A few probable cores were identified and some grains show thin later zir-con growth.
Fifteen zircon spots were dated using SHRIMP II (Appendix 1). As the supposed metamorphic rims were too thin for dating, all the age data come from magmatic domains only. On the concordia diagram (Fig. 4C), the concordant to nearly concordant data scatter between 760 and 920 Ma. The upper inter-cept age and the weighted average of the 207Pb/206Pb ages are equivalent. Thus, the age of the aplogranite gneiss is 852 ± 15 Ma. Later, most probably Pan-African metamorphism is evidenced by the thin zir-con envelopes around the magmatic crystals.
Aplogranite gneiss Mos-4 yielded a large amount of zircon with varying grain-size. It is predominant-ly almost colourless, transparent, and euhedral to subhedral (l:w = 3–5), and frequently contains dark inclusions. In the < 75 μm grain-size fraction, the grains have smooth surfaces. In the coarser grain-size fraction, dark brown and formless, most proba-bly inherited zircon grains also occur. For U-Pb dat-ing only the bright euhedral crystals were selected.
Four zircon fractions were analysed for their Pb/
U ratios using TIMS (App. 2). The zircon fractions have moderate U concentrations and the abraded fractions show the lowest U contents and the high-est 206Pb/204Pb ratios within a grain-size group. In general, the 206Pb/204Pb ratios are high and especially the abraded analyses show only minor discordance. The four analysed zircon fractions plot well on the same discordia line with concordia intercept ages of 867 ± 9 Ma and 389 ± 61 Ma (MSWD = 1; n = 4) (Fig. 3D).
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Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
The amount of zircon in Chacocoma granite is large, the population is morphologically homoge-neous, and its grain-size varies. Zircon is euhedral, long (l:w ~4–5), transparent to translucent, and col-ourless to brownish. Among these, elongated and more tabular grains, as well as grains with poorly de-veloped crystal faces were detected. In CL (Fig. 2), the zircon is commonly dark, shows magmatic zon-ing, and is occasionally enveloped by thin, or rarely wider, metamorphic CL-bright, structurally homo-geneous rims. These, in turn, can be corroded and replaced or enveloped by a still later and thinner zircon phase. In a few grains, metamorphic or mag-matic CL-medium dark rims occur between the CL-bright rims and core domains. Furthermore, some zircon grains or zircon domains show disturbed magmatic zoning to more blurry structures indicat-ing the beginning of metamictization.
A total of 15 zircon domains were dated using SHRIMP II (App. 1). Nine of these represent mag-
matically zoned crystals with or without thin meta-morphic rims. In addition, two CL-bright and one CL-medium dark rim domains were wide enough for dating. The CL-dark, mostly zoned core do-mains of the grains with wide rim domains were also dated.
On the concordia diagram (Fig. 3E), the rather concordant age data scatter primarily between 960 and 1080 Ma. One zoned zircon (Mos-5.8.1) gives an apparently higher 207Pb/206Pb age of ~1.2 Ga. However, the error is large and it partly overlaps with the other data. The U-Pb data from rim and core domains in single zircon grains are coeval. Be-cause there is no way to divide the data into separate age/domain groups and the age data are scattered, the weighted average of 207Pb/206Pb ages would give an age estimate for the rock. The data with the ap-parently highest 207Pb/206Pb age are excluded from the 1046 ± 20 Ma mean age.
Mos-7 / 1284-03 gneiss, Mudzi Metamorphic Complex
The amount of zircon in supposed Arcahean Massanga gneiss is extremely low. Zircon is either euhedral elongated (l:w ~2) or round to oval, very bright, and rather colourless. The grain-size varies from medium to extremely fine-grained.
Only three zircon fractions were analysed for their Pb/U ratios (App. 2) with TIMS as the zircon amount was extremely small. In general, the 206Pb/204Pb ra-tios are high. On the concordia diagram (Fig. 3F), the three fractions give an upper intercept age of
2.63 Ga for the gneiss. Although the discordia line is practically determined only by two data points, the Archaean age is evident. This is already seen in ~2.6 Ga 207Pb/206Pb ages for the analysed zircon fractions. However, as the age data from gneiss Mos-37 from the same metamorphic complex most probably in-dicate a ~2.71 Ga magmatic age and metamorphism at ~2.5 Ga, it may be that the 2.63 Ga age estimate from Massanga gneiss is an average age.
The zircon in Mos-7 gneiss splits into two main populations. One population consists of mainly long or elongated (l:w ~4–2), euhedral, partly cor-roded (?), pale brown, translucent to turbid grains and the other of very bright, colourless, elongated to oval or round grains. Among these, other inter-mediate phases with varying grain-sizes also occur. In CL images (Fig. 2), the majority of the zircon grains show magmatic zoning, which in a few cases is disturbed with a blurry structure. Only small, of-ten disturbed/altered possible cores were found. In addition to zoned zircons, there are also rounded, internally relatively homogeneous, CL-dark, prob-
ably metamorphic grains. Many zircons are envel-oped by metamorphic CL-bright and/or darker rim phases.
A total of 15 zircon domains were dated us-ing SHRIMP (App. 1). As the zircon material was shown to be quite complex internally, the analyses were performed on zoned zircons, CL-bright rims, and CL-dark, supposedly metamorphic grains. On the concordia diagram (Fig. 3G), the U-Pb data plot partly in a cluster and most of the data are discord-ant. The age results are divided into three groups according to the dated zircon domains: 1) The zoned zircon domains form the oldest ~2.71 Ga
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Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Mos-3 / 1024-02 Mos-4 / 1072-02
Mos-6 / 1170-03 Mos-5 / 1097-03
Mos-8 / 2450-03 Mos-7 / 1284-03
Mos-1 / 1055-02
Dashed line ellipses:
rejected data with high
common lead
Mos-2 / 2253-03
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Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
Mos-16 / 13016-03
rim
discordant, oldest 207 Pb/ 206 Pb age
Mos-9 / 2007-03 Mos-10 / 2001-02
Mos-13 / 6035-03 Mos-15 / 4241-03
Mos-11 / 2297-03 Mos-12 / 4493-03
Mos-18 / 13032
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Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Mos-21 / 1519-04 Mos-22 / 2893-4
Mos-23 / 13625-04 Mos-24 / 15273-4
Mos-26 / 1011-02
(most concordant data)
Mos-28 / 19313-04
Mos-19 / 2638-04
magmatic zircon
Mos-20 / 2943-04
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Mos-34 / 3157-03
Mos-30 / 19140-04
Mos-31 / 6845-04 Mos-33 / 4158-03
Mos-29 / 19290-04
Fig. 3. Concordia plots showing SHRIMP and TIMS zircon U-Pb isotopic data, samples from NW Mozambique. A) Mos-1/1055-02 Rio Capoche granite gneiss (SHRIMP); B) Mos-2/2253-03 Monte Dombe granite, Cassacatiza Suite (TIMS); C) Mos-3/1024-02 aplite granite, Guro Suite (SHRIMP). The inset shows the weighted average of the 207Pb/206Pb ages; D) Mos-4/1072-02 aplite granite, Guro Bimodal Suite (TIMS); E) Mos-5/1097-03 Chacocoma granite (SHRIMP). The inset shows the weighted average of the 207Pb/206Pb ages; F) Mos-6/1170-03 Maassanga gneiss, Mudzi Metamorphic Complex (TIMS); G) Mos-7/1284-03 gneiss, Mudzi Metamorphic Complex (SHRIMP); H) Mos-8/2450-03 Macanga granite (SHRIMP). The inset shows the weighted average of the 207Pb/206Pb ages I) Mos-9/2007-03 granite, Cassacatiza Suite (TIMS); J) Mos-10/2001-02 granite, Monte Sanja Suite (TIMS); K) Mos-11/2297-03 Desaranhama granite, Furancungo Suite (TIMS); L) Mos-12/4493-03 granite, Sinda Suite (SHRIMP); M) Mos-13/6035-03 granite, Castanho Granite (TIMS); N) Mos-15/4241-03 granite, Cassacatiza Suite (SHRIMP); O) Mos-16/13016-03 granite gneiss, Matunda Suite (SHRIMP). The inset shows the weighted average of the 207Pb/206Pb ages for the older group data (zoned cores, healthy magmatic crystal, and an internally quite homogeneous grain); P) Mos-18/13032 Monte Capirimpica granite (TIMS); Q) Mos-19/2638-04 aplite granite, Guro Suite (SHRIMP). The inset shows the weighted average of the 207Pb/206Pb ages for the older group magmatic zircon grains; R) Mos-20/2943-04 garnet-sillimanite gneiss, Rushinga Group (SHRIMP); S) Mos-21/1519-04 Fudeze orthogneiss, Mudzi Metamorphic Complex (SHRIMP); T) Mos-22/2893-04 granite, Rukore Suite (TIMS); U) Mos-23/13625-04 tonalite, Mavonde Complex (SHRIMP). Discordant Pb/U data from rim domains; V) Mos-24/15273-04 syenite, Gorongosa intrusive Suite (TIMS); W) Mos-26/1011-02 garnet gneiss, Gairezi Group (SHRIMP). The inset shows the weighted average of the 207Pb/206Pb ages; X) Mos-28/19313-04 granite, Báruè Complex (SHRIMP); Y) Mos-29/19290-04 In-chapa granodiorite, Báruè Complex (zircon SHRIMP and monazite TIMS); Z) Mos-30/19140-04 Messeca granodiorite, Mavonde Complex (TIMS); Å) Mos-31/6845-04 Monte Chissui tonalite, Báruè Complex (TIMS); Ä) MOS-33/4158-03 metasandstone, Zámbuè Group (SHRIMP); Ö) MOS-34/3157-03 felsic/intermediate metavolcanic rock, Fíngoè Supergroup (SHRIMP).
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Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
age group. 2) The ~2.54 Ga upper intercept age for three rounded, internally homogeneous grains and a metamorphic rim (Mos7.7.1, 8.1, 13.1, 3.1) pre-sumably reflects metamorphism at that time. This group also includes analyses from another internal-
ly homogeneous rim (Mos7.15.1) and from a zircon domain showing disturbed zoning (Mos7.10.1). 3) The Pan-African metamorphism at 520 ± 16 Ma is indicated by two CL-bright, low Th/U rim growths (Mos7.5.1 and 11.1).
Mos-8 / 2450-03 Macanga Granite
The Macanga granite yielded abundant zircon with a fairly heterogeneous population. In addi-tion to long prismatic slim, principally translucent crystals, the large, mostly translucent to turbid, short/equidimensional, and brownish zircon grains are the most common ones. In CL images (Fig. 2), the zircon mainly shows dark CL and blurry or al-ready nonexistent zoning due to the high degree of metamictization in most of the U-rich grains. The dated spots have been selected to represent as un-disturbed zoning as possible.
A total of fifteen zircon domains were dated using SHRIMP (App. 1). One data point was reject-ed due to a high common lead content. On the con-cordia diagram (Fig. 3H), the U-Pb data are mostly concordant and scatter between 350 Ma and 650 Ma. A weighted average of the 207Pb/206Pb ages is considered to give the best age estimate for the rock. Thus, the age for the Macanga granite is 470 ± 14 Ma. However, although the dated domains re-pre-sented as undisturbed zoned domains as possib-le, they may still show lead loss and the original age of the rock could be older.
The Cassacatiza granite contains abudant zircon that is either transparent and colourless or trans-parent-translucent and yellowish. The crystals are chiefly long prismatic (l:w = 3–7), medium to coarse-grained (>200 μm), and inclusion rich.
Four zircon fractions were analysed for their Pb/U ratios using TIMS (App. 2). Zircon is quite poor in U and has uniform radiogenic 208Pb/206Pb ratios.
Mos-9 / 2007-03 granite, Cassacatiza Suite
Two fractions (A and B) with the longest air-abra-sion times show the highest 206Pb/204Pb ratios and the U-Pb results of these are concordant and equal. They give a concordia age of 1077 ± 2 Ma (Fig. 3I). The fraction C shows the most discordant age result with the lowest 206Pb/204Pb ratio. The fourth, non-abraded fraction D plots just below points A and B, but the result is not equal with these.
Monte Sanja granite contains a large amount of medium- to fine-grained, transparent to translucent, colourless or yellowish zircon with short prismatic to almost needle-like morphologies. Some of the zircon grains contain dark inclusions.
Four zircon fractions were dated using TIMS
Mos-10 / 2001-02 granite, Monte Sanja Suite
(App. 2). Zircon is quite low in U, has uniform radiogenic 208Pb/206Pb ratio, and an extremely low 206Pb/204Pb ratio. The dated zircon fractions spread well along the discordia line that intercepts the concordia curve at 1050 ± 8 Ma and 81 ± 45 Ma (Fig. 3J).
Mos-11 / 2297-03 Desaranhama granite, Furancungo Suite
Desaranhama granite yielded a large amount of mainly coarse- to medium-grained, reddish, trans-lucent to turbid zircon with sharp edges and vary-ing prism lengths (l:w = 3–8). Especially the larger crystals contain inclusions.
Using TIMS, four zircon fractions were dated (Appendix 2). The zircon is quite low in U, has
uniform radiogenic 208Pb/206Pb, and low 206Pb/204Pb ratios. The longest abraded zircon fraction D with a 207Pb/206Pb age of 1037 Ma plots near to concordia curve and the other fractions are rather discordant (Fig. 3K). The upper intercept age 1041 ± 4 Ma de-termines the age for the Desaranhama granite.
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Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
Mos-12 / 4493-03 granite, Sinda Suite
Mos-13 / 6035-03 granite, Castanho Granite
Mos-14 / 2395-03 gabbro, Atchiza Suite
Mos-15 / 4241-03 granite, Cassacatiza Suite
Sinda granite contains abundant, short to long pris-matic zircon that is either quite colourless or yellow-ish, has a moderately coarse grain-size, and is largely transparent. In addition to a prismatic morphology, flat, equidimensional, and subhedral types also oc-cur. In CL images (Fig. 2), zircon frequently shows magmatic zoning. In a few grains, the zoning is quite blurry or homogenized and some show homogeneous zircon growth cutting the initial zoned phase. In ad-dition, a few cores were detected. However, these are mostly disturbed and/or too small for reliable dating.
A total of 15 zircon domains were dated using SHRIMP (App. 1). Dated zircon domains include zoned crystals and rim growths. All the data are concordant and plot in a same cluster on a concor-dia diagram (Fig. 3L), despite the different type of the dated domains. The concordia age for most of the data is 502 ± 8 Ma (n = 14/15). Accordingly, the seemingly younger cutting zircon phase (see Fig. 2: Mos-12/10.1) must represent later phases of the same magmatic event.
The zircon content of the Castanho granite is very high. The coarser grain-size fraction (>75 μm) mainly consists of long prismatic (l:w ~3–5), pale brown and transparent zircon, while the fine-grained (<75 μm) zircon is relatively colourless, transpar-ent, and the grains are generally shorter and more oval shaped. The zircon occasionally contains small inclusions.
Four zircon fractions were analysed for their Pb/U ratios using TIMS (App. 2). The zircon is quite poor in U, has an extremely high 206Pb/204Pb ratio, and uni-form radiogenic 208Pb/206Pb ratios. On the concordia diagram (Fig. 3M), three dated zircon fractions are just concordant with 0.65% errors for the Pb/U ra-tios. The concordia age for the concordant data is 1050 ± 2 Ma (n = 3). The slightly discordant fraction D also plots together with the other data.
The mineral separation of the Atchiza gabbro yielded abundant fresh plagioclase and pyroxene. The Sm-Nd data (App. 3 and Fig. 4D) reveal a low REE level and trend almost parallel with the chon-dritic trend. The whole rock, plagioclase, and py-
roxene analyses yield an isochron with an age of 864 ± 30 Ma (MSWD = 1) (Fig. 4A). This is the crystallization age of the main magmatic minerals. The initial epsilon value is –3.0.
The major part of the zircon in Cassacatize gran-ite is long (l:w ~3.5–5) prismatic, has a varying grain size, and is covered by yellowish to brown-ish pigment. The medium-sized grains are normally translucent, the largest are turbid, and the smaller ones quite bright. Among the long crystals, there are also a small amount of short (l:w ~2) ones. The pop-ulation looks quite uniform and the zircon shows sharp crystal edges. In CL images (Fig. 2), the zir-con generally shows well preserved oscillatory zon-ing. Only a few grains demonstrate blurry zoning and the start of homogenisation of the internal struc-tures. Many have a thin, CL-brighter rim around the
zoned zircon domains.A total of 14 zircon domains were dated using
SHRIMP (Appendix 1). The age data mostly comes from the zoned, magmatic domains and only few supposed rim and core phases were suitable for dat-ing. On the concordia diagram (Fig. 3N), the entire data plot in a cluster and 10 of the 14 spots define a concordia age of 1117 ± 12 Ma. Two of the rejected analyses have higher common lead contents, one is discordant, and the fourth one has an anomalously high U concentration. The quite homogeneous age data indicate zircon crystallization at 1117 ± 12 Ma.
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Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Fig. 4. Sm-Nd data. A) Mos-14/2395-03 gabbro, Atchiza Suite and Mos-17/13014-03 gabbro, Chipera Massif; B) Mos-25/25416-04 dolerite, Archaean domain and Mos-27/14410-03 Moeza Dike, Rukore Suite; C) Mos-32/13888-04 Post-Umkondo dolerite, Mashonaland dolerite and Mos-37/1714-05 Post-Gairezi dolerite; D) Whole rock evolution lines for Mos-14/2395-03, Mos-17/13014-03, Mos-25/25416-04, Mos-27/14410-03, Mos-32/13888-04, and Mos-37/1714-05.
Mos-16 / 13016-03 granite gneiss, Matunda Suite
Matunda gneiss yielded abundant, mostly rela-tively fine-grained zircon with an apparently hetero-geneous population. The zircon is mostly prismatic (l:w ~4–2) and has clear crystal faces. Colourless, mostly transparent grains are either short prismat-ic or oval-shaped and turbid ones show anhedral forms. In CL images (Fig. 2), the zircon population looks quite heterogeneous, including at least the fol-lowing types: 1) Totally altered/metamict, CL-dark zircon with occasional thin, CL-bright rims. These are the most common ones. 2) Zircon with preserved zoning in core domains. The corroded, CL-bright core domains are enveloped by a CL-dark zircon phase. 3) A few moderately healthy looking zoned crystals without rims or replacing/enveloping zircon material.
Only 15 zircon domains were dated using SHRIMP (App. 1). One data point was rejected due to a high common lead content. On the concordia diagram (Fig. 3O), the age data divides into two separate age groups: 1) The younger group consists of ages from low Th/U rim and/or replacing zircon phases, metamict and already quite homogenized grains, and from a new tip growth. A concordia age of 528 ± 4 Ma can be calculated for the late meta-morphism. 2) The older data deviate between 700 Ma and 830 Ma and come from zoned core domains and healthy zoned crystals. The six apparently older analyses deviate on the concordia curve (Fig. 3O) and therefore no concordia age can be calculated. The weighted average of the 207Pb/206Pb ages for these zircon domains is 784 ± 36 Ma.
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Mos-17 / 13014 gabbro, Chipera Massif
Mos-18 / 13032 Monte Capirimpica granite
Mos-19 / 2638-04 aplitie granite, Guro Suite
A ~700 Ma healthy, long, and zoned zircon crys-tal (Mos16.10.1) and the core (Mos16.12.1) with the highest 207Pb/206Pb age of over 900 Ma plot outside the two main age groups. However, as the error for the >900 Ma Pb-Pb age is very high and the ~700
Ma zircon has an anomalous appearance, these de-viating analyses may be considered unimportant. The initial age of the abundant rounded, metamict grains remains unresolved as they now show similar ages to the clearly metamorphic zircon phases.
Chipera gabbro yielded a relatively small amount of brown pyroxene and abundant fresh plagioclase. The Sm-Nd data (App. 3 and Fig. 4A) yield an iso-chron, which gives an age of 1047 ± 29 Ma for the
gabbro. The initial ratio of +1.4 is still much lower than the coeval depleted mantle, which according to the model by DePaolo (1981), for example has an εNd(1047 Ma) of +5.6.
Monte Capirimpica granite has abudant brown, transparent to translucent, prismatic (l:w = 3–4) zir-con. The population is quite homogeneous and the zircon mostly medium grained with a rather even size distribution.
Four zircon fractions were dated using TIMS
(App. 2). The zircon has a moderate U concentra-tion and varying 206Pb/204Pb ratios, one being rather low. The radiogenic 208Pb/206Pb ratios are uniform. On the concordia diagram (Fig. 3P), the four frac-tions plot well on the same discordia line with an upper intercept age of 1086 ± 7 Ma.
In aplite granite Mos-19, the zircon content of the nonmagnetic fraction is extremely low and the population looks quite heterogeneous in terms of outlook and grain size. The fine-grained zircon is transparent, colourless to brownish and has either tabular or oval to prismatic morphology. The larger grains are either turbid and dark brown or transpar-ent and quite colourless. The shapes vary from short prismatic to longer crystals. The number of flat, rounded grains is significantly high. The magnetic fraction contains abundant dark brown, turbid, paler coloured, and translucent zircon, principally with a euhedral shape. The zircon in CL (Fig. 2) shows a variety of internal structures. Most of the rounded and flat grains have a CL-dark and spotty internal structure with sporadic CL-paler rims and spots in-side. In addition, there are clearly-zoned crystals with or without structurally homogeneous rim do-mains.
Using SHRIMP, a total of 21 zircon domains were dated (App. 1). One analysis was rejected due to a high common lead content. On the concordia
diagram (Fig. 3Q), the data divide into two main age groups. The older data, including both zoned (n = 11) zircon domains and metamorphic, homo-geneous rims and their metamict core domains (n = 4), plot roughly between 850 Ma and 800 Ma. These data seemingly split further into two sub-clusters. However, because the Pb/Pb ages are over-lapping, all the data are considered as a single age group. The weighted average of the 207Pb/206Pb ages for the zoned zircon only is 867 ± 15 Ma (Fig. 3Q). The younger group includes five analyses: three de-termines a concordia age of 512 ± 4 Ma and two show slightly older ages. All these show an excep-tionally low Th/U ratio.
In summary, the zircon crystallized at 867 ± 15 Ma. Approximately coevally at 850–830 Ma, the flat, round, and metamict zircon suffered radiogenic lead loss (see Fig. 2; zircon 3). This zircon feasibly has a sedimentary origin and its initial age is un-known, as the U-Pb system of a metamict zircon is easily affected by hydrothermal events. Cambrian metamorphism at 512 ± 4 Ma is evident.
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Mos-20 / 2943-04 Garnet-sillimanite gneiss, Rushinga Group
Rushinga Group garnet-sillimanite gneiss yield-ed a small amount of zircon with a fine and uniform grain-size. The general tone is quite pinkish but sin-gle crystals are almost colourless, transparent, and elongated. Zircon shows either clear crystal faces or the surfaces are quite smooth. The darker grains are translucent. It is supposed that the older grains are healed/metamorphosed to transparent, colour-less grains. Almost every one of the mounted zir-con grains is enveloped by a CL-bright rim (Fig. 2). The mostly CL-dark inner/core domains are either altered or show compositional zoning. A few zoned cores are surrounded first by a CL-dark phase and secondly by a thin CL-bright rim (Fig. 2).
Using SHRIMP, 17 zircon domains were dated (App. 1). Two analyses have high common lead contents and were therefore rejected. On the ccon-cordia diagram (Fig. 3R), the U-Pb data divide into four separate groups: 1) Five concordant or slightly discordant, low Th/U analyses determine a concor-dia age of 518 ± 6 Ma. These youngest ages were measured from either CL-bright rims or CL-dark, compositionally zoned or homogeneous zircon do-mains (Fig. 2). 2) Four discordant data points from
zircon cores and grains fall on the same discordia line. Calculating these data solely or combined with the ~500 Ma data, the upper intercept age will be ~2.0 Ga. 3) Five discordant analyses from cores enveloped by CL-bright rims determine an upper intercept age of ~2.54 Ga when calculated with or without the youngest ~500 Ma data. 4) The highly discordant analysis (1.2; see also Fig. 2) from a CL-dark zoned core has a 207Pb/206Pb age of ~2.7 Ga and the enveloping CL-bright rim plots in the ~500 Ma group. When plotted together, an age of ca. 2.8 Ga can be estimated for the zircon core.
From the limited available age data, it is clear that the provenance is composed at least from rocks with ages of ~2.8 Ga, ~2.5 Ga, and ~2.0 Ga. The maximum age for sedimentation would be ~2.0 Ga. On the other hand, as the U-Pb data are highly dis-cordant and the metamorphism at ~500 Ma could have shifted the older data points slightly, the ages should only be considered as rough estimates. The concordia age of 518 ± 6 Ma (Fig. 3R) determined by analyses from the low Th/U and CL-bright zir-con rims records Pan-African metamorphism. This age is also a minimum age for the sedimentation.
Fudeze orthogneiss contains abundant pris-matic zircon with a varying grain size. The popu-lation looks homogeneous and only the degree of colour and brightness varies between the smallest and the largest zircons. The zircon shows composi-tional zoning in CL images (Fig. 2). A few inherited cores were detected. However, with the few excep-tions they are too small or altered for reliable U-Pb dating.
Using SHRIMP, a total of 16 zircon domains were dated (App. 1). One analysis has a high com-mon lead content and was therefore rejected. Unfor-tunately, this analysis was the only one from a thin CL-bright zircon rim. Furthermore, the four most
discordant data are ignored in this context. On the concordia diagram (Fig. 3S), the concordant and nearly concordant U-Pb data plot mostly between 2.6 and 2.8 Ga. Four discordant and two concordant analyses on zoned zircon define a discordia line that intercepts the concordia curve at ~2.59 Ga.
In addition to ~2.6 Ga zircon, five older ages be-tween 3.05 Ga and 2.65 Ga were measured from zoned zircon and an inherited core. These commonly also show higher Th/U compared to those of the ~2.6 Ga zircon. The apparent core in zircon 1 has a 207Pb/206Pb age of 3.05 Ga, whereas the main zircon domain belongs to the ~2.6 Ga age group (see Fig. 2). Thus, the age for the Fudeze orthogneiss is ~2.59 Ga.
Mos-22 / 2893-04 granite, Rukore Suite
Rukore granite yielded abundant zircon with a homogeneous population. The long to short crys-tals are mainly transparent, almost colourless, have clear crystal faces, and occasionally contain dark inclusions.
Three zircon fractions were dated using TIMS (App. 2). Two of them give concordant Lower Jurassic ages (Fig. 3T). As the Pb-U data from the
two individual, young, and low-U fractions are not exactly equal, the results may indicate some uncer-tainty within Pb and U fractionation during the mass spectrometry. Therefore, it is suggested that an age approximation of 195–180 Ma is used for the gran-ite. The third analysis (B) is discordant and suggests the involvement of some older lead.
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Mos-23 / 13625-04 tonalite, Mavonde Complex
Mos-24 / 15273-04 syenite, Gorongosa Intrusive Suite
Mos-25 / 25416-04 dolerite, Archaean terrain
Mos-26 / 1011-02 garnet gneiss, Gairezi Group
The zircon content of the Mavonde Complex tonalite is anomalously low. The very fine-grained zircon is largely brown, transparent, and prismatic. The large grains are either white to yellowish, totally turbid, and stubby or dark brown, translucent/trans-parent, prismatic (stubby to l:w ≤ 4). In CL images (Fig. 2), most of the zircons show clear magmatic zoning. A few are totally altered (turbid whitish/yel-lowish) and altered inherited cores are thought to be quite common.
The SHRIMP U-Pb age results from the tonalite are quite unambiguous and therefore only 12 anal-
yses were carried out (App. 1). On the concordia diagram (Fig. 3U), the ten concordant or nearly con-cordant analyses from magmatic, zoned zircon plot in a cluster at 2.9 Ga. The upper intercept age of 2907 ± 16 Ma is the age for the tonalite. Thus, this deformed tonalite is Mesoarchaean. The altered/metamict cores indicate even older zircon ages for inherited components. Two analyses give very dis-cordant age results (Fig. 3U). These were measured from a structurally rather homogeneous core and from a low Th/U zircon rim phase.
The zircon in Gorongosa syenite is mostly trans-parent to translucent, almost colourless to yellow-ish, and elongated. The crystal faces are frequently striated and the grains are preferably quite platy. In addition to this type of zircon, a small quantity of darker brown, stubby grains were detected. These
are considered as inherited.The two zircon fractions analysed using TIMS
(App. 2) give concordant and equal Lower Jurassic ages. The concordia age of 181 ± 2 Ma (Fig. 3V) determines the age for the syenite.
The dolerite Mos-25 contains abundant pyroxene and plagioclase for Sm-Nd isochron. The pyroxene is fresh, transparent, and brown. Plagioclase ranges from clear colourless to turbid white.
The Sm-Nd data (App. 3; Figs. 4B and 4D) reveal a relatively high REE level and the trend shows sig-nificant enrichment in LREE (cf. chondritic 147Sm/144Nd = 0.1966; Jacobsen and Wasserburg 1980). The whole rock, plagioclase, and pyroxene analy-
ses do not yield any decent isochron (MSWD = 17) (Fig. 4B). An anomalous feature is the relatively high Sm/Nd in the analyzed plagioclase fraction. The age of 1783 ± 51 Ma derived from the analyses on whole rock and pyroxene may be considered as the best estimate for the magmatic crystallization of the rock. The initial epsilon-value is –2.2 and sug-gests the involvement of older LREE-enriched ma-terial in the genesis of the rock.
The garnet-kyanite gneiss contains several zircon types with quite a uniform grain-size. These include: 1) transparent, colurless, round to oval and elongat-ed grains, which are at least partly metamorphic, 2) translucent to turbid, white prismatic crystals, and 3) thoroughly turbid, usually yellowish, most prob-ably metamict zircon. In CL images (Fig. 2), the zircon frequently shows compositional zoning. The few roundish, structurally fairly homogeneous zir-con grains are the clear exceptions. The CL-bright zircon rims are very few in this sample.
Using SHRIMP, 17 zircon domains were dated (App. 1). On the concordia diagram (Fig. 3W), the
majority of the U-Pb data plot on the same regres-sion line, intercepting the concordia curve at 2.06 Ga. These are mostly magmatic zircons. The lower intercept age of 0.86 Ga is quite high and therefore may indicate some real thermal event. However, as it is determined only by a few discordant data points the age is absolutely not an exact age. If well de-termined, the lower intercept age may have an im-portant role in estimating the minimum age for the sedimentation. The maximum age of 2041 ± 15 Ma for the sedimentation is determined by calculating the mean age for the 207Pb/206Pb ages of concordant data.
99
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Mos-27 / 14410-03 Moeza dike, Rukore Suite
Mos-28 / 19313-04 granite, Báruè Complex
In addition to ~2.04 Ga zircons, the SHRIMP age data also indicate Archaean provenances for the sed-
iment. The four Archaean zircons have 207Pb/206Pb ages of ~3.1 Ga, 2.7 Ga, and ~2.6 Ga (n = 2).
The mafic Moeza dike contains abundant py-roxene and plagioclase for Sm-Nd isochron dating with whole-rock powder. The pyroxene is fresh and brown, and the plagioclase looks somewhat hetero-geneous in transparency and colour.
The results of the Sm-Nd analyses are shown in
Appendix 3 and Figures 4B and 4D. The REE-level is high and the pattern clearly LREE enriched. The Sm-Nd analyses on minerals and whole rock yield an age of 180 ± 43 Ma, thus suggesting an age close to Jurassic Karoo basalts. The initial epsilon value of –0.3 is clearly low compared to coeval MORB.
The granite sample from Báruè Complex con-tains abundant rather homogeneous-looking zircon. The grain size of the usually stubby or short pris-matic zircon is largely fine to medium. It is totally transparent and colourless or turbid to translucent and pale brown. The larger grains are usually deep-er in colour and less transparent compared to finer-grained zircons. In CL images (Fig. 2), the mount-ed zircon shows generally compositional zoning. Moreover, evident core and rim domains are quite common.
A total of 14 zircon domains were SHRIMP dated (App. 1). Five concordant analyses from zoned zir-con crystals determine an age of 1119 ± 21 Ma (Fig. 3X). The older zircon domains have ages of ~1.83 Ga, 2.03–2.05 Ga, and 2.50 Ga. For the most part these were dated from cores enveloped by thin, CL-dark zircon rims around them (Fig. 2). The magmat-ic age for the granite is 1119 ± 21 Ma and the older data from inherited zircon indicate either a sedimen-tary precursor or the inherited grains originate from neighbouring quartzite.
The Inchapa granodiorite yielded only a small amount of brownish, turbid to translucent, coarse- to fine-grained zircon and abundant monazite. The larger zircon grains are typically shorter prismatic and the smaller grains show long prismatic mor-phology. Among these, a few transparent and mere-ly colourless grains were detected. In CL images (Fig. 2), the short grains show oscillatory zoning. CL-dark zircon rims frequently envelope the zoned centre domains. A few completely CL-dark grains were also detected.
Using SHRIMP, 17 zircon domains were dated (App. 1). Three analyses were rejected due to high
common lead contents. On the concordia diagram (Fig. 3Y), the U-Pb data from zoned zircon largely plot at around 1100 Ma. The seven concordant anal-yses define an age of 1079 ± 7 Ma for the grano-diorite. The U-Pb data from the CL-dark rims are highly discordant, indicating lead loss from high U zircon domains
TIMS analysis of monazite gives slightly re-versely discordant age data (App. 2 and Fig. 3Y). This may be due to the excess of 206Pb from 230Th of a high Th-mineral (Schärer 1984). However, the re-sult clearly indicates the Pan–African metamorphic effect at ~520 Ma.
The zircon population in Messeca granodiorite looks rather homogeneous. Larger grains are com-pletely turbid, grey-brown, and mostly euhderal, although sub- to anhedral forms also exist. The fine-grained zircon is mostly translucent, gray-brown, and short prismatic (l:w = 2–3).
Five zircon fractions were analysed using TIMS U-Pb (App. 2). The U-Pb data are highly discordant and plot in two clusters (Fig. 3Z), in spite of the dif-ferent analysed grain-size fractions and air-abrasion times used. The practically two-point reference line intercepts the concordia curve at ~2.5 Ga and 0.56
100
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
Mos-31 / 6845-04 Monte Chissui tonalite, Báruè Complex
MOS-32 / 13888-04 Mashonaland dolerite
MOS-33 / 4158-03 metasandstone, Zámbuè Supergroup
Ga. It may be argued that the seemingly Archaean, high-U zircon was affected by later metamorphism. Therefore, the upper intercept age of the extremely
discordant data could only be taken as a rough age estimate.
The main part of the zircon in Monte Chissui to-nalite is extremely bright, has a tint of pink colour, and is either euhedral or more oval in shaped. The length to width ratio of the crystals and grains is mostly 2 to 4. In addition to the bright ones, only a few translucent and turbid grains were detected.
The TIMS dating of four zircon fractions (App. 2 and Fig. 3Å) yielded discordant U-Pb data despite the very bright appearance of zircon. The analyses A and D plot close each other and therefore the
discordia line is practically determined by three points only. The apparent concordia intercept ages are ~1.30 Ga and 0.60 Ga. The fairly high lower intercept age most probably indicates the effect of metamorphism(s) and the discordia upper intercept may therefore have been shifted to an older age. Consequently, it is suggested that this age is consid-ered merely as a maximum age for the tonalite. The highest 207Pb/206Pb ages of ~1150 Ma would then be the minimum age for the rock.
The Mashonaland dolerite contains abundant pyroxene and plagioclase for Sm-Nd isochron dat-ing with whole-rock powder. Pyroxene in the sam-ple Mos-32 is fresh, fairly transparent and green-ish-grey. Plagioclase ranges from clear colourless to slightly turbid white. The Sm-Nd data (App.3;
Figs. 4C and 4D) reveal a relatively high level of REE in plagioclase. The data on minerals and whole rock give an age of 1102 ± 52 Ma. The initial ЄNd of –7.3 suggests major involvement of older LREE-enriched material in the genesis of this rock.
The Zámbuè Supergroup metasandstone yielded only a small amount of zircon with varying grain size. The zircon morphology varies from long pris-matic (l:w = 3–5) to oval-shaped, it is transparent to translucent, and reddish-brownish to almost colour-less. Many grains are pigmented. The zircon in CL (Fig. 2) shows a range of complex internal struc-tures. Cores are often rounded and/or corroded and surrounded by CL-dark zircon rims. There are also mixed types, from totally metamict CL-dark zircon to zoned euhedral grains. Almost all the grains are enveloped by CL-dark rims.
Eighteen zircon domains were dated using SHRIMP (Appendix 1 and Fig. 3Ä). The U-Pb data are concordant and show varying ages and Th/U ra-tios. The analyses from CL-dark rim phases show high common lead contents but only two analyses showing the highest common lead were rejected from data processing, as zircon rim data would oth-erwise be totally missing. Zoned, mostly rounded cores yield Archaean (~2.7 Ga and 2.5 Ga) and Palaeoproterozoic (2.1 Ga and 1.9 Ga) sources for the sandstone. Four analyses from zoned cores and
euhedral zircon grains plot around 1.3–1.2 Ga. Fur-thermore, a zircon rim around a rounded zoned core plots on the younger end of this group.
Three analyses plot around 1.07 Ga. Two of these analyses (1.1 and 11.1) have very high common lead contents: one comes from a younger, low Th/U zircon phase of zircon 1 and the other probably hit on marginal zone between the zoned core and rim domains. The third analysis (7.1) was performed from a zoned, CL-dark zircon.
The ~0.83 Ga age was measured from a mag-matically zoned zircon (2.1). A CL-dark, low Th/U zircon rim (Appendix 1: analysis 8.1) with a Palaeo-proterozoic rounded core indicates metamorphism at ~ 0.4 Ga. However, as this analysis shows an ex-tremely high common lead content its age result is inaccurate.
The maximum sedimentation age determined from these limited data is certainly ~1.2 Ga. The two single younger magmatic ages of ~1.07 Ga and 0.83 Ga may indicate an even younger maximum sedimentation age. Nevertheless, single data points are not considered to provide reliable evidence.
101
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
MOS-37 / 1714-05 dolerite, Post-Gairezi Group
MOS-34/ 3157-03 felsic/intermediate metavolcanic rock, Fíngoè Supergroup
The metavolcanic rock from Fíngoè Supergroup yielded abundant zircon. The crystals are mostly prismatic (l:w = 3–4), transparent, and either quite colourless or weakly brownish. The colourless grains contain inclusions. In CL (Fig. 2), the zircon shows oscillatory zoning. A few grains have homo-geneous zircon growth around corroded and zoned centre domains and several apparent cores were de-tected. However, due to the limited number of anal-yses the cores were ignored during dating.
Using SHRIMP, a total of 12 zircon domains were dated (App. 1). All the data are concordant or nearly concordant and the analyses are all from zoned, euhe-dral zircons. On the concordia diagram (Fig. 3Ö), the data scatter between 950 and 1400 Ma. The six oldest analyses plot in a cluster determining the con-cordia age of 1327 ± 16 Ma for the zircon crystal-lization. The younger U-Pb data most probably in-dicate lead loss connected to metamorphism at ~0.8 Ga, which is the lower intercept age of the discordia line defined by all the data (See Fig. 3Ö).
Post-Gairezi dolerite yielded garnet and transpar-ent plagioclase for Sm-Nd analyses. The quality of pyroxene was too poor for analysis. For analysis, the garnet separate was ground and leached step-wise in HCl according to the method of DeWolf et al. (1996). The Sm-Nd data (App. 3; Figs. 4C and 4D) reveal a relatively high REE level and the trend shows significant enrichment in LREE (cf. chon-dritic 147Sm/144Nd = 0.1966). Three analyses do not
plot on the same isochron. The age estimate for the garnet-whole rock pair is 503 ± 8 Ma, whereas anal-yses on plagioclase and whole rock define a slope that gives an age of 973 ± 73 Ma and an initial ep-silon value of –1.3. Provided that the plagioclase has remained as a closed system since its magmatic crystallization, the age estimate for the dike is 973 ± 73 Ma. The ~500 Ma is consistent with the Pan-African metamorphism.
SUMMARY OF THE AGE RESULTS
General summary
This report presents isotopic ages for 35 rock samples from NW Mozambique sampled during geological mapping of the LOT 2 area. The age range of felsic to mafic magmatic rocks varies from 2.91 Ga to 0.18 Ga. Several samples have ~500 Ma low Th/U zircon phases evidencing Pan-African
metamorphism. An indication for the existence of a ~3.1 Ga protolith was found from two samples. The age data and comments on these are summarized in Table 2 and the age distribution of 32 supposedly magmatic rock samples is illustrated in Figure 5.
Archaean domain – Zimbabwe craton
The Archaean Zimbabwe craton extends margin-ally into Mozambique. The oldest dated rock with a zircon U-Pb age of 2907 ± 16 Ma is a tonalite located near the town of Manica, south of the Mani-ca greenstone belt. No inherited zircon was found from this tonalite. Four apparently Archaean ages of 2.71-2.50 Ga were dated from TTG gneisses lo-cated in southern to northern parts of the Archaean domain. 3.1 Ga and 2.7 Ga inherited zircon grains were found from the 2.60 Ga orthogneiss. Further-more, the 2.71 Ga gneiss has metamorphic zircon
domains indicating either metamorphism or a pro-longed thermal history at ca. 2.54 Ga and finally Pan-African metamorphism at 520 ± 16 Ma.
A Palaeoproterozoic Sm-Nd mineral age of ~1.8 Ga was measured for a dolerite intruding the Ar-chaean Manica greenstones. An initial ЄNd of –2.2 suggests the involvement of older LREE-enriched material in the genesis of the rock. Garnet in ~1.0 Ga dolerite crosscutting the Palaeoproterozoic Gai-rezi mica schist within the Archaean domain reflects Pan-African metamorphism at ~500 Ma. Palaeopro-
102
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
Tabl
e 2.
Sum
mar
y of
the
age
resu
lts, s
ampl
es fr
om N
W M
ozam
biqu
e.
LA
BID
FIE
LD
NU
MB
ER
RO
CK
TY
PESU
ITE
/G
RO
UP
DA
TIN
GM
ET
HO
DA
GE
RE
SUL
TA
GE
TY
PE, N
UM
BE
R O
F FR
AC
TIO
NS,
ET
C.
AG
ER
EM
AR
KS
Mos
-110
55-0
2G
rani
te g
neis
sR
io C
apoc
he
gran
iteSH
RIM
PU
-Pb
1201
±10
Ma
Con
cord
ia a
ge; n
=5/1
1; z
oned
zirc
onM
agm
atic
age
6/11
ana
lyse
s sho
w le
ad lo
ss a
t 105
0−11
50 M
a.
Mos
-222
53-0
3M
onte
Dom
be
gran
iteC
assa
catiz
aSu
iteTI
MS
U-P
b11
02 ±
24
Ma
Upp
er in
terc
ept a
ge; n
= 4/
4 ~M
agm
atic
age
H
eter
ogen
eous
zirc
on p
opul
atio
n. M
SWD
=4.4
. R
athe
r dis
cord
ant P
b/U
dat
a. M
axim
um a
ge?
Mos
-310
24-0
2A
plite
gra
nite
Gur
o B
imod
al
Suite
SHR
IMP
U-P
b85
2 ±
15 M
aM
ean
of 20
7 Pb/20
6 Pb a
ges;
n=1
5/15
Mag
mat
ic a
geA
ge d
ata
scat
ter b
etw
een
760
and
920
Ma.
R
ims t
oo th
in fo
r rea
sona
ble
datin
g
Mos
-410
72-0
2A
plite
gra
nite
Gur
o B
imod
al
Suite
TIM
SU
-Pb
867
± 9
Ma
Upp
er in
terc
ept a
ge; n
= 4/
4 M
agm
atic
age
MSW
D=1
.0
Mos
-510
97-0
3G
rani
teC
haco
com
agr
anite
SHR
IMP
U-P
b10
46±
20 M
aM
ean
of 20
7 Pb/20
6 Pb a
ges;
n=1
4/15
; m
ostly
zon
ed z
ircon
Mag
mat
ic a
geA
ge d
ata
scat
ter b
etw
een
960
and
1080
Ma.
A fe
w th
in, l
ow T
h an
dU
met
amor
phic
zirc
on ri
ms a
re c
oeva
l with
the
mag
mat
ic z
ircon
gr
ains
. One
zirc
on sh
ows a
n ap
pare
ntly
hig
her 20
7 Pb/20
6 Pb a
ge o
f ca
. 1.2
Ga.
M
os-6
1170
-03
Mas
sang
agn
eiss
Mud
ziM
etam
orph
icC
ompl
ex
TIM
SU
-Pb
~2.6
3 G
aU
pper
inte
rcep
t age
; n=
3/3
Mag
mat
ic a
ge
(met
amor
phic
?)A
ctua
lly, a
lmos
t a tw
o po
int l
ine.
No
mat
eria
l for
furth
er a
naly
ses.
Just
a ro
u gh
age
estim
ate.
Mos
-712
84-0
3G
neis
sM
udzi
Met
amor
phic
Com
plex
SHR
IMP
U-P
b~2
.71
Ga
~2.5
4 G
a
520
± 16
Ma
Upp
er in
terc
ept a
ge;
n= 6
/6; z
oned
Upp
er in
terc
ept a
ge: n
=4/6
; m
etam
orph
ic g
rain
s,rim
Con
cord
ia a
ge: n
=2/2
; Cl-b
right
, low
Th
/U ri
ms
Mag
mat
ic a
geM
etam
orph
ic a
ge?
Met
amor
phic
age
~2.
70−2
.72
Ga
zirc
ons.
Scat
terin
g an
d ov
erla
ppin
g m
agm
atic
and
met
amor
phic
age
dat
a.
Mos
-824
50-0
3G
rani
teM
acan
gaG
rani
teSH
RIM
PU
-Pb
470
± 14
Ma
Mea
n of
207 Pb
/206 Pb
age
s; n
=13/
14;
zone
dM
agm
atic
age
?M
etam
orph
ic a
ge?
The
fact
s tha
t the
Pb/
U d
ata
scat
ter b
etw
een
350
Ma
and
650
Ma
and
zirc
ons s
how
Cl-d
ark,
som
etim
es b
lurr
y in
tern
al st
ruct
ure
may
si
gnify
dis
turb
ing
of th
e or
igin
al m
agm
atic
age
.M
os-9
2007
-03
Gra
nite
Cas
saca
tiza
Suite
TIM
SU
-Pb
1077
± 2
Ma
Con
cord
ia a
ge; n
= 2/
4 M
agm
atic
age
Fr
actio
n D
onl
y sl
ight
ly d
isco
rdan
t but
not
equ
al w
ith A
and
B
frac
tions
. C is
cle
arly
dis
cord
ant .
Mos
-10
2001
-02
Gra
nite
Mon
te S
anja
Su
iteTI
MS
U-P
b10
50 ±
8 M
aU
pper
inte
rcep
t age
; n=
4/4
Mag
mat
ic a
ge
MSW
D=0
.3. L
ow 20
6 Pb/20
4 Pb ra
tios.
Mos
-11
2297
-03
Des
aran
ham
agr
anite
Fura
ncun
goSu
iteTI
MS
U-P
b10
41 ±
4 M
aU
pper
inte
rcep
t age
; n=
4/4
Mag
mat
ic a
ge
MSW
D=1
.0
Mos
-12
4493
-03
Gra
nite
Sind
a Su
iteSH
RIM
PU
-Pb
502
± 8
Ma
Con
cord
ia a
ge; n
=14/
15; m
ostly
zon
edM
agm
atic
age
R
epla
cing
stru
ctur
ally
hom
ogen
eous
zirc
on p
hase
and
zon
ed c
ore
dom
ains
are
coe
val .
Mos
-13
6035
-03
Gra
nite
Cas
tanh
oG
rani
teTI
MS
U-P
b10
50 ±
2 M
aC
onco
rdia
age
; n=3
/4M
agm
atic
age
O
ne fr
actio
n sl
ight
ly d
isco
rdan
t but
plo
ts o
n a
sam
e cl
uste
r.
Mos
-14
2395
-03
Gab
bro
Atc
hiza
Sui
teSm
-Nd
864±
30
Ma
Min
eral
isoc
hron
age
; n=3
; py
roxe
ne+p
lagi
ocla
se+w
hole
-roc
kM
agm
atic
age
In
itial
eN
d = −3
.0
Mos
-15
4241
-03
Gra
nite
Cas
saca
tiza
Suite
SHR
IMP
U-P
b11
17 ±
12
Ma
Con
cord
ia a
ge; n
=10/
14; m
ostly
zon
ed
zirc
on d
omai
n sM
agm
atic
age
103
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Tabl
e 2.
Con
tinue
d.
LA
BID
FIE
LD
NU
MB
ER
RO
CK
TY
PESU
ITE
/G
RO
UP
DA
TIN
GM
ET
HO
DA
GE
RE
SUL
TA
GE
TY
PE, N
UM
BE
R O
F FR
AC
TIO
NS,
ET
C.
AG
ER
EM
AR
KS
Mos
-16
1301
6-03
Gra
nite
gne
iss
Mat
unda
Sui
teSH
RIM
PU
-Pb
784
± 36
Ma
528
± 4
Ma
Mea
n of
207 Pb
/206 Pb
age
s; n
=6; m
ostly
zo
ned
zirc
on d
omai
nsC
onco
rdia
age
; n=3
/6 (r
im, t
ip, m
etam
ict
grai
n - a
ll lo
w T
h/U
)
Age
s for
zon
ed
zirc
on d
omai
nsM
etam
orph
ic a
ge
The
olde
r dat
a sc
atte
r rou
ghly
bet
wee
n 70
0 an
d 85
0 M
a.
The
met
amic
t gra
ins m
ost p
roba
bly
even
old
er!
One
zirc
on h
as a
207 Pb
/206 Pb
age
of c
a. 0
.9 G
a (o
lder
?).
Mos
-17
1301
4-03
Gab
bro
Chi
pera
Mas
sif
Sm-N
d10
47±
29 M
aM
iner
al is
ochr
on a
ge; n
=3;
pyro
xene
+pla
gioc
lase
+who
le-r
ock
Mag
mat
ic a
ge
Initi
al e
Nd
=+1.
4
Mos
-18
1303
2-03
Gra
nite
Mon
teC
apiri
mpi
cagr
anite
TIM
SU
-Pb
1086
± 7
Ma
Upp
er in
terc
ept a
ge; n
=4/4
Mag
mat
ic a
ge
MSW
D=0
.03
Mos
-19
2638
-04
Apl
ite g
rani
teG
uro
Bim
odal
Su
iteSH
RIM
PU
-Pb
867±
15 M
a
512±
4 M
a
Mea
n of
207 Pb
/206 Pb
age
s; n
=11;
all
zone
dC
onco
rdia
age
; n=3
/5; l
ow T
h/U
Mag
mat
ic a
ge?
Met
amor
phic
age
Con
tain
s als
o fla
t, ro
unde
d de
trita
l-typ
e m
etam
ict z
ircon
gra
ins
show
ing
now
eith
er 8
50-8
00 M
a or
~50
0 M
a ag
es.
Mos
-20
2943
-04
Gar
net-
silli
man
itegn
eiss
Rus
hing
aG
roup
SHR
IMP
U-P
b2.
0 G
a
518±
6 M
a
Upp
er in
terc
ept a
ge o
f you
nges
t det
rital
zi
rcon
gra
ins
Con
cord
ia a
ge; n
=3/5
; low
Th/
U
Max
imum
sedi
men
tatio
n ag
eM
etam
orph
ic a
ge
Prov
enan
ces:
ca.
2.8
Ga,
2.5
Ga,
and
2.0
Ga
~500
Ma
min
imum
age
for s
edim
enta
tion
Mos
-21
1519
-04
Fude
zeor
thog
neis
sM
udzi
Met
amor
phic
Com
plex
SHR
IMP
U-P
b~2
.59
Ga
Upp
er in
terc
ept a
ge; n
=6; a
ll zo
ned
zirc
ons
Mag
mat
ic a
geIn
herit
ed z
ircon
s ~2.
7 an
d ~3
.1 G
a
Mos
-22
2893
-04
Gra
nite
Ruk
ore
Suite
TIM
SU
-Pb
195−
180
Ma
Con
cord
ia a
ge; n
=2M
agm
atic
age
The
two
data
poi
nts a
re n
ot e
xact
ly e
qual
Mos
-23
1362
5-04
Tona
lite
Mav
onde
Com
plex
SHR
IMP
U-P
b29
07±1
6 M
aU
pper
inte
rcep
t age
; n=1
0/12
; all
zone
d zi
rcon
sM
agm
atic
age
No
inhe
rited
age
s for
zirc
ons.
Mos
-24
1527
3-04
Syen
iteG
oron
gosa
Intru
sive
Sui
teTI
MS
U-P
b18
1±2
Ma
Con
cord
ia a
ge; n
=2M
agm
atic
age
Mos
-25
2541
6-04
Dol
erite
Arc
haea
nte
rrai
nSm
-Nd
1783
±51
Ma
Min
eral
isoc
hron
age
; n=2
; py
roxe
ne+w
hole
-roc
kM
agm
atic
age
Initi
al e
Nd
=−2.
2. P
lagi
ocla
se a
nom
alou
s (hi
gh S
m/N
d).
Mos
-26
1011
-02
Gar
net g
neis
sG
aire
zi G
roup
SHR
IMP
U-P
b20
41 ±
15
Ma
~0.8
5 G
a
Mea
n of
207 Pb
/206 Pb
age
s; n
=6; m
ostly
zo
ned
Low
er in
terc
ept a
ge
Max
imum
sedi
men
tatio
n ag
eLe
ad lo
ss
Prov
enan
ces:
3.1
Ga,
2.7
-2.6
Ga,
and
2.0
Ga
Min
imum
sedi
men
tatio
n ag
e?
Mos
-27
1441
0-03
Dol
erite
Moe
za D
ike,
R
ukor
e Su
iteSm
-Nd
180±
43 M
aM
iner
al is
ochr
on a
ge; n
=3;
plag
iocl
ase+
pyro
xene
+who
le-r
ock
Mag
mat
ic a
geIn
itial
eN
d = −0
.2.
Mos
-28
1931
3-04
Gra
nite
Bár
uèC
ompl
e xSH
RIM
PU
-Pb
1119
±21
Ma
Con
cord
ia a
ge; n
=5; a
ll zo
ned
Mag
mat
ic a
geIn
herit
ed z
ircon
s ~2.
5 G
a, ~
2.03
Ga,
and
~1.
83 G
a
Mos
-29
1929
0-04
Inch
apa
gran
odio
rite
Bár
uèC
ompl
exSH
RIM
PTI
MS
U-P
b
1079
±7 M
a~5
20 M
aC
onco
rdia
age
; n=7
; all
zone
d zi
rcon
sM
onaz
ite; n
=1M
agm
atic
age
Met
amor
phic
age
No
inhe
rited
zirc
on.
Slig
htly
reve
rsel
y di
scor
dant
dat
a po
int.
104
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
rock
LA
BID
FIE
LD
NU
MB
ER
RO
CK
TY
PESU
ITE
/G
RO
UP
DA
TIN
GM
ET
HO
DA
GE
RE
SUL
TA
GE
TY
PE, N
UM
BE
R O
F FR
AC
TIO
NS,
ET
C.
AG
ER
EM
AR
KS
Mos
-30
1914
0-04
Mes
seca
gran
odio
rite
Mav
onde
Com
plex
TIM
SU
-Pb
~2.5
Ga
(?)
Ref
eren
ce li
ne in
terc
ept a
ge; n
=5
Low
er in
terc
ept a
t ~0.
5 G
a
Mag
mat
ic a
ge w
ith
effe
ct o
f ~0.
5 G
a m
etam
orph
ism
?
Inac
cura
te a
ge: h
ighl
y di
scor
dant
dat
a, p
ract
ical
ly a
two
poin
t lin
e,
affe
cted
by
~0.5
Ga
met
amor
phis
m. S
IMS
datin
g is
nee
ded
to so
lve
the
prob
lem
.
Mos
-31
6845
-04
Mon
te C
hiss
ui
tona
lite
Bár
uèC
ompl
exTI
MS
U-P
b~1
.3 G
a (~
1.15
Ga)
Upp
er in
terc
ept a
ge; n
=4(H
ighe
st20
7 Pb/20
6 Pb a
ge)
~Mag
mat
ic a
geD
isco
rdan
t dat
a w
ith a
nom
alou
sly
high
low
er in
terc
ept a
ge.
Ther
efor
e, th
e up
per i
nter
cept
age
may
be
too
high
.
Mos
-32
1388
8-04
Dol
erite
Mas
hona
land
dole
rite
(Pos
t-U
mko
ndo)
Sm-N
d11
02±5
2 M
aM
iner
al is
ochr
on a
ge;
plag
iocl
ase+
pyro
xene
+who
le-r
ock
Mag
mat
ic a
geIn
itial
eN
d = −7
.3.
Mos
-33
4158
-03
Met
a-sa
ndst
one
Zám
buè
Supe
rgro
upSH
RIM
PU
-Pb
1.2
(-1.
3) G
an=
4 (z
oned
dom
ains
)M
axim
umse
dim
enta
tion
age
Sing
le a
naly
ses o
n zo
ned
zirc
ons a
t 1.0
7 G
a an
d 0.
83 G
a? D
etrit
al
core
s 2.7
Ga,
2.5
2 G
a, 2
.1 G
a, a
nd 1
.3-1
.2 G
a. M
etam
orph
ic z
ircon
do
mai
ns a
t ~1.
2, ~
1.07
, and
~0.
4 G
aM
os-3
431
57-0
3Fe
lsic
/in
term
edia
tem
etav
olca
nic
Fíng
oèSu
preg
roup
SHR
IMP
U-P
b13
27 ±
16 M
aC
onco
rdia
age
; n=6
; zon
ed z
ircon
Mag
mat
ic a
geA
nom
alou
sly
high
low
er in
terc
ept a
ge o
f ~0.
8 G
a m
ay in
dica
te le
a dlo
ss a
t tha
t tim
e.
Mos
-37
1714
-05
roc k
Dol
erite
Post
-Gai
rezi
dole
rite
Sm-N
d~1
.0 G
a
~500
Ma
Min
eral
isoc
hron
age
: pla
gioc
lase
+
who
le-r
ock
Min
eral
isoc
hron
age
: gar
net +
who
le-
Mag
mat
ic a
ge
Met
amor
phic
age
Tabl
e 2.
Con
tinue
d.
105
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Mesoproterozoic domains – Grenvillian orogeny
Fig. 5. Age distribution of magmatic (n = 32) and metamorphic (n = 5) ages, samples from NW Mozambique. Corresponding major tectonic events are also indicated.
terozoic Gairezi Group garnet gneiss and Rushinga Group garnet-sillimanite gneiss indicate a maxi-mum sedimentation age of ~2.0 Ga and additionally
Archaean provenances. These sedimentary rocks suffered metamorphism at ~0.85 Ga and at 518 ± 6 Ma.
Báruè Complex
This Mesoproterozoic unit is tectonically em-placed to its present position in the central and southern part of the LOT2 area. A 1.12 Ga granite (Mos-28) intruding quartzite contains 2.50 Ga, 2.03 Ga, and 1.8 Ga inherited zircon grains. Further, a granodiorite east of Inchapa has a zircon age of 1079 ± 7 Ma and Pan-African metamorphism is indicated by ~520 Ma monazite. The age for the Monte Chis-sui tonalite is poorly constrained and estimated to be 1.15–1.30 Ga.
Area north of the E–W trending Zambezi rift covering the northern part of Tete Province
A felsic/intermediate volcanic rock from the Fín-goè Supergroup yields a zircon U-Pb age of 1327 ± 16 Ma with an anomalous lower intercept age of ~0.8 Ga, possibly reflecting a thermal event at
that time. The few dated detrital zircon cores from Zámbuè Supergroup metasandstone definitely indi-cate a 1.3–1.2 Ga maximum sedimentation age and additional 2.7 Ga, 2.52 Ga, and 2.1 Ga sedimenta-tion provinces. The two single younger magmatic ages of ~1.07 Ga and 0.83 Ga may indicate an even younger maximum sedimentation age.
The following lists of granite ages show that all the dated granitic rocks are younger than the Fíngoè Supergroup. A Rio Capoche granite has a zircon U-Pb age of 1201 ± 10 Ma. Zircon from granite be-longing to the Cassacatiza Suite has an age of 1117 ± 12 Ma. Six other granites show ages clustering between 1.10 Ga and 1.04 Ga. These are ~1.10 Ga Ma Monte Dombe granite, 1086 ± 7 Ma Monte Ca-pirimpica granite, 1077 ± 2 Ma Cassacatiza granite, 1050 ± 2 Ma Castanho granite, 1050 ± 8 Ma gran-ite from the Monte Sanja Suite, and 1041 ± 4 Ma Desaranhama granite from the Furancungo Suite. A gabbro sample from Chipera Massif equivalent to
0
400
800
1200
1600
2000
2400
2800
3200
Age
/ M
a
MAGMATIC AGES: n=32METAMORPHIC AGES: n=5 data-point error symbols are 2s
Archaean Zimbabwe Craton
Palaeoproterozoic Ubendian orogenic belt, late phase
Mesoproterozoic Grenvillian (Kibaran) orogeny
Neoproterozoic Early Pan-African
Pan-African orogeny
Jurassic Karoo event
106
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
Neoproterozoic Suites – Early phases of Pan African orogeny
the Tete Suite has a Sm-Nd mineral age of 1047 ± 29 Ma and an ЄNd of +1.4.
Others
South of the Tete Suite mafic and ultramafic plu-tonic rocks, a Chacocoma granite yielded a Pb-Pb
mean age of 1046 ± 20 Ma. Further to the south of the LOT2 area, a sill-like Mashonaland dolerite intruding Umkondo metasediments yields an age of 1.1 Ga with an ЄNd value of –7.3, indicating major involvement of LREE-enriched material in the ge-nesis of this rock.
Palaeozoic and Mesozoic Suites
ACKNOWLEDGEMENTS
Guro Bimodal Suite
Three aplite granites in Guro Bimodal Igneous Suite, close to the northern part of the Archaean ter-rain, yield zircon ages of 867 ± 9 Ma, 852 ± 15 Ma, and 867 ± 15 Ma. Pan-African metamorphism at 512 ± 4 Ma is evidenced by low Th/U metamorphic zircon domains.
Atchiza and Matunda Suites
Atchiza Suite gabbro, NW of the lake Cahora Bassa in the northern part of the LOT 2 area, has an age of ~ 860 Ma and an ЄNd of -3.0. The mean Pb-Pb age for the Matunda Suite gneiss located west of the Atchiza gabbro is ~ 0.8 Ga, but the oldest magmatic zircon is 0.85 Ga. 528 ± 4 Ma metamorphic zircon domains indicate the strong effect of Pan-African metamorphism.
Pan-African felsic intrusive rocks
Two Palaeozoic granites intruding the Mesopro-terozoic northern part of the LOT2 area, N of Tete Province have ages of 470 ± 14 Ma and 502 ± 8 Ma.
Karoo event
Three samples show Jurassic Karoo igneous ages.
A syenite from the Gorongosa Intrusive Suite in-truding the Mesoproterozoic Báruè Complex has an age of 181 ± 2 Ma. Granite of the Rukore Suite in-truding the Palaeoproterozoic Rushinga Group su-pracrustals next to the Zimbabwe border yields an age of 195–180 Ma. A N–S trending Moeza dyke in Mesoproterozoic bedrock north of Tete has a Sm-Nd age of 180 ± 43 Ma with an initial ЄNd of –0.3.
The personnel, namely A. Larionov, D. Matukov, S. Presniakov, and N. Rodionov of CIR/VSEGEI in St. Petersburg, are thanked for the SHRIMP anal-yses. H. Huhma was responsible for the Sm-Nd analyses, A. Pulkkinen helped with the mass spec-trometry, and E. Kuosmanen produced the geologi-cal map. They are all thanked. M. Karhunen, M. Niemelä, and T. Hokkanen all from GTK are warmly
thanked for rock crushing and milling, heavy min-eral separation, and laboratory work, respectively. Last but definitively not least, I am grateful to the project geologists who did the sampling and helped with the geological aspects, to R. Lahtinen for the manuscript review, to P. Hölttä and A. B. Westerhof for comments on manuscript, and to R. Siddall for revising the English.
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108
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
App
endi
x 1.
Zirc
on S
HR
IMP
U-P
b is
otop
ic d
ata,
sam
ples
from
NW
Moz
ambi
que.
Spo
tD
ated
zir
con
dom
ain
% 206 Pb
c
ppm
Upp
mT
h
232 T
h/23
8 Upp
m20
6 Pb*
(1)
206 Pb
/238 U
Age
(1)
207 Pb
/206 Pb
Age
% Dis
-co
r-da
ncy
(1)
207 Pb
*
/206 Pb
*±%
(1)
207 Pb
*
/235 U
±%(1
)20
6 Pb*
/238 U
±%er
rco
rr
Mos
-1 /
1055
-02
Rio
Cap
oche
gra
nite
gne
iss
MO
S-1.
1.1
quite
hom
ogen
eous
, CL-
brig
ht c
ore
dom
ain
3.80
2913
0.48
510
87±2
413
55±3
4025
0.08
7018
.02.
200
18.0
0.18
362.
40.
13M
OS-
1.1.
2zo
ned,
CL-
dark
tip
dom
ain
0.17
754
520.
0712
311
21±
411
17±
190
0.07
69 0
.92.
012
1.0
0.18
980.
40.
38M
OS-
1.2.
1zo
ned,
CL-
med
ium
0.92
4927
0.56
911
98±1
712
51±1
304
0.08
22 6
.8
2.32
0 6
.90.
2042
1.5
0.22
MO
S-1.
3.1
zone
d, C
L-m
ediu
m0.
4915
392
0.62
2712
10±
911
79±
52-3
0.07
93 2
.6
2.25
8 2
.80.
2065
0.8
0.29
MO
S-1.
4.1
zone
d, C
L-br
ight
cen
tre
dom
ain
7.23
146
0.48
312
16±3
7 8
25±6
40-3
20.
0670
31.0
1.91
031
.00.
2077
3.3
0.11
MO
S-1.
5.1
zone
d, C
L-br
ight
cen
tre
dom
ain
5.27
219
0.47
411
92±2
612
61±3
806
0.08
3019
.02.
310
19.0
0.20
322.
40.
12M
OS-
1.6.
1zo
ned,
CL-
pale
cen
tre d
omai
n1.
7051
210.
439
1191
±14
1171
±150
-20.
0789
7.4
2.
210
7.5
0.20
301.
30.
18M
OS-
1.7.
1zo
ned,
CL-
pale
cen
tre
dom
ain
3.23
157
0.47
313
59±2
615
73±2
2016
0.09
7012
.03.
150
12.0
0.23
472.
20.
18M
OS-
1.8.
1zo
ned,
CL-
pale
cen
tre
dom
ain
3.20
3422
0.65
612
09±1
710
32±2
10-1
50.
0736
11.0
2.09
011
.00.
2062
1.6
0.15
MO
S-1.
9.1
zone
d, C
L-br
ight
cen
tre
dom
ain
4.29
1910
0.56
311
74±2
713
26±3
9013
0.08
5020
.02.
350
20.0
0.19
972.
50.
12M
OS-
1.10
.1zo
ned,
CL-
dark
, tip
dom
ain
0.55
316
960.
3156
1207
± 6
1136
± 38
-60.
0776
1.9
2.
260
2.0
0.20
600.
60.
28M
OS-
1.11
.1zo
ned,
CL-
dark
, tip
dom
ain
0.81
169
170.
1027
1094
± 7
1028
± 58
-60.
0735
2.9
1.
874
3.0
0.18
490.
70.
23M
OS-
1.12
.1zo
ned
Cl-d
ark
0.67
182
790.
4532
1187
± 9
1190
± 5
30
0.07
97 2
.72.
222
2.8
0.20
220.
80.
28M
OS-
1.13
.1zo
ned,
CL-
pale
cen
tre
dom
ain
5.54
125
0.41
211
25±4
4 2
50±1
200
-77
0.05
1051
.01.
350
52.0
0.19
084.
20.
08M
OS-
1.14
.1zo
ned
Cl-d
ark
0.34
353
400.
1254
1056
± 6
1056
± 3
50
0.07
45 1
.71.
829
1.9
0.17
790.
70.
35M
OS-
1.15
.1zo
ned
Cl-d
ark
0.89
237
750.
3337
1061
± 7
1003
± 5
4-6
0.07
26 2
.71.
791
2.8
0.17
900.
70.
25M
OS-
1.16
.1zo
ned
Cl-d
ark
0.58
249
410.
1741
1125
± 8
1095
± 4
6-3
0.07
60 2
.31.
997
2.4
0.19
060.
80.
32M
OS-
1.17
.1zo
ned
Cl-d
ark
0.18
505
113
0.23
8211
11±
510
89±
23
-20.
0758
1.1
1.96
6 1
.20.
1882
0.5
0.38
MO
S-3
/ 102
4-02
apl
ite g
rani
te, G
uro
Suite
MO
S3.1
.1zo
ned
--36
920
70.
5848
904
± 6
863
±19
-50.
0678
0.9
1.40
81.
10.
1506
0.7
0.60
MO
S3.2
.1zo
ned
--76
325
40.
3497
891
±16
882
±36
-10.
0684
1.7
1.
399
2.6
0.14
821.
90.
74M
OS3
.3.1
zone
d--
199
106
0.55
2486
1±
785
0±2
6-1
0.06
74 1
.3
1.32
71.
50.
1428
0.8
0.54
MO
S3.4
.1zo
ned
0.03
586
208
0.37
7286
5±
684
6±2
3-2
0.06
73 1
.1
1.33
11.
30.
1436
0.7
0.55
MO
S3.5
.1zo
ned
0.03
427
245
0.59
5285
6±
684
8±2
1-1
0.06
7310
.01.
318
1.2
0.14
193
0.7
0.57
MO
S3.6
.1zo
ned
0.17
1036
485
0.48
113
767
± 6
902
±66
150.
0691
3.2
1.
203
3.3
0.12
630.
80.
24M
OS3
.7.1
zone
d (d
ark
CL)
0.16
466
233
0.52
5481
3±1
982
4±5
61
0.06
65 2
.7
1.23
33.
70.
1344
2.5
0.68
MO
S3.8
.1zo
ned
(dar
k C
L)0.
0311
8134
30.
3013
379
2±
581
9±6
73
0.06
64 3
.2
1.19
73.
30.
1308
0.7
0.20
MO
S3.9
.1zo
ned
--24
211
30.
4827
794
± 8
902
±28
120.
0691
1.3
1.
248
1.7
0.13
101.
00.
61M
OS3
.10.
1zo
ned
0.04
280
149
0.55
3383
7±
781
3±3
9-3
0.06
62 1
.9
1.26
62.
10.
1386
0.8
0.41
MO
S3.1
1.1
zone
d0.
0657
326
90.
4869
840
±11
844
±19
00.
0672
0.9
1.29
01.
70.
1392
1.4
0.84
MO
S3.1
2.1
zone
d0.
0931
119
90.
6638
845
± 6
820
±35
-30.
0664
1.7
1.
283
1.8
0.14
010.
80.
41M
OS3
.13.
1zo
ned
0.10
261
131
0.52
3286
9±
784
9±3
2-2
0.06
74 1
.5
1.34
01.
80.
1443
0.9
0.50
MO
S3.1
4.1
zone
d0.
0332
320
00.
6438
826
± 7
859
±42
40.
0677
2.0
1.
276
2.2
0.13
670.
90.
40M
OS3
.15.
1zo
ned
--18
772
0.40
2387
2±
684
1±3
1-4
0.06
71 1
.5
1.34
01.
70.
1448
0.8
0.45
109
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
App
endi
x 1.
Con
tinue
d.
Spo
tD
ated
zir
con
dom
ain
% 206 Pb
c
ppm
Upp
mT
h
232 T
h/23
8 Upp
m20
6 Pb*
(1)
206 Pb
/238 U
Age
(1)
207 Pb
/206 Pb
Age
% Dis
-co
r-da
ncy
(1)
207 Pb
*
/206 Pb
*±%
(1)
207 Pb
*
/235 U
±%(1
)20
6 Pb*
/238 U
±%er
rco
rr
MO
S-5
/ 109
7-03
Cha
coco
ma
gran
iteM
OS5
.1.1
rim (p
ale
CL)
0.09
105
230.
2315
973
±16
1092
±38
110.
0759
1.9
1.70
42.
60.
1629
1.8
0.69
MO
S5.1
.2co
re (z
oned
,dar
k C
L)0.
0445
716
40.
3764
979
±18
1002
±16
20.
0726
0.8
1.64
12.
20.
1640
2.0
0.93
MO
S5.2
.1co
re (d
ark
CL)
0.07
451
860.
2066
1011
±56
1041
±22
30.
0740
1.1
1.73
6.1
0.17
006.
00.
98M
OS5
.2.2
rim (m
ediu
m C
L en
velo
ped
by th
in C
L-pa
le ri
m)
0.11
127
200.
1619
1052
± 10
1058
±40
10.
0746
2.0
1.82
42.
20.
1773
1.0
0.45
MO
S5.3
.1zo
ned(
unal
tere
d)--
494
225
0.47
7510
45±
710
97±1
75
0.07
610.
91.
845
1.1
0.17
590.
70.
61M
OS5
.4.1
zone
d(un
alte
red)
0.02
600
201
0.35
9110
52±
710
55±1
30
0.07
450.
61.
821
1.0
0.17
730.
70.
75M
OS5
.5.1
zone
d(un
alte
red)
0.03
965
283
0.30
135
969
±23
1104
±30
120.
0763
1.5
1.70
72.
90.
1622
2.5
0.86
MO
S5.6
.1rim
(CL-
pale
)0.
8596
240.
2613
963
± 9
1071
±58
100.
0751
2.9
1.66
83.
10.
1611
1.0
0.33
MO
S5.6
.2co
re(d
istu
rbed
zon
ing,
dark
CL)
0.17
1212
533
0.45
171
979
± 8
955
±75
-30.
0709
3.7
1.60
43.
80.
1640
0.8
0.22
MO
S5.7
.1zo
ned
(dar
k C
L)--
995
351
0.36
148
1031
± 6
983
±36
-50.
0719
1.8
1.72
01.
90.
1735
0.7
0.36
MO
S5.8
.1zo
ned
(dar
k C
L+th
in ri
m)
0.01
547
175
0.33
8310
48±1
211
93±5
912
0.07
983.
01.
943
3.2
0.17
651.
30.
40M
OS5
.9.1
zone
d (d
ark
CL+
thin
rim
)0.
0041
712
60.
3162
1027
± 8
1064
±68
40.
0748
3.4
1.78
13.
50.
1726
0.9
0.25
MO
S5.1
0.1
zone
d(da
rk C
L)0.
0644
616
40.
3862
971
±13
1013
±16
40.
0730
0.8
1.63
51.
70.
1626
1.4
0.87
MO
S5.1
1.1
zone
d(da
rk C
L)0.
2717
454
0.32
2710
72±
810
48±3
2-2
0.07
431.
61.
852
1.8
0.18
090.
80.
46M
OS5
.12.
1zo
ned(
dark
CL)
0.05
492
154
0.32
7810
96±
6010
53±1
4-4
0.07
440.
71.
900
6.0
0.18
506.
00.
99M
OS-
7 / 1
284-
03 g
neis
s, M
udzi
Met
amor
phic
Com
plex
MO
S7.1
.1zo
ned(
osc)
0.01
284
122
0.44
116
2497
± 19
2670
± 7
60.
1819
0.4
11.8
6 1
.00.
4730
0.9
0.91
MO
S7.2
.1zo
ned(
strip
ed)
0.06
318
204
0.66
110
2184
± 35
2585
± 22
160.
1728
1.3
9
.610
2
.30.
4033
1.9
0.82
MO
S7.3
.1rim
(hom
og,C
L-pa
le+d
ark
core
)0.
0428
497
0.35
8418
97±1
1024
69±
2523
0.16
12 1
.5
7.6
10
6.6
0.34
206.
40.
97M
OS7
.4.1
zone
d(os
c)0.
0151
863
0.13
127
1621
± 48
2373
± 21
320.
1524
1.3
6
.010
3
.60.
2858
3.3
0.94
MO
S7.5
.1rim
(lig
ht C
L+da
rk, a
ltere
d co
re)
0.92
270
0.00
2 5
16±
12 6
80±3
6024
0.06
217
.0 0
.710
17
.00.
0834
2.4
0.14
MO
S7.6
.1zo
ned(
strip
ed)
--47
634
10.
7419
525
13±
1627
28±
258
0.18
84 1
.5
12.3
80 1
.70.
4767
0.8
0.45
MO
S7.7
.1ho
mog
CL-
dark
inne
r dom
ain/
roun
ded
(+th
in ri
m)
0.01
361
102
0.29
141
2411
± 37
2523
± 70
40.
1665
4.2
10
.410
4.5
0.45
361.
80.
40M
OS7
.8.1
hom
og C
L-da
rk in
ner d
omai
n/ro
unde
d (+
thin
rim
)--
361
980.
2813
222
84±
2826
20±
9213
0.17
65 5
.5
10.3
50 5
.70.
4252
1.5
0.26
MO
S7.9
.1zo
ned(
strip
ed)
0.05
265
440.
1774
1814
± 90
2461
± 59
260.
1605
3.5
7
.190
6
.70.
3250
5.7
0.85
MO
S7.1
0.1
zone
d(di
stur
bed,
dark
CL)
0.02
554
230
0.43
206
2321
±110
2495
± 7
70.
1638
0.4
9.7
90
5.5
0.43
305.
51.
00M
OS7
.11.
1rim
(CL-
pale
/met
am)
1.57
501
0.01
452
2±
9 4
75±2
70-1
00.
0566
12.0
0.6
5812
.00.
0843
1.7
0.14
MO
S7.1
2.1
zone
d(os
c,C
L-da
rk)
0.10
614
980.
1785
966
± 15
1860
± 17
480.
1137
0.9
2.5
35 1
.90.
1617
1.6
0.87
MO
S7.1
3.1
hom
og,C
L da
rk/m
etam
?/ro
unde
d0.
0034
311
40.
3415
226
81±1
3025
53±
7-5
0.16
960.
412
.050
5.9
0.51
605.
91.
00M
OS7
.14.
1zo
ned(
strip
ed)
0.08
136
470.
3651
2339
± 46
2610
± 37
100.
1754
2.2
10
.580
3.2
0.43
702.
30.
73M
OS7
.15.
1tip
/rim
?,ho
mog
(dar
k C
L)0.
0234
611
40.
3413
123
56±
1925
55±
78
0.16
970.
410
.320
1.1
0.44
111.
00.
92M
os-8
/ 24
50-0
3 M
acan
ga g
rani
teM
OS-
8.1.
1zo
ned(
dark
CL)
0.07
2098
931
0.46
157
540
± 5
484
± 14
-11
0.05
68 0
.60.
684
1.1
0.08
730.
880.
81M
OS-
8.2.
1zo
ned(
dark
CL)
0.22
690
161
0.24
47
488
± 4
525
± 31
70.
0579
1.4
0.
628
1.6
0.07
870.
80.
50M
OS-
8.3.
1zo
ned(
dark
CL)
1.25
4456
2196
0.51
283
454
±40
369
± 75
-23
0.05
40 3
.3
0.54
2 9
.70.
0729
9.1
0.94
MO
S-8.
4.1
zone
d(da
rk C
L)0.
1485
1889
751.
0982
468
7±1
648
0±
14-4
30.
0567
0.6
0.87
9 2
.60.
1125
2.5
0.97
MO
S-8.
5.1
zone
d9.
6754
529
70.
56 3
845
5±1
358
6±3
8022
0.06
0018
.00.
600
18.0
0.07
313.
00.
17M
OS-
8.6.
1zo
ned(
dark
CL)
0.17
1677
623
0.38
120
516
±34
488
± 17
-60.
0569
0.8
0.65
4 7
.00.
0833
6.9
0.99
110
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
App
endi
x 1.
Con
tinue
d.
Spo
tD
ated
zir
con
dom
ain
% 206 Pb
c
ppm
Upp
mT
h
232 T
h/23
8 Upp
m20
6 Pb*
(1)
206 Pb
/238 U
Age
(1)
207 Pb
/206 Pb
Age
% Dis
-co
r-da
ncy
(1)
207 Pb
*
/206 Pb
*±%
(1)
207 Pb
*
/235 U
±%(1
)20
6 Pb*
/238 U
±%er
rco
rr
MO
S-8.
7.1
zone
d(da
rk C
L)2.
2314
7221
071.
4812
660
1±2
753
1±
77-1
30.
0580
3.5
0.
782
5.9
0.09
774.
70.
80M
OS-
8.8.
1zo
ned(
dark
CL)
0.98
2480
2741
1.14
169
488
±35
381
± 32
-28
0.05
42 1
.4
0.58
8 7
.70.
0786
7.5
0.98
MO
S-8.
9.1
zone
d(da
rk C
L)0.
2471
5758
920.
8547
948
2±
442
9±
42-1
20.
0554
1.9
0.
594
2.1
0.07
770.
90.
41M
OS-
8.10
.1zo
ned(
dark
CL)
0.36
1800
2058
1.18
119
477
± 3
464
± 23
-30.
0563
1.0
0.
596
1.2
0.07
680.
70.
56M
OS-
8.11
.1zo
ned(
dark
CL)
1.51
2290
3419
1.54
113
356
±20
432
± 54
180.
0555
2.4
0.
434
6.2
0.05
675.
70.
92M
OS-
8.12
.1zo
ned(
dark
CL)
1.27
3798
1714
0.47
371
685
±39
388
± 47
-76
0.05
44 2
.1
0.84
2 6
.40.
1122
6.0
0.94
MO
S-8.
13.1
zone
d(da
rk C
L)0.
6839
3719
600.
5130
354
9±2
945
3±
19-2
10.
0560
0.9
0.68
6 5
.70.
0889
5.6
0.99
MO
S-8.
14.1
zone
d(da
rk C
L)0.
1839
9928
820.
7429
052
1±
445
2±
13-1
50.
0560
0.6
0.65
0 1
.00.
0841
0.8
0.82
MO
S-8.
15.1
zone
d(da
rk C
L)0.
8651
6736
660.
7330
642
6±
347
3±
2110
0.05
65 0
.90.
532
1.1
0.06
830.
70.
58M
OS-
12 /
4493
-03
gran
ite, S
inda
Sui
teM
OS-
12.1
.1zo
ned(
dark
CL)
0.05
694
597
0.89
4849
8±1
140
3±
54-2
40.
0548
2.4
0.60
73.
40.
0804
2.4
0.70
MO
S-12
.2.1
zone
d(da
rk C
L)0.
3434
636
71.
1024
498
± 8
425
± 50
-17
0.05
532.
30.
612
2.8
0.08
031.
70.
60M
OS-
12.2
.2co
re/in
ner d
omai
n?(h
omog
)0.
2637
674
92.
0626
505
± 8
425
± 47
-19
0.05
532.
10.
622
2.7
0.08
151.
70.
64M
OS-
12.3
.1rim
/hom
og d
omai
n cu
tting
the
zoni
ng0.
2727
011
30.
4319
509
± 9
463
± 58
-10
0.05
632.
60.
638
3.2
0.08
221.
70.
55M
OS-
12.3
.2zo
ned
0.04
486
416
0.88
3349
4±
854
2±
309
0.05
831.
40.
640
2.2
0.07
961.
70.
78M
OS-
12.4
.1zo
ned(
+sm
all c
ore)
0.22
414
321
0.80
2950
2±
851
7±
403
0.05
771.
80.
645
2.5
0.08
111.
70.
69M
OS-
12.5
.1rim
/hom
og d
omai
n cu
tting
the
zoni
ng0.
0923
214
70.
6516
494
± 9
589
± 44
160.
0596
2.0
0.65
42.
80.
0796
1.8
0.67
MO
S-12
.5.2
zone
d1.
2311
718
11.
60 8
510
±10
295
±160
-73
0.05
227.
00.
593
7.3
0.08
242.
10.
28M
OS-
12.6
.1zo
ned
0.07
159
201
1.31
1151
5±
1062
3±
5617
0.06
062.
60.
694
3.2
0.08
311.
90.
60M
OS-
12.7
.1zo
ned
0.41
329
293
0.92
2350
4±
954
4±
627
0.05
842.
80.
654
3.3
0.08
121.
80.
53M
OS-
12.8
.1zo
ned
0.26
344
181
0.55
2449
2±
954
5±
4410
0.05
842.
00.
639
2.7
0.07
941.
80.
67M
OS-
12.9
.1ne
w ti
p?, w
eakl
y zo
ned,
CL-
pale
0.
0429
617
70.
6220
483
±17
604
± 53
200.
0600
2.4
0.64
44.
40.
0778
3.7
0.83
MO
S-12
.9.2
zone
d in
ner d
omai
n0.
1734
556
71.
7024
506
± 8
517
± 44
20.
0577
2.0
0.64
92.
70.
0817
1.7
0.65
MO
S-12
.10.
1rim
,hom
og0.
5918
212
20.
6913
491
± 9
513
± 99
40.
0576
4.5
0.62
74.
90.
0791
1.8
0.38
MO
S-12
.10.
2zo
ned,
inne
r dom
ain
0.68
352
397
1.16
2550
0±
833
1±
69-5
10.
0530
3.1
0.59
03.
50.
0807
1.7
0.49
MO
S-15
/ 42
41-0
3 gr
anite
, Cas
saca
tiza
Suite
MO
S-15
.1.1
zone
d0.
1163
877
91.
26 9
810
60±
1611
26±1
46
0.07
720.
71.
903
1.8
0.17
88 1
.70.
92M
OS-
15.2
.1zo
ned
0.11
226
116
0.53
36
1102
± 18
1127
±24
20.
0772
1.2
1.98
5 2
.20.
1864
1.8
0.83
MO
S-15
.3.1
zone
d(da
rk C
L)0.
0249
5163
80.
1386
711
96±
1911
17±
6-7
0.07
680.
32.
159
1.7
0.20
38 1
.70.
98M
OS-
15.3
.2rim
/tip,
CL-
pale
0.00
559
450.
08 8
910
91±
1711
48±3
25
0.07
801.
61.
984
2.4
0.18
45 1
.70.
73M
OS-
15.4
.1zo
ned
0.07
590
329
0.58
96
1120
± 17
1130
±15
10.
0774
0.7
2.02
4 1
.80.
1898
1.7
0.91
MO
S-15
.5.1
zone
d0.
2544
943
31.
00 7
811
86±
3810
99±1
9-8
0.07
621.
02.
121
3.6
0.20
19 3
.50.
96M
OS-
15.6
.1zo
ned
0.42
1371
494
0.37
188
952
± 44
1080
±15
120.
0754
0.7
1.65
4 5
.00.
1591
5.0
0.99
MO
S-15
.6.2
zone
d(C
L-pa
le)
0.10
1254
495
0.41
209
1143
±120
1162
±28
20.
0786
1.4
2.10
011
.00.
1940
11.0
0.99
MO
S-15
.7.1
zone
d0.
1558
955
70.
9810
211
87±1
1010
66±4
3-1
10.
0749
2.1
2.09
010
.00.
2020
9.7
0.98
MO
S-15
.8.1
zone
d0.
3419
681
0.43
32
1128
± 18
1097
±34
-30.
0761
1.7
2.00
5 2
.50.
1912
1.8
0.71
MO
S-15
.9.1
core
/inne
r dom
ain?
(CL-
pale
,hom
og)
0.26
200
236
1.22
33
1120
± 18
1060
±37
-60.
0747
1.8
1.95
4 2
.60.
1898
1.8
0.70
MO
S-15
.9.2
rim, d
ark
CL
0.11
1237
137
0.11
198
1100
± 21
1125
±14
20.
0772
0.7
1.98
0 2
.20.
1861
2.1
0.95
MO
S-15
.10.
1zo
ned
0.51
1418
270
0.20
208
1010
± 41
1022
±43
10.
0733
2.1
1.71
3 4
.80.
1695
4.4
0.90
MO
S-15
.11.
1zo
ned
0.16
1117
378
0.35
202
1231
±130
1140
±29
-80.
0777
1.5
2.25
012
.00.
2100
12.0
0.99
111
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
App
endi
x 1.
Con
tinue
d.
MO
S-19
.18.
1 zo
ned
(hit
partl
y on
CL-
dark
cen
ter d
omai
n?)
2.13
699
276
0.41
8179
8
±10
84
0±6
85
0.06
71
3.3
1.21
9 3.
5 0.
1318
1.
4 0.
39
Spo
tD
ated
zir
con
dom
ain
% 206 Pb
c
ppm
Upp
mT
h
232 T
h/23
8 Upp
m20
6 Pb*
(1)
206 Pb
/238 U
Age
(1)
207 Pb
/206 Pb
Age
% Dis
-co
r-da
ncy
(1)
207 Pb
*
/206 Pb
*±%
(1)
207 Pb
*
/235 U
±%(1
)20
6 Pb*
/238 U
±%er
rco
rr
MO
S-16
/ 13
016-
03 g
rani
te g
neis
s, M
atun
da S
uite
MO
S-16
.1.1
rim, d
ark
CL,
hom
og1.
7016
7923
0.01
108
457
±41
594
± 84
230.
0597
3.9
0.60
510
.00.
0734
9.3
0.92
MO
S-16
.1.2
MO
S-16
.2.1
core
, pal
e C
L, z
oned
hom
og,m
ediu
m C
L/m
etam
? /ro
unde
d(+t
hin
dark
CL
0.12
--99 33
686 19
60.
900.
60 1
1 3
780
678
4±
8±
683
882
2±
59±
294 5
0.06
700.
0665
2.8
1.4
1.23
01.
186
3.0
1
.6
0.13
310.
1294
1.0
0.8
0.34
0.49
rim)
MO
S-16
.3.1
rim,d
ark
CL(
+met
amic
t cor
e?)
0.78
574
70.
01 4
151
2±
752
8±
463
0.05
802.
10.
660
2.5
0.
0826
1.3
0.54
MO
S-16
.4.1
MO
S-16
.4.2
met
amic
t mai
n do
mai
n (+
thin
CL-
pale
rim
)zo
ned,
smal
l gra
in in
side
a m
etam
ict g
rain
0.
430.
3599
836
429 29
50.
030.
84 8
0 3
957
074
9±1
5±
559
174
9±
27±
344 0
0.05
970.
0642
1.2
1.6
0.76
01.
090
3.0
1
.8
0.09
240.
1231
2.8
0.7
0.91
0.42
MO
S-16
.5.1
hom
og,d
ark
CL,
roun
ded
(+th
in C
L-pa
le ri
m)
0.02
1770
120.
0113
053
1±
348
2±
43-1
00.
0568
2.0
0.67
1 2
.1
0.08
580.
70.
32M
OS-
16.6
.1co
re,z
oned
,pal
e C
L0.
5911
710
30.
91 1
377
3±
781
3±
755
0.06
623.
61.
163
3.7
0.
1274
1.0
0.26
MO
S-16
.6.2
rim,h
omog
,dar
k C
l0.
3918
8414
0.01
139
528
± 3
555
± 19
50.
0587
0.9
0.69
1 1
.0
0.08
540.
60.
57M
OS-
16.7
.1zo
ned/
dist
urbe
d(+t
hin
rim)
2.27
506
386
0.79
51
703
± 5
733
± 71
40.
0637
3.4
1.01
3 3
.4
0.11
530.
70.
21M
OS-
16.8
.1zo
ned,
pale
CL,
fres
h cr
ysta
l0.
0026
121
90.
87 2
977
1±
683
0±
267
0.06
681.
21.
169
1.5
0.
1271
0.9
0.57
MO
S-16
.9.1
zone
d,da
rk C
L0.
1314
0863
10.
4614
673
6±
576
3±
144
0.06
460.
71.
077
1.0
0.12
090.
70.
72M
OS-
16.1
0.1
zone
d,fr
esh
grai
n0.
5082
586
61.
08 8
169
6±
474
7±
257
0.06
421.
21.
009
1.3
0.
1141
0.7
0.49
MO
S-16
.11.
1zo
ned
tip d
omai
n (z
oned
,repl
aced
inne
r dom
ain)
0.13
696
40.
01 5
152
2±
356
4±
267
0.05
891.
20.
685
1.4
0.
0844
0.7
0.48
MO
S-16
.12.
1 co
re?/
zone
d do
mai
n--
48
150
41.
08 4
870
7±
691
2±
6722
0.
0694
3.
3 1.
110
3.4
0.
1160
0.
90.
26M
os-1
9 / 2
638-
04 a
plite
gra
nite
, Gur
o Su
iteM
OS-
19.1
.1zo
ned,
CL-
pale
inne
r dom
ain
0.11
486
311
0.66
6085
8±4
804
±40
-60.
0659
1.9
1.29
42.
00.
1424
0.5
0.26
MO
S-19
.1.2
quite
hom
ogen
eous
, CL-
dark
rim
0.11
2071
313
0.16
245
832
±283
4±1
30
0.06
690.
61.
270
0.7
0.13
770.
30.
39M
OS-
19.2
.1qu
ite h
omog
eneo
us, C
L-pa
le ri
m1.
1858
116
20.
2969
824
±481
0±5
4-2
0.06
612.
61.
243
2.7
0.13
630.
60.
21M
OS-
19.3
.1qu
ite h
omog
eneo
us, C
L-pa
le ri
m0.
3864
513
50.
2279
857
±486
3±3
51
0.06
781.
71.
330
1.7
0.14
220.
50.
27M
OS-
19.3
.2C
L-da
rk a
nd sp
otty
inne
r dom
ain
0.04
2475
625
0.26
290
825
±283
6±1
21
0.06
690.
61.
259
0.6
0.13
640.
30.
46M
OS-
19.4
.1zo
ned,
CL-
dark
0.44
522
354
0.70
6182
5±4
834
±37
10.
0669
1.8
1.25
81.
80.
1364
0.5
0.28
MO
S-19
.5.1
zone
d, C
L-da
rk0.
2067
548
20.
7482
852
±486
9±2
42
0.06
801.
21.
325
1.3
0.14
120.
40.
35M
OS-
19.6
.1zo
ned,
CL-
brig
ht0.
7028
116
70.
6133
827
±579
8±6
3-4
0.06
573.
01.
241
3.1
0.13
690.
70.
22M
OS-
19.7
.1C
L-pa
le re
plac
ing
phas
e2.
6848
012
20.
2656
796
±575
0±9
6-6
0.06
434.
51.
164
4.6
0.13
140.
70.
15M
OS-
19.8
.1qu
ite h
omog
eneo
us, C
L-m
ediu
m in
ner d
omai
n0.
5299
16
0.01
7251
8±2
528
±42
20.
058
1.9
0.66
92.
00.
0837
0.5
0.24
MO
S-19
.9.1
quite
hom
ogen
eous
, Cl-d
ark
core
dom
ain
0.07
651
300.
0546
513
± 3
515
±30
10.
0576
1.4
0.65
81.
50.
0828
0.6
0.38
MO
S-19
.9.2
quite
hom
ogen
eous
, CL-
dark
rim
0.08
662
419
0.65
8185
4±
484
3±2
4-1
0.06
721.
11.
312
1.2
0.14
160.
40.
36M
OS-
19.1
0.1
zone
d, C
L-da
rk0.
1364
649
60.
7978
848
± 4
863
±23
20.
0678
1.1
1.31
41.
20.
1406
0.5
0.41
MO
S-19
.11.
1w
eakl
y zo
ned,
CL-
dark
0.16
1079
140.
0180
530
± 2
485
±30
-80.
0568
1.4
0.67
11.
40.
0857
0.4
0.27
MO
S-19
.12.
1zo
ned,
CL-
dark
0.01
782
363
0.48
9181
4±
487
2±1
77
0.06
810.
81.
265
0.9
0.13
470.
50.
49M
OS-
19.1
3.1
zone
d, C
L-m
ediu
m0.
1650
338
40.
7962
857
± 5
849
±32
-10.
0674
1.5
1.32
01.
60.
1421
0.6
0.35
MO
S-19
.14.
1zo
ned,
CL-
med
ium
0.18
915
345
0.39
107
822
± 3
879
±21
70.
0684
1.0
1.28
11.
10.
1360
0.4
0.40
MO
S-19
.15.
1zo
ned/
spot
ty, C
L-da
rk0.
0313
1530
0.02
9350
9±
250
7±2
10
0.05
741.
00.
650
1.0
0.08
210.
40.
39M
OS-
19.1
6.1
zone
d, C
L-da
rk0.
5113
7711
00.
0810
856
1±
261
8±4
910
0.06
042.
30.
757
2.3
0.09
090.
40.
18M
OS-
19.1
7.1
zone
d, C
L-da
rk0.
1397
952
90.
5611
381
3±
390
3±1
911
0.06
920.
91.
281
1.0
0.13
430.
40.
37
112
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
App
endi
x 1.
Con
tinue
d.
MO
S-21
.13.
1zo
ned,
Cl-m
ediu
m0.
0525
021
80.
9010
726
09±1
226
54+9
20.
1801
0.6
12.3
860.
80.
4988
0.6
0.72
Spo
tD
ated
zir
con
dom
ain
% 206 Pb
c
ppm
Upp
mT
h
232 T
h/23
8 Upp
m20
6 Pb*
(1)
206 Pb
/238 U
Age
(1)
207 Pb
/206 Pb
Age
% Dis
-co
r-
(1)
207 Pb
*
/206 Pb
*±%
(1)
207 Pb
*
/235 U
±%(1
)20
6 Pb*
/238 U
±%er
rco
rrda
ncy
Mos
-20
/ 294
3-04
gar
net-
silli
man
ite g
neis
s, R
ushi
nga
Gro
upM
OS-
20.1
.1C
L-br
ight
rim
2.09
120
60.
059
506
± 8
490
+247
-30.
0570
11.2
0.64
111
.30.
0816
1.7
0.15
MO
S-20
.1.2
zone
d m
ain
dom
ain
(+C
L-br
ight
rim
)0.
1327
446
0.18
8419
59±1
126
73+1
236
0.18
220.
78.
922
1.0
0.35
520.
70.
68M
OS-
20.2
.1C
L-da
rk, s
moo
thly
zon
ed (+
thin
CL-
brig
ht ri
m)
1.65
845
230.
0369
576
±395
1+6
565
0.07
083.
20.
911
3.2
0.09
340.
50.
16M
OS-
20.3
.1C
L-da
rk, s
moo
thly
zon
ed (
thin
CL-
brig
ht ri
m)
0.33
485
140.
0335
521
±352
8+8
31
0.05
793.
80.
673
3.8
0.08
430.
60.
17M
OS-
20.4
.1C
L-br
ight
rim
on
zirc
on 8
6.71
567
0.12
447
5±1
661
9+
795
300.
0604
36.8
0.63
837
.00.
0765
3.4
0.09
MO
S-20
.4.2
core
(CL-
dark
and
brig
ht ri
ms a
roun
d it)
0.47
293
610.
2276
1691
±923
67+1
640
0.15
190.
96.
281
1.1
0.30
000.
60.
54M
OS-
20.5
.1C
L-br
ight
rim
on
zirc
on 8
1.17
127
70.
059
497
±763
1+2
4627
0.06
0811
.40.
671
11.5
0.08
011.
50.
13M
OS-
20.6
.1zo
ned,
CL-
dark
0.36
656
820.
1384
891
±415
53+2
374
0.09
621.
21.
967
1.3
0.14
820.
50.
36M
OS-
20.7
.1C
L-br
ight
rim
on
zirc
on 8
21.0
032
50.
163
500
±28
-263
6+
0-6
280.
0806
5.9
MO
S-20
.8.1
cent
er/c
ore?
, CL-
dark
1.87
225
490.
2341
1211
±11
2244
+38
850.
1414
2.2
4.02
92.
40.
2067
1.0
0.41
MO
S-20
.9.1
CL-
dark
dom
ain
(+co
re+C
L-br
ight
rim
)1.
9212
1830
0.03
8449
1±2
351
+87
-29
0.05
353.
90.
584
3.9
0.07
920.
50.
12M
OS-
20.9
.2co
re, C
L-m
ediu
m0.
4837
981
0.22
6812
20±7
1810
+30
480.
1106
1.6
3.17
91.
70.
2084
0.6
0.34
MO
S-20
.10.
1sm
ooth
ly z
oned
, CL-
dark
(+m
etam
ict c
ore)
0.91
501
90.
0236
515
±452
0+1
101
0.05
775.
00.
661
5.1
0.08
310.
70.
15M
OS-
20.1
1.1
cent
er, z
oned
CL-
pale
dom
ain
0.29
308
137
0.46
8417
76±1
019
08+1
97
0.11
681.
05.
106
1.2
0.31
710.
70.
53M
OS-
20.1
2.1
zone
d co
re (+
CL-
brig
ht ri
m)
0.03
467
920.
2012
817
87±7
2426
+12
360.
1572
0.7
6.92
60.
80.
3195
0.5
0.56
MO
S-20
.13.
1zo
ned
core
(+C
L-br
ight
rim
)0.
2837
662
0.17
6211
22±6
2149
+21
910.
1338
1.2
3.50
81.
30.
1901
0.6
0.42
MO
S-20
.14.
1co
re, C
L-m
ediu
m1.
6425
810
50.
4269
1720
±11
2449
+30
420.
1593
1.8
6.71
91.
90.
3058
0.7
0.39
Mos
-21
/ 151
9-04
Fud
eze
orth
ogne
iss,
Mud
zi M
etam
orph
ic C
ompl
exM
OS-
21.1
.1zo
ned
core
0.
2660
718
60.
3224
925
11±8
3048
+621
0.22
940.
415
.061
0.5
0.47
620.
40.
72M
OS-
21.1
.2zo
ned,
CL-
dark
0.19
747
115
0.16
251
2128
±825
09+8
180.
1652
0.5
8.90
50.
60.
3910
0.4
0.68
MO
S-21
.2.1
zone
d, C
L-da
rk0.
1446
743
0.10
188
2474
±10
2599
+85
0.17
430.
511
.239
0.7
0.46
780.
50.
72M
OS-
21.3
.1zo
ned,
CL-
dark
0.71
672
115
0.18
252
2324
±925
98+9
120.
1742
0.6
10.4
240.
70.
4340
0.4
0.62
MO
S-21
.4.1
zone
d, C
L-da
rk0.
2696
877
0.08
255
1721
±623
61+8
370.
1513
0.5
6.38
40.
60.
3060
0.4
0.64
MO
S-21
.5.1
zone
d, C
L-m
ediu
m, t
ip
0.14
314
102
0.34
121
2389
±11
2595
+10
90.
1739
0.6
10.7
540.
80.
4486
0.6
0.68
MO
S-21
.5.2
zone
d, C
L-da
rk, m
iddl
e 0.
2169
969
0.10
179
1677
±76
2073
+133
240.
1282
7.6
5.25
19.
20.
2972
5.2
0.57
MO
S-21
.5.3
zone
d, C
L-m
ediu
m,c
ente
r 0.
0145
937
30.
8421
427
88±1
228
66+1
293
0.20
507.
915
.291
7.9
0.54
100.
50.
07M
OS-
21.6
.1zo
ned,
CL-
med
ium
-0
.01
211
720.
3590
2596
±16
2489
+75
-40.
1632
4.4
11.1
594.
50.
4958
0.8
0.17
MO
S-21
.7.1
CL-
brig
ht ri
m31
.01
303
0.12
576
0±6
220
22+
1606
166
0.12
4590
.62.
148
91.0
0.12
518.
70.
10M
OS-
21.8
.1zo
ned,
Cl-m
ediu
m
--55
033
70.
6324
627
02±9
2756
+86
20.
1916
5.3
13.7
505.
30.
5205
0.4
0.08
MO
S-21
.9.1
zone
d, C
l-med
ium
0.16
208
600.
3088
2569
±27
2589
+21
10.
1732
1.2
11.6
931.
80.
4896
1.3
0.71
MO
S-21
.10.
1zo
ned,
Cl-m
ediu
m
0.32
180
840.
4972
2463
±14
2597
+13
50.
1740
0.8
11.1
641.
00.
4653
0.7
0.65
MO
S-21
.11.
1zo
ned,
Cl-m
ediu
m
0.36
491
920.
1912
816
98±8
2365
+12
390.
1517
0.7
6.30
60.
90.
3014
0.5
0.61
MO
S-21
.12.
1zo
ned,
Cl-m
ediu
m0.
0932
819
50.
6114
326
50±1
327
14+1
22
0.18
670.
713
.091
0.9
0.50
840.
60.
62
113
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
App
endi
x 1.
Con
tinue
d.
MO
S-28
.7.1
quite
hom
ogen
eous
cen
tre d
omai
n0.
1718
512
10.
6874
2475
+20
2495
+15
10.
1638
0.9
10.5
711.
30.
4681
1.0
0.75
Spo
tD
ated
zir
con
dom
ain
% 206 Pb
c
ppm
Upp
mT
h
232 T
h/23
8 Upp
m20
6 Pb*
(1)
206 Pb
/238 U
Age
(1)
207 Pb
/206 Pb
Age
% Dis
-co
r-
(1)
207 Pb
*
/206 Pb
*±%
(1)
207 Pb
*
/235 U
±%(1
)20
6 Pb*
/238 U
±%er
rco
rrda
ncy
Mos
-23
/ 136
25-0
4 to
nalit
e, M
avon
de C
ompl
exM
OS-
23.1
.1zo
ned,
CL-
dark
0.11
425
292
0.71
204
2861
±16
2909
+92
0.21
040.
516
.206
0.9
0.55
860.
70.
79M
OS-
23.2
.1C
L-m
ediu
m d
ark,
wea
kly
zone
d co
re/c
entre
dom
ain
0.16
136
640.
4968
2934
±39
2911
+15
-10.
2108
0.9
16.7
471.
90.
5763
1.6
0.87
MO
S-23
.3.1
zone
d, C
L-da
rk0.
0522
386
0.40
110
2930
±19
2909
+9-1
0.21
050.
616
.702
1.0
0.57
540.
80.
81M
OS-
23.4
.1zo
ned,
CL-
dark
0.08
384
203
0.55
184
2862
±16
2900
+71
0.20
930.
416
.130
0.8
0.55
890.
70.
84M
OS-
23.5
.1zo
ned,
CL-
dark
0.56
426
187
0.45
199
2793
±18
2921
+11
50.
2121
0.7
15.8
551.
00.
5423
0.8
0.77
MO
S-23
.6.1
zone
d, C
L-da
rk0.
2329
314
50.
5113
126
94±1
628
98+9
80.
2090
0.6
14.9
490.
90.
5188
0.7
0.80
MO
S-23
.7.1
zone
d, C
L-da
rk0.
2525
913
70.
5511
827
36±1
928
73+1
05
0.20
580.
615
.008
1.0
0.52
880.
90.
81M
OS-
23.8
.1C
L-da
rk, q
uite
hom
ogen
eous
cor
e0.
2656
530
50.
5621
423
51±1
327
29+8
160.
1884
0.5
11.4
360.
80.
4402
0.7
0.82
MO
S-23
.8.2
CL-
med
ium
dar
k, w
eakl
y zo
ned
tip0.
2320
679
0.40
9728
21±1
928
83+1
12
0.20
710.
715
.671
1.0
0.54
890.
80.
78M
OS-
23.9
.1zo
ned,
CL-
dark
0.19
254
147
0.60
121
2838
±19
2901
+92
0.20
940.
615
.969
1.0
0.55
320.
80.
82M
OS-
23.1
0.1
zone
d, C
L-da
rk0.
1035
214
20.
4216
828
47±1
628
88+8
10.
2077
0.5
15.9
020.
90.
5552
0.7
0.83
MO
S-23
.10.
2C
l-dar
k re
plac
ing
hom
ogen
eous
pha
se0.
1589
634
0.04
236
1724
±924
63+8
430.
1607
0.5
6.79
40.
80.
3066
0.6
0.79
Mos
-26
/ 101
1-02
gar
net g
neis
s, G
aire
zi G
roup
MO
S-26
.1.1
hom
ogen
eous
, CL-
dark
0.12
270
207
0.79
108
2460
+16
2574
+11
50.
1717
0.7
10.9
981.
00.
4646
0.8
0.75
MO
S-26
.2.1
zone
d, d
ark
and
pale
strip
es0.
1519
594
0.50
7122
70+1
621
31+1
6-6
0.13
250.
97.
708
1.3
0.42
210.
90.
67M
OS-
26.3
.1zo
ned,
CL-
med
ium
dar
k--
279
580.
2193
2109
+14
2063
+14
-20.
1275
0.8
6.80
01.
10.
3869
0.8
0.71
MO
S-26
.4.1
zone
d, C
L-da
rk0.
1150
956
0.11
153
1930
+12
2035
+12
50.
1254
0.7
6.03
71.
00.
3490
0.7
0.74
MO
S-26
.5.1
zone
d, d
ark
and
pale
strip
es0.
3411
241
0.38
3519
94+1
820
48+2
43
0.12
631.
46.
313
1.7
0.36
241.
00.
60M
OS-
26.6
.1zo
ned,
Cl-m
ediu
m d
ark
0.11
293
116
0.41
9320
27+1
320
61+1
62
0.12
730.
96.
485
1.2
0.36
940.
80.
64M
OS-
26.7
.1qu
ite h
omog
eneo
us, C
L-pa
le, r
ound
0.18
7750
0.67
2420
21+2
120
44+3
11
0.12
611.
76.
400
2.1
0.36
821.
20.
57M
OS-
26.7
.2ho
mog
eneo
us, C
L-da
rk, r
ound
0.11
328
302
0.95
102
1994
+13
2015
+14
10.
1240
0.8
6.20
11.
10.
3625
0.8
0.71
MO
S-26
.8.1
wea
kly
zone
d, C
L-br
ight
, rou
nd (m
etam
orph
ic?)
0.61
9422
92.
5123
1602
+18
1885
+54
180.
1153
3.0
4.48
63.
30.
2821
1.3
0.40
MO
S-26
.9.1
zone
d, C
L-da
rk, r
ound
0.04
335
198
0.61
153
2755
+17
3063
+711
0.23
160.
417
.031
0.9
0.53
330.
80.
86M
OS-
26.1
0.1
zone
d, C
L-m
ediu
m0.
1121
610
90.
5269
2024
+14
2049
+19
10.
1264
1.1
6.42
91.
40.
3688
0.8
0.61
MO
S-26
.11.
1zo
ned,
CL-
med
ium
dar
k0.
1250
019
70.
4114
018
15+1
119
81+1
29
0.12
170.
75.
453
1.0
0.32
510.
70.
73M
OS-
26.1
2.1
zone
d, C
L-da
rk0.
1544
824
40.
5613
419
29+1
120
24+1
25
0.12
460.
75.
995
1.0
0.34
890.
70.
70M
OS-
26.1
3.1
wea
kly
zone
d, C
L-pa
le0.
3713
352
0.40
4119
66+1
720
65+2
95
0.12
761.
76.
270
1.9
0.35
651.
00.
51M
OS-
26.1
4.1
quite
hom
ogen
eous
, CL-
pale
(?zo
ned
rim)
0.12
210
790.
3988
2571
+19
2636
+12
30.
1781
0.7
12.0
361.
20.
4901
0.9
0.79
MO
S-26
.15.
1zo
ned,
dar
k an
d pa
le st
ripes
0.12
194
157
0.84
8326
11+1
826
98+1
33
0.18
490.
812
.732
1.1
0.49
930.
90.
75M
OS-
26.1
6.1
zone
d, C
L-m
ediu
m d
ark
0.21
169
980.
6054
2047
+16
2051
+22
00.
1266
1.2
6.52
11.
50.
3737
0.9
0.60
Mos
-28
/ 193
13-0
4 gr
anite
, Bár
uè C
ompl
ex
MO
S-28
.1.1
zone
d, C
L-da
rk0.
1339
028
00.
7414
022
45+1
424
10+1
07
0.15
580.
68.
945
1.0
0.41
650.
70.
78M
OS-
28.2
.1zo
ned,
CL-
dark
0.27
348
327
0.97
5711
20+8
1162
+34
40.
0786
1.7
2.05
71.
90.
1898
0.8
0.42
MO
S-28
.3.1
zone
d ce
nter
dom
ain,
CL-
dark
0.06
386
256
0.69
128
2101
+36
2049
+12
-20.
1264
0.7
6.71
42.
10.
3852
2.0
0.95
MO
S-28
.4.1
quite
hom
ogen
eous
, CL-
brig
h0.
4314
352.
583
1269
+34
2090
+89
650.
1294
5.0
3.88
45.
80.
2176
2.9
0.50
MO
S-28
.5.1
zone
d, C
L-m
ediu
m0.
4536
038
31.
1057
1088
+810
90+4
00
0.07
582.
01.
921
2.2
0.18
390.
80.
38M
OS-
28.6
.1zo
ned,
CL-
dark
1.14
687
479
0.72
7677
0+5
1073
+48
390.
0752
2.4
1.31
42.
50.
1268
0.7
0.29
114
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
App
endi
x 1.
Con
tinue
d.
MO
S-33
.10.
1zo
ned,
CL-
med
ium
0.00
185
660.
3733
1216
±18
1251
± 69
30.
0822
3.5
2.35
33.
90.
2076
1.7
0.43
Spo
tD
ated
zir
con
dom
ain
% 206 Pb
c
ppm
Upp
mT
h
232 T
h/23
8 Upp
m20
6 Pb*
(1)
206 Pb
/238 U
(1)
207 Pb
/206 Pb
% Dis
-co
r-
(1)
207 Pb
*
206
*±%
(1)
207 Pb
*
235
±%(1
)20
6 Pb*
238
±%er
rco
rrA
geA
geda
ncy
/Pb
/U
/U
MO
S-28
.8.1
zone
d, C
L-m
ediu
m0.
0534
444
51.
3457
1130
+811
80+3
34
0.07
931.
72.
095
1.9
0.19
160.
80.
42M
OS-
28.9
.1zo
ned,
CL-
brig
ht1.
6895
124
1.34
1499
7+1
412
21+1
3322
0.08
106.
81.
867
6.9
0.16
721.
50.
22M
OS-
28.1
0.1
zone
d, C
L-da
rk1.
4763
419
20.
3190
976
+612
76+4
231
0.08
332.
21.
877
2.3
0.16
350.
70.
30M
OS-
28.1
1.1
zone
d, C
L-da
rk0.
9218
319
71.
1130
1123
+13
1080
+82
-40.
0754
4.1
1.97
94.
30.
1903
1.2
0.29
MO
S-28
.12.
1zo
ned,
CL-
dark
0.09
246
152
0.64
7118
79+1
518
30+1
7-3
0.11
191.
05.
219
1.3
0.33
840.
90.
68M
OS-
28.1
3.1
wea
kly
zone
d, C
L-br
ight
0.01
269
188
0.72
8520
17+1
420
27+1
40
0.12
490.
86.
324
1.1
0.36
730.
80.
71M
OS-
28.1
4.1
zone
d, C
L-da
rk0.
5722
023
11.
0937
1139
+11
1133
+57
00.
0775
2.9
2.06
43.
00.
1932
1.0
0.34
Mos
-29
/ 192
90-0
4 In
chap
a gr
anod
iori
te, B
áruè
Com
plex
MO
S-29
.1.1
zone
d, C
L-m
ediu
m, l
ong
(+C
L-da
rk ri
m)
0.26
630
741
1.22
8897
1±
410
87±
2812
0.07
57 1
.41.
697
1.4
0.16
260.
50.
32M
OS-
29.1
.2ho
mog
eneo
us C
L-da
rk ri
m4.
3822
2016
40.
0825
276
8±
3 9
02±
8317
0.06
914.
01.
205
4.0
0.12
650.
40.
11M
OS-
29.2
.1zo
ned,
CL-
pale
, lon
g (+
CL-
dark
rim
)6.
1527
097
0.37
1741
8±
5 7
62±2
3082
0.06
4611
.00.
597
11.0
0.06
701.
20.
11M
OS-
29.3
.1zo
ned,
CL-
pale
, lon
g (+
CL-
dark
rim
)0.
6612
499
0.82
1910
65±
911
66±
659
0.07
87 3
.31.
950
3.4
0.17
961.
00.
28M
OS-
29.4
.1zo
ned,
CL-
pale
, lon
g (+
CL-
dark
rim
)0.
3417
470
0.42
2710
63±
811
23±
676
0.07
71 3
.41.
905
3.5
0.17
920.
80.
24M
OS-
29.5
.1zo
ned,
CL-
med
ium
, lon
g (+
CL-
dark
rim
)0.
2474
692
81.
2910
810
06±
410
76±
227
0.07
528
1.1
1.75
2 1
.20.
1688
0.4
0.35
MO
S-29
.5.2
hom
ogen
eous
CL-
dark
rim
0.65
1792
710.
0416
765
9±
2 9
02±
2837
0.06
912
1.4
1.02
6 1
.40.
1076
0.4
0.26
MO
S-29
.6.1
zone
d, C
L-m
ediu
m, l
ong
(+C
L-da
rk ri
m)
0.15
567
475
0.86
8910
83±
510
70±
22-1
0.07
504
1.1
1.89
2 1
.20.
1829
0.5
0.39
MO
S-29
.7.1
zone
d, C
L-pa
le, s
hort
(+C
L-da
rk ri
m)
2.38
160
165
1.07
2611
09±
1011
04±1
100
0.07
63 5
.61.
980
5.6
0.18
771.
00.
17M
OS-
29.8
.1zo
ned,
CL-
pale
, sho
rt (+
CL-
dark
rim
)1.
0511
111
51.
0718
1081
±10
1017
± 77
-60.
0731
3.8
1.84
0 3
.90.
1826
1.0
0.26
MO
S-29
.9.1
zone
d, C
L-m
ediu
m d
ark,
shor
t0.
0849
812
40.
26 7
810
79±
510
88±
221
0.07
573
1.1
1.90
2 1
.20.
1822
0.5
0.41
MO
S-29
.10.
1zo
ned,
CL-
pale
, sho
rt (+
CL-
dark
rim
)0.
6615
515
81.
0525
1099
± 9
1037
± 65
-60.
0738
3.2
1.89
2 3
.40.
1858
0.9
0.27
MO
S-29
.11.
1zo
ned,
CL-
med
ium
, sho
rt (+
CL-
dark
rim
)0.
3929
218
20.
65 4
610
81±
710
76±
410
0.07
53 2
.11.
894
2.2
0.18
250.
70.
30M
OS-
29.1
2.1
zone
d, C
L-pa
le, s
hort
(+C
L-da
rk ri
m)
0.96
7911
01.
44 1
210
42±1
211
37±
979
0.07
76 4
.91.
877
50.
1754
1.3
0.25
MO
S-29
.13.
1zo
ned,
CL-
pale
, sho
rt (+
CL-
dark
rim
)1.
5891
127
1.45
1410
41±1
1 9
99±1
00-4
0.07
25 5
.11.
751
5.2
0.17
521.
10.
21M
OS-
29.1
3.2
hom
ogen
eous
CL-
dark
rim
3.86
3664
640.
0219
337
0±
2 9
92±
6916
80.
0722
3.4
0.58
8 3
.40.
0591
0.4
0.11
MO
S-29
.14.
1 zo
ned,
CL-
med
ium
, lon
g (+
CL-
dark
rim
)0.
4172
544
50.
63 7
0
684
± 3
1101
± 32
61
0.07
62
1.6
1.17
7 1
.70.
1120
0.5
0.30
MO
S-33
/ 41
58-0
3 m
etas
ands
tone
, Zám
buè
Supe
rgro
upM
OS-
33.1
.1ha
zy z
onin
g, y
oung
er, C
L-da
rk d
omai
n9.
6669
518
0.03
117.
010
51±1
410
66±
283
10.
0749
14.1
1.82
914
.20.
1771
1.5
0.11
MO
S-33
.1.2
zone
d, C
L-br
ight
dom
ain
5.43
199
119
0.62
6018
61±3
318
80±
168
10.
1150
9.3
5.30
59.
60.
3346
2.0
0.21
MO
S-33
.2.1
zone
d, C
L-da
rk (+
dark
thin
rim
)9.
8896
952
80.
5612
682
7±1
286
1±
333
40.
0678
16.0
1.27
916
.10.
1369
1.5
0.09
MO
S-33
.3.1
zone
d, C
l-brig
ht, r
ound
ed c
ore
(+th
in C
l-dar
k rim
)6.
8016
718
21.
1335
1310
±27
1324
± 31
81
0.08
5416
.42.
652
16.6
0.22
542.
30.
14
MO
S-33
.4.1
Cl-b
right
, rou
nded
cor
e1.
4526
585
0.33
9221
55±2
321
54±
610
0.13
423.
57.
348
3.7
0.39
701.
30.
35M
OS-
33.5
.1ho
mog
eneo
us, C
L-da
rk ri
m (+
roun
ded
core
)0.
4590
211
60.
1315
711
85±8
1166
± 49
-20.
0788
2.4
2.19
12.
60.
2017
0.8
0.30
MO
S-33
.6.1
quite
hom
ogen
eou,
CL-
dark
rim
41.5
917
0840
50.
2425
061
1±2
863
5±
1446
40.
0609
67.2
0.83
567
.30.
0995
4.8
0.07
MO
S-33
.6.2
zone
d, C
L-m
ediu
m ro
unde
d co
re0.
1318
221
31.
2181
2683
±36
2689
± 27
00.
1839
1.6
13.0
902.
30.
5161
1.6
0.71
MO
S-33
.7.1
zone
d, C
L-da
rk, e
uhed
ral
3.53
1017
860.
0916
710
89±1
011
10±
128
20.
0766
6.4
1.94
36.
50.
1841
1.0
0.16
MO
S-33
.8.1
CL-
dark
rim
21.9
126
8810
30.
0417
637
3±9
385
± 81
73
0.05
4336
.40.
446
36.4
0.05
952.
40.
06M
OS-
33.8
.2zo
ned,
CL-
brig
ht c
ore
0.00
5967
1.16
1920
51±4
520
58±
670
0.12
713.
86.
567
4.6
0.37
472.
60.
56M
OS-
33.9
.1zo
ned,
CL-
dark
euh
edra
l gra
in0.
3387
012
70.
1515
011
77±9
1147
± 47
-30.
0780
2.3
2.15
42.
50.
2003
0.8
0.33
115
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
App
endi
x 1.
Con
tinue
d.
for M
os-3
3-M
os35
.
Spo
tD
ated
zir
con
dom
ain
% 206 Pb
c
ppm
Upp
mT
h
232 T
h/23
8 Upp
m20
6 Pb*
(1)
206 Pb
/238 U
(1)
207 Pb
/206 Pb
% Dis
-co
r-
(1)
207 Pb
*±%
(1)
207 Pb
*±%
(1)
206 Pb
*±%
err
corr
Age
Age
danc
y/20
6 Pb*
/235 U
/238 U
MO
S-33
.11.
1zo
ned,
CL-
med
ium
(+da
rk ri
m; m
argi
nal p
hase
?)13
.79
571
126
0.23
100
1041
±20
1071
± 42
63
0.07
5121
.21.
814
21.3
0.17
522.
10.
10M
OS-
33.1
2.1
hom
ogen
eous
, CL-
dark
rim
(+ro
unde
d co
re)
69.0
180
6732
330.
4110
1528
6±3
616
78±
1802
487
0.10
3097
.60.
644
98.4
0.04
5412
.80.
13M
OS-
33.1
2.2
zone
d, C
L-m
ediu
m ro
unde
d co
re0.
0015
121
51.
4768
2733
±39
2720
± 28
00.
1875
1.7
13.6
512.
50.
5281
1.8
0.72
MO
S-33
.13.
1ha
zily
zon
ed d
omai
n in
blu
rry
CL-
dark
gra
in0.
0053
916
30.
3122
225
25±2
125
24±
170
0.16
661.
011
.014
1.4
0.47
941.
00.
70M
OS-
33.1
4.1
zone
d, C
L-da
rk c
ente
r dom
ain
(+th
in ri
m)
4.05
1990
1752
0.91
380
1247
±912
86±
953
0.08
374.
92.
464
4.9
0.21
350.
80.
16M
OS-
34 /
315
7-03
fels
ic/in
term
edia
te m
etav
olca
nic
rock
, Fín
goè
Supe
rgro
upM
OS-
34.1
.1zo
ned,
qui
te d
ark
in C
L0.
0071
532
80.
4714
113
34±1
313
31±
370
0.08
571.
92.
717
2.2
0.22
991.
10.
49M
OS-
34.2
.1zo
ned,
qui
te d
ark
in C
L --
-90
810
381.
1817
913
33±1
013
24±
42-1
0.08
542.
22.
704
2.3
0.22
970.
90.
37M
OS-
34.3
.1zo
ned,
qui
te d
ark
in C
L0.
0056
738
30.
7011
113
19±1
413
25±
420
0.08
542.
12.
674
2.5
0.22
711.
20.
49M
OS-
34.4
.1zo
ned,
qui
te d
ark
in C
L 0.
0072
813
661.
9414
213
21±1
313
14±
57-1
0.08
492.
92.
664
3.1
0.22
751.
10.
35M
OS-
34.5
.1zo
ned,
qui
te d
ark
in C
L -0
.28
461
236
0.53
9013
21±1
413
19±
630
0.08
523.
22.
671
3.4
0.22
751.
20.
34M
OS-
34.6
.1zo
ned,
qui
te d
ark
in C
L -0
.40
374
258
0.71
6411
78±1
712
18±
933
0.08
094.
72.
236
5.0
0.20
051.
60.
31M
OS-
34.7
.1zo
ned,
CL-
med
ium
0.
0016
068
0.44
3213
31±3
913
34±
780
0.08
584.
02.
714
5.2
0.22
933.
30.
63M
OS-
34.8
.1zo
ned,
CL-
med
ium
---
187
780.
4333
1212
±23
1260
± 83
40.
0826
4.3
2.35
64.
70.
2068
2.1
0.43
MO
S-34
.9.1
zone
d, C
l-dar
k ce
nter
dom
ain
0.29
265
166
0.65
4611
76±1
812
19±
694
0.08
093.
52.
231
3.9
0.20
011.
70.
43M
OS-
34.1
0.1
zone
d, C
L-m
ediu
m0.
3723
316
70.
7433
983
±16
1061
± 85
80.
0747
4.2
1.69
74.
60.
1647
1.8
0.39
MO
S-34
.11.
1zo
ned,
CL-
med
ium
0.52
155
650.
4325
1124
±23
1176
± 10
45
0.07
915.
32.
078
5.7
0.19
052.
20.
38M
OS-
34.1
2.1
zone
d, C
L-m
ediu
m
0.50
169
710.
4331
1232
±21
1275
± 97
40.
0832
5.0
2.41
65.
30.
2105
1.8
0.35
Erro
rs a
re 1
-sig
ma;
Pbc
and
Pb*
indi
cate
the
com
mon
and
radi
ogen
ic le
ad p
ortio
ns, r
espe
ctiv
ely.
(1) C
omm
on P
b co
rrec
ted
usin
g m
easu
red 20
4 Pb.T
he re
ject
ed d
ata
are
in it
alic
s.
2σ e
rror
s in
stan
dard
cal
ibra
tion
(not
incl
uded
in a
bove
err
ors)
: 0.2
8% fo
r MO
S-1(
1-11
) and
0.3
7% fo
r MO
S-1(
12-1
7);
0.34
% fo
r MO
S-3,
MO
S-5,
and
MO
S-7;
0.7
7% fo
r Mos
-8; 1
.25%
for
MO
S-12
and
MO
S-15
; 0.3
8% fo
r MO
S-16
; 0.3
7% fo
r M
OS-
19 (9
-18)
, 0.4
0% fo
r MO
S-19
(1-8
), M
OS-
20 a
nd M
OS-
21; 1
.15%
for M
OS-
23, M
OS-
26 a
nd M
OS-
28; 0
.28%
MO
S-29
; 0.7
0%
116
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
App
endi
x 2.
TIM
S-ID
U-P
b is
otop
ic d
ata
on z
ircon
and
mon
azite
, sam
ples
from
NW
Moz
ambi
que.
Sam
ple
info
rmat
ion
Sam
ple
UPb
206 Pb
/204 Pb
208 Pb
/206 Pb
ISO
TO
PIC
RA
TIO
S1)R
ho2
)
APP
AR
EN
T A
GE
S / M
a±2�
Ana
lyse
d m
iner
al a
nd fr
actio
nw
eigh
tm
gpp
mm
easu
red
radi
ogen
ic20
6 Pb/23
8 U±2
�%
207 Pb
/235 U
±2�
%20
7 Pb/20
6 Pb±2
�%20
6 Pb/23
8 U20
7 Pb/23
5 U20
7 Pb/20
6 Pb
Mos
-2 /
2253
-03
Mon
te D
ombe
gra
nite
, Cas
saca
tiza
Suite
A) z
r >4.
2 g
cm-3
, >75
μm, c
olou
rless
, ± F
e pi
gmen
ted,
trans
pare
nt, p
rism
atic
, abr
aded
10
h0.
4250
582
842
0.14
0.14
490.
651.
511
0.65
0.07
562
0.18
0.97
873
935
1085
±4
B) z
r >4.
2 g
cm-3
, <75
μm, b
row
nish
-yel
low
ish,
± F
e pi
gmen
ted,
shor
t to
med
ium
pris
mat
ic, t
rans
luce
nt,
abra
ded
1 h
0.35
1871
196
330
0.12
0.08
600.
650.
868
0.65
0.07
323
0.40
0.81
532
635
1020
±8
C) z
r >4.
2 g
cm-3
, <75
μm, c
olou
rless
, ± F
e pi
gmen
ted,
trans
pare
nt, p
rism
atic
, abr
aded
4 h
0.28
1053
149
622
0.12
0.12
550.
651.
294
0.65
0.07
480
0.22
0.94
762
843
1063
±4
D) z
r >4.
2 g
cm-3
, >75
μm, b
row
nish
-yel
low
ish,
± F
e pi
gmen
ted,
long
pris
mat
ic, t
rans
luce
nt, a
brad
ed 1
0 h
0.44
1307
152
469
0.12
0.10
060.
651.
029
0.65
0.07
418
0.28
0.91
618
718
1046
±6
Mos
-4 /
1072
-02
aplit
e gr
anite
, Gur
o Su
iteA
) zr>
4.2
g c
m-3
, >75
μm, t
rans
pare
nt, q
uite
col
ourle
ss
pris
mat
ic, i
nclu
sion
s, ab
rade
d 22
h0.
5022
031
7499
0.14
0.13
690.
651.
273
0.65
0.06
741
0.15
0.97
827
833
850±
2
B) z
r>4.
2 g
cm
-3, >
75μm
, tra
nspa
rent
, qui
te c
olou
rless
pr
ism
atic
, inc
lusi
ons
0.55
331
4352
400.
110.
1273
0.65
1.16
80.
650.
0665
40.
150.
9777
378
682
3±2
C) z
r>4.
2 g
cm
-3, <
75μm
, tra
nspa
rent
, qui
te c
olou
rless
pr
ism
atic
, inc
lusi
ons,
abra
ded
17 h
0.31
377
5414
457
0.16
0.13
620.
651.
264
0.65
0.06
733
0.15
0.97
823
830
848±
2
D) z
r>4.
2 g
cm
-3, <
75μm
, tra
nspa
rent
, qui
te c
olou
rless
pr
ism
atic
, inc
lusi
ons
0.48
390
5210
674
0.14
0.12
910.
651.
190
0.65
0.06
684
0.15
0.97
783
796
833±
2
Mos
-6 /
1170
-03
Mas
sang
a gn
eiss
, Mud
zi M
etam
orph
ic C
ompl
exA
) zr>
4.2
g c
m-3
, >75
μm, t
rans
pare
nt, e
long
ated
, ab
rade
d 20
h0.
4621
110
627
622
0.11
0.45
540.
3310
.987
0.33
0.17
497
0.05
0.99
2419
2522
2606
±1
B) z
r>4.
2 g
cm
-3, <
75μm
, tra
nspa
rent
, elo
ngat
ed,
abra
ded
10 h
0.45
258
119
2415
40.
090.
4209
0.35
10.0
170.
350.
1726
00.
060.
9922
6524
3625
83±1
C)
zr>4
.2 g
cm
-3, t
rans
pare
nt, e
long
ated
, abr
aded
30
h0.
5119
096
4366
60.
110.
4583
0.32
11.0
660.
330.
1751
00.
050.
9924
3225
2926
07±1
Mos
-9 /
2007
-03,
gra
nite
, Cas
saca
tiza
Suite
A) z
r >4.
2 g
cm-3
, >15
0μm
, pris
mat
ic, a
lmos
t col
ourle
ss,
trans
pare
nt, i
nclu
sion
s, ab
rade
d 10
h0.
5413
928
4094
0.20
0.18
050.
651.
876
0.65
0.07
539
0.15
0.97
1070
1073
1079
±2
B) z
r >4.
2 g
cm-3
, 150
-75
μm, p
rism
atic
, alm
ost c
olou
rless
, tra
nspa
rent
, inc
lusi
ons,
abra
ded
20 h
0.53
163
3262
110.
190.
1811
0.65
1.88
30.
650.
0754
20.
150.
9710
7310
7510
80±2
C) z
r >4.
2 g
cm-3
, <75
μm
, pris
mat
ic, a
lmos
t col
ourle
ss,
trans
pare
nt, i
nclu
sion
s, ab
rade
d 2
h0.
5723
946
1839
0.19
0.17
410.
651.
818
0.65
0.07
571
0.15
0.97
1035
1052
1088
±2
D) z
r >4.
2 g
cm-3
, 150
-75
μm, p
rism
atic
, alm
ost c
olou
rless
, tra
nspa
rent
, inc
lusi
ons
0.56
179
3525
530.
180.
1793
0.65
1.85
70.
650.
0751
10.
150.
9710
6310
6610
72±2
117
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
App
endi
x 2.
Con
tinue
d.
Sam
ple
info
rmat
ion
Sam
ple
UPb
206 Pb
/204 Pb
208 Pb
/206 Pb
ISO
TO
PIC
RA
TIO
S1)R
ho2
)
APP
AR
EN
T A
GE
S / M
a±2�
Ana
lyse
d m
iner
al a
nd fr
actio
nw
eigh
tm
gpp
mm
easu
red
radi
ogen
ic20
6 Pb/23
8 U±2
�%
207 Pb
/235 U
±2�
%20
7 Pb/20
6 Pb±2
�%20
6 Pb/23
8 U20
7 Pb/23
5 U20
7 Pb/20
6 Pb
Mos
-10
/ 200
1-02
gra
nite
, Mon
te S
anja
Sui
teA
) zr >
4.2
g cm
-3, >
75μm
, pris
mat
ic, a
lmos
t col
ourle
ss,
trans
pare
nt, a
brad
ed 2
0 h
0.27
108
2441
40.
310.
1676
0.36
1.71
30.
520.
0741
60.
330.
7799
910
1410
46±7
B#2
) zr >
4.2
g cm
-3, >
75μm
, pris
mat
ic, a
lmos
t col
ourle
ss,
trans
pare
nt, a
brad
ed 2
h0.
4713
929
348
0.29
0.15
160.
371.
547
0.56
0.07
405
0.37
0.75
910
949
1043
±8
C#2
) zr >
4.2
g cm
-3, <
75μm
, pris
mat
ic, a
lmos
t col
ourle
ss,
trans
pare
nt, a
brad
ed 1
7 h
0.46
213
4073
30.
310.
1468
0.33
1.49
50.
400.
0738
40.
190.
8888
392
810
37±4
D) z
r >4.
2 g
cm-3
, >75
μm, p
rism
atic
, alm
ost c
olou
rless
, tra
nspa
rent
0.36
306
5447
90.
300.
1351
0.42
1.37
20.
520.
0736
50.
270.
8681
787
710
32±6
Mos
-11
/ 229
7-03
Des
aran
ham
a gr
anite
, Fur
ancu
ngo
Suite
A) z
r >4.
2 g
cm-3
, 150
-75μ
m, p
rism
atic
, red
dish
, tra
nslu
cent
, inc
lusi
ons,
abra
ded
17 h
0.49
324
6132
80.
130.
1525
0.35
1.53
50.
620.
0730
246
.00
0.68
915
945
1015
±9
B) z
r >4.
2 g
cm-3
, 150
-75μ
m, p
rism
atic
, red
dish
, tra
nslu
cent
, inc
lusi
ons
0.54
282
5127
20.
120.
1436
0.34
1.44
00.
650.
0727
40.
490.
6786
590
610
07±1
0
C) z
r >4.
2 g
cm-3
, <75
μm, p
rism
atic
, red
dish
, tra
nslu
cent
, in
clus
ions
, abr
aded
17
h0.
3742
370
466
0.13
0.14
290.
341.
436
0.46
0.07
288
0.28
0.79
861
904
1011
±6
D) z
r >4.
2 g
cm-3
, 150
-75μ
m, p
rism
atic
, red
dish
, tra
nslu
cent
, inc
lusi
ons,
abra
ded
30 h
0.50
140
2611
170.
130.
1705
0.33
1.73
60.
370.
0738
40.
140.
9310
1510
2210
37±3
Mos
-13
/ 603
4-03
gra
nite
, Cas
tanh
o G
rani
teA
) zr >
4.2
g cm
-3, >
75μm
, lon
g pr
ism
atic
, tra
nspa
rent
, ab
rade
d 17
h0.
5425
346
1087
60.
110.
1760
0.65
1.80
70.
650.
0744
70.
150.
9710
4510
4810
54±2
B) z
r >4.
2 g
cm-3
, >75
μm, l
ong
pris
mat
ic, t
rans
pare
nt,
abra
ded
2h0.
5621
138
1418
90.
110.
1760
0.65
1.80
20.
650.
0742
80.
150.
9710
4510
4610
49±2
C) z
r >4.
2 g
cm-3
, <75
μm, l
ong
pris
mat
ic, t
rans
pare
nt,
abra
ded
30 h
0.53
282
5025
921
0.11
0.17
570.
651.
801
0.65
0.07
435
0.15
0.97
1044
1046
1051
±2
D) z
r >4.
2 g
cm-3
, <75
μm, l
ong
pris
mat
ic, t
rans
pare
nt0.
2933
259
8217
0.11
0.17
440.
651.
787
0.65
0.07
428
0.15
0.97
1037
1041
1049
±2
Mos
-18
/ 130
32-0
3 gr
anite
, Mon
te C
apir
impi
ca G
rani
teA
) zr >
4.2
g cm
-3, >
75μm
, pris
mat
ic, b
row
nish
, tra
nslu
cent
to
tran
spar
ent,
abra
ded
10 h
0.53
554
105
1127
0.16
0.16
890.
331.
763
0.35
0.07
573
0.13
0.94
1006
1032
1088
±3
B) z
r >4.
2 g
cm-3
, >75
μm, p
rism
atic
, bro
wni
sh, t
rans
luce
nt
to tr
ansp
aren
t0.
5546
191
421
0.16
0.16
370.
331.
710
0.47
0.07
578
0.30
0.78
977
1012
1089
±6
C) z
r >4.
2 g
cm-3
, <75
μm, p
rism
atic
, bro
wni
sh, t
rans
luce
nt
to tr
ansp
aren
t, ab
rade
d 20
h0.
4456
711
194
50.
170.
1727
0.33
1.80
20.
360.
0757
00.
140.
9210
2710
4610
87±3
D) z
r >4.
2 g
cm-3
, <75
μm, p
rism
atic
, bro
wni
sh, t
rans
luce
nt
to tr
ansp
aren
t0.
4761
611
712
650.
160.
1717
0.33
1.79
20.
350.
0757
20.
120.
9410
2110
4310
88±3
118
Geological Survey of Finland, Special Paper 48Irmeli Mänttäri
App
endi
x 2.
Con
tinue
d.
Sam
ple
info
rmat
ion
Sam
ple
UPb
206 Pb
/204 Pb
208 Pb
/206 Pb
ISO
TO
PIC
RA
TIO
S1)R
ho2
)
APP
AR
EN
T A
GE
S / M
a±2�
Ana
lyse
d m
iner
al a
nd fr
actio
nw
eigh
tm
gpp
mm
easu
red
radi
ogen
ic20
6 Pb/23
8 U±2
�%
207 Pb
/235 U
±2�
%20
7 Pb/20
6 Pb±2
�%20
6 Pb/23
8 U20
7 Pb/23
5 U20
7 Pb/20
6 Pb
Mos
-22
/ 289
3-04
gra
nite
, Ruk
ore
Suite
A) z
r >4.
2 g
cm-3
, 150
-75μ
m, p
rism
atic
, tra
nspa
rent
, ab
rade
d 17
h0.
5910
14
419
0.28
0.02
930.
700.
203
1.90
0.05
011.
600.
5018
618
720
1±39
B) z
r >4.
2 g
cm-3
, <75
μm, p
rism
atic
, tra
nspa
rent
, ab
rade
d 9
h0.
4816
36
508
0.32
0.03
080.
700.
241
1.90
0.05
671.
600.
5019
621
947
9±39
C) z
r >4.
2 g
cm-3
, 150
-75μ
m, p
rism
atic
, tra
nspa
rent
, ab
rade
d 26
h0.
5310
24
382
0.25
0.02
970.
700.
204
1.90
0.04
971.
600.
5018
918
817
9±39
Mos
-24
/ 152
73-0
4 sy
enite
, Gor
ongo
sa In
trus
ive
Suite
A) z
r >4.
2 g
cm-3
, 150
-75μ
m, e
long
ated
, tra
nspa
rent
, qui
te
colo
rless
, abr
aded
17
h0.
5331
9411
215
920.
340.
0284
0.33
0.19
50.
360.
0497
0.14
0.92
181
181
182±
3
B) z
r >4.
2 g
cm-3
, <75
μm, e
long
ated
, tra
nspa
rent
, qui
te
colo
rless
, abr
aded
9 h
0.57
1822
6411
360.
330.
0285
0.33
0.19
50.
380.
0498
0.18
0.88
181
181
183±
4
Mos
-29
/ 192
90-0
4 In
chap
a gr
anod
iori
te, B
arue
Com
plex
A) m
onaz
ite: t
rans
pare
nt, a
brad
ed 2
0 m
inut
es0.
4626
9616
9030
007.
420.
0851
0.92
0.67
40.
980.
0575
0.30
0.95
526
523
509±
7M
os-3
0 / 1
9140
-04
Mes
seca
gra
nodi
orite
, Mav
onde
Com
plex
A) z
r >4.
0 g
cm-3
, >75
μm, t
rans
luce
nt, p
rism
atic
, ab
rade
d 17
h0.
5013
9233
039
240.
090.
2217
0.65
4.07
30.
650.
1332
0.15
0.97
1291
1649
2141
±3
B) z
r >4.
0 g
cm-3
, <75
μm, t
rans
luce
nt, p
rism
atic
, ab
rade
d 9
h0.
4712
6626
924
160.
110.
1964
0.65
3.44
10.
650.
1271
0.15
0.97
1156
1514
2058
±3
C) z
r >4.
0 g
cm-3
, <75
μm, t
rans
luce
nt, p
rism
atic
, ab
rade
d 20
h0.
1312
8827
913
380.
100.
1979
30.
653.
4907
0.65
0.12
790.
150.
9711
6415
2520
69±3
D) z
r >4.
0 g
cm-3
, >75
μm, t
rans
luce
nt, p
rism
atic
, ab
rade
d 30
h0.
2714
6831
341
150.
110.
1974
0.65
3.47
00.
650.
1275
0.15
0.97
1162
1521
2063
±3
E) z
r >4.
0 g
cm-3
, >75
μm, t
rans
luce
nt, p
rism
atic
, ab
rade
d 5
h0.
5014
0633
818
030.
110.
2194
0.65
4.06
00.
650.
1342
0.15
0.97
1278
1646
2154
±3
Mos
-31
/ 684
5-04
Mon
te C
hiss
ui to
nalit
e, B
áruè
Com
plex
A) z
r >4.
0 g
cm-3
, >75
μm, t
rans
pare
nt, e
uhed
ral t
o su
bher
dal,
abra
ded
17 h
0.64
149
2867
250.
220.
1667
0.65
1.79
00.
650.
0779
0.15
0.97
994
1042
1144
±3
B) z
r >4.
0 g
cm-3
, <75
μm, t
rans
pare
nt, e
uhed
ral t
o su
bhed
ral,
abra
ded
9 h
0.44
156
2452
890.
180.
1425
0.65
1.44
60.
650.
0736
0.15
0.97
859
908
1030
±3
C) z
r >4.
0 g
cm-3
, <75
μm, t
rans
pare
nt, e
uhed
ral t
o su
bhed
ral,
abra
ded
20 h
0.45
268
3613
252
0.16
0.12
750.
651.
235
0.65
0.07
020.
150.
9777
481
693
5±3
D) z
r >4.
0 g
cm-3
, >75
μm, t
rans
pare
nt, e
uhed
ral t
o su
bhed
ral,
abra
ded
30 h
0.33
136
2563
260.
210.
1653
0.65
1.77
40.
650.
0779
0.15
0.97
986
1036
1143
±3
1) Is
otop
ic ra
tios c
orre
cted
for f
ract
iona
tion,
bla
nk (3
0-50
pg)
, and
age
rela
ted
com
mon
lead
(Sta
cey
and
Kra
mer
s, 19
75; 20
6 Pb/20
4 Pb±0
.2; 2
07Pb
/204 Pb
±0.1
;208 Pb
/204 Pb
±0.2
;2)
Err
ors f
or c
omm
on le
ad c
ompo
sitio
n of
low
-U, y
oung
zirc
ons i
n sa
mpl
e M
OS-
22 a
re 20
6 Pb/20
4 Pb±0
.5;20
7 Pb/20
4 Pb±0
.3;20
8 Pb/20
4 Pb±0
.5 ).
3)
Rho
=Err
or c
orre
latio
n be
twee
n 207
Pb/23
5 U a
nd 20
6 Pb/23
8 U ra
tios.
Abb
revi
atio
ns: z
r=zi
rcon
119
Geological Survey of Finland, Special Paper 48Mesoarchaean to Lower Jurassic U-Pb and Sm-Nd ages from NW Mozambique
Appendix 3. Sm-Nd isotopic data, samples from NW Mozambique.