iii ABSTRACT The study area (Penjom Gold Deposit, Pahang, Malaysia) lies 30 km east of the major terrane boundary Bentong-Raub Suture within the central belt of Peninsular Malaysia along the NNE trending splay from the Suture line. Host rock is comprised of turbiditic sequence of Early to Late Permian ranging from well bedded siltstone, calcareous shale, carbonaceous shale, tuffaceous sandstone and conglomerate. These sequences were intruded by fine grained and porphyritic medium grained felsite intrusives (222.4 +/- 1.8 Ma). Quartz veins found here are categorized into two main types, namely shear veins and extension veins. Shear veins are ribbon to laminated veins developed only in carbonaceous units and are either thick or very thin units, parallel to bedding or shearing. This vein type is interpreted as formed during folding and thrusting events involving repeated opening of bedding and shearing planes. Associated with shear veins are several types of extensional veins including sub-vertical extensional vein arrays, hydrothermal quartz breccias and stockwork in felsite rocks. NE to NNE thrust-parallel reverse to dextral faults overprinted the earlier D2 event and generated extensional veins of similar morphology, mostly at intersections of sediment-intrusive contact or as shallowly dipping veins within the intrusive bodies. Local NNW fault controls significant mineralization at the west wall of Jalis Corridor in the form of shear vein, massive to sheeted extension vein. Several north-south trending sinistral faults, intercept at the footwall folded sequence initiated mainly after the main veining event interpreted as during D4. Normal sense of movement of the same fault crosscut and displace the vein is occurring during D5 event, are not associated with the above style of veins but locally host barren quartz calcite-veins and are in certain areas associated with the late stage galena. Common alteration minerals based on XRD analysis are fine grain muscovite, chlorite and illite, which is typically characterized the phyllic alteration. Fluid inclusions were analyzed using eleven doubly polished sections of veins including
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iii
ABSTRACT
The study area (Penjom Gold Deposit, Pahang, Malaysia) lies 30 km east of the major
terrane boundary Bentong-Raub Suture within the central belt of Peninsular Malaysia
along the NNE trending splay from the Suture line. Host rock is comprised of turbiditic
sequence of Early to Late Permian ranging from well bedded siltstone, calcareous shale,
carbonaceous shale, tuffaceous sandstone and conglomerate. These sequences were
intruded by fine grained and porphyritic medium grained felsite intrusives (222.4 +/- 1.8
Ma). Quartz veins found here are categorized into two main types, namely shear veins
and extension veins. Shear veins are ribbon to laminated veins developed only in
carbonaceous units and are either thick or very thin units, parallel to bedding or
shearing. This vein type is interpreted as formed during folding and thrusting events
involving repeated opening of bedding and shearing planes. Associated with shear veins
are several types of extensional veins including sub-vertical extensional vein arrays,
hydrothermal quartz breccias and stockwork in felsite rocks. NE to NNE thrust-parallel
reverse to dextral faults overprinted the earlier D2 event and generated extensional veins
of similar morphology, mostly at intersections of sediment-intrusive contact or as
shallowly dipping veins within the intrusive bodies. Local NNW fault controls
significant mineralization at the west wall of Jalis Corridor in the form of shear vein,
massive to sheeted extension vein. Several north-south trending sinistral faults, intercept
at the footwall folded sequence initiated mainly after the main veining event interpreted
as during D4. Normal sense of movement of the same fault crosscut and displace the
vein is occurring during D5 event, are not associated with the above style of veins but
locally host barren quartz calcite-veins and are in certain areas associated with the late
stage galena. Common alteration minerals based on XRD analysis are fine grain
muscovite, chlorite and illite, which is typically characterized the phyllic alteration.
Fluid inclusions were analyzed using eleven doubly polished sections of veins including
iv
two calcite veins and one quartz sample from hanging wall. No measureable fluid
inclusions were found in calcite and hanging wall vein. Fluid inclusions fall in two
populations. Population 1 is made up of H2O-NaCl were having Thfinal between 145oC
and 265oC while population 2 is consist of H2O-NaCl-CO2 fluid inclusions with higher
Thfinal from 200oC to 375
oC. Sulphides are comprised of pyrite, arsenopyrite, galena,
sphalerite and chalcopyrite. Gold is commonly found with galena but also can be found
together with early sulphide. Galena samples from two groups (6 from the mineralised
zone and 3 from the non mineralised area) have been sampled and analyzed for trace
element geochemistry and lead isotopes. The lead isotope ratios for both groups plot
around the bulk crustal growth curve of the plumbotectonic model indicating Pb derived
from mixed crustal and magmatic sources. Based on the Cumming and Richards (1975)
growth curves, two groups of lead can be interpreted as having formed at 250 Ma and
160 Ma. The Penjom gold deposit shows many similarities with other orogenic gold
deposits formed in a terrain subjected to compressional to transpressional event. Gold
and other metal could be derived from mix metamorphic-magmatic sources migrated
from deeper sources and deposited at mid crustal level during the late stages of an
orogenic event.
v
ABSTRAK
Kawasan kajian (Lombong Emas Penjom) terletak 30km timur daripada sempadan
terrain utama, Bentong-Raub Suture di dalam jalur tengah semenanjung Malaysia di
lineament berarah NNE iaitu cabang daripada jalur suture. Unit batuan utama adalah
jujukan turbidit yang berusia Permian awal hingga Lewat yang terdiri daripada
perlapisan batu lodak, shale berkapur, shale berkarbon, batu pasir bertuf dan
conglomerate. Jujukan ini di terobosi oleh batuan felsic (222.4 +/- 1.8 Ma) yang bersize
halus dan berporfir. Telerang kuarzayang terdapat di sini diklasifikasikan kepada dua
jenis iaitu telerang ricih dan telerang ekstensi. Telerang ricih adalah berbentuk ribbon
dan berlaminasi yang terbentuk di dalam unit berkarbon sama ada tebal atau nipis, selari
dengan satah perlapisan dan ricih. Telerang jenis ini ditafsirkan sabagai terbentuk
semasa proses perlipatan dan sesar sungkup yang melibatkan proses pembukaan dan
penutupan ruang perlapisan atau zon ricih. Berkait dengan telerang ricih adalah
beberapa telerang ekstensi termasuk telerang hampir menegak, hidroterma quartz
breksia dan stockwork di dalam batuan felsik. Sesar sungkup berarah NNE dan sesar
yang selari dengannya bersifat songsang dan dextral bertindan terhadap peristiwa yang
awal dan menghasilkan telerang kuarza dengan ciri yang sama, terutamanya di kawasan
sentuhan intrusive dan batuan sedimen. Sesar NNW mengawal pemineralan yang
penting di barat koridor Jalis dalam bentuk telerang ricih dan ekstensi. Beberapa sesar
berarah utara-selatan dengan ciri sinistral memotong jujukan yang terlipat yang
terbentuk selepas pembentukan telerang utama iaitu semasa D4. Pergerakan normal
pada sesar yang sama memotong dan mengalihkan vein semasa D5 berkait dengan
telerang calcite yang tidak berkait dengan emas dan di beberapa kawasan berkait dengan
mineral galena fasa lewat. Mineral ubahan batuan yang biasa berdasarkan kajian XRD
adalah muskovit, klorit, illit yang mencirikan perubahan batuan jenis phyllic. Kajian
inklusi terkandung terdiri dari sebelas sampel kilatan telerang termasuk dua telerang
vi
kalsit dan satu sampel kuarza di bahagian atas daripada Sesar Penjom. Tiada inklusi
terkandung di dalam kalsit dan vein di atas Sesar Penjom. Populasi inklusi terkandung
boleh dibahagikan kepada dua populasi. Populasi 1 terdiri dari pada sistem H2O-NaCl
yang mempunyai suhu Thfinal diantara 145oC to 265
oC manakala populasi 2 terdiri dari
H2O-NaCl-CO2 dengan bacaan Thfinal dari 200oC to 375
oC. Mineral sulfida utama
terdiri dari pirit, arsenopirit, galena, sphalerite dan chalcopirit. Emas selalu berada
bersama galena tetapi juga selalu bersama sulfida yang awal. Galena dari dua kumpulan
(6 dari zone bermineralisasi dan 3 dari zon yang tidak bermineralisasi) telah di sampel
dan di analisi untuk mineral surih dan Pb isotop. Nisbah isotop Pb di plotkan dan berada
pada lengkungan pertumbuhan model plumbotectonic yang menunjukkan
kedudukannya pada campuran kerak bumi dan sumber magmatic. Berdasarkan pada
lengkungan pertumbuhan Cumming dan Richards (1975), dua kumpulan Pb boleh di
tafsirkan sebagai terbentuk pada usia 250 Ma dan 160 Ma. Lombong Emas Penjom
menunjukkan persamaan dengan jenis Orogenic Gold yang terletak di terrain yang
mengalami tegasan compressive dan transpressive. Emas dan base metal mungkin
berpunca dari gabungan sumber metamorphic-magmatic yang bergerak dari sumber
yang dalam dan termendap di kerak pertengahan semasa fasa orogenic lewat.
vii
ACKNOWLEDGMENTS
I would like to express my gratitude to Assoc Prof Dr. Ng Tham Fatt, Dr. Jasmi Hafiz
Abdul Aziz and Prof Dr. Teh Guan Hoe for being my supervisors and for their
invaluable encouragement, support and guidance in completing this thesis. I would also
like to acknowledge the supports from other lecturers and staffs at Geology Department,
University Malaya. They are Dr. Iskandar Taib (XRD and Micro-XRF analysis), Prof.
Wan Hasiah Abdullah (carbon analyzer), En Zamrud (thin section), En Zaharuddin
(XRD analysis) and other staffs at Geology Department. I am most grateful to Head of
Deparment Prof. Dr Azman Abdul Ghani and Prof. Dr Ismail Yusof for the support.
Great thanks extended to Assoc. Prof. Zhaoshan Chang from University of James Cook,
Australia for the fluid inclusion study and Dr Sebastien Meffre and Charles Makoundi
from University of Tasmania, Australia for the LA ICP MS analyses.
My deepest appreciation goes to all geologists and management at Penjom Gold
Mine including general managers and managers at Specific Resources Sdn. Bhd. and
management at Avocet Gold (UK) and JResources, Jakarta.
I would like to extend my appreciation to my lovely wife Suziati Mustaffa for
the support, patient and understanding throughout my study and also to my three lovely
daughter and sons (Farah, Farhan and Fahmi) for their encouragement and inspiration.
Thank you also to my mother Khatijah Setapa and other family members for the
supports and prayer for my success. Finally, to my late father Endut Bin Musa who is
always in my heart and my prayers. Thank you Allah Almighty for giving me a
wonderful life, opportunities and energy to complete this study and for everything.
viii
TABLE OF CONTENTS
TITLE PAGE i
DECLARATION ii
ABSTRACT iii
ABSTRAK v
ACKNOWLEDGMENT vii
TABLE OF CONTENTS viii
LIST OF FIGURES xix
LIST OF TABLES
LIST OF APPENDICES
xxxi
xxxiii
CHAPTER 1 INTRODUCTION
1.0 Introduction
1
1.1 Location
2
1.2 Objective
2
1.3 Scope of study
2
1.4 Method of mapping
6
1.4.1 Introduction
6
1.4.2 Geological mapping and methodology
7
1.4.2.1 Pit wall mapping
8
1.4.2.2 Temporary bench face mapping
8
1.4.2.3 Mapping during the ore excavation
10
1.4.2.4 Floor mapping
11
1.4.2.5 Mapping from blast hole sample logging
11
1.4.2.6 Core samples
12
1.5 Geological observation
12
ix
1.6 Previous study
13
1.7 Conclusion
14
CHAPTER 2 GOLD DEPOSIT CLASSIFICATION
2.1 Introduction
16
2.2 Ore forming process
18
2.2.1 Igneous/magmatic process
18
2.2.2 Hydrothermal process
19
2.2.3 Sedimentary and surficial process
19
2.3 Several class of gold deposit
20
2.3.1 Orogenic gold deposit
22
2.3.1.1 Geology of the host terrains
22
2.3.2 Intrusion Related Gold Deposit
23
2.3.2.1 Geology of the host terranes
24
2.3.3 Porphyry (copper) and gold deposit
24
2.3.3.1 Geology of the host terranes
25
2.3.4 Epithermal gold deposit
25
2.3.4.1 Geology of the host terranes
25
2.4 Other subclass of gold deposit
26
2.4.1 Disseminated sedimentary hosted/Carlin type
26
2.4.2 Volcanogenic massive sulphide
26
2.5 Gold deposits related to vein textures
27
2.6 Tectonic setting and gold deposit: Mainland South East Asia (SEA)
28
x
CHAPTER 3 HOST ROCK OF THE PENJOM GOLD DEPOSIT
3.1 Regional geology
33
3.2 District geology and stratigraphy
34
3.3 Stratigraphy setting of PGM
35
3.3.1 Introduction
35
3.3.2 Mine stratigraphy
36
3.4 Detail description of sedimentary rock units
37
3.4.1 Upper well-bedded laminated siltstone and shale (UMS 1)
37
3.4.2 Sandstone with minor thinly bedded shale and siltstone (UMS 2)
37
3.4.3 Lower well bedded laminated siltstone (UMS 3)
Figure 1.3: Flow chart of mapping activity and compilation into geological map.
7
Figure 1.4: Example of pit wall map of southern wall across the ore zone. Scale
1:1000.
9
Figure 1.5: Geological observation during ore excavation has been plot on grade
control mining plan.
10
Figure 2.1: Tectonic settings of gold-rich epigenetic mineral deposits. Vertical
scale is exaggerated to allow schematic depths of formation of various deposit
styles to be shown (Groves et al., 1998).
20
Figure 2.2: Idealised cross section of gold deposit in different tectonic regime
(after Groves, 1999).
21
Figure 2.3: Conceptual model for styles of magmatic arc epithermal Au-Ag and
porphyry Au-Cu mineralization (Corbett, 1997)
21
Figure 2.4: Gold deposit environment used by Morrison (2007) for vein texture
classification
28
Figure 2.5: Location of primary gold deposit in Malaysia Peninsular (after Yeap,
1999). Gold deposit in between purple and blue line lineament in inset figure
hosted within vein system.
30
Figure 2.6: Gold deposits along Central Belt (Malaysia Peninsula)-Sukhotai Fold
Belt and South East Asia granite provinces (after Cobbing et al., 1986; Ng et al.,
2015)
31
Figure 2.7: Hydrothermal ore deposit and its location in geological setting of
magmatic bodies and major shear/ fault system (Stephens, 2004). a: Orogenic
gold, b: Intrusion related, c: Porphyry gold.
32
Figure 3.1: (Left) Well bedded sandstone of upper mine sequence. (Right)
Photomicrograph of sandstone with poorly sorted quartz fragment (Q) dominant
and minor lithic (L) fragment with sericite and patch of carbonate (UMS2).
38
Figure 3.2: (Left) Flaser bedding at upper part of sandstone bed. (Right) Pebbles
of carbonaceous mudstone occasionally found in sandstone unit.
38
Figure 3.3: (Left) Parallel lamination in lower well bedded siltstone, (Right) cross
lamination in the same unit.
39
xx
Figure 3.4: Rock samples locations for greenish grey tuffaceous siltstone UMS4
(looking south).
39
Figure 3.5: (Left): Photomicrograph of light grey shale (UMS4) with minor
quartz grain in matrix of fine grain lithic dominant and minor quartz. Sericite and
patch of carbonate (yellowish) aligned parallel to foliation (S0) or bedding.
(Right): Photomicrograph of calcareous shale comprised of recrystallized calcite
grain size is less than 0.2mm. Aligned dark opaque streak is carbon parallel to
bedding (So).
39
Figure 3.6: Figure 3.6: Carbon result (%) from grade control ore block 924mRL Grey
dot is 0.2 to 0.5 %C. Ore mark-out string comprised of ore grade above 0.8 g/t, red string ore block is above 6 g/t. Continuation of the high carbon ore zones along the Penjom
thrust and NS corridor (western limb). High carbon content in the western limb is
originated from carbonaceous shale.
41
Figure 3.7: Photomicrograph of sandstone in MMS comprised of dominant
altered lithic (L) and quartz (Q) in sericitised matrix (location Western Limb