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1
LIST OF CONTENTS Page .
Executive Summary 3
Location and Access 4
Geophysics 4
Mineral Occurrences (Historical data) 5
PL Mineralisation 5
Regional Geology 6-7
C-66 Area Geology 7-8
Structure and relative age 8
Comments & Conclusions 9
References 19
2
List of Figures
Page
Figure 1. Location Map 10
Figure 2. Gold Geochemistry Summary map 11
Figure 3. Mineral Occurrence Summary Map. 12
Figure 4. Geological Summary Map 13
Figure 5. Geological Summary Map 14
Figure 6. Geological Summary Map. 15
Figure 7. Structural Summary Map 16
Figure 8. Aeromagnetic Map 17
Figure 9. Topographic Map 18
3
Executive Summary
The Prospecting Licence (C-66) located in the Cuyuni Mining District No. 4 as shown on
Terra Surveys Topographic Map 18SW, as shown in fig 9 and enclosing an area of
approximately 5541 acres of the headwaters Ekabago River. The potential of the area
for gold is very good.
The PL is presently under mining license by C B & R Mining Enterprises. Active gold
extraction is presently undertaken by land dredging, using excavators on mining concesions
bordering this PL area.
The PL area is located in the upper drainage portion of the Ekabago River that drains in
the Puruni River,and close to the mouth of the Waikuri River that drains into the Cuyuni
River, approximately 150 km due west of the city of Georgetown .
Based on information from surface mapping in the areas of the soil geochemical anomalies
suggest the majority of the alluvial gold and gold anomaly areas are located to the
north/west of this PL, see fig 3. The PL area is likely to be related to zones of weakly
mineralized, structurally deformed, lithological contact between mafic and felsic volcanic or
intrusive rocks which interlayer with more extensive packages of sedimentary formations,
however because of limited data available for this PL,it is just an assumption. A portion
(perhaps the majority) of the gold mineralization may have been derived from quartz lode
type occurrences in lithologically controlled shear structures in the area.
The geology of the area consists of Lower Proterozoic Mazaruni Supergroup (greenstone
belts) consisting of meta-sediments and meta-volcanic rocks, intruded by Younger Granites.
Unconformably overlying these rocks is the Roraima Formation, a generally flat lying series
of conglomerates, sandstones, shales and with minor interbedded volcanics. All of these
rocks (greenstones, granites, and post-orogenic sedimentary series), are intruded by
doleritic and gabbroic dikes and sills (the Younger Basic Intrusive Suite), see fig 4-6.
4
Location and Access
The PL area can be accessed by 4WD vehicle or Bedford truck via a logging and mining
road from Bartica, crossing the Mazaruni at Itaballi,from Itaballi the journey by truck/pick up
is approximately 5-6 hours to the PL.0.. . Bartica is accessed from Georgetown via speed
boat from Parika, or by road via the Georgetown-Linden Highway crossing the Essequibo
River at the Shirima crossing, see fig 1.
Geophysics
The first systematic geophysical survey in Guyana was an aeromagnetic survey flown by
Aero Services Corporation, funded by the United Nations in 1963. The survey used a set of
N-S flight lines at a spacing of approximately 1.6 to 2.4 km, and a height of 300m. In 1971-
72 additional areas in Guyana were flown by Terra Surveys, funded by the Canadian
Commonwealth Bureau, and older data was incorporated in a set of 1:200,000 scale maps.
These sheets were then re-issued with an interpretation by Tyl & Reford of Terra Surveys
Ltd in 1973. In 1994 aeromagnetic data covering Guyana was converted to digital form by
Gtech Ltd, a commercial group attached to the University of Leeds in the UK as part of the
“South American Magnetic Mapping Project” (SAMMP). A relief-shaded map compiled
recently (Heesterman 2004) from this data. It should be noted that this data has not been
reduced to the pole.
The aeromagnetic data shows distinct areas with magnetic highs, or abrupt magnetic
gradients,see fig 7. The Quartzstone mountains, which trend north-south, directly to the west
of the study locations (excluding Wiamu) show elevated geophysics results to the immediate
background geophysics. `
5
Mineral Occurrences
Historical Data
Historically the plains underlain by granitic saprolite in the area has been a good source of
gold. However recent sampling from this area has not determined a significant source of
gold in the granitic saprolite, which is now exposed. It is therefore suggested that historical
extraction of gold has derived from alluvial material deposited on the bed rock which has
subsequently been removed and processed for gold. The alluvial material is most likely to be
derived from lode structures and schistose rocks observed and from the hill ranges. It is
therefore seen as an important exercise to study the hill range of the area for primary
mineralization.
The Quartzstone – Aremu Batholith which may be present within the PL area is associated
with extensive surface gold workings along the contact zone with the country rock. Gold
occurs in the contact zone, marginal granite and gold bearing quartz veins, which are
usually associated with shear zones in this area (Annual Report, 1964)
PL Mineralisation
From data on the mining activities bordering the PL, gold is found to be present in quartz
veins and quartz rich lodes and well foliated saprolitic schist which in general all strike north-
south throughout the area. The gold bearing quartz veins are usually associated with a black
mineral (tourmaline?). Active extraction of gold from saprolite and quartz material in areas
bordering the PL area is presently undertaken by small and medium scale miner. In some
areas saprolite and quartz is being crushed and washed. One notably anomalous area is
located within the PL area with an Au assay value 25-38 ppb,see fig 2,however it should be
noted that only approximately thirty five percent (35%) of the PL area have subjected to
geochemical sampling .
6
Regional Geology Two major lithological sequences, the Bartica Assemblage and the Barama – Mazaruni
Supergroup Greenstone sequences, underlie the northwestern area of Guyana.
Basement – the Kanuku complex is considered to be part of the Archean basement. It
consists of paragneisses and migmatites, granulites (Kanuku Mts.) and granite
gneisses.
Greenstones - The Barama and Mazaruni groups have been classically considered as
part of the Guiana Shield’s widespread Birrimian Age Greenstone Belts (2.2 G.a). The
Barama group outcrops in the northwestern region of Guyana, close to the border with
Venezuela. It consists of a predominantly sedimentary sequence with locally developed
Annual Report of Geological Services Department, British Guiana. 1964. Special geological problems. Granite studies: Quartzstone – Aremu, Rupa, Kopang. 33-35
Learmont J W. 1954. Area vbetween Aremu and Quartzstone Rivers, Cuyuni Rivers. Annual Report on the Geological Survey Department for the Year 1954 (British Guiana Geological Survey). 42-43, 88-89
Lloyd JW. 1958, Area North-west of Quartzstone Landing, Cuyuni River. Annual Report on the Geological Survey Department for the Year 1958 (British Guiana Geological Survey). 42-43
Gibbs, A.K. and Barron, C.N. – 1993 – The Geology of the Guiana Shield. Oxford Univ. Press. Gibbs, A.K. – 1984 – Review of the geology and mineral deposits of the Guiana shield. Report for Utah International Inc.
Goodwin, Alan M. – 2000 – Precambrian Geology of South American Platform. Academic Press