Description
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Summary Statistics
Recommended Concentrations and Limits
(at two Standard Deviations) Certified Concentrations
Au 2A_MICP 0.550 0.076 g/t
Au CL 0.729 0.37 g/t
Au PA 0.609 0.055 g/t
Au Pb Collection 0.605 0.071 g/t
Cu 4A_MICP 46 3 ppm
S 4A_MICP 0.93 0.07 %
S Combustion/LECO 0.93 0.03 %
C Combustion/LECO 4487 358 ppm
Al 4A_MICP 5.11 0.22 %
As 4A_MICP 235 24 ppm
Ba 4A_MICP 692 71 ppm
Be 4A_MICP 1 0.09 ppm
Ca 4A_MICP 9576 478 ppm
Co 4A_MICP 15 1 ppm
Cr 4A_MICP 237 14 ppm
Fe 4A_MICP 7.49 0.33 %
K 4A_MICP 1.56 0.063 %
La 4A_MICP 27 2 ppm
Li 4A_MICP 14 0.9 ppm
Mg 4A_MICP 1.10 0.070 %
Mn 4A_MICP 1745 54 ppm
Mo 4A_MICP 1 0.5 ppm
Na 4A_MICP 1.02 0.035 %
Ni 4A_MICP 75 10 ppm
P 4A_MICP 244 36 ppm
Pb 4A_MICP 17 2 ppm
Sb 4A_MICP 6 0.4 ppm
Sc 4A_MICP 8 0.5 ppm
Sr 4A_MICP 216 10 ppm
Ti 4A_MICP 1332 89 ppm
V 4A_MICP 57 5 ppm
W 4A_MICP 12 1 ppm
Y 4A_MICP 8 1 ppm
Zn 4A_MICP 87 10 ppm
Zr 4A_MICP 42 3 ppm
Major Oxides
Certified Concentrations (at two Standard Deviations)
Al2O3 XRF 9.75 0.13 %
CaO XRF 1.29 0.023 %
Cr2O3 XRF 0.039 0.005 %
Fe2O3 XRF 11.04 0.45 %
K2O XRF 1.87 0.072 %
MgO XRF 1.88 0.046 %
Na2O XRF 1.38 0.040 %
P2O5 XRF 0.054 0.01 %
SiO2 XRF 69.38 0.17 %
TiO2 XRF 0.25 0.02 %
Origin of Material
This standard was made using ore material from 3 active pits (SUBIKA, AMOMA and AWONSU) within Newmont Ghana Gold Limited, Ahafo. The Ahafo Project is in south-western Ghana, approximately 300 km northwest from the Capital of Accra. The south-western part of Ghana hosts the Birimian Super-Group which comprises several narrow north-east-trending belts of volcanic and volcaniclastic rocks of tholeiitic to acidic composition. These are separated by broad sedimentary basins dominated by turbidites. The Ahafo projects are in the Sefwi Belt, one of the five Birimian volcanic belts. The Sefwi Belt is bounded to the northwest by the Sunyani Basin and to the southeast by the Kumasi Basin. The Dixcove suite or “belt-type” granitoids intrude the contact and predominate in the metavolcanics that form elongate bodies parallel to the regional strike. Cape Coast or “basin-type” granitoid intrusions are found in the southern-most part of the project area.
Regionally, the sedimentary succession consists mainly of fine to medium-grained lithologies (argillites and wackes) with variable amounts of volcaniclastic material. Cape Coast type granitoids intrude the metasediments. The volcanics are mainly basaltic and have been metamorphosed to varying degrees from Lower Greenschist to Amphibolite Facies.
Approximate Mineral and Chemical Composition
Gold mineralization within the Subika deposit in the southern portion of the project area is located within a fracture zone within a host of Dixcove Suite granitoids. Gold mineralization in the southern part of the Sefwi Belt within the Amoma and Awonsu deposits is hosted at or near the contact between the overthrust of the Dixcove granite with underlying meta-volcano sedimentary units.
The mineral composition for the Subika samples are: Quartz – 17%, Albite – 54%, Ankerite – 15%, Calcite – 2%, Muscovite – 7%, Chlorite – 2%, Pyrite – 3%. The mineral composition for the Amoma and Awonsu samples are: Quartz – 15%, Plagioclase – 51%, Muscovite – 15%, Chlorite – 2%, Ankerite – 16%, Pyrite – 1%, Calcite/Siderite – trace amounts.
