Journal of Geosciences and Geomatics
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Journal of Geosciences and Geomatics. 2015, 3(4), 96-108
DOI: 10.12691/jgg-3-4-2
Open AccessArticle

Mineral Alteration and Chlorite Geothermometry in Platinum Group Element (PGE)- Bearing Meta-ultramafic Rocks from South East Cameroon

Ako T. A.1, 2, , A. Vishiti1, 3, K. I. Ateh1, A. C. Kedia1 and C. E. Suh1

1Economic Geology Unit, Department of Geology, University of Buea, Buea South West Region, Cameroon

2Department of Geology, Federal University of Technology, Minna, Niger State, Nigeria

3Higher Institute of Science, Engineering and Technology, Cameroon Christian University, Bali, North West Region, Cameroon

Pub. Date: August 14, 2015

Cite this paper:
Ako T. A., A. Vishiti, K. I. Ateh, A. C. Kedia and C. E. Suh. Mineral Alteration and Chlorite Geothermometry in Platinum Group Element (PGE)- Bearing Meta-ultramafic Rocks from South East Cameroon. Journal of Geosciences and Geomatics. 2015; 3(4):96-108. doi: 10.12691/jgg-3-4-2

Abstract

The meta-ultramafic rocks that are part of the Paleoproterozoic unit termed the Nyong Series in SE Cameroon were investigated in this study. The lithologic assemblage mapped is exposed on a cliff face and consists of distinguishable horizons that include least, moderately to intensely altered pyroxenite to amphibolite units. The rocks are partially to completely serpenitinized and foliated. The main mineral phases identified under the microscope include pyroxenes (clinopyroxene and orthopyroxene), olivine, hornblende, plagioclase, garnet and sulphides. The rocks depict variable alteration of the pyroxenes and other primary minerals such as olivine to actinolite, chlorite, serpentine, talc, epidote and tremolite. Electron microprobe analysis on chlorite show that the principal chlorite type ranges from talc-chlorite to penninite. Using the chlorite geothermometer it is observed that the hydrothermal alteration temperatures vary between 160-180°C. This has been overprinted by surface temperatures (20 - 40°C) during the process of weathering.

Keywords:
meta-ultramafics intrusive layered sequence alteration serpentinisation chlorite South East Cameroon

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