A New Occurrence of (Gold-Bearing) Graphite in the Assosa Region, Benishangul-Gumuz State, W Ethiopia

Liam A Bullock; Owen J Morgan

doi:10.17265/2159-581X/2015.07.003

A New Occurrence of (Gold-Bearing) Graphite in the Assosa Region, Benishangul-Gumuz State, W Ethiopia

Liam A Bullock, Owen J Morgan

Geology and Geophysics

Tactical Environmental Response Ltd

Research output: Contribution to journal › Article › peer-review

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Abstract

The Assosa region of western Ethiopia hosts newly discovered and potentially highly economic graphite-bearing schist units. Due to its unique physical and chemical properties, graphite is quickly becoming an increasingly important economic resource. Graphite occurs over much of the area, and is hosted predominantly by quartz-graphitic schist, quartz-feldspar-mica schist and quartzite. The quartz-graphitic schist covers an area of 37 km2, forming steep valleys and ridges across a 190 km long belt. Graphite is texturally-variable within and across units. Crystal habit varies from highly crystalline to irregular flakes. Flake sizes range from amorphous and crystalline small flake to coarse large flake (> 150 μm), with beneficiation of ~ 70% and yield potential of > 95% (froth flotation methods). The license area is already a well-known gold-hosting area, and potentially economic gold deposits occur within the graphite-bearing units. Overall, the site shows excellent geochemical indicators, field observations and historical accounts of high gold content. It is suggested that textural variations may be the product of (1) early in-situ formation during (early- to late-Proterozoic) prograde metamorphism and (2) later vein-type mineralization during retrograde metamorphism. The discovery of graphite in western Ethiopia is the first documented and preliminary studies suggest a high economic potential for the deposits.

Original language	English
Pages (from-to)	417-435
Number of pages	19
Journal	Journal of Earth Science and Engineering
Volume	5
Issue number	7
DOIs	https://doi.org/10.17265/2159-581X/2015.07.003
Publication status	Published - Jul 2015

Bibliographical note

Acknowledgements
Fieldwork and mapping was carried out by GP Resource Mining PLC in partnership with Tactical Environmental Response Ltd (TER). TER was responsible for the geochemical analysis, with the
exception of XRD. The authors wish to greatly thank David Evans (XRD), Peter Greatbatch and David Wilde (thin sectioning) of Keele University. The authors also wish to thank the anonymous reviewers for manuscript feedback and comments.

Keywords

graphite
gold
Ethiopia
metamorphism
X-ray fluorescence
X-Ray diffraction

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A New Occurrence of (Gold-Bearing) Graphite in the Assosa Region, Benishangul-Gumuz State, W Ethiopia
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Cite this

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title = "A New Occurrence of (Gold-Bearing) Graphite in the Assosa Region, Benishangul-Gumuz State, W Ethiopia",

abstract = "The Assosa region of western Ethiopia hosts newly discovered and potentially highly economic graphite-bearing schist units. Due to its unique physical and chemical properties, graphite is quickly becoming an increasingly important economic resource. Graphite occurs over much of the area, and is hosted predominantly by quartz-graphitic schist, quartz-feldspar-mica schist and quartzite. The quartz-graphitic schist covers an area of 37 km2, forming steep valleys and ridges across a 190 km long belt. Graphite is texturally-variable within and across units. Crystal habit varies from highly crystalline to irregular flakes. Flake sizes range from amorphous and crystalline small flake to coarse large flake (> 150 μm), with beneficiation of ~ 70% and yield potential of > 95% (froth flotation methods). The license area is already a well-known gold-hosting area, and potentially economic gold deposits occur within the graphite-bearing units. Overall, the site shows excellent geochemical indicators, field observations and historical accounts of high gold content. It is suggested that textural variations may be the product of (1) early in-situ formation during (early- to late-Proterozoic) prograde metamorphism and (2) later vein-type mineralization during retrograde metamorphism. The discovery of graphite in western Ethiopia is the first documented and preliminary studies suggest a high economic potential for the deposits.",

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author = "Bullock, {Liam A} and Morgan, {Owen J}",

note = "Acknowledgements Fieldwork and mapping was carried out by GP Resource Mining PLC in partnership with Tactical Environmental Response Ltd (TER). TER was responsible for the geochemical analysis, with the exception of XRD. The authors wish to greatly thank David Evans (XRD), Peter Greatbatch and David Wilde (thin sectioning) of Keele University. The authors also wish to thank the anonymous reviewers for manuscript feedback and comments. ",

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N2 - The Assosa region of western Ethiopia hosts newly discovered and potentially highly economic graphite-bearing schist units. Due to its unique physical and chemical properties, graphite is quickly becoming an increasingly important economic resource. Graphite occurs over much of the area, and is hosted predominantly by quartz-graphitic schist, quartz-feldspar-mica schist and quartzite. The quartz-graphitic schist covers an area of 37 km2, forming steep valleys and ridges across a 190 km long belt. Graphite is texturally-variable within and across units. Crystal habit varies from highly crystalline to irregular flakes. Flake sizes range from amorphous and crystalline small flake to coarse large flake (> 150 μm), with beneficiation of ~ 70% and yield potential of > 95% (froth flotation methods). The license area is already a well-known gold-hosting area, and potentially economic gold deposits occur within the graphite-bearing units. Overall, the site shows excellent geochemical indicators, field observations and historical accounts of high gold content. It is suggested that textural variations may be the product of (1) early in-situ formation during (early- to late-Proterozoic) prograde metamorphism and (2) later vein-type mineralization during retrograde metamorphism. The discovery of graphite in western Ethiopia is the first documented and preliminary studies suggest a high economic potential for the deposits.

AB - The Assosa region of western Ethiopia hosts newly discovered and potentially highly economic graphite-bearing schist units. Due to its unique physical and chemical properties, graphite is quickly becoming an increasingly important economic resource. Graphite occurs over much of the area, and is hosted predominantly by quartz-graphitic schist, quartz-feldspar-mica schist and quartzite. The quartz-graphitic schist covers an area of 37 km2, forming steep valleys and ridges across a 190 km long belt. Graphite is texturally-variable within and across units. Crystal habit varies from highly crystalline to irregular flakes. Flake sizes range from amorphous and crystalline small flake to coarse large flake (> 150 μm), with beneficiation of ~ 70% and yield potential of > 95% (froth flotation methods). The license area is already a well-known gold-hosting area, and potentially economic gold deposits occur within the graphite-bearing units. Overall, the site shows excellent geochemical indicators, field observations and historical accounts of high gold content. It is suggested that textural variations may be the product of (1) early in-situ formation during (early- to late-Proterozoic) prograde metamorphism and (2) later vein-type mineralization during retrograde metamorphism. The discovery of graphite in western Ethiopia is the first documented and preliminary studies suggest a high economic potential for the deposits.

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ER -

A New Occurrence of (Gold-Bearing) Graphite in the Assosa Region, Benishangul-Gumuz State, W Ethiopia

Abstract

Bibliographical note

Keywords

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