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GEOREF RECORD

Drainage basin evolution in Southeast Guinea and the development of diamondiferous placer deposits

Donald G. Sutherland
Drainage basin evolution in Southeast Guinea and the development of diamondiferous placer deposits
Economic Geology and the Bulletin of the Society of Economic Geologists (February 1993) 88 (1): 44-54

Abstract

Three contiguous drainage basins in the Guinean diamond fields all contain alluvial diamond deposits. The basins are similar in size and underlying geology and all occur within the same morphogenetic and tectonic environment. However, despite these similarities their geomorphological histories are quite distinct and this, together with variations in known occurrences of kimberlitic diamond sources, explains the differences in the distribution and concentration of diamonds in the alluvial deposits. One of the basins has been captured in the last 1.5 m.y. and the consequent lowering of base level has resulted in the reworking of sediment, flushing of tributaries and slopes, and concentration of diamonds in the trunk channel. In contrast, the other two basins have been reduced in size by capture of portions of their headwaters. As a consequence the diamonds have been retained in tributaries close to their source and only low to moderate concentrations of diamonds are found in the trunk channels.


ISSN: 0361-0128
EISSN: 1554-0774
Coden: ECGLAL
Serial Title: Economic Geology and the Bulletin of the Society of Economic Geologists
Serial Volume: 88
Serial Issue: 1
Title: Drainage basin evolution in Southeast Guinea and the development of diamondiferous placer deposits
Affiliation: Placer Analysis, Edinburgh, United Kingdom
Pages: 44-54
Published: 199302
Text Language: English
Publisher: Economic Geology Publishing Company, Lancaster, PA, United States
References: 19
Accession Number: 1993-010709
Categories: Economic geology, geology of nonmetal deposits
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables, sketch maps
N07°15'00" - N12°40'00", W15°00'00" - W07°40'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, Copyright, Society of Economic Geologists
Update Code: 1993
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