岡山大学 地球科学研究報告
Published by Okayama University Earth Science Reports Editorial Committee

Heavy mineral analysis of alluvial aedinents from the Akwatia area of the Birim diamonndierous field, Ghana

Samuel Dampare Graduate School of Natural Science and Technology, Okayama University
Daniel Asiedu Department of Geology, University
Bruce Banoeng-yakubo Department of Geology, University
柴田 次夫 Department of Earth Sciences, Okayama University
抄録
Heavy mineral analysis was carried out on Pliocene to Recent alluvial sediments from the Birim diamondiferous field od Ghana. The main objective of the study was to examine the mineral composition of heavy fractions in order to identify : (1) the heavy mineral assenblage that occur in the sediments, (2) particular diamond indicator minerals associated with the diamonds, and (3) the provenance of the alluvial sediments. The heavy minerals are essentially composed of staurolite, ilmenite and magnetite in varying proportions, with trace amounts of leucoxene, rutile, garnet and zircon. The heavy mineral assenblage and chemical composition of ilmenite and gamet suggest their derivation from phyllites and schists which reflect directly the composition of the basement rocks developed in the study area. The absence of diamond indicatior minerals such as apatite, pyrope garmet, chromian spinel, and picroilmenite in the heavy fraction is unlikely to be due to their destruction during intense weathering and/or diagenesis but rarher their non-occurrence in the area.
キーワード
Heavy minerals
provenance
sediments
diamonds
Ghana
ISSN
1340-7414
NCID
AN10506284
NAID