GEOCHEMICAL STUDIES ON PLACER GOLD DEPOSIT AT
MARAHIQ GOLD MINE, SOUTH-EASTERN DESERT, EGYPT
KHAYRIA M. FAWZY1, EZZAT ABDEL
RAHMAN1 and NAGDY M. ABDOU2
1 South Valley Univ. Fac. of Science, Aswan.
2 Nuclear Materials Authority, Cairo.
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This contribution deals with a detailed geochemical studies on behavior of gold and associated elements in the alluvial deposits filling the wadi (placer gold) at Marahiq gold mine. The grain size analysis of the alluvial sediments points out to a decrease in the frequencies of the outputs of the fine admixture classes as far as they were transported and vice versa for the coarse admixture. The distribution curves of outputs of the grain size classes indicate predominant frequencies of the coarse relative to the fine grain size classes.
The coarse sand grain size classes contain higher amount of heavy minerals than the fine ones. The heavy minerals show high amounts and predominant in the grain size classes - 1.0 +0.25 mm of the studied alluvial sediments than in the fine class -0.25 +0.08 mm. Moreover, higher amounts of heavy minerals are obtained from the samples far transported from the mineralization zone. The lowest values of heavy minerals are obtained from the 4 sand grain sizes of the less transported sediments
The content is high in the bulk samples representing the alluvial (from 16 g/t to 44 g/t).
Gold content in the heavy fractions separated from the 3 sand classes +0.08-0.125 mm, + 0.125 -0.250 mm and + 0.250 - 0.5 mm is 1 to 2 times its concentration in the bulk samples. Consequently the heavy fractions of the sand grain size classes can be recommended for analysis in lithochemical survey for gold.
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