THE LITHOLOGICAL CONDITIONS OF FINE GOLD ACCUMULATION IN THE RECENT CHERNOMORIAN SEDIMENTS OF THE BLACK SEA

Abstract

Fine gold is typical for shelf sediments of the Black Sea. Its accumulation is not associated with only one source, it occurs in different terrigenousmineralogical provinces of the shelf. Fine gold has different genesis; its distribution in sediments is extremely uneven. Its highest content is found in the Dnieper depression, near Tendra spit and Zhebriyany bay.The increased content of gold is often found in multicomponent nongraded recent sediments of the shelf – in the muddy and sandy shell deposits. The accumulation of fine gold is confined to the very fine sand in the Dnieper depression. There is a high negative correlation between gold content and psephites, which is represented exclusively by shelly material in these sediments. This negative relationship is natural, because there is no genetic relationship between biogenic psephites and predominantly terrigenous fine gold. Positive correlation between gold and the very fine sand in the sediments indicate that the determining factor is the hydrodynamic regime for the accumulation of fine gold in marine sediments.Fine gold tends to accumulate in sediments with a high content of minerals residue near Tendra spit. Here the accumulation of gold is directly related to the formation of coastal marine titanium-zirconium placers, evidenced by positive correlations between gold and zircon, ilmenite and anatase.The maximum gold content occurs in well-graded fine sand sediments in Zhebriyany bay and Zmeinyi Island area.The lithological control of accumulation of fine gold in the sediments appears differently in various parts of the north-western shelf of the Black Sea and in different terrigenous-mineralogical provinces of the shelf.