FOSSIL IVORY – A SPECIFIC PLACER OCCURRENCES OF RUSSIA’S ARCTIC

Specific environments that existed in northern Siberia in the Late Pleistocene and predetermined the expansion of the mammoth fauna serve as a critical factor in subsequent formation of placer-type accumulations of specific of biogenetic raw material – fossil ivory(tusks). Technological and decorative features of fossil ivory are practically similar to contemporary one. Despite the exogenous origin, unusual sizes and morphology of monoblocks of fossil ivory, its accumulations in recent sediments conform in their formation and location to the main laws of placer formation. The northern regions of the Republic of Sakha (Yakutia), including coastal plains, shelf, and islands, are the main area where most of the pay ivory deposits are located. They are closely related to areas of distribution of specific aeolian-cryogenic ice-bearing loess-like sediments of the so called ‘Edoma Suite’ (‘muck’), which appears as an unique primary collector of fossil ivory. The most significant ivory placers suitable for commercial operation under present conditions represent contemporary residual coastal and littoral deposits located on beach and mud flats along termo-abrasion cliffs. Residual ivory occurrences on river beaches are of lesser importance. Summary annual mining of high-quality fossil ivory from placers may reach 5-10 t. Reserves of coastal and littoral placer ivory accumulations are renewed after operation; that is the most important condition for the long-term production of fossil ivory from placer deposits. In connection with the short life of exposed fossil ivory accumulations, the periodical monitoring of productive deposits and concurrent ivory collection without environments disturbing are to be appropriate.