EDIACARAN (VENDIAN)-PERIOD ALLUVIAL AND COASTAL GEOMORPHOLOGY APPLIED TO DEVELOPMENT OF VERKHNECHONSKOYE AND YARAKTINSKOYE FIELDS, EAST SIBERIA, RUSSIAN FEDERATION

摘要

Ediacaran-age (635-542 Ma) oil-bearing strata in the Yarakta Horizon at the Verkhnechonskoye and Yaraktinskoye fields, East Siberia, consist of conglomerate, sandstone, dolomitic sandstone, and mudstone overlying and onlapping igneous to metasedimentary highlands of the East Siberia craton. Initial drainage networks formed within structurally defined valleys, and early deposition occurred in localized alluvial to shallow-marine depositional systems. Base-level-controlled depositional cycles aggraded the valleys; thus, as valleys aggraded, they buried interfluves and coalesced forming broad alluvial and coastal plains.