Boreskov

PP‐20In 2010, these hydrocarbons (fig. 1) were first identified by the authors in mudstonesfrom the Kumakha Formation of the Upper Proterozoic Lakhanda Group, Maya depression inthe Southeastern Siberian platform (7.3‐9.0% of the total alkanes), in mudstones from theLower Cambrian Kuonamka Formation in the Northeastern Siberian Platform (18%), and inMiddle Cambrian marls and mudstones encountered in the Nizhneimbakskaya‐219 well(about 7%) drilled in the Bakhta mega‐salient, western Siberian platform. This allowedidentification of a possible source for specific Precambrian oils of the Siberian Platform. Thisis the first report of 12‐, 13‐mmas identified in Cambrian rocks, which allows us to extent thestratigraphic range of organisms that contained precursor structures for the mid‐chainbranched alkanes.This work was supported by RFBR (10‐05‐00705) and the Earth Sciences DepartmentProgram N 15.References[1]. Aref’ev, O.A., et al. (1980) Izvestiya AN SSSR, Ser.geol. (in Russian), N 3, 135‐140.[2]. Petrov, A.A. (1984) Hydrocarbons of oil (in Russian), Moscow, Nauka, 263 p.[3]. Grantham, P.J., et al. (1988) Journal of Petroleum Geology 11, 61‐80.[4]. Kontorovich, A.E., et al. (2005) Petroleum Frontiers 20, N 3, 11‐26.[5]. Bazhenova, O.K., Aref’ev, O.A. (1998) Geokhimiya, N 3, 286‐294.166