Facies analysis of the Neogene delta of the Amur river, Sakhalin, Russian Far East: controls on sand distribution

• Main Authors: Davies, C. E., Poynter, S., Macdonald, D., Flecker, R., Voronova, L., Galverson, V., Kovtunovich, P., Fot'yanova, L., Blanc, E.
• Other Authors: Giosan, L., Bhattacharya, J. P.
• Format: Book Part
• Language: English
• Published: Society of Economic Paleontologists and Mineralogists 2005
• Subjects: 05 - Petrology - Igneous; Metamorphic and Volcanic Studies; Sakhalin
• Online Access: http://eprints.esc.cam.ac.uk/1532/; http://eprints.esc.cam.ac.uk/1532/1/Davies%20SEPM%20special%20pub%20no.%2083%202005.pdf

Miocene–Pliocene sediments in the northern part of Sakhalin, in the Russian Far East, contain substantial hydrocarbon reservoirs and are the target of further exploration. These sandstones are well sorted and have been interpreted as the deltaic deposits of the paleo– Amur River, sourced from the Russian mainland. Despite their economic importance, no facies interpretation of the sediments from the onshore sections, nor the paleogeographic evolution of the delta through the Neogene, have previously been published. From outcrop we have identified nine facies associations recording deposition in delta-top, beach, delta-front, transitional, and offshore marine settings. The distribution of these facies associations through time indicates that the paleo–Amur delta prograded east across Sakhalin in two major episodes: first in the Early–Middle Miocene and later in the Late Miocene–Pliocene. These delta-top to delta-front sandstone deposition events are separated by a more mud-rich episode. To the east, limited terrigenous supply resulted in accum ulation of biosiliceous sediments. Paleogeographic reconstructions show that the distribution of sand and biosiliceous marine sediment was probably controlled by a combination of tectonic configuration and persistent patterns of longshore currents