The sedimentary and tectonic evolution of the Amur River and North Sakhalin Basin: new evidence from seismic stratigraphy and Neogene– Recent sediment budgets

• Published in: Basin Research
• Main Authors: Nicholson, Uisdean, van der Es, Bas, Clift, Peter D., Flecker, Rachel, Macdonald, David I. M.
• Other Authors: Natural Environment Research Council
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2015
• Subjects: Sakhalin
• Online Access: http://dx.doi.org/10.1111/bre.12110; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbre.12110; https://onlinelibrary.wiley.com/doi/pdf/10.1111/bre.12110

Abstract The N orth S akhalin B asin in the western S ea of O khotsk has been the main site of sedimentation from the A mur R iver since the E arly M iocene. In this article, we present regional seismic reflection data and a N eogene– R ecent sediment budget to constrain the evolution of the basin and its sedimentary fill, and consider the implications for sediment flux from the A mur R iver, in particular testing models of continental‐scale N eogene drainage capture. The A mur‐derived basin‐fill history can be divided into five distinct stages: the first A mur‐derived sediments (>21–16.5 Ma) were deposited during a period of transtension along the S akhalin‐ H okkaido S hear Z one, with moderately high sediment flux to the basin (71 Mt year −1 ). The second stage sequence (16.5–10.4 Ma) was deposited following the cessation of transtension, and was characterised by a significant reduction in sediment flux (24 Mt year −1 ) and widespread retrogradation of deltaic sediments. The third (10.4–5.3 Ma) and fourth (5.3–2.5 Ma) stages were characterised by progradation of deltaic sediments and an associated increase in sediment flux (48–60 Mt year −1 ) to the basin. Significant uplift associated with regional transpression started during this time in southeastern S akhalin, but the north‐eastward propagating strain did not reach the NE shelf of S akhalin until the P leistocene (<2.5 Ma). This uplift event, still ongoing today, resulted in recycling of older deltaic sediments from the island of S akhalin, and contributed to a substantially increased total sediment flux to the adjacent basinal areas (165 Mt year −1 ). Adjusted rates to discount these local erosional products (117 Mt year −1 ) imply an A mur catchment‐wide increase in denudation rates during the L ate P liocene– P leistocene; however, this was likely a result of global climatic and eustatic effects, combined with tectonic processes within the A mur catchment and possibly a smaller drainage capture event by the S ungari tributary, rather than ...