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

Abstract

The North Sakhalin Basin in the western Sea of Okhotsk has been the main site of sedimentation from the Amur River since the Early Miocene. In this article, we present regional seismic reflection data and a Neogene–Recent sediment budget to constrain the evolution of the basin and its sedimentary fill, and consider the implications for sediment flux from the Amur River, in particular testing models of continental‐scale Neogene drainage capture. The Amur‐derived basin‐fill history can be divided into five distinct stages: the first Amur‐derived sediments (>21–16.5 Ma) were deposited during a period of transtension along the Sakhalin‐Hokkaido Shear Zone, 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 Sakhalin, but the north‐eastward propagating strain did not reach the NE shelf of Sakhalin until the Pleistocene (<2.5 Ma). This uplift event, still ongoing today, resulted in recycling of older deltaic sediments from the island of Sakhalin, 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 Amur catchment‐wide increase in denudation rates during the Late Pliocene–Pleistocene; however, this was likely a result of global climatic and eustatic effects, combined with tectonic processes within the Amur catchment and possibly a smaller drainage capture event by the Sungari tributary, rather than continental‐scale drainage capture involving the entire upper Amur catchment.

East Asian winter monsoon evolution since the late Pliocene based on a pollen record from Lake Xingkai, northeast Asia

“…This tectonic activity and associated volcanism resulted in major modification of the Heilongjiang River system and the disappearance of paleolakes such as Dalianhe-Xiangshun paleolake in the western part of Sanjiang Plain (Qiu et al, 2014). As a direct result of tectonic uplift, the denudation rate in the Heilongjiang River catchment increased substantially during the late Pliocene–Pleistocene (Nicholson et al, 2016). This series of major hydrologic and geomorphic changes substantially altered the sedimentary environment throughout the entire Heilongjiang River catchment and resulted in the widespread paraconformity between the Neogene and Quaternary series.…”

Seismic stratigraphy of the Guinea Plateau before, during and after the opening of the Equatorial Atlantic Gateway

“…Seismic horizons were used to reconstruct a sediment budget for the Guinea Plateau and constrain changes in sediment accumulation through time. The workflow for this was adapted from Nicholson et al (2016). The top and base of the mapped seismic units were gridded to generate regional surfaces across the Guinea Plateau.…”

“…The major uncertainties in estimating the sediment budget are the seismic horizon mapping across the Guinea margin (u1 = 10%), the uncertainty in assigning age horizons and major unconformities (u2 = 10%), velocity modelling (u3 = 10%), the domain conversion process (u4 = 7.5%), and porosity correction (u5 = 5%). These are used to calculate the overall uncertainty (uT) using the Root Sum Square (RSS) method (Nicholson et al, 2016):…”

Defining Regional and Local Sediment Sources in the Ancestral Colorado River System: A Heavy Mineral Study of a Mixed Provenance Unit in the Fish Creek-Vallecito Basin, Southern California

“…The FCVB also holds one of the richest, most varied fossil records of the past 7 Ma in North America [11]. Globally, the basin is significant as a record of one of the very few great rivers to deposit its delta across a strike-slip plate boundary, along with the Orinoco [12] and the Amur [13,14]; it is also unique in that the delta is partly deposited across a spreading ridge [15]. (A) regional tectonic elements map (after Dorsey et al [8]) showing locations of major faults of the North America-Pacific (NAM:PAC) plate boundary system in the northern Gulf of California and the Salton Trough (ST).…”