气候变化领域集成服务门户(CCPortal): Sediment dynamics of estuarine Holocene incised-valley fill deposits recorded by Siphonichnus (ancient Red River; Gulf of Tonkin)

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DOI	10.1016/j.palaeo.2020.110041
	Sediment dynamics of estuarine Holocene incised-valley fill deposits recorded by Siphonichnus (ancient Red River; Gulf of Tonkin)
	Wetzel A.; Unverricht D.
发表日期	2020
ISSN	0031-0182
卷号	560
英文摘要	The Holocene muddy infill of the valley incised by the ancient Red River during Pleistocene sea-level lowstand records a change from fluvial to estuarine and finally marine depositional conditions. Siphonichnus, a mainly vertical trace fossil produced by burrowing bivalves, documents otherwise unrecorded episodes of enhanced erosion, bypass and deposition of, on average, rapidly aggrading (> 1 m kyr−1), mainly completely bioturbated sediments within the fluvial-marine transition zone (FMTZ), supposedly within the polyhaline domain. The producers of Siphonichnus moved nearly 1 m downward or upward in response to erosional or depositional phases, respectively. The fill of Siphonichnus burrows, in addition, records erosion and/or bypass of sediment: The traces were produced in mud, but many of them are filled with coarse silt and sand that is otherwise not present in the studied intervals in distinct layers. Obviously, this material was available when Siphonichnus was produced and connected to the sediment surface. In addition to seasonal erosion and deposition during freshet and its waning stage, Siphonichnus records exceptional events that displace the sediment surface by >0.5 m. Such events occurred episodically at an estimated frequency of 1 event per several hundreds of years. The complete bioturbation of the deposits suggests apparent continuous accumulation, but in fact they represent a pile of stacked event deposits resulting from depositional phases and intermittent severe erosion. © 2020 The Authors
英文关键词	Deposition; Equilibrichnia; Erosion; Fluvio-marine transition; Ichnology; Open estuary
语种	英语
scopus关键词	bioturbation; bivalve; burrowing; depositional environment; episodic event; erosion; fluvial deposit; Holocene; incised valley; infill; lowstand; sea level; sedimentation; transition zone; Gulf of Tonkin; Pacific Ocean; Red River [Asia]; South China Sea; Bivalvia
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150269
作者单位	Department of Environmental Sciences – Geology, University of Basel, Basel, CH-4056, Switzerland; Institut für Geowissenschaften, Christian-Albrechts-Universität, Otto-Hahn-Platz 1, Kiel, D-24118, Germany
推荐引用方式 GB/T 7714	Wetzel A.,Unverricht D.. Sediment dynamics of estuarine Holocene incised-valley fill deposits recorded by Siphonichnus (ancient Red River; Gulf of Tonkin)[J],2020,560.
APA	Wetzel A.,&Unverricht D..(2020).Sediment dynamics of estuarine Holocene incised-valley fill deposits recorded by Siphonichnus (ancient Red River; Gulf of Tonkin).Palaeogeography, Palaeoclimatology, Palaeoecology,560.
MLA	Wetzel A.,et al."Sediment dynamics of estuarine Holocene incised-valley fill deposits recorded by Siphonichnus (ancient Red River; Gulf of Tonkin)".Palaeogeography, Palaeoclimatology, Palaeoecology 560(2020).