干旱区生态环境知识资源中心(Arid): Factors influencing flashflood deposit preservation in shallow marine sediments of a hyperarid environment

Arid

DOI	10.1016/j.margeo.2019.01.010
	Factors influencing flashflood deposit preservation in shallow marine sediments of a hyperarid environment
	Mathalon, Alysse 1,2; Goodman-Tchernov, Beverly 3; Hill, Paul 1; Kalman, Akos 2,3; Katz, Timor 4
通讯作者	Mathalon, Alysse
来源期刊	MARINE GEOLOGY
ISSN	0025-3227
EISSN	1872-6151
出版年	2019
卷号	411 页码:22-35
英文摘要	Flashfloods entering marine basins can introduce large quantities of terrigenous sediment that deposit on the shallow seafloor. Over time, biological and physical disturbances can induce post-depositional sediment transport to deeper depths. In the hyperarid desert region surrounding Eilat, Israel, flashfloods discharge into the northern Gulf of Eilat-Aqaba, Red Sea episodically. Their deposits may leave useful records of flood events in the marine sediment record. What is poorly understood, however, are the processes of post-depositional alteration of flashflood sediments and the resulting effects on the preservation of the deposits. To address this knowledge gap, short sediment cores (similar to 15-30 cm length, 13 m water depth) were collected at bi/tri-monthly intervals following two different flashflood events in the Gulf of Eilat-Aqaba. Concurrently, mechanisms for resuspension, transport, and vertical mixing of flashflood sediments were investigated by measuring near-bottom water currents and suspended sediment concentrations, photographing demersal fish activities, and measuring the depths and magnitudes of bioturbation using fluorescent sediment tracers. The aim was to record the changing grain size of surface flashflood sediments over time, and identify correlative physical and biological factors. The results show that the original fine-grained flashflood deposits coarsened rapidly following each event. Of the mechanisms recorded, currents generally were too weak to entrain sediment, but did influence the transport of sediment in suspension to deeper depths. Demersal fish resuspended sediment when present, and bioturbation was strongest in the upper 2 cm of the seabed. Despite the rapid reworking of surficial sediments and dissipation of surface flood layers, irregular lenses of fine sediment persisted within the shallow seafloor (down core). Deposition within seafloor holes and depressions, and rapid burial by biologically constructed sediment mounds and ensuing flashflood deposits are proposed as mechanisms for this patchy, localized preservation of flood layers. These findings are useful for identification and interpretation of isolated fine-grained layers in older sedimentary deposits, and for understanding the dynamics influencing the marine sediment stratigraphy in arid, coastal environments.
英文关键词	Flashflood deposit Shelf stratigraphy Bioturbation Resuspension Transport Red Sea
类型	Article
语种	英语
国家	Canada ; Israel
收录类别	SCI-E
WOS记录号	WOS:000463302100003
WOS关键词	HYPERPYCNAL FLOWS ; EEL SHELF ; BIOTURBATION ; GULF ; AQABA ; RESUSPENSION ; CHLOROPHYLL ; TRACERS ; REEFS ; RATES
WOS类目	Geosciences, Multidisciplinary ; Oceanography
WOS研究方向	Geology ; Oceanography
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/217551
作者单位	1.Dalhousie Univ, Dept Oceanog, 1355 Oxford St,POB 15000, Halifax, NS B3H 4R2, Canada; 2.Intenutiv Inst Eilat, POB 469, IL-88103 Elat, Israel; 3.Univ Haifa, Dept Marine Geosci, Leon Charney Sch Marine Sci, IL-3498838 Haifa, Israel; 4.Management & Natl Inst Oceanog, Israel Oceanog & Limnol Res, POB 8030, IL-31080 Haifa, Israel
推荐引用方式 GB/T 7714	Mathalon, Alysse,Goodman-Tchernov, Beverly,Hill, Paul,et al. Factors influencing flashflood deposit preservation in shallow marine sediments of a hyperarid environment[J],2019,411:22-35.
APA	Mathalon, Alysse,Goodman-Tchernov, Beverly,Hill, Paul,Kalman, Akos,&Katz, Timor.(2019).Factors influencing flashflood deposit preservation in shallow marine sediments of a hyperarid environment.MARINE GEOLOGY,411,22-35.
MLA	Mathalon, Alysse,et al."Factors influencing flashflood deposit preservation in shallow marine sediments of a hyperarid environment".MARINE GEOLOGY 411(2019):22-35.