干旱区生态环境知识资源中心(Arid): The aggradation of alluvial fans in response to monsoon variability over the last 400 ka in the Hajar Mountains, south-east Arabia

Arid

DOI	10.1016/j.quascirev.2023.108384
	The aggradation of alluvial fans in response to monsoon variability over the last 400 ka in the Hajar Mountains, south-east Arabia
	Woor, Sam; Thomas, David S. G.; Durcan, Julie A.; Burrough, Sallie L.; Parton, Ash
通讯作者	Woor, S
来源期刊	QUATERNARY SCIENCE REVIEWS
ISSN	0277-3791
EISSN	1873-457X
出版年	2023
卷号	322
英文摘要	The preservation and interpretation of past external forcings within sedimentary archives can be complicated. Marine proxy records show that, throughout the Mid-Late Quaternary, monsoon rainfall in south-east Arabia has varied at precessional timescales (similar to 23 ka). By contrast, terrestrial environmental records from the region, such as speleothems and palaeolake sequences, generally only capture rainfall variability at eccentricity (similar to 100 ka) timescales and geomorphological archives rarely record events over multiple glacial cycles. Previous work has suggested that the alluvial fan systems of the Hajar Mountains record aggradation coincident with precessional peaks because of more northerly Indian Ocean Summer Monsoon (IOSM) rainfall, relative to present. However, the alluvial record is complex: there is a growing body of 'anomalous' aggradation age data from periods of precessional minima and it is spatially uneven, mainly being derived from fans at either the northern-or southern-most extents of the western side of the mountains. We present optically stimulated luminescence (OSL) ages of alluvial aggradation from new sites in the central portion of the western and eastern sides of the Hajar mountains. Sedimentary units that show evidence of more sustained flow conditions, such as coarse conglomerate deposition and the development of thick floodplain deposits, typically date to periods of higher IOSM rainfall at precessional timescales. Sites where there is evi-dence of deposition under more ephemeral flow conditions, like today, yield ages corresponding to precessional minima. We synthesise these data with similarly interpreted alluvial and lacustrine deposits from across the region, employing a hierarchical clustering approach to generate clusters of ages representing periods of increased hydrological activity. This objective approach to regional chronological data suggests that ten periods of more sustained hydrological activity are evidenced across the Hajar region, broadly aligning to precessional and eccentricity peaks over the last 400 ka. These clusters show that Hajar fans predominately aggrade because of increasing rainfall over their catchments, with the central ages of clusters often aligning with the onset of precessional forcing. Hajar alluvial systems preserve important records of Quaternary climate variability over long timescales in an arid region where terrestrial records are scarce due to preservation issues.
英文关键词	Climate change Indian ocean monsoon Luminescence dating palaeoenvironments Geomorphology Arabia
类型	Article
语种	英语
开放获取类型	Green Published, hybrid
收录类别	SCI-E
WOS记录号	WOS:001112703100001
WOS关键词	RUB AL-KHALI ; DOSE-RATE ; INDIAN MONSOON ; CLIMATE-CHANGE ; NORTHERN OMAN ; SINGLE ; DEPOSITS ; QUARTZ ; RECORD ; GRAINS
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS研究方向	Physical Geography ; Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/398206
推荐引用方式 GB/T 7714	Woor, Sam,Thomas, David S. G.,Durcan, Julie A.,et al. The aggradation of alluvial fans in response to monsoon variability over the last 400 ka in the Hajar Mountains, south-east Arabia[J],2023,322.
APA	Woor, Sam,Thomas, David S. G.,Durcan, Julie A.,Burrough, Sallie L.,&Parton, Ash.(2023).The aggradation of alluvial fans in response to monsoon variability over the last 400 ka in the Hajar Mountains, south-east Arabia.QUATERNARY SCIENCE REVIEWS,322.
MLA	Woor, Sam,et al."The aggradation of alluvial fans in response to monsoon variability over the last 400 ka in the Hajar Mountains, south-east Arabia".QUATERNARY SCIENCE REVIEWS 322(2023).