气候变化领域集成服务门户(CCPortal): Quantitative analysis of the stratigraphic architecture of incised-valley fills: A global comparison of Quaternary systems

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DOI	10.1016/j.earscirev.2019.102988
	Quantitative analysis of the stratigraphic architecture of incised-valley fills: A global comparison of Quaternary systems
	Wang R.; Colombera L.; Mountney N.P.
发表日期	2020
ISSN	0012-8849
卷号	200
英文摘要	Facies models of the internal fills of incised valleys developed in shelf and coastal settings during cycles of relative sea-level change are largely conceptual, descriptive and qualitative in form; moreover, they are commonly bespoke to individual examples. Here, a database-driven quantitative statistical analysis of 87 late-Quaternary incised-valley fills (IVFs) has been undertaken to assess the general validity and predictive value of classical facies models for IVFs, and to investigate the relative importance of possible controls on their stratigraphic organization. Based on datasets from the published literature stored in a sedimentological database, the geometry and proportion of systems tracts, and of architectural elements of different hierarchies within IVFs are quantified. These variables were analysed to assess how they vary in relation to parameters that represent potential controlling factors: relative sea-level stage, continental-margin type, drainage-basin area, valley geometry, basin physiography and shoreline hydrodynamics. The stratigraphic organization of the studied coastal-plain IVFs is generally consistent with that represented in facies models, the primary control being the rate and magnitude of relative sea-level change. However, results from this study demonstrate significant variability in the stratigraphic architectures of IVFs, which is not accounted for by existing models. Variations in the facies architecture of coastal-plain and cross-shelf valley fills can be attributed to controls other than sea level, and expressed in relationships with continental-margin type, basin physiography, catchment area, river-system size and shoreline hydrodynamics. The following primary findings arise from this research. (i) Compared to their counterparts on passive margins, coastal-plain IVFs hosted on active margins contain, on average, a higher proportion of fluvial deposits and a lower proportion of central-basin estuarine deposits; estuarine deposits tend however to be thicker. This suggests a control on IVF stratigraphic architecture exerted by distinct characteristics of the tectonic setting of the host continental margins, notably basin physiography, rates and mode of sediment supply, and nature of sediment load. (ii) The thickness and proportion of lowstand systems tract are positively correlated with coastal-plain IVF dimensions, likely reflecting the role of drainage-basin area in dictating the scale of the fluvial systems that carved and infilled the valleys. (iii) Positive correlations are observed between the thickness of fluvial deposits, bayhead-delta deposits and central-basin estuarine deposits, versus coastal-plain IVF dimensions and valley catchment area. This suggests a control exerted by the river-system scale on sediment-supply rates and on the accommodation determined by valley size. (iv) Positive correlations between the thickness and proportion of barrier-complex deposits within cross-shelf IVFs versus mean shelf gradient indicate that the geometry of the shelf might control the establishment and preservation of barrier-island environments in incised valleys located on the shelf. (v) Correlations between the width of coastal-plain IVFs and present-day mean tidal range at the shoreline indicate that tidal dynamics may contribute to the widening of the incised valleys. Positive correlation is observed between the proportion of tide-dominated elements in highstand IVF deposits and IVF width, suggesting possible effects of interplays between hydrodynamic conditions and the geometry of incised valleys on their infills. This study highlights the complexity of the internal fills of incised valleys, which must be considered when attempting the application of facies models of IVFs to rock-record interpretations or as predictive tools in subsurface studies. © 2019 The Authors
英文关键词	Continental margin; Drainage basin; Hydrodynamics; Incised valley; Quaternary; Sea-level change
语种	英语
scopus关键词	continental margin; continental shelf; depositional environment; drainage basin; fluvial deposit; hydrodynamics; incised valley; Quaternary; sea level change; stratigraphy
来源期刊	EARTH-SCIENCE REVIEWS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/209778
作者单位	Fluvial & Eolian Research Group and Shallow-Marine Research Group, School of Earth & Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
推荐引用方式 GB/T 7714	Wang R.,Colombera L.,Mountney N.P.. Quantitative analysis of the stratigraphic architecture of incised-valley fills: A global comparison of Quaternary systems[J],2020,200.
APA	Wang R.,Colombera L.,&Mountney N.P..(2020).Quantitative analysis of the stratigraphic architecture of incised-valley fills: A global comparison of Quaternary systems.EARTH-SCIENCE REVIEWS,200.
MLA	Wang R.,et al."Quantitative analysis of the stratigraphic architecture of incised-valley fills: A global comparison of Quaternary systems".EARTH-SCIENCE REVIEWS 200(2020).