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DOI	10.1016/j.earscirev.2019.103062
	On the geological significance of clastic parasequences
	Colombera L.; Mountney N.P.
发表日期	2020
ISSN	00128252
卷号	201
英文摘要	Parasequences recognized in clastic sedimentary successions of shallow-marine origin are considered by some geologists to be the fundamental building blocks of depositional sequences, even though problems in their definition and application have been identified by others, who instead advocate their abandonment as formal sequence stratigraphic units. To elucidate the geological significance of clastic parasequences and inform the debate on their use in stratigraphy, a quantitative characterization of the geometry, facies characteristics and timescale of deposition of 1163 parasequences has been undertaken based on a synthesis of data from outcrop and subsurface studies that are available in the scientific literature. Through a database compilation, the attributes of the studied parasequences are analysed with respect to the interpreted geological origin of the units, and with consideration of sources of bias and uncertainty. Particular emphasis is placed on assessing the following: (i) the importance of heuristics, and of data types and coverage in the recognition of parasequences; (ii) differences in parasequence characteristics observed across deltaic and shoreface depositional systems, and between the Quaternary and the ancient rock record; (iii) possible explanations for the range in timescales of deposition of parasequences; and (iv) the role of autogenic dynamics on the development of deltaic parasequences, partly based on a comparison with the recent evolution of modern deltas. The results demonstrate that parasequence definition and physical correlation suffer from subjectivity, and that significant variability exists in the spatio-temporal and architectural attributes of clastic parasequences. This gives rise to uncertainty that affects the use of parasequences as a framework for comparison of the architecture of packages of strata originating via shoreline regression: this uncertainty must be considered when using analogue data for subsurface predictions or when attempting comparative studies of clastic successions. © 2019 The Authors
关键词	Autogenic Delta lobe Sea level Sequence stratigraphy Shallow marine Shoreface
英文关键词	clastic sediment; delta; depositional sequence; parasequence; Quaternary; sea level change; sequence stratigraphy; shoreline; spatiotemporal analysis
语种	英语
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/203672
作者单位	School of Earth & Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
推荐引用方式 GB/T 7714	Colombera L.,Mountney N.P.. On the geological significance of clastic parasequences[J],2020,201.
APA	Colombera L.,&Mountney N.P..(2020).On the geological significance of clastic parasequences.Earth Science Reviews,201.
MLA	Colombera L.,et al."On the geological significance of clastic parasequences".Earth Science Reviews 201(2020).