气候变化领域集成服务门户(CCPortal): Evolution of fluvial meander-belt deposits and implications for the completeness of the stratigraphic record

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DOI	10.1130/B31699.1
	Evolution of fluvial meander-belt deposits and implications for the completeness of the stratigraphic record
	Durkin P.R.; Hubbard S.M.; Holbrook J.; Boyd R.
发表日期	2018
ISSN	167606
起始页码	721
结束页码	739
卷号	130 期号:2021-05-06
英文摘要	The fragmentary nature of the stratigraphic record is particularly evident with respect to fluvial deposits, which are characterized by a hierarchy of depositional units deposited over a wide range of time scales and sedimentation rates. We quantified stratigraphic completeness in meander-belt deposits through deducing the total area of bar sedimentation versus what is ultimately preserved in the depositional record, using area as a surrogate metric for sediment volume. Data sets were evaluated for a numerical model, the modern Mississippi River valley, and the Cretaceous McMurray Formation. In each data set, the evolutionary history of a series of meander-belt elements was discerned. Migrated area between successive reconstructed paleochannel positions was measured, representing: total area of net bar migration (MA), the area of bar preserved (PA), and percent of bar preserved (PA/MA), at the accretion package, bar, and meanderbelt scale. Results of our analysis show that the average preservation percent ranges from 27.3% to 67.8% for an accretion package, 35.0% to 85.1% for a bar, and 38.2% to 67.6% for a meander belt. The processes that lead to a decrease in preservation include intra-meanderbend erosion (due to downstream translation or bar rotation), and increasing meanderbend sinuosity and eventual cutoff (neck and chute), as well as inter-meander-bend erosion due to avulsion and subsequent migration of the meandering channel. The results of this study document a decrease in preservation over time that follows a natural logarithmic function of decay; we have termed this the "survivability" curve. The results presented here document a systematic, monotonic decrease in preservation over time, which is consistent regardless of the spatial or temporal scale and agrees with probabilities of preservation at long time scales proposed by previous workers. A comparison between data sets allows for an estimation of the time span represented by meander-belt deposits in the deep time record. © 2017 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185037
作者单位	Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada; Department of Geology, Texas Christian University, Fort Worth, TX 76129, United States; School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; Department of Geological Sciences, University of Manitoba, 66 Chancellors Circle, Winnipeg, MB R3T 2N2, Canada
推荐引用方式 GB/T 7714	Durkin P.R.,Hubbard S.M.,Holbrook J.,et al. Evolution of fluvial meander-belt deposits and implications for the completeness of the stratigraphic record[J],2018,130(2021-05-06).
APA	Durkin P.R.,Hubbard S.M.,Holbrook J.,&Boyd R..(2018).Evolution of fluvial meander-belt deposits and implications for the completeness of the stratigraphic record.Bulletin of the Geological Society of America,130(2021-05-06).
MLA	Durkin P.R.,et al."Evolution of fluvial meander-belt deposits and implications for the completeness of the stratigraphic record".Bulletin of the Geological Society of America 130.2021-05-06(2018).