气候变化领域集成服务门户(CCPortal): Pliocene short-term climate changes preserved in continental shallow lacustrine-palustrine carbonates: Western opache Formation, Atacama Desert, Chile

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DOI	10.1130/B35227.1
	Pliocene short-term climate changes preserved in continental shallow lacustrine-palustrine carbonates: Western opache Formation, Atacama Desert, Chile
	De Wet C.B.; De Wet A.P.; Godfrey L.; Driscoll E.; Patzkowsky S.; Xu C.; Gigliotti S.; Feitl M.
发表日期	2020
ISSN	167606
起始页码	1795
结束页码	1816
卷号	132 期号:2021-09-10
英文摘要	Multiple climate proxies indicate episodic changes in moisture levels within an ~1 Ma duration (early-mid Pliocene) interval. Limestones within the Opache Formation, Calama Basin, Atacama Desert region, Chile, contain evidence for wetter and drier periods on short time scales. Proxies include carbonate lithological changes, paleontology (stromatolites, oncolites, gastropods, ostracods and diatoms), O and C stable isotopes, geochemistry, and mineralogical changes (aragonite, calcite, Mg-calcite, dolomite and gypsum) throughout a 30 m stratigraphic section. Stromatolite fossil cyanobacteria dark and light laminations and mesohaline to hypersaline diatom species suggest Pliocene annual seasonality. Short-term changes between wetter and drier conditions indicate that at least this part of the Atacama region was experiencing relatively rapid early-mid Pliocene climate instability. The predominance of limestone in the Opache Formation, in contrast to the 1500 m of Oligocene-Miocene siliciclastic conglomerates and sandstones, interpreted as arid climate alluvium, that underlie it, indicates a shift from arid or hyperarid climate to a semi-arid climate. Semi-arid conditions promoted limestone deposition in a shallow lacustrine-palustrine environment. In this setting, events such as storms with associated surface water flow, erosion, siliciclastic sand, gravel, and intraclast deposition, coupled with significant biological activity, represent sedimentation during more humid periods in a shallow lacustrine depositional environment. In contrast, limestone characterized by mudcracks, Navicula diatoms, and vadose syndepositional cementation, reflect periods of enhanced evaporation, water shallowing, and episodic desiccation, characteristic of a palustrine depositional system. These facies shifts, in conjunction with geochemical and isotopic proxy evidence, yield a sedimentary record of wetter and drier climate shifts. © 2019 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/184720
作者单位	Franklin and Marshall College, Department of Earth and Environment, Lancaster, PA 17604, United States; Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, United States; Yale School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, United States; Department of Earth and Atmospheric Sciences, University of Nebraska-Lincoln, Lincoln, NE 68599, United States
推荐引用方式 GB/T 7714	De Wet C.B.,De Wet A.P.,Godfrey L.,et al. Pliocene short-term climate changes preserved in continental shallow lacustrine-palustrine carbonates: Western opache Formation, Atacama Desert, Chile[J],2020,132(2021-09-10).
APA	De Wet C.B..,De Wet A.P..,Godfrey L..,Driscoll E..,Patzkowsky S..,...&Feitl M..(2020).Pliocene short-term climate changes preserved in continental shallow lacustrine-palustrine carbonates: Western opache Formation, Atacama Desert, Chile.Bulletin of the Geological Society of America,132(2021-09-10).
MLA	De Wet C.B.,et al."Pliocene short-term climate changes preserved in continental shallow lacustrine-palustrine carbonates: Western opache Formation, Atacama Desert, Chile".Bulletin of the Geological Society of America 132.2021-09-10(2020).