气候变化领域集成服务门户(CCPortal): Astronomically forced hydrology of the Late Cretaceous sub-tropical Potosí Basin, Bolivia

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DOI	10.1130/B35189.1
	Astronomically forced hydrology of the Late Cretaceous sub-tropical Potosí Basin, Bolivia
	Tasistro-Hart A.; Maloof A.; Schoene B.; Eddy M.P.
发表日期	2020
ISSN	167606
起始页码	1931
结束页码	1952
卷号	132 期号:2021-09-10
英文摘要	Periodic variations in Earth's orbital parameters force climate on local and global scales, with global responses particularly sensitive to the presence of ice sheets and their associated feedbacks. Therefore, determining whether orbital forcings influenced sedimentary records of the past, and if so, which had such an effect, can shed light on Earth's climate sensitivity and global ice volume. To this end, we present a field- and drone-based cyclostratigraphy of the predominantly lacustrine El Molino Formation of the Late Cretaceous- Early Paleogene Potosí Basin in present day Bolivia, which contains carbonate mud parasequences that record fluctuating hydrological conditions, including ephemeral marine connections, from 73 Ma to 64 Ma. We introduce a novel methodology for incorporating drone imagery into a quantitative, three-dimensional stratigraphic model that generates an upward-younging quantity comparable to stratigraphic height, and we find that our model outperforms our own field measurements of stratigraphic height. We project drone imagery at two sites into the stratigraphic model to construct time series of outcrop color, which vary systematically with facies and track basin water depth. Spectral analysis of these time series reveals sedimentary periodicities corresponding to short eccentricity, precession, and semi-precession, which are corroborated with measurements of magnetic susceptibility from mudstones. We generate independent age models at both study areas from four new U-Pb chemical abrasion-isotope dilution-thermal ionization mass spectrometry ( CA-ID- TIMS) ages, which are consistent with an orbital interpretation for observed sedimentary periodicities. Importantly, we observe the presence of obliquity-scale periodicity in sedimentation during a period of marine connection, suggesting that sea level oscillations were driven by obliquity. This observation is consistent with previous claims about the presence of a small, orbitally forced Antarctic ice sheet during the latest Cretaceous. © 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/184717
作者单位	Department of Earth Science, University of California, Santa Barbara, CA 93106, United States; Department of Geosciences, Princeton University, Princeton, NJ 08544, United States
推荐引用方式 GB/T 7714	Tasistro-Hart A.,Maloof A.,Schoene B.,et al. Astronomically forced hydrology of the Late Cretaceous sub-tropical Potosí Basin, Bolivia[J],2020,132(2021-09-10).
APA	Tasistro-Hart A.,Maloof A.,Schoene B.,&Eddy M.P..(2020).Astronomically forced hydrology of the Late Cretaceous sub-tropical Potosí Basin, Bolivia.Bulletin of the Geological Society of America,132(2021-09-10).
MLA	Tasistro-Hart A.,et al."Astronomically forced hydrology of the Late Cretaceous sub-tropical Potosí Basin, Bolivia".Bulletin of the Geological Society of America 132.2021-09-10(2020).