气候变化领域集成服务门户(CCPortal): Tracking drainage basin evolution; continental tectonics; and climate change: Implications from osmium isotopes of lacustrine systems

CCPortal

DOI	10.1016/j.palaeo.2019.109471
	Tracking drainage basin evolution; continental tectonics; and climate change: Implications from osmium isotopes of lacustrine systems
	Pietras J.T.; Selby D.; Brembs R.; Dennett A.
发表日期	2019
ISSN	0031-0182
英文摘要	Organic matter in the lacustrine Eocene Green River Formation in two cores separated by 16 km in the Uinta Basin record similar centimeter-scale initial 187Os/188Os (denoted as Osi) stratigraphic profiles. This demonstrates that the Os isotopic composition of lacustrine organic matter is spatially homogeneous and in this case documents variation on the time scale of thousands of years. The Osi stratigraphy developed here indicates temporal change in the Os isotopic composition of lake water which is regulated by the Os isotopic composition of inflowing chemical weathering products from the surrounding drainage basin. Although observed Osi variability is just above the level of analytical uncertainty, it can be modeled with less than a 6% change in water input from radiogenic to nonradiogenic sources. This highlights the sensitivity of this isotopic tracer. Changes in Os isotope composition may reflect changes in relative discharge of rivers with different Os isotope composition, changes in the footprint of the drainage area to include or exclude different rock types, or unroofing. Thus, this study suggests that Os isotope stratigraphy in lacustrine settings can be used to link basin stratigraphy to changes in the drainage basin which are driven by climatic, tectonic, and geomorphic processes. The similarity in Os isotope stratigraphy between the two cores documented here highlights its utility for detailed chronostratigraphic correlation within and between lacustrine basins. A conservative sedimentation rate suggests that Osi in these lacustrine deposits changed at a rate of ~0.01 per kiloyear, two orders of magnitude faster than has been reported in marine organic-rich sedimentary rocks (Ravizza, 2007). Furthermore, linear regression of 187Re/188Os and 187Os/188Os ratios of all samples yields a Model 3 depositional age determination of 48.3 ± 2.8 Ma (2σ, MSWD = 8.2) which statistically indistinguishable from a weighted mean laser fusion 40Ar/39Ar sanidine age of 49.58 ± 0.32 Ma (Smith and Carroll, 2015) of a temporally adjacent volcanic ash. © 2019 Elsevier B.V.
语种	英语
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151190
作者单位	Department of Geological Sciences, Binghamton University, 4400 Vestal Pkwy E, Binghamton, NY 13902, United States; Department of Earth Sciences, Durham University, Stockton Road, Durham, DH1 3LE, United Kingdom; State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Resources, China University of Geosciences, Wuhan, Hubei 430074, China
推荐引用方式 GB/T 7714	Pietras J.T.,Selby D.,Brembs R.,et al. Tracking drainage basin evolution; continental tectonics; and climate change: Implications from osmium isotopes of lacustrine systems[J],2019.
APA	Pietras J.T.,Selby D.,Brembs R.,&Dennett A..(2019).Tracking drainage basin evolution; continental tectonics; and climate change: Implications from osmium isotopes of lacustrine systems.Palaeogeography, Palaeoclimatology, Palaeoecology.
MLA	Pietras J.T.,et al."Tracking drainage basin evolution; continental tectonics; and climate change: Implications from osmium isotopes of lacustrine systems".Palaeogeography, Palaeoclimatology, Palaeoecology (2019).