气候变化领域集成服务门户(CCPortal): Astronomical forcing of terrestrial climate recorded in the Pleistocene of the western Tarim Basin; NW China

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DOI	10.1016/j.palaeo.2019.05.039
	Astronomical forcing of terrestrial climate recorded in the Pleistocene of the western Tarim Basin; NW China
	Zhang R.; Li L.; Nai W.; Gu Y.; Huang C.; Ogg J.; Li Q.; Lu C.; Wang Z.
发表日期	2019
ISSN	0031-0182
起始页码	78
结束页码	89
卷号	530
英文摘要	Astronomically forced variations of climate are well documented in lacustrine and marine settings. However, few studies have examined astronomical forced cycles within Quaternary fluvial-fan successions. To explore whether Milankovitch cyclicity might also be present in fluvial-fan successions, we carried out high-resolution gamma-ray (GR) from downhole logging, magnetic susceptibility (MS), Rb/Sr and total organic carbon (TOC) analysis of a core from an 800-m borehole (KT11) from the Kashgar region in the western Tarim Basin, China. Spectral analyses of the GR, MS and Rb/Sr data reveal cycles with ~70 m, ~30 m and ~14 m wavelengths. These pertain to relative variations in grain size. Electron spin resonance (ESR) dating and magnetostratigraphy imply that the cored interval spans the past 1.1 Myr. This age-span constraint, coupled with the comparison of the ratios of these cycle wavelengths to expected ratios of Milankovitch frequencies, suggests that these cycles represent ~100-kyr short-eccentricity, ~40-kyr obliquity and ~20-kyr precession frequencies, respectively. We constructed an astronomical time scale (ATS) spanning the past 1.13 Myr using the ~100-kyr short-eccentricity period. The average accumulation rate is about 70 cm/kyr for this 800-m core succession, and the evolutive spectrum emphasizes that long-term sedimentation rates were stable. We also applied correlation coefficient (COCO) analysis to identify the astronomical forcing. Thus, we conclude that orbitally forced climate change was the main driver of stratigraphic alternations between sand- and clay-rich intervals in the Kashgar region. During maxima of the 100-kyr short-eccentricity cycles, which correspond to interglacial intervals, more chemical weathering and increased seasonal runoff delivered a larger amount of relatively coarser-grained sediments to the fluvial fan in the Kashgar region, and vice versa. The Mid-Pleistocene Transition (MPT) at ca. 0.9 to 0.65 Ma is also well recorded in our GR and Rb/Sr data, and is characterized by a shift in dominant cycle period from 41 kyr obliquity to 100 kyr eccentricity. After 0.65 Ma, the average TOC content decreases whilst Rb/Sr values increase, which suggests that there was an increase in regional aridity of the Kashgar region in the western Tarim Basin following the MPT. This regional change is synchronous with the trend toward aridification observed throughout central Asia. © 2019 Elsevier B.V.
英文关键词	Aridification; Central Asia; Mid-Pleistocene transition; Milankovitch; Quaternary core sediments
语种	英语
scopus关键词	accumulation rate; aridification; aridity; astronomy; climate change; climate forcing; detection method; eccentricity; interglacial; Milankovitch cycle; paleoclimate; Pleistocene; Quaternary; runoff; sediment core; sedimentation rate; total organic carbon; Central Asia; China; Kashi; Tarim Basin; Xinjiang Uygur
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/150907
作者单位	State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; No. 2 Hydrological and Engineering Geology Party of Xinjiang Bureau of Geology and Mineral Resources Exploration and Development, Changji, 831100, China; Hubei Key Laboratory of Wetland Evolution & Eco-Restoration (WEER), China University of Geosciences, Wuhan, 430074, China; Hubei Key Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, 610059, China; Department of Earth, Atmospheric and Planetary Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051, United States
推荐引用方式 GB/T 7714	Zhang R.,Li L.,Nai W.,et al. Astronomical forcing of terrestrial climate recorded in the Pleistocene of the western Tarim Basin; NW China[J],2019,530.
APA	Zhang R..,Li L..,Nai W..,Gu Y..,Huang C..,...&Wang Z..(2019).Astronomical forcing of terrestrial climate recorded in the Pleistocene of the western Tarim Basin; NW China.Palaeogeography, Palaeoclimatology, Palaeoecology,530.
MLA	Zhang R.,et al."Astronomical forcing of terrestrial climate recorded in the Pleistocene of the western Tarim Basin; NW China".Palaeogeography, Palaeoclimatology, Palaeoecology 530(2019).