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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, Rui1; Li, Lin1; Nai, Weihua2; Gu, Yansheng1,3; Huang, Chunju1,4; Ogg, James5,6; Li, Qinghai2; Lu, Chengxin2; Wang, Zhixiang1 | |
发表日期 | 2019 |
ISSN | 0031-0182 |
EISSN | 1872-616X |
卷号 | 530页码:78-89 |
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 (KM) from the Kashgar region in the western Tarim Basin, China. Spectral analyses of the GR, MS and Rb/Sr data reveal cycles with similar to 70 m, similar to 30 m and similar to 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 similar to 100-kyr short-eccentricity, similar to 40-kyr obliquity and similar to 20-kyr precession frequencies, respectively. We constructed an astronomical time scale (ATS) spanning the past 1.13 Myr using the similar to 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. |
WOS研究方向 | Physical Geography ; Geology ; Paleontology |
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/102929 |
作者单位 | 1.China Univ Geosci, Sch Earth Sci, State Key Lab Biogeol & Environm Geol, Wuhan 430074, Hubei, Peoples R China; 2.Party Xinjiang Bur Geol & Mineral Resources Explo, Hydrol & Engn Geol 2, Changji 831100, Peoples R China; 3.China Univ Geosci, Hubei Key Lab Wetland Evolut & Ecorestorat WEER, Wuhan 430074, Hubei, Peoples R China; 4.China Univ Geosci, Hubei Key Lab Crit Zone Evolut, Sch Earth Sci, Wuhan 430074, Peoples R China; 5.Chengdu Univ Technol, State Key Lab Oil & Gas Reservoir Geol & Exploita, Chengdu 610059, Sichuan, Peoples R China; 6.Purdue Univ, Dept Earth Atmospher & Planetary Sci, 550 Stadium Mall Dr, W Lafayette, IN 47907 USA |
推荐引用方式 GB/T 7714 | Zhang, Rui,Li, Lin,Nai, Weihua,et al. Astronomical forcing of terrestrial climate recorded in the Pleistocene of the western Tarim Basin, NW China[J],2019,530:78-89. |
APA | Zhang, Rui.,Li, Lin.,Nai, Weihua.,Gu, Yansheng.,Huang, Chunju.,...&Wang, Zhixiang.(2019).Astronomical forcing of terrestrial climate recorded in the Pleistocene of the western Tarim Basin, NW China.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,530,78-89. |
MLA | Zhang, Rui,et al."Astronomical forcing of terrestrial climate recorded in the Pleistocene of the western Tarim Basin, NW China".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 530(2019):78-89. |
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