气候变化领域集成服务门户(CCPortal): Palaeoclimatic estimates for a latest Miocene-Pliocene flora from the Siwalik Group of Bhutan: Evidence for the development of the South Asian Monsoon in the eastern Himalaya

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DOI	10.1016/j.palaeo.2018.10.019
	Palaeoclimatic estimates for a latest Miocene-Pliocene flora from the Siwalik Group of Bhutan: Evidence for the development of the South Asian Monsoon in the eastern Himalaya
	Khan M.A.; Bera M.; Spicer R.A.; Spicer T.E.V.; Bera S.
发表日期	2019
ISSN	0031-0182
起始页码	326
结束页码	335
卷号	514
英文摘要	Fossil leaf floras, from the latest Miocene-Pliocene Siwalik Group exposed in Bhutan, sub-Himalaya, are subjected to a CLAMP (Climate Leaf Analysis Multivariate Program) analysis using a high-resolution gridded climate calibration. The CLAMP analysis of 27 different morphotypes of fossil leaves indicates a mean annual temperature (MAT) of 24.1 °C ± 2.8 °C; a cold month mean temperature (CMMT) of 18.9 °C ± 4 °C and a warm month mean temperature (WMMT) of 27.8 °C ± 3.3 °C. The analysis also suggests a weak monsoonal climate (the monsoon index, MSI 46.7; present MSI 52) with growing season precipitation (GSP) of 1819 ± 916 mm (present GSP 2490 mm). Here we also compare palaeoclimate estimates of the latest Miocene-Pliocene Siwalik Group flora from Bhutan (c. 6 to 3.8 Ma) with those of previously investigated Siwalik Group floras from the Miocene-Pleistocene of Arunachal, India and Miocene Siwalik floras of Darjeeling, India which characterise the monsoon signature at the time of deposition. Since all the Siwalik floras of the eastern Himalaya (Darjeeling and Arunachal Pradesh) spanning the mid-Miocene to Pleistocene yield almost the same values we suggest that overall the eastern Himalayan Siwalik climate appears to have been remarkably uniform over the past 15 million years. The MAT result of the Bhutan Siwalik flora differs by just 0.6 °C from Arunachal and 1.2 °C from Darjeeling Siwalik floras. For all Siwalik fossil assemblages, WMMTs, CMMTs and LGSs (length of the growing season) are similar and consistent (WMMTs around 28 °C, CMMTs around 18 °C and LGSs around 12 months). Similarly, the mean annual relative humidity (RH) and specific humidity (SH) appear to have been uniformly around 80% and 14 g/kg respectively throughout the Neogene of the eastern Himalayan Siwaliks. Changes in the monsoon index suggest that in both Bhutan and Arunachal sub-Himalaya, there has been little change in the intensity of the monsoon since mid-Miocene time, while further west in the Darjeeling area precipitation seasonality has increased since the mid-Miocene. © 2018 Elsevier B.V.
英文关键词	CLAMP; Eastern Bhutan; Fossil leaves; MSI; Neogene; Precipitation seasonality
语种	英语
scopus关键词	calibration; estimation method; floral trait; fossil assemblage; fossil record; growing season; leaf; Miocene; monsoon; morphotype; Neogene; paleoclimate; Pliocene; seasonality; Arunachal Pradesh; Bhutan; Darjeeling; Himalayas; India; Siwalik Hills; West Bengal
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/151154
作者单位	Department of Botany, Sidho-Kanho-Birsha University, Ranchi Road, Purulia, 723104, India; Centre of Advanced Study, Department of Botany, University of Calcutta, 35, B.C. Road, Kolkata, 700019, India; School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, MK7 6AA, United Kingdom; Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China; Institute of Botany, The Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing, 100093, China
推荐引用方式 GB/T 7714	Khan M.A.,Bera M.,Spicer R.A.,et al. Palaeoclimatic estimates for a latest Miocene-Pliocene flora from the Siwalik Group of Bhutan: Evidence for the development of the South Asian Monsoon in the eastern Himalaya[J],2019,514.
APA	Khan M.A.,Bera M.,Spicer R.A.,Spicer T.E.V.,&Bera S..(2019).Palaeoclimatic estimates for a latest Miocene-Pliocene flora from the Siwalik Group of Bhutan: Evidence for the development of the South Asian Monsoon in the eastern Himalaya.Palaeogeography, Palaeoclimatology, Palaeoecology,514.
MLA	Khan M.A.,et al."Palaeoclimatic estimates for a latest Miocene-Pliocene flora from the Siwalik Group of Bhutan: Evidence for the development of the South Asian Monsoon in the eastern Himalaya".Palaeogeography, Palaeoclimatology, Palaeoecology 514(2019).