| DOI: | 10.1016/j.gloplacha.2013.12.003
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| 论文题名: | Miocene to Pleistocene floras and climate of the Eastern Himalayan Siwaliks, and new palaeoelevation estimates for the Namling-Oiyug Basin, Tibet |
| 作者: | Khan M.A.; Spicer R.A.; Bera S.; Ghosh R.; Yang J.; Spicer T.E.V.; Guo S.-X.; Su T.; Jacques F.; Grote P.J.
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| ISSN: | 0921-8466
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| 出版年: | 2014
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| 卷: | 113 | | 起始页码: | 1
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| 结束页码: | 10
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| 语种: | 英语
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| 英文关键词: | Climate change
; India
; Monsoon
; Neogene
; Palaeoelevation
; Tibet
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| Scopus关键词: | India
; Monsoon
; Neo genes
; Palaeoelevation
; Tibet
; Atmospheric thermodynamics
; Climate change
; Enthalpy
; Estimation
; Multivariant analysis
; Sea level
; Sediments
; Uncertainty analysis
; climate variation
; floristics
; fossil record
; Miocene
; paleobotany
; paleotemperature
; Pliocene
; taxonomy
; China
; Siwalik Hills
; Thailand
; Xizang
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| 英文摘要: | Four fossil floras ranging in age from the mid Miocene to the early Pleistocene from the eastern Siwaliks near Darjeeling and in Arunachal Pradesh (AP) were compared taxonomically and subjected to a CLAMP (Climate Leaf Analysis Multivariate Program) analysis using a new calibration dataset that includes sites from India, southern China and Thailand and high resolution gridded climate data. Two lower Siwalik mid Miocene floras yielded almost the same values suggesting mean annual temperatures (MATs) of 25.4 and 25.3 °C ± 2.8 °C (all uncertainties ± 2 sigma) with warm month mean temperatures (WMMTs) of 28.4 and 27.8 ± 3.39 °C and cold month mean temperatures (CMMTs) of 17.9 and 21.3 ± 4 °C. Precipitation estimates have high uncertainties but suggest a weak monsoon with growing season precipitations of 242 ± 92 cm for Darjeeling and 174 ± 92 cm for AP. Leaves from the middle Siwalik (Pliocene) sediments of AP indicate a lowering of the MAT to 23.7. °C, a function of cooler winter months (CMMT 16.9. °C). The AP early Pleistocene temperatures and rainfall were similar to those of the mid Miocene. Changes in the monsoon index suggest that in the AP area there has been little change in the intensity of the monsoon since mid Miocene time, while further west at Darjeeling there has been an intensification since the mid Miocene. Mid Miocene CLAMP-derived enthalpy estimates provide sea level (< 200 a.m.s.l) data for a re-evaluation of the palaeoelevation of a 15. Ma flora from the Namling-Oiyug Basin, southern Tibet. Enthalpy values from Darjeeling and AP were 354.1 and 355.8 ± 10.3 kJ/kg respectively, while that derived from the Namling-Oiyug flora was 296.3. kJ/kg. This yields a palaeoelevation of 5888. m for the Namling site using the Darjeeling enthalpy estimate as a sea level datum and 6065. m using the AP assemblage. The combined uncertainty is ± 728 m. Model corrected enthalpy trends at sea level across palaeolatitude and longitude reduce the mean elevation to 5.54. km. These elevations are higher than earlier estimates from the same site (but within uncertainty) and the corrected mean is ~. 1. km higher than the present day basin floor elevation in the region, suggesting some deflation since 15. Ma associated with east-west extension, particularly if a shift in the locus of deformation and uplift south to the Himalayas in post middle Miocene times relieved N-S compressional stress on southern Tibet. © 2013 Elsevier B.V. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84890887514&doi=10.1016%2fj.gloplacha.2013.12.003&partnerID=40&md5=9848e78bbc1eeb0f640f95c49f452b18
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/11372
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| Appears in Collections: | 全球变化的国际研究计划
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作者单位: | Centre of Advanced Study, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India
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| Recommended Citation: | |
Khan M.A.,Spicer R.A.,Bera S.,et al. Miocene to Pleistocene floras and climate of the Eastern Himalayan Siwaliks, and new palaeoelevation estimates for the Namling-Oiyug Basin, Tibet[J],2014-01-01,113.
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