DOI: 10.1016/j.palaeo.2012.10.019
论文题名: Isotopic and palynological evidence for a new Early Jurassic environmental perturbation
作者: Riding J.B. ; Leng M.J. ; Kender S. ; Hesselbo S.P. ; Feist-Burkhardt S.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2013
卷: 374 起始页码: 16
结束页码: 27
语种: 英语
英文关键词: Central England
; Early Jurassic (Late Sinemurian)
; Environmental change
; Palynomorphs
; Stable isotopes
英文摘要: The Early Jurassic Epoch was a predominantly greenhouse phase of Earth history, but a comprehensive understanding of its climate dynamics is hampered by a lack of high resolution multi-proxy environmental records. Here we report a geologically brief (approximately several hundred thousand years) negative carbon isotope excursion (CIE) of 2-3‰ in both marine and terrestrial materials, recognised for the first time for the Late Sinemurian Substage (Early Jurassic, ~. 194. Ma) of eastern England. The Late Sinemurian carbon isotope excursion, which is termed the S-CIE herein, is accompanied by peaks in the abundance of the pollen grain Classopollis classoides and the dinoflagellate cyst Liasidium variabile. Classopollis classoides was thermophilic and is a reliable proxy for hot/warm climatic conditions. Liasidium variabile is interpreted as thermophilic and eutrophic using multivariate statistics, its fluorescence properties being similar to living heterotrophic dinoflagellate cysts, and its association with C. classoides. Moreover, the morphological and ecological similarities of L. variabile to the Cenozoic genus Apectodinium are noteworthy. The co-occurrence of the acmes of C. classoides and L. variabile with a negative CIE is interpreted here as having wide geographical significance due to the marine and terrestrial carbon isotope signals being precisely in phase within an open marine setting. This is consistent with an oceanic-atmospheric injection of isotopically-light carbon, coupled with global warming and increased marginal marine nutrient supply, possibly the result of increased precipitation due to an enhanced hydrological cycle or a seasonally-stratified water column. A probable sea level rise of at least regional extent has been identified at the L. variabile event in other records, which supports this putative phase of global warming. All these features are common to the Paleocene/Eocene thermal maximum (PETM, ~. 56. Ma), and there are also similarities with the Early Toarcian oceanic anoxic event (T-OAE, ~. 182. Ma). © 2012 Natural Environment Research Council. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69808
Appears in Collections: 过去全球变化的重建
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作者单位: British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, United Kingdom; Department of Geology, University of Leicester, Leicester LE1 7RH, United Kingdom; NERC Isotope Geosciences Laboratory, British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, United Kingdom; Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, United Kingdom; SFB Geological Consulting and Services, Odenwaldstrasse 18, D-64372 Ober-Ramstadt, Germany
Recommended Citation:
Riding J.B.,Leng M.J.,Kender S.,et al. Isotopic and palynological evidence for a new Early Jurassic environmental perturbation[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2013-01-01,374