DOI: 10.1016/j.gloplacha.2013.04.011
论文题名: Palaeoenvironment of Northwestern India during the late Cretaceous Deccan volcanic episode from trace-element and stable-isotope geochemistry of intertrappean ostracod shells
作者: Bajpai S. ; Holmes J. ; Bennett C. ; Mandal N. ; Khosla A.
刊名: Global and Planetary Change
ISSN: 0921-8280
出版年: 2013
卷: 107 起始页码: 82
结束页码: 90
语种: 英语
英文关键词: Cretaceous
; Deccan
; Ostracod
; Stable isotope
; Trace element
Scopus关键词: Aquatic environments
; Cretaceous
; Deccan
; Freshwater bodies
; Geochemical signatures
; Ostracod
; Palaeoenvironmental reconstruction
; Stable isotopes
; Animals
; Basalt
; Exploratory geochemistry
; Isotopes
; Trace elements
; Cretaceous
; geochemical survey
; marine ecosystem
; mass extinction
; ostracod
; paleoenvironment
; seawater
; sediment chemistry
; stable isotope
; timescale
; trace element
; volcanism
; Assam
; India
; Lakhimpur
英文摘要: The Deccan Traps are flood basalts distributed widely across western and central peninsular India and formed at the end of the Cretaceous. The Deccan volcanism has been implicated in the mass extinctions that occurred at this time. Sediments preserved within the basalts are known as the Deccan intertrappeans. Many of the intertrappean rock sequences are fossiliferous and therefore provide an excellent opportunity to reconstruct terrestrial palaeoenvironments of peninsular India during the late Cretaceous. We evaluate the use of, and apply, trace-element (Mg/Ca and Sr/Ca) and stable isotope (δ18O and δ13C) ratios from well-preserved ostracod shells, from intertrappean localities, with particular focus on one site, Lakshmipur, in northwestern India. We show that variations in preservation within well-defined limits do not appear to have significant effects on the geochemical signatures. Differences in stable isotope values between individual species are most likely related to species-specific offsets from equilibrium for oxygen, and differences in habitat for carbon. The geochemical data for the Lakshmipur section suggest that it represents a freshwater body that underwent significant evaporative enrichment, with evidence of wide variability in the aquatic environment on short timescales. These findings are broadly consistent with the palaeoecological evidence from this site and with other palaeoenvironmental reconstructions from the region. Any marine influence at this near-coastal site was probably too minor to have had any effect on the trace-element or stable isotope geochemistry of the ostracods at Lakshmipur, although other sites with palaeocological evidence for an unequivocal marine influence also show some geochemical signs of seawater intrusion. We conclude that the trace-element and stable isotope determinations of intertrappean ostracods have good potential for reconstructing late Cretaceous climate and aquatic environments. © 2013 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878188538&doi=10.1016%2fj.gloplacha.2013.04.011&partnerID=40&md5=4f3e7610623eb0a20b3fd95cdd77e202
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11186
Appears in Collections: 全球变化的国际研究计划
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作者单位: Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
Recommended Citation:
Bajpai S.,Holmes J.,Bennett C.,et al. Palaeoenvironment of Northwestern India during the late Cretaceous Deccan volcanic episode from trace-element and stable-isotope geochemistry of intertrappean ostracod shells[J]. Global and Planetary Change,2013-01-01,107.