DOI: 10.1016/j.palaeo.2017.06.032
论文题名: Extinction, dissolution, and possible ocean acidification prior to the Cretaceous/Paleogene (K/Pg) boundary in the tropical Pacific
作者: Dameron S.N. ; Leckie R.M. ; Clark K. ; MacLeod K.G. ; Thomas D.J. ; Lees J.A.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
语种: 英语
英文关键词: Deccan Traps volcanism
; Foraminiferal dissolution
; Inoceramid extinction
; Mid-Maastrichtian Event
; Paleoceanography
英文摘要: Biotic perturbations and changes in ocean circulation during the Maastrichtian stage of the latest Cretaceous raise questions about whether the biosphere was preconditioned for the end-Cretaceous mass extinction of calcareous plankton. A brief acme of inoceramid clams at ~71Ma on Shatsky Rise in the tropical North Pacific was followed by their extinction during the "mid-Maastrichtian event" at 70.1Ma associated with an abrupt warming of deep waters. This was later followed by an interval of intense dissolution beginning ~67.8Ma at ODP Site 1209 (2387m). The late Maastrichtian dissolution interval was initially gradual, and is characterized by a low planktic/benthic (P/B) ratio, highly fragmented planktic foraminifera, mostly an absence of larger taxa, low abundances of smaller taxa, extremely low planktic foraminiferal numbers, and low planktic foraminiferal and nannofossil species richness. A partial recovery in carbonate preservation and calcareous plankton simple diversity began ~250kyr prior to the K/Pg boundary associated with the incursion of a younger (more enriched δ13C) deep water mass, although total abundances of planktic foraminifera in the sediment remained a tiny fraction of their earlier Maastrichtian values. A second, brief dissolution event occurred ~200kyr before the boundary evidenced by renewed increase in planktic fragmentation, but without a decrease in P/B ratio. Our data show that changing deep water masses, coupled with reduced productivity and associated decrease in pelagic carbonate flux was responsible for the first ~1.6-Myr dissolution interval, while Deccan Traps volcanism (?) may have caused surface ocean acidification ~200kyr prior to the K/Pg mass extinction event. © 2017. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68135
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geosciences, University of Massachusetts, Amherst, MA, USA; Department of Geological Sciences, University of Missouri, Columbia, MO, USA; Department of Oceanography, Texas A and M University, College Station, TX, USA; Department of Earth Sciences, University College London, London, UK
Recommended Citation:
Dameron S.N.,Leckie R.M.,Clark K.,et al. Extinction, dissolution, and possible ocean acidification prior to the Cretaceous/Paleogene (K/Pg) boundary in the tropical Pacific[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01