DOI: 10.1016/j.palaeo.2015.07.049
论文题名: Climatic fluctuations and sea-surface water circulation patterns at the end of the Cretaceous era: Calcareous nannofossil evidence
作者: Thibault N. ; Husson D.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 441 起始页码: 152
结束页码: 164
语种: 英语
英文关键词: Calcareous nannofossils
; Cretaceous-Paleogene boundary
; Late Maastrichtian climate
; Micula murus
英文摘要: New paleoecological data are presented for late Maastrichtian calcareous nannofossil assemblages of the Indian Ocean and the Boreal epicontinental Chalk Sea. These data are compiled with recent results in the tropical Atlantic, Pacific, and Tethys oceans in order to characterize environmental changes by the end of the Cretaceous era. The paleobiogeographic distribution of the warm-water species Micula murus is updated and indicates the existence of major sea-surface currents in the late Maastrichtian Atlantic Ocean similar to the present day. The end-Maastrichtian greenhouse warming is characterized at tropical and subtropical latitudes by an increase in abundance of M. murus and the temporary disappearance of the high-fertility marker Biscutum constans. In the Boreal realm, the greenhouse episode is marked by a contemporaneous acme of Watznaueria barnesiae coincident with very rare occurrences of M. murus and other tropical nannofossil species which have never been reported before at boreal latitudes. A review of cyclostratigraphic and calcareous nannofossil data in the Atlantic, Pacific, Indian, and Tethys oceans points to the following evolution of sea-surface paleotemperatures for the last ca. 350-380 kyr of the Cretaceous: the end-Maastrichtian greenhouse warming lasted on average a little more than 200 kyr and was followed by a ca. 100-120 kyr cooling. In the Tethys, a 30-40 kyr additional pulse of warming is highlighted immediately below the Cretaceous-Paleogene boundary. These findings indicate an important instability of the climate system at the end of the Maastrichtian, most likely caused by Deccan volcanism. The calcareous nannofossil species richness dropped during the end-Maastrichtian greenhouse warming, which may indicate environmental stress and/or ocean acidification. However, nannoplankton diversity returned rapidly to higher values after this climatic episode and remained high up to the Cretaceous-Paleogene boundary. No significant extinction is recorded in this biotic group prior to the boundary clay. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68679
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, Copenhagen K, Denmark; Department of Earth and Planetary Sciences, Technological Institute, 2145 Sheridan Road, Evanston, IL, United States; Sorbonne Universités, Université Pierre et Marie Curie Univ Paris 06, Unité Mixte de Recherche (UMR) 7193, Institut des Sciences de la Terre Paris (iSTeP), Paris, France
Recommended Citation:
Thibault N.,Husson D.. Climatic fluctuations and sea-surface water circulation patterns at the end of the Cretaceous era: Calcareous nannofossil evidence[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,441