The end-Cretaceous in the southwestern Tethys (Elles, Tunisia): orbital calibration of paleoenvironmental events before the mass extinction

Nicolas Rudolph Thibault; Bruno Galbrun; Silvia Gardin; Fabrice Minoletti; Laurence Le Callonnec

doi:10.1007/s00531-015-1192-0

The end-Cretaceous in the southwestern Tethys (Elles, Tunisia): orbital calibration of paleoenvironmental events before the mass extinction

Nicolas Rudolph Thibault^*, Bruno Galbrun, Silvia Gardin, Fabrice Minoletti, Laurence Le Callonnec

^*Corresponding author af dette arbejde

Geologi

30 Citationer (Scopus)

Abstract

An integrated study of magnetic mass susceptibility (MS), bulk stable isotopes and calcareous nannofossil paleoecological changes is undertaken on the late Maastrichtian of the Elles section, Tunisia, spanning the last ca. 1 Myr of the Cretaceous. A cyclostratigraphic analysis reveals the presence of Milankovitch frequencies and is used for proposal of two distinct orbital age models and to provide ages of important stratigraphic horizons, relative to the age of the Cretaceous–Paleogene boundary (K–PgB). Principal component analysis (PCA) performed on the nannofossil assemblage reveal two main factors, PCA1, mostly representing fluctuations of D. rotatorius, P. stoveri, Lithraphidites spp., Retecapsa spp., Staurolithites spp., Micula spp., and PCA2, mostly representing fluctuations of A. regularis, C. ehrenbergii, Micula spp., Rhagodiscus spp., W. barnesiae and Zeugrhabdotus spp. Variations in PCA1 and PCA2 match changes in bulk δ¹³C and δ¹⁸O, respectively, and suggest changes in surface-water fertility and temperatures and associated stress. The variations in abundances of high-latitude taxa and the warm-water species Micula murus and in bulk δ¹⁸O delineate fast changes in sea-surface paleotemperatures. As in many other sites, an end-Maastrichtian greenhouse warming is highlighted, followed by a short cooling and an additional warm pulse in the last 30 kyr of the Maastrichtian which has rarely been documented so far. Orbital tuning of the delineated climatic events is proposed following the two different age models. Calcareous nannofossil assemblages highlight a decrease in surface-water nutriency, but their species richness remains high through the latest Maastrichtian, indicating, in Tunisia, a weak impact of Deccan volcanism on calcareous nannoplankton diversity before the mass extinction.

Originalsprog	Engelsk
Tidsskrift	International Journal of Earth Sciences
Vol/bind	105
Udgave nummer	3
Sider (fra-til)	771-795
Antal sider	25
ISSN	1437-3254
DOI	https://doi.org/10.1007/s00531-015-1192-0
Status	Udgivet - 2016

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The end-Cretaceous in the southwestern Tethys (Elles, Tunisia) : orbital calibration of paleoenvironmental events before the mass extinction. / Thibault, Nicolas Rudolph; Galbrun, Bruno; Gardin, Silvia et al.

I: International Journal of Earth Sciences, Bind 105, Nr. 3, 2016, s. 771-795.

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

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title = "The end-Cretaceous in the southwestern Tethys (Elles, Tunisia): orbital calibration of paleoenvironmental events before the mass extinction",

abstract = "An integrated study of magnetic mass susceptibility (MS), bulk stable isotopes and calcareous nannofossil paleoecological changes is undertaken on the late Maastrichtian of the Elles section, Tunisia, spanning the last ca. 1 Myr of the Cretaceous. A cyclostratigraphic analysis reveals the presence of Milankovitch frequencies and is used for proposal of two distinct orbital age models and to provide ages of important stratigraphic horizons, relative to the age of the Cretaceous–Paleogene boundary (K–PgB). Principal component analysis (PCA) performed on the nannofossil assemblage reveal two main factors, PCA1, mostly representing fluctuations of D. rotatorius, P. stoveri, Lithraphidites spp., Retecapsa spp., Staurolithites spp., Micula spp., and PCA2, mostly representing fluctuations of A. regularis, C. ehrenbergii, Micula spp., Rhagodiscus spp., W. barnesiae and Zeugrhabdotus spp. Variations in PCA1 and PCA2 match changes in bulk δ13C and δ18O, respectively, and suggest changes in surface-water fertility and temperatures and associated stress. The variations in abundances of high-latitude taxa and the warm-water species Micula murus and in bulk δ18O delineate fast changes in sea-surface paleotemperatures. As in many other sites, an end-Maastrichtian greenhouse warming is highlighted, followed by a short cooling and an additional warm pulse in the last 30 kyr of the Maastrichtian which has rarely been documented so far. Orbital tuning of the delineated climatic events is proposed following the two different age models. Calcareous nannofossil assemblages highlight a decrease in surface-water nutriency, but their species richness remains high through the latest Maastrichtian, indicating, in Tunisia, a weak impact of Deccan volcanism on calcareous nannoplankton diversity before the mass extinction.",

keywords = "Calcareous nannofossils, Cyclostratigraphy, Late Maastrichtian, Paleoecology, Stable isotopes",

author = "Thibault, {Nicolas Rudolph} and Bruno Galbrun and Silvia Gardin and Fabrice Minoletti and {Le Callonnec}, Laurence",

year = "2016",

doi = "10.1007/s00531-015-1192-0",

language = "English",

volume = "105",

pages = "771--795",

journal = "International Journal of Earth Sciences",

issn = "1437-3254",

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T1 - The end-Cretaceous in the southwestern Tethys (Elles, Tunisia)

T2 - orbital calibration of paleoenvironmental events before the mass extinction

AU - Thibault, Nicolas Rudolph

AU - Galbrun, Bruno

AU - Gardin, Silvia

AU - Minoletti, Fabrice

AU - Le Callonnec, Laurence

PY - 2016

Y1 - 2016

N2 - An integrated study of magnetic mass susceptibility (MS), bulk stable isotopes and calcareous nannofossil paleoecological changes is undertaken on the late Maastrichtian of the Elles section, Tunisia, spanning the last ca. 1 Myr of the Cretaceous. A cyclostratigraphic analysis reveals the presence of Milankovitch frequencies and is used for proposal of two distinct orbital age models and to provide ages of important stratigraphic horizons, relative to the age of the Cretaceous–Paleogene boundary (K–PgB). Principal component analysis (PCA) performed on the nannofossil assemblage reveal two main factors, PCA1, mostly representing fluctuations of D. rotatorius, P. stoveri, Lithraphidites spp., Retecapsa spp., Staurolithites spp., Micula spp., and PCA2, mostly representing fluctuations of A. regularis, C. ehrenbergii, Micula spp., Rhagodiscus spp., W. barnesiae and Zeugrhabdotus spp. Variations in PCA1 and PCA2 match changes in bulk δ13C and δ18O, respectively, and suggest changes in surface-water fertility and temperatures and associated stress. The variations in abundances of high-latitude taxa and the warm-water species Micula murus and in bulk δ18O delineate fast changes in sea-surface paleotemperatures. As in many other sites, an end-Maastrichtian greenhouse warming is highlighted, followed by a short cooling and an additional warm pulse in the last 30 kyr of the Maastrichtian which has rarely been documented so far. Orbital tuning of the delineated climatic events is proposed following the two different age models. Calcareous nannofossil assemblages highlight a decrease in surface-water nutriency, but their species richness remains high through the latest Maastrichtian, indicating, in Tunisia, a weak impact of Deccan volcanism on calcareous nannoplankton diversity before the mass extinction.

AB - An integrated study of magnetic mass susceptibility (MS), bulk stable isotopes and calcareous nannofossil paleoecological changes is undertaken on the late Maastrichtian of the Elles section, Tunisia, spanning the last ca. 1 Myr of the Cretaceous. A cyclostratigraphic analysis reveals the presence of Milankovitch frequencies and is used for proposal of two distinct orbital age models and to provide ages of important stratigraphic horizons, relative to the age of the Cretaceous–Paleogene boundary (K–PgB). Principal component analysis (PCA) performed on the nannofossil assemblage reveal two main factors, PCA1, mostly representing fluctuations of D. rotatorius, P. stoveri, Lithraphidites spp., Retecapsa spp., Staurolithites spp., Micula spp., and PCA2, mostly representing fluctuations of A. regularis, C. ehrenbergii, Micula spp., Rhagodiscus spp., W. barnesiae and Zeugrhabdotus spp. Variations in PCA1 and PCA2 match changes in bulk δ13C and δ18O, respectively, and suggest changes in surface-water fertility and temperatures and associated stress. The variations in abundances of high-latitude taxa and the warm-water species Micula murus and in bulk δ18O delineate fast changes in sea-surface paleotemperatures. As in many other sites, an end-Maastrichtian greenhouse warming is highlighted, followed by a short cooling and an additional warm pulse in the last 30 kyr of the Maastrichtian which has rarely been documented so far. Orbital tuning of the delineated climatic events is proposed following the two different age models. Calcareous nannofossil assemblages highlight a decrease in surface-water nutriency, but their species richness remains high through the latest Maastrichtian, indicating, in Tunisia, a weak impact of Deccan volcanism on calcareous nannoplankton diversity before the mass extinction.

KW - Calcareous nannofossils

KW - Cyclostratigraphy

KW - Late Maastrichtian

KW - Paleoecology

KW - Stable isotopes

U2 - 10.1007/s00531-015-1192-0

DO - 10.1007/s00531-015-1192-0

M3 - Journal article

AN - SCOPUS:84929688382

SN - 1437-3254

VL - 105

SP - 771

EP - 795

JO - International Journal of Earth Sciences

JF - International Journal of Earth Sciences

IS - 3

ER -

The end-Cretaceous in the southwestern Tethys (Elles, Tunisia): orbital calibration of paleoenvironmental events before the mass extinction

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