Environmental effects of Deccan volcanism across the Cretaceous-Tertiary transition in Meghalaya, India

Détails

ID Serval
serval:BIB_296364C24E12
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Environmental effects of Deccan volcanism across the Cretaceous-Tertiary transition in Meghalaya, India
Périodique
Earth and Planetary Science Letters
Auteur⸱e⸱s
Gertsch B., Keller G., Adatte T., Garg R., Prasad V., Berner Z., Fleitmann D.
ISSN-L
0012-821X
Statut éditorial
Publié
Date de publication
2011
Peer-reviewed
Oui
Volume
310
Pages
272-285
Langue
anglais
Résumé
The Urn Sohryngkew section of Meghalaya, NE India, located 800-1000 km
from the Deccan volcanic province, is one of the most complete
Cretaceous-Tertiary boundary (KTB) transitions worldwide with all
defining and supporting criteria present: mass extinction of planktic
foraminifera, first appearance of Danian species, delta(13)C shift, Ir
anomaly (12 ppb) and KTB red layer. The geochemical signature of the KTB
layer indicates not only an extraterrestrial signal (Ni and all Platinum
Group Elements (PGEs)) of a second impact that postdates Chicxulub, but
also a significant component resulting from condensed sedimentation (P),
redox fluctuations (As, Co, Fe, Pb, Zn, and to a lesser extent Ni and
Cu) and volcanism. From the late Maastrichtian C29r into the early
Danian, a humid climate prevailed (kaolinite: 40-60%, detrital
minerals: 50-80%). During the latest Maastrichtian, periodic acid rains
(carbonate dissolution; CIA index: 70-80) associated with pulsed Deccan
eruptions and strong continental weathering resulted in mesotrophic
waters. The resulting super-stressed environmental conditions led to the
demise of nearly all planktic foraminiferal species and blooms (>95%)
of the disaster opportunist Guembelitria cretacea. These data reveal
that detrimental marine conditions prevailed surrounding the Deccan
volcanic province during the main phase of eruptions in C29r below the
KTB. Ultimately these environmental conditions led to regionally early
extinctions followed by global extinctions at the KTB. (C) 2011 Elsevier
B.V. All rights reserved.
Création de la notice
28/09/2012 11:03
Dernière modification de la notice
20/08/2019 14:09
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