TY - CHAP
T1 - Chemostratigraphy across the Cretaceous-Paleogene (K-Pg) boundary
T2 - Testing the impact and volcanism hypotheses
AU - Sial, Alcides Nobrega
AU - Chen, Jiubin
AU - Lacerda, Luis Drude
AU - Frei, Robert
AU - Higgins, John A.
AU - Tewari, Vinod Chandra
AU - Gaucher, Claudio
AU - Ferreira, Valderez Pinto
AU - Cirilli, Simonetta
AU - Korte, Christoph
AU - Barbosa, José Antonio
AU - Pereira, Natan Silva
AU - Ramos, Danielle Santiago
N1 - Publisher Copyright:
© 2019 the American Geophysical Union. All rights reserved.
PY - 2018/12/10
Y1 - 2018/12/10
N2 - The mass extinction which marks the K-Pg has been linked to a catastrophic event. Cr and Os isotopes and 3He4He ratios of He encapsulated in fullerenes within Ir-rich K-Pg layer point to an extraterrestrial cause, while Hg/TOC spikes across the K-Pg boundary suggest Hg loading from the Deccan volcanism. Three Hg/TOC spikes are present in some classical K-Pg sections: (i) spike I within the CF2 planktic foraminiferal biozone, (ii) spike II at the K-Pg boundary layer, and (iii) spike III within the P1a planktic foraminiferal subzone. The spike II has, perhaps, resulted from Hg loading from the asteroid impact and volcanism. We suggest that higher ΣREE+Y values in the K-Pg layers are, perhaps, related to Deccan volcanism or to sea-level fluctuations, coeval to the K-Pg transition that enhanced continental influx. True negative Ce anomaly suggests predominance of oxidized surface waters during the K-Pg transition. In a δ202Hg versus Δ201Hg plot, samples from the spike II and from Bidart-France lie within the Hg volcanic emission box. Samples from spikes I and III from Bidart lie within the volcanic emission/chondrite box. Small positive Δ201Hg favors long-term atmospheric transport and supports Hg loading to the environment by Deccan phase 2 in three distinct episodes.
AB - The mass extinction which marks the K-Pg has been linked to a catastrophic event. Cr and Os isotopes and 3He4He ratios of He encapsulated in fullerenes within Ir-rich K-Pg layer point to an extraterrestrial cause, while Hg/TOC spikes across the K-Pg boundary suggest Hg loading from the Deccan volcanism. Three Hg/TOC spikes are present in some classical K-Pg sections: (i) spike I within the CF2 planktic foraminiferal biozone, (ii) spike II at the K-Pg boundary layer, and (iii) spike III within the P1a planktic foraminiferal subzone. The spike II has, perhaps, resulted from Hg loading from the asteroid impact and volcanism. We suggest that higher ΣREE+Y values in the K-Pg layers are, perhaps, related to Deccan volcanism or to sea-level fluctuations, coeval to the K-Pg transition that enhanced continental influx. True negative Ce anomaly suggests predominance of oxidized surface waters during the K-Pg transition. In a δ202Hg versus Δ201Hg plot, samples from the spike II and from Bidart-France lie within the Hg volcanic emission box. Samples from spikes I and III from Bidart lie within the volcanic emission/chondrite box. Small positive Δ201Hg favors long-term atmospheric transport and supports Hg loading to the environment by Deccan phase 2 in three distinct episodes.
UR - https://www.scopus.com/pages/publications/85189456698
UR - https://www.scopus.com/inward/citedby.url?scp=85189456698&partnerID=8YFLogxK
M3 - Chapter
AN - SCOPUS:85189456698
SN - 9781119382485
SP - 223
EP - 257
BT - Chemostratigraphy Across Major Chronological Boundaries
PB - wiley
ER -