FN Archimer Export Format
PT J
TI Hafnium‑neodymium isotope evidence for enhanced weathering and uplift-climate interactions during the Late Cretaceous
BT 
AF Corentin, Pauline
   Pucéat, Emmanuelle
   Pellenard, Pierre
   Freslon, Nicolas
   Guiraud, Michel
   Blondet, Justine
   Adatte, Thierry
   Bayon, Germain
AS 1:1;2:1;3:1;4:1,2;5:1;6:1;7:3;8:4;
FF 1:;2:;3:;4:;5:;6:;7:;8:PDG-REM-GM-LGS;
C1 Biogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté, 21000 Dijon, France
   ISTO - Université d'Orléans, CNRS, BRGM, UMR 7327, F-45071 Orléans, France
   Institute of Earth Sciences, Géopolis, University of Lausanne, Lausanne, Switzerland
   IFREMER, Unité de Recherche Géosciences Marines, F-29280 Plouzané, France
C2 UNIV BOURGOGNE FRANCHE COMTE, FRANCE
   UNIV ORLEANS, FRANCE
   UNIV LAUSANNE, SWITZERLAND
   IFREMER, FRANCE
SI BREST
SE PDG-REM-GM-LGS
UM GEO-OCEAN
IN WOS Ifremer UMR
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
IF 3.9
TC 8
UR https://archimer.ifremer.fr/doc/00745/85664/90792.pdf
LA English
DT Article
DE ;Paleoclimate;Tectonic-climate interaction;Isotope geochemistry;Clay mineralogy;Brazilian margin
AB The processes initiating the first cooling step of the last greenhouse-to-icehouse transition, from 90 million years ago (Ma) onward still remain enigmatic. While the combination of mountain uplift and continental weathering has been proposed as a major sink for atmospheric CO2 and a climate driver over geological timescales, this hypothesis is much debated and its potential importance in triggering the late Cretaceous global cooling is yet to be explored. In this work, we combined clay mineralogy, trace and major element concentrations, and a new proxy of silicate weathering intensity based on Nd and Hf isotopes (∆ɛHf(t)clay) to explore the potential links between the uplift of the brazilian margin, silicate weathering and climate evolution during the late Cretaceous. Our new ∆ɛHf(t)clay proxy data suggest - for the first time - that marked increase of silicate weathering intensity occurred in southeast Brazil during the late Cretaceous, from ~85 to 70 Ma, related to the tectonic uplift affecting the eastern South American margin at that time. Combined with clay mineralogical analyses, our HfNd isotope data further suggests the existence of a relatively arid local climate during the Turonian-Santonian interval, during which physical disaggregation of rocks most likely prevailed, accompanying the uplift of the Brazilian margin. From the Santonian, we propose that the exposure of new high-elevation regions favored instead locally enhanced precipitations and more hydrolysing conditions, thereby promoting chemical weathering and atmospheric CO2 drawdown. Altogether, our multi-proxy investigation suggests that the uplift of the Brazilian margin could have contributed to the late Cretaceous cooling, potentially playing a key role in the onset of the last greenhouse-to-icehouse transition. 
PY 2022
PD MAR
SO Chemical Geology
SN 0009-2541
PU Elsevier BV
VL 591
UT 000768010400007
DI 10.1016/j.chemgeo.2022.120724
ID 85664
ER

EF