FN Archimer Export Format
PT J
TI Late Cretaceous evolution of chemical weathering at the northeastern South American margin inferred from mineralogy and Hf-Nd isotopes
BT 
AF Corentin, Pauline
   Pucéat, Emmanuelle
   Pellenard, Pierre
   Guiraud, Michel
   Blondet, Justine
   Bayon, Germain
   Adatte, Thierry
AS 1:1;2:1;3:1;4:1;5:1;6:2;7:3;
FF 1:;2:;3:;4:;5:;6:PDG-REM-GEOOCEAN-ASTRE;7:;
C1 Biogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté, 21000 Dijon, France
   Univ Brest, CNRS, Ifremer, Geo-Ocean, F-29280 Plouzané, France
   Institute of Earth Sciences, Géopolis, University of Lausanne, Lausanne, Switzerland
C2 UNIV BOURGOGNE FRANCHE COMTE, FRANCE
   IFREMER, FRANCE
   UNIV LAUSANNE, SWITZERLAND
SI BREST
SE PDG-REM-GEOOCEAN-ASTRE
UM GEO-OCEAN
IN WOS Ifremer UMR
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
IF 2.9
TC 2
UR https://archimer.ifremer.fr/doc/00811/92291/98337.pdf
LA English
DT Article
DE ;Continental weathering;Isotopic geochemistry;Clay mineralogy;Palaeoclimate;Cretaceous
AB The origin of the global temperature decrease that initiated the last greenhouse-icehouse transition about 90 million years ago still remains debated. Among the potential processes driving long-term climate evolution over million-year timescales, this study investigates the possible impact of the uplift-weathering connection on the late Cretaceous atmospheric CO2 drawdown and associated cooling. We analysed a marine sediment record from the Demerara margin, using Nd and Hf isotopes in clay-size detrital fractions (ΔɛHf(t)clay) together with bulk and clay mineralogy and major element abundances to reconstruct the evolution of tectonic uplift and chemical weathering intensity in northeastern South America during the late Cretaceous. Our data indicate that silicate weathering intensified on the northeastern South American margin during the middle Campanian and the Maastrichtian, concomitant with an uplift phase of the Guiana craton. We propose that the tectonic pulse highlighted by apatite fission track data, argon/argon dating and primary silicate mineral evolution, was accompanied by an accelerated chemical weathering, which presumably acted as a sink for atmospheric CO2. By contrast, during the earlier late Turonian to early Campanian, period of relative tectonic quiescence, climate most likely acted as the main driver controlling the evolution of chemical weathering intensity. The main phase of enhanced weathering induced by the uplift of the northeastern South American margin occurred during the Campanian, thereby postdating the onset of global seawater temperature decrease (late Turonian). By inference, this regional event is unlikely to have triggered late Cretaceous cooling but it may have acted as an additional factor stabilizing colder climate conditions at that time. 
PY 2023
PD JAN
SO Marine Geology
SN 0025-3227
PU Elsevier BV
VL 455
UT 000904133900002
DI 10.1016/j.margeo.2022.106968
ID 92291
ER

EF