FN Archimer Export Format
PT J
TI Enhanced continental weathering (Li, Nd) during the rise of East African complex polities: an early large-scale anthropogenic forcing?
BT 
AF Mologni, Carlo
   Revel, Marie
   Bastian, Luc
   Bayon, Germain
   Bosch, Delphine
   Khalidi, Lamya
   Vigier, Nathalie
AS 1:1,2;2:1;3:1,3;4:4;5:5;6:2;7:6;
FF 1:;2:;3:;4:PDG-REM-GEOOCEAN-ASTRE;5:;6:;7:;
C1 Univ. Côte d’Azur, CNRS, OCA, IRD, Geoazur, 250 rue Albert Einstein, 06500 Valbonne, France
   Univ. Côte d’Azur, CNRS, CEPAM – UMR 7264, 24 av. des Diables Bleus 06300 Nice, France
   Laboratoire d’Océanographie de Villefranche sur Mer (LOV, IMEV), CNRS, Sorbonne Université, 181 chemin du Lazaret, 06320, Villefranche sur Mer, France
   IFREMER, Unité de Recherche Géosciences Marines, 29280 Plouzané, France
   Géosciences Montpellier, UMR-CNRS 5243, Université de Montpellier, 34095 Montpellier, France
   Laboratoire d’Océanographie de Villefranche-sur-Mer (LOV, IMEV), CNRS, Sorbonne Université, 181 chemin du Lazaret, 06320, Villefranche sur Mer, France
C2 UNIV COTE D'AZUR, FRANCE
   UNIV COTE D’AZUR, FRANCE
   UNIV SORBONNE, FRANCE
   IFREMER, FRANCE
   UNIV MONTPELLIER, FRANCE
   UNIV SORBONNE, FRANCE
SI BREST
SE PDG-REM-GEOOCEAN-ASTRE
UM GEO-OCEAN
IN WOS Ifremer UMR
   DOAJ
   copubli-france
   copubli-univ-france
IF 1.4
TC 0
UR https://archimer.ifremer.fr/doc/00802/91349/97181.pdf
LA English
DT Article
CR MD 138 / VANIL
   MIMES
BO Marion Dufresne
   Pelagia
DE ;Chemical weathering;Li isotope;Nd isotope;Nile deep sea fan;Anthropogenic forcing;Aksumite civilization;Earth Critical Zone
AB Human-induced environmental disturbances during the Holocene have provided support for the Early Anthropogenic Hypothesis (EAH), which proposes that with the advent of agro-pastoralism and associated deforestation, humans have modified CO2 and CH4 concentrations into the atmosphere. However, only limited evidence exists for human driven chemical alteration of the Earth’s Critical Zone (ECZ) in early antiquity. Here, we explore the impact of human activities on both erosion and chemical weathering patterns in the Nile basin during a time interval that includes the rise of the Aksumite Kingdom and Late Antique Egypt (3–1 ka BP). By coupling lithium and neodymium isotopes (, ) in clay-size fractions of two marine sediment cores from the Nile Deep Sea Fan (NDSF), we reconstruct the variability of sediment provenance and silicate weathering intensity in the Nile basin over the last 9000 years. Our high temporal resolution data show that for the last 3000 years, the Rosetta Nile Deep Sea Fan has been increasingly fed with clays delivered from the Ethiopian basaltic highlands (), despite the absence of hydrological intensification and major climatic drivers over that region. Concomitantly, the clay Li isotopic composition shifted towards lower values ( to 2), yielding unprecedented negative values for at least the last 100,000 years. Combined with other archaeological, paleo-pedological and organic chemistry inferences, the Li–Nd isotope proxy records indicate a link between the intensification of continental weathering and intensified land-use and water management during the Pre-Aksumite (3 to 2 ka BP) and Aksumite (2 to 1 ka BP) periods. Therefore, our results provide direct support to the hypothesis of an early and large scale anthropogenic forcing on continental chemical weathering. A comparison with previously published records for Central Africa, Central Europe and China suggests that the impact of the intensification of early agriculture on the ECZ may have operated at a global scale starting around four thousand years ago. 
PY 2022
SO Comptes Rendus Geoscience
SN 1631-0713
PU Cellule MathDoc/CEDRAM
VL 354
IS G2
UT 000929980200001
BP 319
EP 337
DI 10.5802/crgeos.169
ID 91349
ER

EF