Skip to Main content Skip to Navigation

Welcome to the CEREGE collection

CEREGE, Centre de Recherche et d’Enseignement de Géosciences de l’Environnement (Centre for Research and Teaching in Environmental Geoscience), regroups around 130 permanent staff (45 university lecturers and professors, 40 researchers and 45 engineers, technicians, and administrative staff), and 110 temporary staff including around 60 graduate students. CEREGE is a joint research centre (UM 34), incorporating Aix-Marseille University (AMU), the CNRS (UMR7330), the IRD (UMR 161), and the COLLEGE DE France. The INRA is also a partner. We are located in Provence, at the Technopôle Environnement Arbois Méditerranée, Petit Plateau de l’Arbois (Aix-en-Provence, Les Milles) and on the St Charles campus of AMU in Marseille. Thanks to its theoretical, methodological, and technological approaches to research, CEREGE is strongly interdisciplinary

Latest submissions in HAL !

[hal-03380503] Vegetation dynamics of Kisima Ngeda freshwater spring reflect hydrological changes in northern Tanzania over the past 1200 years: implications for paleoenvironmental reconstructions at paleoanthropological sites.

(10/17/21)  
Kisima Ngeda (KN), a spring on the northern margin of saline Lake Eyasi, Tanzania, sustains an Acacia-Hyphaene palm woodland and Typha swamps, while the surrounding vegetation is semi-desert. To study the vegetation changes associated with this spring, which represents a plausible modern analog for the fossil springs documented in the nearby paleoanthropological and archaeological sites of Olduvai Gorge, we analyzed the pollen content of a 43 cm-long sediment core that documents vegetation changes since the last ~1200 years (from cal yrs. C.E. 841 to 2011). Our results show that (1) Hyphaene palms, which require meso-halophytic soil conditions were most abundant in the area of the coring site until cal yrs. C.E. ~1150 when the groundwater supplying the KN spring was likely lower than at present, allowing intrusions of saline lake waters. (2) From cal yrs. C.E. ~1200, a peat began to develop, the palm woodland was replaced by a Mimosaceae woodland, and the increased presence of Typha pollen indicates the presence of more wetlands. (3) From cal yrs. C.E. 1600, the groundwater level of the KN spring increased and reached its highest level in the last 1200 years. (4) Peaks of wetland expansion, which reflect increased groundwater flow and level in response to amplified rainfall in the recharge area (Mt Oldeani, Ngorongoro Highlands), occurred at cal yrs. C.E. ~1200–1400 and ~1650–2011. These outflows of groundwater at Kisima Ngeda were linked to the intensity and frequency of positive Indian Ocean Dipole (IOD) events, which trigger heavy rains in eastern Africa. We conclude that the Kisima Ngeda hydrological system, which has been active for more than 1200 years, responds rapidly to regional climate change driven by changes in the sea surface temperatures (SSTs) of the Indian Ocean. Yet, it is also capable of remaining active during dry intervals as inferred from the Kisima Ngeda record prior to cal yrs. C.E. 1200. Our results support the hypothesis that this type of system helped to maintain Plio-Pleistocene hominin populations and activities in the arid lowlands of the rift on a multi-decennial scale.

[hal-03379060] Méthodologie et intercomparaison des analyses granulométriques

(10/17/21)  

[hal-03374910] Multiscale Geoelectrical Properties of the Rochechouart Impact Structure, France

(10/14/21)  

 

 

Contact

Catherine Beaussier
Tél. (+33) 4 95 04 41 43
catherine.beaussier@osupytheas.fr

Archive créée et administrée sur la plateforme HAL du CCSD
 

Legal aspects : Contributor obligations


Dépôt de fichier : que faire en fonction de la version que vous déposez

Sherpa/Romeo

 

Domain

 

 

Evolution of the submissions

 

 

 

 

 

INTERNATIONAL COLLABORATIONS