Evolution and controls of the South Gondwana Fauna: An analysis by means of Jurassic and lower Cretaceous ostracods of Madagascar (Morondava Basin)

Research project P 13730 Jurassic and lower Cretaceous ostracods of Madagascar Wolfgang METTE 11.10.1999 The present project is one of five associated projects which are concerned with the origination of the "Proto-Indic" between West and East Gondwana and the involved tectonic, sedimentary and biologic processes. The general project aim is to analyse the development of the Morondava Basin in the Jurassic and Cretaceous and to use these data to reconstruct the geologic history of the "Gulf of Madagascar" and the "South African Seaway". Cooperation of different research projects is essential for the analysis of temporal variations and interactions of endogenic (rifting, uplift, basin development) and exogenic processes (denudation, sedimentation, evolution, faunal migration). The present project is focussed on the evolution, palaeoecology and palaeobiogeography of Jurassic and Cretaceous ostracods of the Morondava Basin. Main scientific questions are the palaeobiogeographic distribution of marine and limnic-brackish ostracods and their significance for the reconstruction of rift and drift processes between East Africa and Madagascar/India in Jurassic and early Cretaceous times. Another general intention of the project is to analyse the evolution of the "South Gondwana Fauna" aspects of the ,Ethiopian Province". These studies are primarily concerned with the spatial and temporal distribution of ostracods, temporal diversity changes, and their controls (i.e. sea level changes, opening and closing of migration pathways, basin development, climatic changes, evolutionary processes). The palaeoecological and palaeobiogeographical analysis of the ostracods are supported by the analysis of associated macrobenthos, sedimentologic studies and isotope ratios of mollusc and ostracod skeletons.