December 9 2021: international seminar PALEVOPRIM n° 28
Speaker
Ilaria Mazzini
Consiglio Nazionale delle Ricerche, IGAG, Rome, Italie
Topic
Ostracoda from the Shungura Formation (Omo Valley, Ethiopia): a reassessment
In the late seventies, the paleoenvironments of the Plio-Pleistocene Shungura Formation (Lower Omo Valley, southwestern Ethiopia) have been investigated through ostracod analyses (Carbonel and Peypouquet, 1979). During the 2016 fieldwork of the Omo Group Research Expedition, 20 out of the 22 ostracod layers described in 1979 were recognized and sampled again, and in addition 75 layers were sampled anew. Three main ostracod assemblages were recognized and their ecological characteristics have been linked to paleoenvironmental changes (mainly water depth and salinity). Variations of water depth and salinity occur within each member of the Shungura Formation and provide insights about the transition from a deep lake (Sclerocypris clavularis, Limnocythere africana) to a very shallow lake. In some cases, this transition corresponds to increased salinity favouring halotolerant species that thrived, forming ostracodite layers (Cyprideis sp., Hemicypris spp.). In other cases, this transition corresponds to a decreased salinity, strongly influenced by freshwater inputs (Ilyocypris spp.) pointing to a deltaic environment.
Ilaria Mazzini is an internationally renowned specialist of ostracods. She is using these shell-protected crustaceans as tools for reconstructions of lacustrine and marginal marine environments of the Neogene and Quaternary of Eurasia and Africa, including for indicating Holocene changes in relation human settlements around the Mediterranean. She is also using the isotope and trace element contents of ostracod shells as additional proxies of environmental change. She obtained her PhD at Ludwig Maximilians University in Munich, and performs her research at the Institute of Environmental Geology and Geoengineering in Rome.
Place
Room 410, build. B35 (3rd floor, northern wing), University of Poitiers.