Vestige of The Ancient Estuarine of Cisaar Valley, Sumedang as One of the Pleistocene Fossil Bearing Site in West Jawa

Abstract

Cisaar Valley is located on the east part of Sumedang Regency, West Jawa Province. It’s close to the boundary of Sumedang-Majalengka Regency. In this location the sandy and clay dominated sedimentary rocks are well exposed along the outcrops in the Cisaar Valley. These sedimentary rocks is inferred from Pliocene-Pleistocene deposits from Kaliwangu and Citalang Formation. Foraminifera microfossil that commonly used for interpretation of depositional environment is rarely found, whereas freshwater mollusk and vertebrate fossils often found in the sediment rocks of this area.  This condition raises a question, what is the environment of this valley in the past? Data obtained from measured stratigraphic sections along Cisaar river and its tributary rivers in Cibengkung and Cirendang hamlets, Jembarwangi village. There are at least three depositional paleoenvironments which from old to young are: shallow marine, estuarine and fluviatil braided channel depositional paleoenvironment.  Characteristics of the lower, middle and upper of the estuarine environment were found in this Cisaar Valley as the evidences of the oceanic regression processes was happened in the past in this area.