Publications

Tonasa Formation is well exposed at Karama, Bangkala Subdistrict, Jeneponto Regency, South Sulawesi. Tonasa Formation is a Middle Eocene carbonate deposit typified by the occurence of allochtonous limestone mudstone, wackstone, packstone, grainstone and slight coralline limestone. Tonasa Formation was deposited during sea level rise that triggers the growth of numerous varieties of micro foram in the Middle Eocene. This study examines the influence of depositional environment setting to the facies development based on sediment carbonate characteristics including lithology, sedimentary structure, and micro-foram content. The results of fossils sample analyses and petrographical thin sections from the allochtonous limestone of Tonasa Formation were analyzed to determine the organisms constituting the rock fabric. Characteristic of sediment lamination and bioturbation provides information about sedimentary depositional processes. Micro forams, including smaller benthic forams like Textularia sp, Cibicides sp, Quinqueloculina sp, are present in the Tonasa Formation which then indicates it is deposited in the shallow marine indicate marine environment. Planktonic foraminifers that are present in the formation are Globigerina senni, Globigerapsis kugleri, Globorotalia increconybescen, which are the index fossils for Middle Eocene. Keywords: Tonasa Formation, allochtonous limestone, micro-forams, depositional environment.