Lithofacies analysis, ichnofacies analysis and depositional environment of Jatiluhur Formation in Cipamingkis area

Abstract

Depositional environment of Jatiluhur Formation is a very interesting research object to study, especially from the geological and biological aspects. This formation is very well exposed in several rivers in Bogor, especially in the Cipamingkis River. Field studies were carried out by measuring section method and ichnofossil description along the section. Stratigraphy log data shows the overall upward coarsening with a length of 66 meters. There are 4 facies associations from stratigraphy log data and the description of ichnofossil, FA1 is interpreted as a classical turbidite deposition process seen from alternating pattern of thin carbonate sandstones with carbonate siltstone in relative depths in the bathyal to sublittoral zone seen from Scolicia, Thalassinoides, and Opiomorpha seen in this section., FA2 is interpreted as a turbidite deposition process in the upper-fan section seen from the lithology of thick carbonate claystone and carbonate sandstones in the form of inserts at a relative depth in the sublittoral zone seen by ichnofossil found in the form of Circulishnis, FA3 is interpreted as an upper fan or channel fill seen from the structure The slump in this section that occurs at a sublittoral depth is seen from its ichnofossils, namely Rhizocorallium and Thalassinoides, and FA4 is interpreted as shallow marine seen from the lithology dominated by carbonate sandstones with tires That is, the sedimentary structure occurs in the relative depths of the sub-littoral to littoral zone seen from its ichnofossils, namely Planolites and Taenidium. Depositional environment of the Jatiluhur Formation shows that depth at bottom of section is deeper than upper section and deposition process from turbidite to shallow marine.