Microfacies and Diagenesis of Limestone in Bojongmanik Formation in the Western Endut Mountain Area, Lebak Regency, Banten Province Based on Petrographical Analysis Methods

Abstract

Bojongmanik Formation which especially formed in the Western Endut Mountain Area just has been done with very rarely research. Bojongmanik Formation exposed in the western Endut Mountain is a Late Miocene rock formation with limestone and sandy limestone lithology. This research used the analysis methods of petrographic observation, especially carried out on limestone lithology. Petrographic analyses have been carried out on 15 limestone samples from the research area. The petrographic analyses’ primary purpose is to determine the facies zone where the limestone are formed and to understand the diagenesis processes experienced by the rocks after its formation. The result shows that the limestone in the research area mainly consisted of framestone, bafflestone, Floatstone, Rudstone, and Packstone. Based on the analysis, limestone in this area has formed in slope, platform margin reef, and platform interior open marine facies zone. From the obtained facies zone, a two-dimensional model was made to get an overview of the paleo facies condition. It was concluded that the seaward was in the north and landward in the south. Various diagenesis processes that occurred after limestone in this area are formed are dolomitization, fracturing, micrite envelope, dissolution, recrystallization, inversion, marine cementation, burial cementation, and phreatic meteoric cementation. The diagenesis indicate burial, marine, and meteoric environment.