Studi Provenance Batupasir Formasi Halang pada Daerah Selajambe dan Sekitarnya Kabupaten Kuningan, Jawa Barat

Abstract

Halang Formation has a great extension and abundance in Java, including in Bogor Basin of West Java. This turbiditic sandstone oftenly discussed in terms of sedimentology and stratigraphy, but lacks of its provenance and parent rock tectonic setting perspective. This research aimed to analyze/interpret Halang Formation sandstones types and characteristics, provenance, tectonic setting, as well as it’s relation with extensive-geological processes undergone. Methods and analysis used in this study are microfossil, petrography, and provenance identification. Provenance analysis subjected through petrography identification and mineral point counting method on a minimum of 300 grains/sample, then the results are plotted to Provenance Ternary Diagram conducted by Dickinson and Suczek (1979). Results of this study indicate that most of Halang Formation’s sandstones determined as Lithic Wacke, which characterized as Lithofeldspathic sands, contains high number of volcanic lithic fragments and followed by plagioclase. Its provenance is a volcanic source in a magmatic arc by an arc orogen sources. Occurrence of two provenance sub-types (Undissected Arc and Transitional Arc) is a result of an advanced volcanism and erosion in a mature magmatic arc causing volcanic’s Cap Rock shattered. Hence, it exposed its plutonic root and eventually be particular sediment source alongside volcanic rock fragments. Southern Mountains is appointed as the highland which fed the sediment source, which is an andesitic volcanic highs and was a paleo magmatic-arc formed in Oligocene Epoch. Sandstone was deposited in Late Miocene-Pliocene (N15-N19) at Inner Bathyal-Outter Bathyal Bathymetry.