Petrology, Geochemistry and K-Ar Dating of Metamorphic Rock in Ciletuh Mélange Complex, West Java Indonesia

The Ciletuh Mélange Complex in West Java, Indonesia, provides evidence of early Cenozoic subduction. This study aims to investigate the stratigraphic position, geological structure, metamorphic facies, and protoliths rock units. research methods employed mapping, petrology, geochemical analysis. samples collected exhibit different including zeolites, greenschist, epidote amphibolite. Protoliths consist metasedimentary rocks such as metapellites, metapsammitics, meta-calcilates, ortho-metamorphs metagabbro metabasalt. Retrograde metamorphism, indicated by epidote, chlorite, calcite amphibolite schists, suggests lower temperature stress conditions. Hydrothermal changes are evidenced some samples’ occurrence quartz veins. Geochemical analysis reveals that provenance originated from a volcanic arc, while metabasalt an island arc tectonic environment. K-Ar dating indicates age range 55.2 - 37.8 million years ago, corresponding Early Late Eocene. These believed have formed through regional metamorphism due subduction formation accretionary prisms. signifies uplift or accretion processes after activity