Bulletin of the Geological Society of Malaysia, Volume 42, Dec. 1998, pp. 257 – 268

Epithermal gold-copper mineralization associated with Late Neogene-magmatism and crustal extension in the Sunda-Banda Arc

R. SOERIA-ATMADJA¹, Y. SUNARYA², SUTANTO³ AND HENDARYONO³

¹Jurusan Teknik Geologi, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung 40132, Indonesia

²PT ANEKA TAMBANG, Jalan Letjen T.B. Simatupang/Lingkar Selatan, Tanjung Barat, Jakarta 12530, Indonesia

³Jurusan Teknik Geologi, Universitas Pembangunan Nasional (UPN), Condong Catur, Yogyakarta, Indonesia

Abstract: The majority of gold-copper mineralization along the Sunda-Banda arc belongs to low-sulfidation epithermal type. Studies by previous authors suggest that mineralization environment changes from low-sulfidation epithermal in the western segment of the arc, minor porphyry and high-sulfidation epithermal to submarine stratiform deposit in the eastern region. It seems that the nature of geologic setting and magmatic evolution exert a profound influence on the mineralization environment.

Most epithermal mineralization are hosted by stratovolcanoes and are associated with old caldera complexes controlled by strike-slip faults and graben subsidence. The present available K-Ar ages of mineralization suggest that the process is related to primarily Late Neogene volcanic eruption of fine silicic pyroclastics of calc-alkaline to potassic calc-alkaline affinity.

https://doi.org/10.7186/bgsm42199821