Volcanic rocks petrology and geochemistry at Kolaka Region: Implications to the tectonic history of the Southeast Arm of Sulawesi, Indonesia
Musri Mawaleda(a*), Adi Maulana(a), Asri Jaya(a), Sun-Lin Chung(b,c), Hao-Yang Lee(b,c), Xiaoran Zhang(b,c), Marnie Forster(d), Johannes Hutabarat(e)

(a) Department of Geology Engineering, Faculty of Engineering, Hasanuddin University; Kampus II,
Jl. Poros Malino Km.6-Borongloe, Gowa, Indonesia.
(b) National Taiwan University; Department of Geosciences, National Taiwan University, P.O. Box13-318, Taipei 10617, Taiwan
(c) Institute of Earth Sciences, Academia Sinica; 128, Sec. 2, Academia Road, Nangang, Taipei 11529, Taiwan.
(d) Research School of Earth Sciences, ANU College of Physical and Mathematical Sciences, The Australian National University, Canberra ACT 0200, Australia.
(e) Geology Engineering Faculty, Padjadjaran University, Jatinangor, West Java. Indonesia

Abstract

The presence of Late Miocene trachyte-dacite volcanic rocks in the Kolaka District, Southeast Arm of Sulawesi, provides a new understanding of the geological and tectonic history of the region. These volcanic rocks intruded metamorphic rocks and produce hydrothermal alteration and mineralization. Hydrothermal mineralization includes Antimony, Arsenopyrite, Chalcopyrite, Pyrite, Galena and gold with the host of Mica Schist and Chlorite Schist metamorphic rocks. The results of geochemical analysis of trachyte-dacite show the affinity "High-K Calc-Alkaline Series". Whereas based on the Zr/Y - Zr discriminant diagram showing the geological environment of its formation on "E-MORB + Within Plate.

Keywords: Volcanic, Miocene, tectonic, gold, mineralization, Southeast, Sulawesi, Indonesia

Topic: Disaster analysis