Miocene catastrophic at Rumbia Complex based on 40Ar/39Ar radiometric age dating: Implications to geological history and Metallogeny in the Southeast Sulawesi, Indonesia
Musri MAWALEDA(a*), Marnie FORSTER(b), Emmy SUPARKA(c), Chalid Idham ABDULLAH(c), and Jamal Rauf HUSAIN(a)

(a) Department of Geology Engineering, Hasanuddin University; Kampus II Jl. Poros Malino Km.6 Borongloe, Gowa, Indonesia.
(b) Research School of Earth Sciences, The Australian National University, Canberra 0200, Australia
(c) Institute of Technology Bandung; Jl. Ganeca No. 10 Bandung, Indonesia

Abstract

The Rumbia Complex is located in the Southern part of the Southeast Arm of Sulawesi is one of the regional Metamorphic Complexes in the Sulawesi Island. Based on the results of 40Ar/39Ar radiometric age dating of three metamorphic rock units from this area, it is shows the age spectrum reflecting that there have been three major geologic events at the Rumbia Complex during the Miocene. This great geological event is interpreted as a result of amalgamation between the microplates of Rumbia, Mekongga, and Meluhu, forming the Southeast Arm of Sulawesi, as we known today. It appears that this great popular geological event referred to as this catastrophic, is responsible for the abundance of Nickel Laterite ore deposits, and other sulfide ore minerals in the Southeast Arm of Sulawesi.

Keywords: Dating, 40Ar/39Ar, catastrophic, Miocene, Southeast, Arm, Sulawesi, Indonesia

Topic: Disaster analysis