Ultramafic Rock and Their Nickel Deposit Occurences in Halmahera & West Papua Indonesia
Halmahera and West Papua of Eastern Indonesia hosted exposed ultramafic rocks on the surface. These rock are a part of ultramafic layer of ophiolite belt with origins ranging from typical mid oceanic ridge to a supra-subduction zone settings. The Halmahera ophiolite belt is interpreted to represent a section of the margins of the Philippine Sea Plate, whereas West Papua ultramafic belts as a part of complex zone that has recorded the convergent history between the large Australia plate and numerous small oceanic plate.
Nickel laterite deposit in this region as weathering profiles in the ultramafic rocks contribute to major Nickel resources in Indonesia, and constitute to major mining development in Halmahera and Papua. Due to poor infrastructure and under the protected forest or marine conservation, not all Nickel lateritic deposits can be explored and exploited to become major mining production. The major Nickel ore production are derived mostly from Halmahera, and then a lesser amount from Gebe and Obi. This is only a small part of all Nickel resources in this region.
