La succession lithostratigraphique du bloc de Banda dans la region de Kolonodale (Sulawesi central, Indonesie)

Abstract

Abstract Sulawesi island is the convergence area of the Eurasian, the Pacific and the Australian plates. Villeneuve et al. demonstrated, from both lithostratigraphic and tectonic studies, that east and southeast Sulawesi was composed of two major continental blocks. - The "Banda block", including also Buru, Seram and Sinta Ridge, collided with the Asian volcanic arc of west Sulawesi during Oligocene times, then was dismembered during the Late Neogene Banda sea opening. - The Banggai-Sula block which was drifted from Irian Jaya and collided with the Banda block during Mid-Late Pliocene times. One of the fragments of the Banda block is in East Sulawesi, corresponding to the ophiolitic zone. There, in the Kolonodale area, it is possible to reconstruct the sedimentary succession under the ophiolite, despite intensive deformations. Over several years the stratigraphic framework of this area was detailed, following general mapping, and it is now possible, by including unpublished data concerning Cainozoic rocks, to reconstruct the Mesozoic-Cainozoic succession. Reconstructing the succession was possible by joint structural, stratigraphic and palaeoenvironmental studies. An example of structural cross-sections around the Kolonodale gulf is given on figure 4, from which local successions were built. We can now propose the general succession.