Bulletin of the Geological Society of Malaysia, Volume 37, July 1995, pp. 101 – 116
Research School of Geological and Geophysical Sciences, Birkbeck College and University College London, Gower Street, London, WC1E 6BT
Abstract: The structural geology of Nias is described in this paper via a transect across the strike of the island. Three sub-basins and a basement high are identified and the structure at depth is explored. The results show that the Nias area was subject to Oligocene and Early Miocene extension with the development of half grabens dropping down to the south-west.
The basinal successions were subject to two distinct phases of uplift and deformation; western areas were inverted during the Early Miocene whilst the whole of the island was subject to Pliocene tectonism. The structural interpretation for the geology of Nias is supported by the stratigraphic record. The evidence presented in this paper suggests that the geology of the island is best explained by forearc extension and subsequent inversion rather than by the primary accretionary model.