The central Sumatra fore-arc basin is made up of two subbasins (Singkel and Pini basins) separated by a structural high. Our seismic sequence and facies analyses identify eleven sequences that define the Neogene subsidence history of the fore arc. A comparison of Neogene structure and seismic facies maps reveals that, during the Miocene and early Pliocene, the two subbasins subsided independently and the subsidence was controlled by local structure. In the late Pliocene, basin subsidence was largely controlled by regional tectonic factors. Initial subsidence of Singkel Basin resulted from the lateral translation of the structural block between the Batee and Singkel faults. Regional basin subsidence resulted from the deflection of the descending oceanic plate created when aterial was added to and/or redistributed in the accretionary wedge. The following structural influences on the fore-arc basin subsidence have been identified: (1) the location of the continental margin; (2) the presence of strike-slip faults traversing the fore arc; and (3) local and regional deformation within the accretionary wedge.

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