STRUCTURE OF THE SUNDA TRENCH LOWER SLOPE OFF SUMATRA FROM MULTICHANNEL SEISMIC REFLECTION DATA

摘要: Multichannel seismic reflection profiles across the Sunda Trench slope off central Sumatra reveal details of subduction zone structure. Normal faults formed on outer ridge trench offset deep strate and oceanic crust, but die out upsection under sediments. At base inner slope, shallow reflectors are tilted seaward, while deeper dip landward parallel to underlying crustal reflector. Intermediate depth can be traced through a seaward-dipping monocline. We interpret this fold as expression landward-dipping thrust fault at depth. Landward flexure, relatively undeformed strata have been stripped plate, uplifted 700 meters, accreted slope. The crust is not involved in deformation toe it observed dipping about 25 km accretionary prism.