MORPHOLOGICAL AND SEISMIC CHARACTERISTICS OF THE KAOPING SUBMARINE-CANYON

SeaMARC II side-scan sonar images and swath bathymetry plus 6-channel seismic reflection profiles reveal details of major canyons in the sub marine portion of the Taiwan collision belt. The Kaoping Submarine Can yon is the largest of these, extending over 240 km from the mouth of t he Kaoping River across the accretionary wedge to the Manila Trench. M orphological features and structural settings vary along the course of the Kaoping Submarine Canyon, defining three sections. The first sect ion extends southwest from the mouth of the Kaoping River, cutting acr oss the shelf and upper slope roughly perpendicular to local bathymetr ic contours, to about 22-degrees-03'N, where the canyon turns sharply southeast. From this point, the second section of the canyon follows t he trace of a major thrust fault, paralleling local structure to 21-de grees-35'N, at which point the canyon turns southwest again. Over the third section the canyon meanders, cutting through low-relief fault-be nd anticlines and distributing orogenic sediments in intervening slope basins, to where it joins the Manila Trench. Seismic profiles reveal that this canyon, which forms a major sediment conduit between the Tai wan mountain belt and the Manila Trench, has a complicated evolutionar y history, and that its development has been controlled strongly by ac cretionary structural processes.