Site U1470: Expedition 359

Abstract

Site U1470 is part of the southern transect of the platform to drift succession cored during Expedition 359. The site is located 15.6 km south of Site U1469 at the western entrance of the Kardiva Channel, which connects the open Indian Ocean with the Inner Sea of the Maldives, in a water depth of 399.7 m. Inner Sea sediments are periplatform carbonate oozes consisting of a mixture of components derived from the nearby atolls and pelagic sources. The seafloor is relatively flat and covered by 400 m wide and 4 m high submarine mud waves. Site U1470 was chosen to recover the sedimentary succession deposited during the growth of the middle Miocene bank and to characterize the drift sedimentation at this location. Specific objectives were (1) to provide a detailed reconstruction of the predrowning, drowning, and postdrowning evolution of the carbonate bank by linking the seismic stratigraphic record to the sedimentary record (i.e., depositional facies); (2) to constrain the timing of this platform drowning and the burial by drift sediments; and (3) to reconstruct the neritic carbonate factory of a bank growing in the current-dominated depositional system.