S.C. Clemens , W. Kuhnt , L.J. LeVay , P. Anand , T. Ando , M. Bartol , C.T. Bolton , X. Ding , K. Gariboldi , L. Giosan , E.C. Hathorne , Y. Huang , P. Jaiswal , S. Kim , J.B. Kirkpatrick , K. Littler , G. Marino , P. Martinez , D. Naik , A. Peketi , S.C. Phillips , M.M. Robinson , O.E. Romero , N. Sagar , K.B. Taladay , S.N. Taylor , K. Thirumalai , G. Uramoto , Y. Usui , J. Wang , M. Yamamoto , L. Zhou
29 July 2016
The Andaman Sea is situated between the Andaman Islands and the Malay Peninsula. The Andaman-Sumatra island arc system results from the oblique subduction of the Indo-Australian plate beneath the Eurasian plate. Stretching and rifting of the overriding plate during the early Miocene (~25 Ma) resulted in two distinct plates separated by an active spreading center located in the deepest portion of the Andaman Sea. An accretionary wedge complex scraped off the subducting slab lies west of the spreading center, forming a series of shallower basins associated with back-thrust faulting within the accreted sediments. The Andaman Sea drilling sites are within the Nicobar-Andaman Basin, bounded on either side by the Diligent and Eastern margin faults. Site U1447 is located at 1391 mbsl, ~45 km offshore Little Andaman Island within a basin on the eastern flank of a rise separating north-south–oriented basins associated with the Eastern Margin and Diligent fault zones. The objective at this site is to recover Miocene to Holocene sediments from multiple holes in order to reconstruct changes in surface water salinity and runoff associated with summer monsoon rainfall at tectonic to suborbital timescales. Sites U1448 and U1447 will constitute the middle (10°N) portion of a meridional salinity transect that includes sites on the northeast Indian margin (19°N) and is anchored by IODP Site U1443 at 5°N.