S.J. Gallagher , C.S. Fulthorpe , K. Bogus , G. Auer , S. Baranwal , I.S. Castañeda , B.A. Christensen , D. De Vleeschouwer , D.R. Franco , J. Groeneveld , M. Gurnis , C. Haller , Y. He , J. Henderiks , T. Himmler , T. Ishiwa , H. Iwatani , R.S. Jatiningrum , M.A. Kominz , C.A. Korpanty , E.Y. Lee , E. Levin , B.L. Mamo , H.V. McGregor , C.M. McHugh , B.F. Petrick , D.C. Potts , A. Rastegar Lari , W. Renema , L. Reuning , H. Takayanagi , W. Zhang
26 February 2017
International Ocean Discovery Program (IODP) Site U1462 is 50 km north of the Montobello Islands in the Northern Carnarvon Basin, ~150 m from the Fisher-1 industry well. Site U1462 is on the outer edge (87 m water depth) of a middle ramp. The seabed in the region is carbonate-rich (>90%) gravel and sand with minor mud. Coring at Site U1462 targeted a sequence of shelfal to shelf-edge carbonates that overlie a Miocene sand unit (the Bare Formation). The primary aim of coring Site U1462 was to obtain a record of the secular variation in Indonesian Throughflow (ITF) connectivity over the last 5 My. Previous analyses of foraminifers in 28 sidewall cores from the adjacent Fisher-1 Well revealed carbonates that contain horizons of biogeographically significant Indo-Pacific foraminifers, suggesting intermittent ITF connectivity. Further analyses are likely to reveal a more complete record of ITF connectivity than previously recognized. Another objective of Site U1462 was to date strata adjacent to several drowned reefs to determine the age and environmental conditions for their onset. Facies and fossil paleoenvironmental analyses of the succession recovered will shed light on when, how, and why these reefs first developed and why they drowned. An additional aim was to obtain an interglacial Pliocene–Pleistocene record of the Australian monsoon. Site U1462 was closer to the shoreline during this time than Site U1461 and could therefore yield significantly more terrigenous material. Shore-based analyses of the fossil pollen, clays, and other terrestrial sediments at this site will reveal a proximal Pliocene–Pleistocene history of the Australian monsoon. Finally, a variety of deepwater and shallow-water carbonate facies were anticipated. Postexpedition analyses of these strata will allow detailed estimates of Pliocene–Pleistocene paleobathymetry and subsidence.