Annotated record of the detailed examination of Mn deposits from DSDP Leg 61 (Holes 462 and 462A)

The goal of Site 462 was to study the paleontologic, sedimentary, petrologic, tectonic, and magnetic histories of that area through Recent to Late Jurassic time by drilling a deep re-entry site into the Nauru Basin west of the Ralik Chain of the Marshall Islands. This area formed at a fast-spreading Pacific Plate boundary 145 to 155 m.y. ago, in the Late Jurassic. Cores from this area allow to better understand the biostratigraphic evolution and sedimentary processes in a Mesozoic open-ocean environment, the petrologic nature of fast-spreading oceanic crust, the tectonic history of the Late Jurassic Pacific Plate, and the nature of the Jurassic magnetic quiet zone.

462号钻探站位的研究目标为：通过在马绍尔群岛拉利克群岛链西侧的瑙鲁海盆布设深重返钻井点位，研究该区域自全新世至晚侏罗世的古生物学、沉积学、岩石学、构造学及磁学演化历史。该区域于1.45亿至1.55亿年前的晚侏罗世，在太平洋板块快速扩张边界处形成。本站位获取的岩芯可助力学界更深入地理解中生代远洋环境中的生物地层演化与沉积过程、快速扩张洋壳的岩石学属性、晚侏罗世太平洋板块的构造历史，以及侏罗纪磁静带的本质特征。