Evaluation of cored carbonates (COREF): a transect in the tropical to subtropical realm in the Ryukyu Islands (Japan)

ICDP COREF项目的目标是在琉球群岛从热带到亚热带的横断面上恢复不同环境下的第四纪生物礁复合体沉积。两个主要目标是：(1)追踪珊瑚礁形成和相关碳酸盐系统的南北界限，推测它们已分别迁移到较高和较低纬度，以响应第四纪冰川和间冰期旋回；(2)研究碳酸盐系统和珊瑚群落如何对以前的高海平面和相关的中更新世温暖时段作出反应。研究不同纬度范围的碳酸盐环境将提供有关这些环境对过去变暖事件的响应情况的信息，从而能够预测未来哪些变化可能是持续的全球变暖的结果。为了实现这些目标，已经选择了5个地点。从2013年11月开始，日本PIS开始了取心计划，到目前为止，已经在拟议的5个地点中的3个(2、4和5个)上钻了11个孔。目前，约有500米的岩芯未经处理储存在高知(日本)的储存库中。2016年7月，在波茨坦OSG办公室举行的COREF项目状况研讨会上，决定必须对岩心进行科学评估，然后才能决定如何继续进行进一步钻探。在波茨坦的讨论之后，日本的私人投资机构要求我们帮助处理岩芯。我们非常高兴这样做，因为这为我们提供了一个机会，以加强日本和国际私人投资机构之间的合作，并更好地协调国际社会今后的工作。因此，在这个短短一年的项目中，我们要求提供资金来准备和描述岩芯，整合ICDP DIS系统中的数据，开展岩性和沉积学研究，并测试三维可视化技术对项目目标的适用性。这项简短的研究还将为如何规划钻探的最后步骤提供见解。

Objective of the ICDP Project COREF is to recover Quaternary reef-complex deposits in different settings across a transect from the tropical to subtropical realm in the Ryukyu Islands. Two major objectives are to (1) track the northern and southern limits of coral reef formation and associated carbonate systems, supposed to have migrated to higher and lower latitudes, respectively, responding to Quaternary glacial and interglacial cycles; (2) to examine how carbonate systems and coral communities have responded to previous high stands of sea-level and associated warm intervals of the mid-Pleistocene. Examining different carbonate settings across a latitudinal spectrum will provide information on how these responded to warmer episodes in the past, enabling to predict which future changes which may occur as a consequence of the ongoing global warming. To achieve these goals, 5 Sites have been choosen.Starting in November 2013, the Japanese PIs have started the coring program and have so far cored 11 Holes on three of the proposed five Sites (2, 4 and 5). At present, approximately 500 meters of cores are stored unprocessed at the repositories in Kochi (Japan). During a COREF project status workshop at the OSG Office in Potsdam, in July 2016, it was decided that the cores must be assessed scientifically before making a decision on to how to proceed with further drilling. Following the discussions in Potsdam, the Japanese PIs have requested our help to process the cores. We are very happy to do so, as it provides us with an opportunity to strengthen the cooperation between Japanese and international PIs and to better coordinate future work within the international community. Therefore, with this short 1-year project, we request funds to prepare and describe the cores, integrating the data in the DIS system of ICDP, to carry out a lithological and sedimentological study and to test the applicability of 3D visualization to the goals of the project. This short study will also provide insights on how to plan the final steps of the drilling.