Cenozoic Deep Water History on Ceara Rise: An Integrated Geophysical and Sedimentological Survey

在过去的几年里，海洋钻探方案采用了一种采样策略，即在无地震的海脊上钻取测深断面，以重建新生代碳酸盐产生和溶解的历史，以及深水化学和循环。这一战略是从研究第四纪晚期海洋学历史的类似浅层取心计划演变而来的。碳酸盐在深部断面最浅部位的聚集接近于上覆水域的碳酸盐生产力。如果两个地点靠得很近，只有深度不同，则堆积速率将记录到碳酸盐溶解，这将受到底水化学变化的控制。本项目的目标是从赤道大西洋西部的塞拉隆起获取地震数据和岩心样本。塞拉隆起被厚厚的新生代沉积物覆盖，应该是进行深度横断面研究的理想地点。此外，将获得的数据将成为为该地区提出的详细的ODP型钻探计划的基础。

During the last few years, the Ocean Drilling Program has employed a sampling strategy in which bathymetric transects are drilled on aseismic ridges in order to reconstruct the Cenozoic history of carbonate production and dissolution, and deep water chemistry and circulation. This strategy has evolved from similar shallow coring programs examining late Quaternary oceanographic history. Carbonate accumulation in the shallowest sites of the depth transect approximates carbonate productivity in the overlying waters. If the sites are close together and only vary in depth, the accumulation rates will record carbonate dissolution which will be controlled by changes in bottom water chemistry. The objective of the present project is to acquire seismic data and core samples from the Ceara Rise in the western equatorial Atlantic. The Ceara Rise is capped by a thick section of Cenozoic sediments and should be an ideal site for a depth transect study. Additionally, the data to be acquired will form the basis for a detailed ODP drilling program which has been proposed for this area.