Study of Ocean Floor Structure and Evolution by Drilling

通过钻探研究洋底结构及演化

基本信息

批准号：
06044051
负责人：
SUYEHIRO Kiyoshi
金额：
$ 20.86万
依托单位：
Ocean Research Institute, Univ.of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

The purpose of this research project is to investigate the history of Earth's environmental changes and geodynamics of the Earth interior through ocean drilling. This year, the following four main themes were investigated.1) Study of sea level changes and carbonate platform sequence stratigraphy based on the drilling in the Bahama bank. The study showed that progradation, agradation and hiatus formation were closely related to sea level changes and verified the use of sequence stratigraphy in this kind of setting.2) Investigation of the records and causes of rapid climatic and paleoceanographic changes recorded in the high-resolution core samples of the California margin and Sanich Inlet. The results showed that both rapid cooling and warming events were recorded in these cores suggesting that similar rapid events revealed by ice cores and hig latidude ocean such as Heinrich Event are in global scale nature.3) Study of hydrothermal system and ore deposits in the Juan de Fuca Ridge and its sedimented part based on a long-term borehole observatory (CORK). The area of hydrothermal fluid discharge and recharge was specified and the magnitude of circulation cell was determined. This result contributed significantly to the simulation of the hydrothermal system.4) Study of plate subduction, accretionary prism hydrogeology, tectonic erosion in the Barbados and Costa Rica margins. The CORK experiment and logging while drilling was found to be extremely useful for the study of fluid flow and physical properties of the subduction complex. The Costa Rica margin turned out to be a boundary which is dominated by large-scale subduction erosion, not by sediment underplating which was preferred interpretation before drilling.

该研究项目的目的是通过海洋钻探研究地球环境变化的历史和地球内部的地球动力学。今年主要研究了以下四个主题：1）基于巴哈马岸钻探的海平面变化和碳酸盐台地层序地层学研究。研究表明，进积、退化和间断的形成与海平面变化密切相关，验证了层序地层学在这种背景下的应用。2）高分辨率记录的气候和古海洋快速变化的记录和原因调查加利福尼亚州边缘和萨尼奇湾的岩心样本。结果表明，这些岩芯中同时记录了快速变冷和增温事件，表明冰芯和高纬度海洋揭示的类似快速事件（例如海因里希事件）具有全球尺度的性质。 3）胡安河热液系统和矿床研究德富卡海岭及其沉积部分基于长期钻孔观测站（CORK）。指定了热液排出和补给的面积并确定了循环单元的大小。这一成果对热液系统的模拟具有重要意义。4)巴巴多斯和哥斯达黎加边缘板块俯冲、增生棱柱水文地质、构造侵蚀研究。人们发现 CORK 实验和随钻测井对于研究俯冲复合体的流体流动和物理性质非常有用。哥斯达黎加边缘原来是一个以大规模俯冲侵蚀为主的边界，而不是钻探前首选解释的沉积物底侵作用。