REU: SeaMARC II Investigations of the Mid-Atlantic Ridge Between 24'N and 29'N and the Australian-Antarctic Discordance

REU：SeaMARC II 对北纬 24 英尺至 29 英尺之间的大西洋中脊以及澳大利亚-南极不一致的调查

• 批准号: 8722980
• 负责人: Jean-Christophe Sempere
• 金额: $ 23.21万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-12-01 至 1990-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8722980&HistoricalAwards=false
• 关键词: REU; SeaMARC; II; Investigations; Mid

This is a proposal for two field programs to study the tectonics of two regions of the mid-ocean ridge system. The principal tool is SeaMARC II, and these data will be complemented by gravity and magnetics data. The first region of study is the Mid-Atlantic Ridge from 24 to 29 degrees North latitude. Continuous coverage of the axial discontinuities and the morphotectonic variations along the rift valley over a distance of at least 100 km will be obtained. The main objective is to understand the variations in volcanic and tectonic activity along a slow spreading center, the nature of small axial discontinuities that offset the MAR, and the mantle processes that lead to segmentation of the MAR. The second project focuses on the Australian-Antarctic Discordance (AAD). This is a unique and poorly understood region of the mid-ocean ridge system, characterized by rugged topography and a wide range of axial morphologies. The geophysical data will be complemented by a dredging program. The objectives are (1) to map the region and determine the tectonic structure and the temporal evolution of the region, (2) to determine the nature of geochemical discontinuities in the region, and the nature of the marked boundaries of the AAD, and (3) to determine the interrelationships among geochemistry, tectonic structure, gravity, and magnetics within and outside of the AAD in an effort to understand its nature, origin and evolution. These projects use an important, relatively new tool for exploring the structure of the sea floor along mid-ocean ridges. The data obtained from these studies should provide important information about the mid- ocean ridge system and its tectonic and volcanic evolution.

这是两个实地项目的建议， 大洋中脊系统两个区域的构造。 的 主要工具是SeaMARC II，这些数据将得到补充 重力和磁力数据。 研究的第一个领域是 北纬24至29度的大西洋中脊。 连续覆盖轴向不连续和 沿着裂谷的地貌构造变化 将达到100公里。主要目标是 了解沿着火山和构造活动的变化 一个缓慢蔓延的中心，小轴向的性质 抵消MAR的不连续性，以及地幔过程 导致MAR的分割。第二个项目的重点是 澳大利亚-南极不一致（AAD） 这是一个独特 对大洋中脊系统了解甚少的区域， 其特点是地形崎岖， 形态学 地球物理数据将由 疏浚方案 目标是：（1）绘制区域地图， 确定了构造结构和时间演化 （2）确定地球化学性质 在该地区的不连续性，以及显着的性质 （3）确定AAD的边界; 地球化学、构造构造 重力和磁力在AAD内外， 来了解它的本质，起源和进化这些项目 使用一个重要的，相对较新的工具来探索结构 沿着沿着大洋中脊的海底。 获得的数据 这些研究应该提供关于中期的重要信息， 洋脊系统及其构造和火山演化