Collaborative Research: Plate Tectonic and Geochemical Evolution of the Young Walvis Ridge and Implications for African Plate Motion Modeling

合作研究：年轻沃尔维斯海岭的板块构造和地球化学演化及其对非洲板块运动模型的影响

• 批准号: 0961450
• 负责人: Cornelia Class
• 金额: $ 27.2万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0961450&HistoricalAwards=false
• 关键词: Collaborative; Research; Plate; Tectonic; Geochemical

The cause of the bifurcating tracks of seamounts and seafloor swells in the Walvis Ridge area in the South Atlantic just off South Africa has been a longstanding enigma in Marine Geology and in our understanding of hotspots and the plate tectonic evolution of Africa. This project will go to sea to dredge and analyze rocks from the part of the seafloor to the west of the Walvis Ridge and examine changes from hotspot to diffuse volcanism. The present location of the Walvis hotspot and the reason for its waning volcanic activity over the last 60 Myr will also be determined. Argon trapped in minerals in the collected seafloor volcanic rocks will be used to determine the age progression of the volcano tracks. Rock, major and trace element geochemistry and isotopes will be used to see if the younger rocks in the bifurcated tracks can be linked to the older Walvis Ridge. Multibeam bathymetric mapping and a map of seafloor magnetics will also be generated to examine structural trends and plate tectonic motions of this part of the ocean floor. Broader impacts of the work include international collaboration with a complementary German effort that is studying the older part of the Walvis Ridge, K-12 teacher and graduate and undergraduate student training, and support of a PI whose gender is under-represented in the sciences.

南非附近南大西洋沃尔维斯海岭地区海山和海底隆起分叉轨迹的原因，长期以来一直是海洋地质学以及我们对热点和非洲板块构造演化的理解中的一个谜。该项目将出海挖掘和分析沃尔维斯海岭以西部分海底的岩石，并研究从热点到扩散火山活动的变化。沃尔维斯热点的当前位置以及过去6000万年火山活动减弱的原因也将被确定。收集到的海底火山岩矿物中的氩将用于确定火山轨迹的年龄进程。岩石，主要和微量元素地球化学和同位素将被用来看看是否年轻的岩石在分叉的轨道可以连接到老沃尔维斯岭。还将制作多波束测深图和海底磁性图，以研究这一部分海底的结构趋势和板块构造运动。这项工作的更广泛的影响包括与德国的一项补充努力进行国际合作，该努力正在研究沃尔维斯岭的旧部分，K-12教师和研究生及本科生培训，以及支持在科学领域性别代表不足的PI。