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

在南非附近的南大西洋沃尔维斯山脊地区，海山和海底隆起的分叉轨迹的原因一直是海洋地质学和我们对非洲热点和板块构造演化的理解中的一个长期谜。该项目将出海，对沃尔维斯山脊以西部分海底的岩石进行疏浚和分析，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60万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含有的氩气将被用来确定火山足迹的年龄进程。岩石、主要元素和微量元素的地球化学和同位素将被用来观察分叉轨道上较年轻的岩石是否与较老的沃尔维斯岭有关。还将生成多波束测深测绘和海底磁力图，以检查这部分海底的结构趋势和板块构造运动。这项工作的更广泛影响包括与德国的一项补充性工作进行国际合作，该工作正在研究沃尔维斯岭的旧部分，对K-12教师、研究生和本科生进行培训，并支持在科学领域性别代表性不足的PI。

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.