Construction and evolution of slow spreading crust-Atlantis Bank, SWIR

根据该合同，pi将研究位于西南印度洋脊亚特兰蒂斯II转换以东的亚特兰蒂斯滩海洋核杂岩的缓慢扩张地壳的增生、结构和热演化。它们将确定非常缓慢扩张脊的地壳生长和增生的时间和过程，并对海洋核杂岩的拆离断裂和隆升过程以及横向脊进行约束。他们将进行热时测量和地球物理建模。温度测量将包括：1。2.单锆石U/Pb定年，确定整个亚特兰提斯滩地区辉长岩及伴生长英质脉的侵位年龄；对磷灰石、锆石和榍石进行(U-Th)/He计时，以限制正常断裂导致的冷却/剥蚀的时间和速率。地球物理模拟将包括：1。处理2002年收集的新磁重数据，以约束更精确的板块扩张速率、板块运动过去变化的时间，并推导出地壳厚度图；开发区域和局部三维热模式，以便充分解释热时数据。

Under this award the PIs will investigate the accretionary, structural, and thermal evolution of slow-spreading crust, at the Atlantis Bank oceanic core complex, east of the Atlantis II transform on the Southwest Indian Ridge. They will determine the timing and processes of crustal growth and accretion at very slow spreading ridges, and place constraints on the processes of detachment faulting and uplift of oceanic core complexes, and transverse ridges. They will undertake thermochronometry and geophysical modeling. The thermochronometry will include: 1.Single zircon U/Pb dating to define the emplacement age of gabbro and associated felsic veins found throughout the Atlantis Bank region, and 2. (U-Th)/He chronometry on apatite, zircon and sphene to constrain the timing and rate of cooling/denudation resulting from normal faulting. The geophysical modeling will consist of: 1. Processing new magnetic and gravity data collected in 2002 in order to constrain more accurate plate spreading rates, the timing of past changes in plate motion, and the derivation of a crustal thickness map, and 2. development of both a regional and local 3-D thermal model in order to fully interpret the thermochronometric data.