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

根据这一奖项，PIS将在西南印度洋海脊亚特兰蒂斯二世转型以东的亚特兰蒂斯浅滩海洋核心复合体调查缓慢扩张地壳的沉积、结构和热演化。它们将确定在非常缓慢的扩张海脊上地壳生长和吸积的时间和过程，并对大洋核心复合体和横向海脊的滑脱断层和隆起过程施加限制。他们将进行热时计和地球物理建模。热计时将包括：1.单一的锆石U/Pb测年，以确定整个亚特兰蒂斯浅滩地区发现的辉长岩和伴生的长英脉的侵位年龄，以及2.磷灰石、锆石和辉石的(U-Th)/He计时，以限制正常断裂导致的冷却/剥蚀的时间和速度。地球物理模拟将包括：1.处理2002年收集的新的磁力和重力数据，以限制更准确的板块扩张率、板块运动过去变化的时间，并得出地壳厚度图；2.开发区域和局部3-D热模型，以充分解释热计时数据。

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.