Accomplishment Based Renewal: Comparing the Thermal Histories of Fast- and Slow-spreading Oceanic Crust

在这笔资金的资助下，PI将对在海洋扩张中心下形成的火成岩下地壳样本进行岩石学研究，以约束作为深度和扩张速度函数的较低地壳冷却速率。拟议的研究将使用PI在阿曼工作的样本和数据，并补充北大西洋中脊（MAR, ODP Leg 209），西南印度脊（SWIR, ODP Leg 118, 176和179）和东太平洋隆起（EPR, Hess Deep, ODP Leg 147）的北14至16度的辉长岩和橄榄岩。PI将采用一系列“地质测速”技术来确定火成岩和变质平衡的闭合温度和压力，出溶层的宽度和组成，矿物颗粒和露头中的主要和微量元素扩散曲线，以及晶体尺寸分布。利用这些数据，他将估算相对和绝对冷却速率。

Under this funding, the PI will carry out a petrological study of samples from igneous lower crust formed beneath oceanic spreading centers, in order to constrain lower crustal cooling rates as a function of depth and spreading rate. The proposed study will use samples and data from the PI's Oman work, supplemented by gabbro and peridotite from 14 to 16 degrees North on the Mid-Atlantic Ridge (MAR, ODP Leg 209), the SW Indian Ridge (SWIR, ODP Legs 118, 176 and179), and the East Pacific Rise (EPR, Hess Deep, ODP Leg 147). The PI will employ an array of "geospeedometry" techniques to determine closure temperatures and pressures for igneous and metamorphic equilibria, widths and compositions of exsolution lamellae, major and trace element diffusion profiles within mineral grains and outcrops, and crystal size distributions. Using these data, he will estimate relative and absolute cooling rates.