Mantle Control of a Dynamically Evolving Spreading Center: Temporal Aspects

OCE-9314483 在本项目中，P.I.S将对31- 35 S处缓慢-中等扩展MAR的两个部分进行综合现场（地球化学）和模拟研究。 私人侦探们希望利用尤因在大西洋这一地区的机会之窗。 他们将重点关注33 S附近的两个沿着轴地球化学异常：第一个是第4段的206 Pb/204 Pb尖峰，第二个是第3段的高Na 8.0/低Fe 8.0异常。 的PI的主张，在后一个领域，他们可以获得最好的约束的时间分量的变换故障效应（TFE）。 这两个异常的零年龄和离轴采样（到8 Ma老地壳）将使他们能够破译地幔地球化学非均质性和熔融过程的程度。 利用这些限制，研究人员最终希望发展出令人满意的上地幔非均匀性和对流模型。 迈克尔·哈南将担任联合酋长。 Michael将在塔尔萨对玻璃进行电子探针分析，并使用离子探针（WHOI）、DCP（拉蒙）或ICP-MS（康奈尔）对微量元素进行分析。 哈南将负责同位素工作。

OCE-9314483 In this project, the P.I.s will carry out a combined field (geochemical) and modelling study on two segments of the slow- intermediate spreading MAR at 31-35S. The P.I.s wish to capitalize on a possible window of opportunity of Ewing being in this part of the Atlantic around the proposed time. They will focus on two along axis geochemical anomalies near 33S: the first is a 206Pb/204Pb spike at segment 4, and the second is high Na8.0/low Fe8.0 anomaly at segment 3. The P.I.s contend that in the latter area they can obtain best constraints on the temporal component of a transform fault effect (TFE). Zero-age and off-axis sampling (to 8 Ma old crust) of these two anomalies will allow them to decipher the extent of mantle geochemical heterogeneities and melting processes. Using such constraints the P.I.s ultimately wish to develop satisfactory models of upper mantle heterogeneities and convection. Michael & Hanan will be co-chiefs. Michael will perform electron probe analysis of glasses at Tulsa and trace elements with Ion Probe (WHOI), DCP (Lamont) or ICP-MS (Cornell). Hanan will be responsible for isotopic work.