Magnetic and Structural Study of Sub-Volcanic Oceanic Lithosphere Exposed in Kane Megamullion, Mid-Atlantic Ridge, 23deg30min N

Tivey 0118445的摘要拟议的项目将研究凯恩巨砾，这被解释为一个长期存在的正常剥离断层的下盘附近的凯恩断裂带在大西洋中脊。断层似乎暴露了一个深地壳和可能的上地幔，岩石圈的一部分，使其能够进行调查，取样和最终钻探。 拟议的实地项目将使用自主水下航行器（ABE）、MK-Jason和疏浚，以及实验室分析来解决以下问题：1）如何在地壳中部和更深层次记录地球磁场的磁化和极性反转历史？2)在裂谷轴的岩浆活动的条件是什么参与形成的巨糜棱岩，以及在中地壳和更深层次的结果是什么组成和侵入关系？洋壳主正断层剪切带的应变协调和应变局部化演化的本质是什么？ 这是一个独特的可进入部分，在这里进行调查和取样将使人们对缓慢扩张地壳的增生和分解过程有新的重要认识。 调查数据将提供数据，以扩大和限制解释从钻到巨型，到三维。

Abstract of Tivey 0118445The proposed project will study the Kane megamullion, which is interpreted to be the exhumed footwall of a long-lived normal detachment fault near the Kane Fracture Zone on the Mid-Atlantic Ridge. The faulting appears to have exposed a deep-crustal and possibly upper mantle, section of lithosphere, making it accessible to survey, sampling and eventual drilling. The proposed field program will use the autonomous underwater vehicle (ABE), ROV Jason and dredging, together with laboratory analyses to address the questions of 1) how are magnetization and polarity -reversal history of Earth's magnetic field recorded at mid-crustal and deeper levels?, 2) what conditions of magmatism at the rift axis attend formation of megamullions,and what are the resulting composition and intrusive relations at mid-crustal and deeper levels? and 3) what are the nature of strain accomodation and evolution of strain localization in the shear zone of a major normal fault in ocean crust? This is a uniquely accessible section where survey and sampling will allow significant new insights into the processes of accretion and dissection of slow-spreading crust. The survey data will provide data to extend and constrain interpretations from drilling into megamullions, into three dimensions.