Collaborative Research: Electromagnetic Studies of the Continents (EMSOC): Trans-Hudson Orogen and Southeast Applachians

电导率取决于离子流体、金属或碳含量和温度，为地震或势场数据确定的特性提供了补充信息。我们成像电导率结构的能力最近经历了一场革命。这是一个涉及跨哈德逊造山带（THO）和阿巴拉契亚山脉东南部（SEA）的高分辨率大地电磁（MT）剖面的项目。这两个实验的共同之处是阐明了大陆碰撞化石带的作用过程。THO实验将与横跨威利斯顿盆地的850通道COCORP地震反射线重合，并将与THO的Lithoprobe样带密切协调。THO项目将重点关注北美已知最大的电导率异常和该地区的上地幔结构。SEA实验将利用海洋边缘可以放大MT对某些结构的响应这一事实。它有望解决关于阿勒加尼亚缝合线位置的争议，绘制与这次碰撞事件相关的冲断作用下的沉积包，为了解大陆地壳深处的逆变质条件的保存提供重要的见解，并估计非常古老的海洋岩石圈中的挥发性含量（以及下面部分熔融的存在）。

Electrical conductivity, which depends on ionic fluids, metal or carbon content and temperature, provides complementary information to properties determined from seismic or potential field data. Our ability to image conductivity structure has recently undergone a revolution. This is a project involving high resolution magnetotelluric (MT) profiling in the Trans-Hudson Orogen (THO) and the southeast Appalachians (SEA). The common element in the two experiments is illumination of processes in fossil zones of continental collision. The THO experiment will coincide with an 850 channel COCORP seismic reflection line across the Williston Basin and will be closely coordinated with the Lithoprobe transect of the THO. The THO project will focus on the largest known conductivity anomaly in N. America and on the upper mantle structure of the area. The SEA experiment will take advantage of the fact that the ocean edge can amplify MT response to certain structures. It is expected to settle the controversy about the location of the Alleghanian suture, map the sedimentary package under the thrust associated with this collision event, provide important insight into the preservation of retrograde metamorphic conditions in deep continental crust and estimate the volatile content in (and the presence of partial melt beneath) very old oceanic lithosphere.