Basin and Range Geoscientific Experiment (BARGE)

该项目涉及一个综合的，多学科的 调查，以量化如何深大陆地壳和 最上层地幔响应伸展，从而建立如何 岩石圈大的水平应变与垂直应变有关， 由等压线控制的运动。 首席研究员计划 使用大应变梯度的“自然实验”， 岩石圈的最上部， 高度延伸的地形和构造稳定的 块 他们选择了科罗拉多高原的西部边缘 学习 它非常适合完成他们的研究 主要原因有：（1）转型期 （2）地质环境表明一个简单的前， （3）有一个很好的理解， 大尺度伸展运动史 提供了一个独特的环境，在其中执行深 地球物理研究，横切边界， 地质研究确定地壳隆起界限的位置 在扩展期间。 他们建议将地质和 地质年代学研究，“海洋”多道地震反射， 在湖泊中进行剖面分析，结合陆地记录 在三分量地震仪阵列上， 地震速度结构和开发层析成像图像的 这一地区，加上重力模型，将使他们能够 揭示岩石圈响应的运动学和动力学 严重的拉伸应变

This project involves an integrated, multi-disciplinary investigation to quantify how the deep continental crust and uppermost mantle respond to extension, and to thus establish how large horizontal strains of the lithosphere relate to vertical motions controlled by isostasy. The principal investigators plan to use the "natural experiment" of a large strain gradient in the uppermost part of the lithosphere associated with the abrupt boundary between highly extended terrain and a tectonically stable block. They have chosen the western margin of the Colorado Plateau to study. It is ideally suited for accomplishing their research objectives for several reasons: (1) the transition is particularly abrupt here; (2) the geologic setting indicates a simple pre- extensional crustal structure; (3) it has a well-understood large- scale extensional kinematic history; (4) the large inland waterway of Lake Mead provides a unique environment in which to perform deep geophysical studies that transect the boundary in precisely the location where geological studies place bounds on crustal uplift during extension. They propose to integrate geological and geochronologic studies, "marine" multi-channel seismic reflection profiling in the lake itself, integrated with land-based recordings on an array on three-component seismometers to provide control on seismic velocity structure and to develop tomographic images of the region which, together with gravity modeling will allow them to unravel the kinematics and dynamics of the lithosphere's response to severe extensional strain.