Multichannel Seismic Study of the Deep Structure of a Cordilleran Orogen: The Southernmost Andes

安第斯造山带是典型的山脉 由构造和岩浆作用形成， 从大洋岩石圈俯冲到大陆之下 裕度对山脉深层结构的了解， 然而，大陆边缘仅基于有限的地震 折射曲线是在20世纪60年代获得的。地表地质 安第斯山脉南部的地图显示 是通过浓缩和缩短 大陆地壳对俯冲相关构造作用的响应， 纳斯卡板块俯冲到南美洲之下， 由此产生的岩浆活动与这次俯冲有关。 目前建议的赔偿额将用于研究 利用海洋多通道研究安第斯山脉下的地壳结构 地震反射技术数据将在峡湾采集 穿越安第斯山脉，以及邻近的 大陆架地区。这些数据将与其他 研究山脉下的地壳结构， 模型的形成，并检查假设， 大陆地壳的演化这是一个合作项目 德克萨斯大学和拉蒙特-多尔蒂大学的科学家 地质观测站。现场数据将在 康拉德

The Andean orogen is the type example of a mountain range formed by tectonic and magmatic processes resulting primarily from the subduction of oceanic lithosphere beneath a continental margin. Knowledge of the deep structure of the mountain range and continental margin, however, is based on only limited seismic refraction profiles obtained in the 1960s. Surface geologic mapping in the southern Andes indicates that the mountain belt has been produced by both thickening and shortening of the continental crust in response to subduction related tectonism, underthrusting of the Nazca Plate beneath South America, and resulting magmatic activity related to this subduction. The present recommended award will support a study of the crustal structure beneath the Andes using marine multichannel seismic reflection techniques. Data will be acquired in fjords which traverse the Andean range, as well as in the adjacent continental shelf areas. These data will be compared to other studies of crustal structure beneath mountain ranges to test models for their formation and to examine hypotheses for the evolution of the continental crust. This is a cooperative project involving scientists at the Univ. of Texas and Lamont-Doherty Geological Observatory. Field data will be acquired aboard the R.V. Conrad.