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

安第斯造山带是由构造和岩浆作用形成的山脉的典型例子，主要是由于大洋岩石圈俯冲到大陆边缘之下而形成的。然而，对山脉和大陆边缘深部结构的了解仅基于20世纪60年代获得的有限地震折射剖面。南安第斯山脉的地表地质填图表明，该山带是大陆地壳因俯冲相关的构造作用而增厚和缩短、纳斯卡板块向南美洲下方俯冲以及与此俯冲有关的岩浆活动所产生的。本推荐奖将支持利用海洋多道地震反射技术研究安第斯山脉之下的地壳结构。将在横跨安第斯山脉的峡湾以及邻近的大陆架地区获取数据。这些数据将与其他关于山脉下方地壳结构的研究相比较，以检验其形成模型，并检验大陆地壳演化的假说。这是一个由大学科学家参与的合作项目。和拉蒙特-多尔蒂地质观测站。现场数据将在康拉德号航空母舰上获取。

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.