Collaborative Research: Colorado Rockies Experiment and Seismic Transects (CREST): Time-space Patterns of Cenozoic Uplift-magmatism and their Correspondence to the Aspen Anomaly

[607808 . karlstrom]这个项目是之前一系列由CD资助的落基山重点项目的后续，这些项目建立在发现科罗拉多州中部地幔下的低速异常上。拟议的项目涉及各种各样的技术，以解决所谓的“阿斯彭异常”的原因，它的历史，以及它对地壳演化的影响。pi感兴趣的是地幔变化引起地表形貌改变之间的联系。他们观察到阿斯彭异常位于落基山脉的最高部分之下。他们将低地幔地震速度与低地幔密度等同起来，以引起隆升。他们将研究这一地区下面地幔的巨大速度变化是否：a)在岩石圈或软流圈中，b)反映了新生代构造活动重新激活的元古代岩石圈缝线，c)由羽流引起，d)由熔体的存在引起。这些都是与大陆动力有关的重要问题。具体来说，pi将使用：被动地震学，通过断层扫描、接收函数、表面波和各向异性来更好地定义异常；-地质研究（岩浆史、低温热年代学、构造地貌学），确定新生代构造和岩浆史，确定长期和当前历史；-地形隆起和地幔过程的地球动力学模型，研究它们之间的联系。

0607808KarlstromThis project is a follow up to a series of previous CD funded Rocky Mountain focused projects building on the discovery of a low velocity anomaly in the mantle beneath central Colorado. The proposed project involves a wide variety of techniques assembled to address the cause of the so called "Aspen anomaly", its history, and its effect on crustal evolution. The PIs are interested in the connection between changes in the mantle causing modification of surface topography. They have observed that the Aspen anomaly is located beneath the highest portion of the Rocky Mountains. They equate low mantle seismic velocities with low mantle densities to cause uplift. They will investigate whether the very large velocity variations in the mantle beneath this area are: a) in the lithosphere or asthenosphere, b) reflect Proterozoic lithospheric sutures reactivated by Cenozoic tectonism, c) are caused by a plume, and d) are caused by the presence of melt. These are all important and relevant questions for Continental Dynamics. Specifically, the PIs will use: - passive seismology to better define the anomaly using tomography, receiver functions, surface waves, and anisotrophy;- geological studies (magmatic history, low temperature thermochronology, tectonic geomorphology) to identify Cenozoic tectonic and magmatic history to define long term and current history;- geodynamical models of topography uplift and mantle processes to study their connection.