Collaborative Research: High Resolution Teleseismic Crust-Mantle Studies Across a Major Archean-Proterozoic Suture in Western United States

正在进行的“Deep Probe”远震样带研究跨越了怀俄明州和科罗拉多州的太古宙-元古代主要缝合线，提出了对Lodore宽带数据的分析可以解决的问题。该阵列提供的非常密集的远震采样——从分布在5-10公里站间距的二维网格中的33个站点进行一年的记录——将允许对地壳和地幔结构进行详细成像。我们建议使用三维Kirchoff偏移来：1)深度偏移在100 km以上观测到的Pms和Ppms Moho到达和其他潜在不连续面；2)由于地形和沉积盆地的影响，对p波尾波进行偏移，寻找相干的近地表散射；3)成像410 km和660 km不连续面振幅/锐度/散射特征。将这一建议的研究与我们的深探测结果相结合，将使我们能够更好地定义当前是什么过程在改造这个环克拉通区域，以及太古宙和元古代岩石圈是否对改造事件有不同的反应。

Ongoing studies of the "Deep Probe" teleseismic transects, which cross a major Archean-Proterozoic suture in Wyoming and Colorado, pose questions that analysis of the co-located Lodore broadband data can address. The very dense teleseismic sampling provided by this array - one year of recording from 33 stations distributed in a 2-D grid at 5-10 km station spacing - will allow detailed imaging of crustal and mantle structure. We propose to use 3-dimensional Kirchoff migration to: 1) depth migrate Pms and Ppms Moho arrivals and other potential discontinuities observed in the upper 100 km; 2) migrate the P-wave coda to search for coherent near-surface scattering due to topography and sedimentary basins; 3) image the amplitude/sharpeness/scattering characteristics of the 410 and 660 km discontinuities. Integration of this proposed research with our Deep Probe results will allow us to better define what processes are currently reworking this circum-cratonic region, and if the Archean and Proterozoic lithosphere is responding differently to the reworking event.