Investigation of Lower Crustal and Uppermost Mantle Structure beneath the Illinois Basin Based on Reprocessing of High-Quality Industry Seismic Reflection Profiles

基于高质量工业地震反射剖面再处理的伊利诺斯盆地下地壳和上地幔结构研究将重新处理，以便将目前处理的记录从4秒（~12公里深度）延长到20秒（~68公里深度），以便提供有关美国中部大陆研究较少地区下地壳和上地幔的结构和起源的信息。记录的初步测试处理证实，亚莫霍岩石圈具有高反射性（包括交叉线之间的相关性），这在美国的深地震反射记录中是不寻常的，因此保证了提供下地壳和上地幔结构新图像的高概率。最终目标是为解释像伊利诺斯盆地这样的克拉通内盆地的起源提供地球物理约束。经过验证的可控震源扩展再相关技术将与最先进的数据处理技术结合使用，包括广泛测试各种滤波程序，以抑制噪声、叠前深度和常规时间偏移，以及使用Landmark Graphics工作站处理模块对下地壳和地幔反射体进行2.5维可视化和映射。事实上，在美国进行的数千公里深地震反射调查中，明确的地幔反射率实际上是未知的，这意味着目前的研究将大大增加我们对北美地下地幔反射率的了解。该项目将为一名地质学硕士研究生提供独特的研究经验，利用最先进的技术处理和解释高质量的深地震反射数据。此外，一名地球科学与空间教育专业的本科生将与该名研究生合作并协助该名研究生制定一套用于中学（K-12）应用的深部地震学课堂和海报/计算机演示。

Investigation of Lower Crustal and Uppermost Mantle Structure beneaththe Illinois Basin Based on Reprocessing of High-Quality IndustrySeismic Reflection ProfilesEAR-0307539John McBrideABSTRACTHigh-quality vibroseis-source seismic reflection profiles from the Illinois Basin, will be reprocessed in order to extend the presently processed record from 4 seconds (~12 km depth) to 20 seconds (~68 km depth) in order to provide information on the structure and origin of the lower crust and uppermost mantle beneath a poorly studied area of the Midcontinent USA. Preliminary test processing of the records confirms that the sub-Moho lithosphere is highly reflective (including correlations between cross lines), which is unusual for deep seismic reflection records from the USA, and thus assures a high probability of providing new images of lower crust and uppermost mantle structure. An ultimate objective will be to furnish geophysical constraints on interpreting the origin of an intra-cratonic basin, like the Illinois Basin. The proven technique of vibroseis extended re-correlation will be used in conjunction with state-of-the-art data processing, including extensive testing of various filtering routines for noise suppression, pre-stack depth and conventional time migration, and 2.5-D visualization and mapping of lower crust and mantle reflectors using Landmark Graphics work-station based processing modules. The fact that unambiguous mantle reflectivity has been virtually unknown from the many thousands of kilometers of deep seismic reflections surveys conducted in the USA means that the present study will add considerably to our knowledge of mantle reflectivity beneath North America. This project will provide one M. S. Geology graduate student with a unique research experience in processing and interpreting high-quality deep seismic reflection data using state-of-the-art technology. In addition, one Earth Science and Space Education undergraduate major will work with and assist the graduate student in formulating a classroom and poster/computer demonstration of deep seismology for secondary (K-12) application.