COLLABORATIVE RESEARCH: Strain Distribution within the Lewis Thrust Sheet and Northern Sawtooth Thrust Belt: Compatibility with Critical Wedge Model

9405557 Mitra这个合作项目将通过对蒙大拿州西北部刘易斯逆冲板块岩石的综合野外和实验室研究，测试普遍接受的用于褶皱和逆冲带发展的关键楔形理论。根据该理论，逆冲带内的应变应随沉积棱柱的几何形状而变化。该地区的地层是众所周知的，这也是对该模型的一种检验。将确定变形前元古代、古生界和下中生界沉积盆地的几何形状，并将应变的大小和分布与模型预测的结果进行比较。无论现有理论是否成立，其结果对其他褶皱冲断带，以及类似构造背景下油气储量的预测和开采都将具有深远的意义。

9405557 Mitra This collaborative project will test the generally accepted critical wedge theory for the development of fold and thrust belts, by an integrated field and laboratory study of rocks in the Lewis thrust sheet in northwest Montana. According to the theory, strain should vary within the thrust belt as a function of the geometry of the sedimentary prism. The stratigraphy of the area is well known and lends itself to a test of the model. The geometry of the pre- deformational Proterozoic, Paleozoic and lower Mesozoic sedimentary basins will be determined and the amount and distribution of strain will be compared with that predicted by the model. Whether the existing theory is upheld or not, the results will have far- reaching significance for other fold and thrust belts, and for the prediction and recovery of oil and natural gas reserves in similar tectonic settings.