Testing Models of Polyphase Tectonism in Northern New Mexico and Characterizing the ~1.4 Ga Tectonic Setting of the Southwest U.S

9909457美国西南部的霍利斯特前寒武纪构造事件涉及岛弧和大陆碎片的增生，伴随着区域变质作用和广泛的岩体侵位。然而，其中一些事件的构造背景并未得到很好的了解，而且由于两期区域高级变质作用影响这些岩石的可能性而变得复杂。这项研究将调查新墨西哥州北部的一个地区，该地区有强烈的1.4Ga区域变质作用，但没有暴露的1.4Ga钚，可能会带来局部的热和应变扰动。这项研究将尝试应用一种新的年龄测定技术，将1.4Ga变质作用与残余1.65Ga变质作用分开，并将结果与构造和变质研究相结合，以更好地了解区域1.4Ga构造背景。

9909457HollisterPrecambrian tectonic events in the southwest United States involved accretion of island arcs and continental fragments accompanied by regional metamorphism and extensive pluton emplacement. However, the tectonic setting of several of these events is not well understood, and is complicated by the possibility of two periods of regional high grade metamorphism affecting these rocks. This research will investigate an area in northern New Mexico having a strong 1.4 Ga regional metamorphism but no exposed 1.4 Ga plutons that might impart a local thermal and strain perturbation. The research will attempt to apply a new age-dating technique to separate the 1.4 Ga metamorphism from residual 1.65 Ga metamorphism and to combine results with structural and metamorphic studies in order to develop a better understanding of the regional 1.4 Ga tectonic setting.