COLLABORATIVE RESEARCH: Crustal Profile of a Major Transpressional Boundary: Tectonic Evolution of the Norumbega Fault Zone, Maine

缅因州的诺鲁贝加断裂带是长期以来被认为是右旋走滑断层系统的一个主要特征。然而，初步观察表明，北东-南西走向断裂带代表了一个主要横流边界的部分地壳剖面，沿走向暴露的地壳水平明显不同。该项目的目的是利用这一特征来描述地壳中随深度增加的变质作用和变形过程的样式。它将使用详细的测绘、岩石学和Ar/Ar地质年代学来限制沿走向的四个区域或横断面的变形事件的时间。这些结果将阐明该断裂带在阿巴拉契亚造山带发育中的构造意义。

The Norumbega Fault Zone in Maine is a major feature long considered to be a dextral strike-slip fault system. Preliminary observations suggest however that the NE-SW striking fault zone represents a partial crustal profile of a major transcurrent boundary, with significantly different crustal levels exposed along strike. This project is aimed at taking advantage of this feature to characterize the styles of metamorphism and deformation processes with increasing depth in the crust. It will employ detailed mapping, petrology and Ar/Ar geochronology to constrain timing of deformation events, along four areas or transects along strike. Results will elucidate the tectonic significance of this fault zone in the development of the Appalachian orogen.