40 Ar/39 Ar Isotope Geochronology of Caledonian Orogenic Collapse, Southwest Norway

构造学中的一个突出问题是造山带先前增厚的地壳的伸展坍缩的性质和时间。这一建议是迄今为止归因于挪威西南部加里东造山带伸展崩塌的构造特征。待定年的构造特征包括：隆起的高压榴辉岩；逆行，角闪岩相变质；主要的，千米厚的糜棱岩带，其中一些为绿片岩级。使用40Ar/39Ar测年法将获得高精度数据，并将允许比较不同地区之间的隆升年龄。与来自奥尔索大学的当地地质学家的合作将确保在良好的构造控制下获得数据。挪威西南部著名的当地地质与优秀的暴露相结合，具有高精度的年龄和可测试的构造模型，将大大提高对造山带崩塌过程的认识。

An outstanding problem in tectonics is the nature and timing of extensional collapse of previously thickened crust in orogenic belts. This proposal is to date structural features attributed to the extensional collapse of the Caledonian orogen in southwest Norway. Structural features to be dated include: uplifted high- pressure eclogite rocks; retrograde, amphibolite facies meta- morphism, and; major, km-thick mylonite zones, some of which are at greenschist grade. High-precision data will be obtained using the 40Ar/39Ar dating method and will allow comparison of uplift ages among different areas. Collaboration with local geologists from the University of Olso will ensure that the data are obtained with good structural control. The combination of well-known local geology and excellent exposure in SW Norway, with high-precision ages and testable tectonic models, will significantly improve the understanding of orogenic collapse processes.