Abstract Rapid glacio-isostatic rebound in Fennoscandia and Canada that is nonuniform in time and space indicates that there is a layer with strongly decreased viscosity at shallow crustal depths. The upper boundary of the layer is near the depth of 15 km, which corresponds to the maximum depth of earthquake hypocenters in the Precambrian cratons of the Kola Peninsula and Karelia. The position of the lower boundary is less distinct; however, most likely it is located near the base of the crust. The formation of such a layer in the Pliocene–Quaternary occurred due to infiltration of a large volume of mantle fluids into the crust. In many regions, this has led to retrograde metamorphism with rock expansion and a strong decrease in rocks viscosity.

中文翻译：

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旧克拉通地壳中低黏度层的出现是冰后隆升强烈分化特征的原因

摘要 Fennoscandia 和Canada 的快速冰川等静压回弹在时间和空间上不均匀，表明在浅地壳深度存在一个粘度急剧下降的层。该层的上边界接近 15 公里的深度，对应于科拉半岛和卡累利阿的前寒武纪克拉通地震震源的最大深度。下边界的位置不太明显；然而，它很可能位于地壳底部附近。由于大量地幔流体渗入地壳，在上新世-第四纪形成了这样的地层。在许多地区，这导致逆变质作用伴随岩石膨胀和岩石粘度的强烈下降。