苏北—鲁东南高压,超高压变质带剥露过程中伸展构造作用

尽管许多地质学家提出了不同的超高压变质岩石形成与折返模式，但高压、超高压变质岩折返与剥露机制仍是大陆造山带动力学研究中的热点和焦点问题。本文明确提出并研究了分布于苏北－胶南变质岩区西北和北部边缘的地壳规模的拆离伸展型韧性剪切带。通过韧性剪切带几何学、运动学、变形环境分析和形成时代的讨论，认为与高压、超高压变质带展布方向斜交的斜向伸展构造作用，是苏北－鲁东南高压、超高压变质带从中地壳抬升至地表的主导

The Role of Extensional Tectonics in the Exhumation of High-and Ultrahigh-Pressure Rocks in Northern Jiangsu and Southeastern Shandong

Although several geotectonic models concerning the formation and exhumation of ultrahigh - pressure rocks have been proposed, the mechanism for exhumation of high-and ultrahigh-pres-sure rocks is still a focus in the investigation of continental erogenic dynamics. The authors have studied a crustal-scale extensional ductile shear zone lying on the northern and northwestern margins of the northern Jiangsu and southeastern Shandong metamorphic terrain. On the basis of studies of the geometry, kinematics, deformational environment and the time of deformation, The authors have found that the extensional tectonic deformation oblique to the trend of the entire high-and ultrahigh-pressure metamorphic belt is responsible for the exhumation of high-and ultrahigh-pressure rocks from the middle crust in northern Jiangsu and southeastern Shandong.