An enormous thrust nappe and a metamorphic core complex of extensional origin have been recently discovered within the Hercynian-Indosinian orogen of Inner Mongolia. Both features are of the Mesozoic age, but the form...An enormous thrust nappe and a metamorphic core complex of extensional origin have been recently discovered within the Hercynian-Indosinian orogen of Inner Mongolia. Both features are of the Mesozoic age, but the former is older. The thrust nappe strikes WNW-ESE and Proterozoic dolomite was thrust southwards atop strata ranging from the Cambrian to the Triassic in age. The visible displacement of the thrust is ca. 70 km and the deduced one is over 140 km. The metamorphic core complex (mainly mylonites) extends in an N-E direction, forming itself into a dome geometry and lying under an extensional detachment fault. The mylonitic foliation dips gently and the stretching mineral lineation, as a whole, plunges SSE. Various shear sense markers show a normal-sense shear movement. Some significant problems atise from the coexistence of nappe and extensional structures at a postoro-genic stage.展开更多
There are many Sinian-Cambrian (Z^c-∈_b) epimetamorphic blocks either in groups or scatteredly covering the granitoids in the area of Guangning-Zhaoqing, the northwestern part of Wuchuan-Sihui faults in western Guang...There are many Sinian-Cambrian (Z^c-∈_b) epimetamorphic blocks either in groups or scatteredly covering the granitoids in the area of Guangning-Zhaoqing, the northwestern part of Wuchuan-Sihui faults in western Guangdong (Fig. 1). It has been shown that the blocks are allochthonous, i. e. klippes of thrust, and the granitoids are of a part of the slip system which consists vertically of mylonites, migmatites and granites from top to bottom in the deep-level nappe structural zone. Based on this discovery, the authors suggest a new model of fractural metamorphism (thermodynamic metamorphism).展开更多
文摘An enormous thrust nappe and a metamorphic core complex of extensional origin have been recently discovered within the Hercynian-Indosinian orogen of Inner Mongolia. Both features are of the Mesozoic age, but the former is older. The thrust nappe strikes WNW-ESE and Proterozoic dolomite was thrust southwards atop strata ranging from the Cambrian to the Triassic in age. The visible displacement of the thrust is ca. 70 km and the deduced one is over 140 km. The metamorphic core complex (mainly mylonites) extends in an N-E direction, forming itself into a dome geometry and lying under an extensional detachment fault. The mylonitic foliation dips gently and the stretching mineral lineation, as a whole, plunges SSE. Various shear sense markers show a normal-sense shear movement. Some significant problems atise from the coexistence of nappe and extensional structures at a postoro-genic stage.
基金Project supported by the National Natural Science Foundation of China.
文摘There are many Sinian-Cambrian (Z^c-∈_b) epimetamorphic blocks either in groups or scatteredly covering the granitoids in the area of Guangning-Zhaoqing, the northwestern part of Wuchuan-Sihui faults in western Guangdong (Fig. 1). It has been shown that the blocks are allochthonous, i. e. klippes of thrust, and the granitoids are of a part of the slip system which consists vertically of mylonites, migmatites and granites from top to bottom in the deep-level nappe structural zone. Based on this discovery, the authors suggest a new model of fractural metamorphism (thermodynamic metamorphism).
