Characteristics of Cleavages with Different Directions in Houshan Area of Karamay,Xinjiang,NW China and Their Geodynamic Background
Li Li
Wang Guocan
Yan Wenbo
Peng Chao
Zhang Yun
Zhao Hongwei
Abstract：Cleavage is a type of penetrative planar rock feature produced under certain stress fields,commonly normal to the di-rection of maximum compression.Detailed investigation into the physical characteristics and sequences of different cleavages can facilitate the understanding of the regional deformational history,and further the tectonic evolution of a given area.Three cate-gories of cleavages have been recognized through systematic observations of the penetrative cleavages developed in the Carbonif-erous turbidites in the Zaire Mountains of western Junggar:(1)relatively earlier cleavages associated with the tectonic emplace-ment of ophiolites;(2)later fault-related cleavages developed along major faults,such as the Darbut and Hatu faults;(3) cleavages with rather consistent east-west strike across region,and at various angles to bedding planes,which denote a wide-spread north-south regional compression.The earlier cleavages were formed during the Early-Late Late Carboniferous,when the older (Ordovician to Devonian)ophiolites got emplaced into the overlying younger (Carboniferous)strata due to the oblique convergence of different blocks and closing of ocean basins.The fault-related cleavages were related to extensive sinistral strike slip along NE-SW trending faults during the Permian-Triassic.The east-west cleavages didn't affect Mesozoic strata (the oldest of Late Triassic)in the region and crosscut granite porphyry veins dated as 305±15 Ma.In the consideration of the extensional tectonic background of the area from the Late Carboniferous to Perimain,the east-west cleavages probably lasted from the lat-est Permian to Middle Triassic,roughly concurrent with the fault-related cleavages of the second type,both of which signify an intracontinental north-south compression concurred with the southward movement of the Siberian plate.
Keywords：cleavageCarboniferousbedding-cleavage intersectiontectonic deformationwestern Junggar
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 521-534 )