Tectonic implication of stockwork microbreccias  

作　　者：ZHANGJiasheng HUANGXiongnan LIUJianmin 

机构地区：[1]InstituteofGeology,ChinaEarthquakeAdministration,Beijing100029,China [2]InstituteofGeomechanics,ChineseAcademyofGeologicalSciences,Beijing100081,China

出　　处：《Chinese Science Bulletin》2005年第1期67-74,共8页

基　　金：the State Major Basic Research Development Program(Grant No.G1999075511);the National Natural Sciences Foundation of China(Grant Nos.40172077,40472114).

摘　　要：The stockwork microbreccia found in the Dabie and Helan Mountains bears no relation to either meteorite impact and cryptoexplosion, or fault displacement. It is con- trolled by tensional or transtensional fracture network in relatively hard felsic crystalline rocks, appearing as breccia with dark cryptocrystalline matrix. The kilometer-scale dis- tribution and complicated relation to fracture system of the stockwork microbreccias, randomly distributed autochtho- nous fragments of host rock, ultracataclasis without notable displacement in the cryptocrystalline matrix, and a probable solid-state amorphization deformation mechanism all suggest that large-scale, high-energy and rapid brittle fracturing event might have occurred in the rocks at relatively deep crustal level in the areas.The stockwork microbreccia found in the Dabie and Helan Mountains bears no relation to either meteorite impact and cryptoexplosion, or fault displacement. It is controlled by tensional or transtensional fracture network in relatively hard felsic crystalline rocks, appearing as breccia with dark cryptocrystalline matrix. The kilometer-scale distribution and complicated relation to fracture system of the stockwork microbreccias, randomly distributed autochthonous fragments of host rock, ultracataclasis without notable displacement in the cryptocrystalline matrix, and a probable solid-state amorphization deformation mechanism all suggest that large-scale, high-energy and rapid brittle fracturing event might have occurred in the rocks at relatively deep crustal level in the areas.

关 键 词：网状脉细角砾岩 大别山脉 隐晶质矩阵 固态非晶化 地壳运动 

分 类 号：P588.212.5[天文地球—岩石学]