The Yunmeng Shan metamorphic core complex （MCC） is composed of the lower plate, the upper plate and the detachment zone. The detachment zone consists of ductile shear zone （mylonite zone）, chloritized microbreccia...The Yunmeng Shan metamorphic core complex （MCC） is composed of the lower plate, the upper plate and the detachment zone. The detachment zone consists of ductile shear zone （mylonite zone）, chloritized microbreccias zone and the brittle fault plane. The ductile shear zone contains mylonitic rocks, protomylonites, and mylonites. Finite strain measurements of feldspar porphyroclasts from those rocks using the Rf/φ method show that the strain intensities increase from mylonitic rocks （Es=0.66-0.72） to protomylonites （Es=0.66-0.83）, and to mylonites （Es=0.71-1.2）. The strain type is close to flatten strain. Kinematic vorticity estimated by Polar Mohr diagrams suggest that foliations and lineation of mylonite （0.47〈Wk〈0.85） record a bulk simple-dominated general shearing at the initial evolution stage of the Yunmeng Shan MCC＇s detachment zone; and the extensional crenulation cleavage（ecc） （0.34〈Wk〈0.77） recorded a bulk pure-dominated general shearing at the later stage of the evolution. Kinematic vorticity measurements also show that the Yunmeng Shan MCC detachment zone is a result of a combination of simple-dominated general shearing caused by crustal extension at the early stage and pure-dominated general shearing caused by MCC uplifting at the late stage. The ductile thinning estimated by finite strain measurements and estimation of Kinematic vorticity ranges from 52% to 82%, which is the minimum thining estimation. Our studies provide new evidence for mechanisms of the Yunmeng Shan MCC detachement zone.展开更多
Mountain Yunmeng(37°20′N,113°54′E)is 1520m above sea level and part of the Taihang Mountains.With a temperate continental monsoon climate,the mountain area belongs to the warm temperate deciduous broad-lea...Mountain Yunmeng(37°20′N,113°54′E)is 1520m above sea level and part of the Taihang Mountains.With a temperate continental monsoon climate,the mountain area belongs to the warm temperate deciduous broad-leaved forest region.This thesis was mostly based on the study of more than 2000 packages of bryophytes which were mainly collected by the authors in Mt.Yunmeng,Hebei Province.Of these specimens,there are 36 families,99 genera,and 244 species(including 17 varieties,5 formes,and 1 subspecies)which have been studied and identified.Moreover,it could be seen that Mt.Yunmeng has a diverse population of bryophytes.The bryoflora could be divided into 10 geographical elements:north temperate element make up the majority,accounting for 52.11%of the entire known bryoflora,and another belongs to the East Asian element,accounting for 19.25%.All temperate elements,not including 14 endemic to China and 31 Cosmopolitans,were added up to 188 species,which took 88.3%of all the entire known bryoflora in Mt.Yunmeng.However,there were only 11 Subtropical and Tropical elements.To all appearances,the bryoflora of Mt.Yunmeng showed obvious temperate characteristics.The authors conclude that the bryoflora in Mt.Yunmeng belongs to the middle type,between the warm and dry northern mountain area and the warm and damp southern mountain area.The microclimatic environment greatly influences the bryoflora.展开更多
基金supported by National Natural Science Foundation of China(Grant No.41102129,90714006 and 41002073)the foundation of Fundamental Science on Radioactive Geology and Exploration Technology Laboratory,East China Institute of Technology(Grant No.REGT1207)+1 种基金the Deep Exploration Technology and Experimentation Program of China(Grant No.SinoProbe-08-01-03)projects of China Geological Survey(1212011120135,1212010611803,1212011085474,1212011085473)
文摘The Yunmeng Shan metamorphic core complex （MCC） is composed of the lower plate, the upper plate and the detachment zone. The detachment zone consists of ductile shear zone （mylonite zone）, chloritized microbreccias zone and the brittle fault plane. The ductile shear zone contains mylonitic rocks, protomylonites, and mylonites. Finite strain measurements of feldspar porphyroclasts from those rocks using the Rf/φ method show that the strain intensities increase from mylonitic rocks （Es=0.66-0.72） to protomylonites （Es=0.66-0.83）, and to mylonites （Es=0.71-1.2）. The strain type is close to flatten strain. Kinematic vorticity estimated by Polar Mohr diagrams suggest that foliations and lineation of mylonite （0.47〈Wk〈0.85） record a bulk simple-dominated general shearing at the initial evolution stage of the Yunmeng Shan MCC＇s detachment zone; and the extensional crenulation cleavage（ecc） （0.34〈Wk〈0.77） recorded a bulk pure-dominated general shearing at the later stage of the evolution. Kinematic vorticity measurements also show that the Yunmeng Shan MCC detachment zone is a result of a combination of simple-dominated general shearing caused by crustal extension at the early stage and pure-dominated general shearing caused by MCC uplifting at the late stage. The ductile thinning estimated by finite strain measurements and estimation of Kinematic vorticity ranges from 52% to 82%, which is the minimum thining estimation. Our studies provide new evidence for mechanisms of the Yunmeng Shan MCC detachement zone.
基金supported by the Natural Science Foundation of Hebei Province (No.301107)the Scientific and Technological Department Brainstorm Plan Project of Hebei Province (No.20034201).
文摘Mountain Yunmeng(37°20′N,113°54′E)is 1520m above sea level and part of the Taihang Mountains.With a temperate continental monsoon climate,the mountain area belongs to the warm temperate deciduous broad-leaved forest region.This thesis was mostly based on the study of more than 2000 packages of bryophytes which were mainly collected by the authors in Mt.Yunmeng,Hebei Province.Of these specimens,there are 36 families,99 genera,and 244 species(including 17 varieties,5 formes,and 1 subspecies)which have been studied and identified.Moreover,it could be seen that Mt.Yunmeng has a diverse population of bryophytes.The bryoflora could be divided into 10 geographical elements:north temperate element make up the majority,accounting for 52.11%of the entire known bryoflora,and another belongs to the East Asian element,accounting for 19.25%.All temperate elements,not including 14 endemic to China and 31 Cosmopolitans,were added up to 188 species,which took 88.3%of all the entire known bryoflora in Mt.Yunmeng.However,there were only 11 Subtropical and Tropical elements.To all appearances,the bryoflora of Mt.Yunmeng showed obvious temperate characteristics.The authors conclude that the bryoflora in Mt.Yunmeng belongs to the middle type,between the warm and dry northern mountain area and the warm and damp southern mountain area.The microclimatic environment greatly influences the bryoflora.
