Discovery and implications of the high-pressure pelitic granulite from the Jiaobei massif  

作　　者：ZHOUXiwen WEIChunjing GENGYuansheng ZHANGLifei 

机构地区：[1]KeyLaboratoryofOrogenicBeltsandCrustalEvolution,SchoolofEarthandSpaceSciences,PekingUniversity,Beijing100871,China [2]InstituteofGeology,ChineseAcademyofGeologicalSciences,Beijing100037,China

出　　处：《Chinese Science Bulletin》2004年第18期1942-1948,共7页

摘　　要：The high pressure pelitic granulite with peak assemblage of garnet + kyanite + ternary feldspar + musco-vite + rutile was discovered in Qixia area in the Precambrian Jiaobei massif, where high pressure basic granulites are widely distributed. The metamorphic peak conditions for the pelitic granulite were calculated as T = 800—840℃ and P = 1.0—1.25 GPa on the basis of P-T pseudosection. The post peak P-T path is characterized first by an isothermal de-compression (ITD) pattern and then by an isobaric cooling (IBC) pattern, indicating a geodynamic process related to thinning of thickened continental crust.The high pressure pelitic granulite with peak assemblage of garnet + kyanite + ternary feldspar + musco-vite + rutile was discovered in Qixia area in the Precambrian Jiaobei massif, where high pressure basic granulites are widely distributed. The metamorphic peak conditions for the pelitic granulite were calculated as T = 800—840℃ and P = 1.0—1.25 GPa on the basis of P-T pseudosection. The post peak P-T path is characterized first by an isothermal de-compression (ITD) pattern and then by an isobaric cooling (IBC) pattern, indicating a geodynamic process related to thinning of thickened continental crust.

关 键 词：高压泥质麻粒岩 THERMOCALC 等压冷却 地球动力学 矿物化学 

分 类 号：P588.22[天文地球—岩石学]