龙门山穹状递增变质作用特征及岩石圈深部作用信息  

THE CHARACTERISTIC OF DOMAL PROGRESSIVE METAM- ORPHISM AND DEEP PROCESS INFORMATION FROM LITHOSPHERE IN LONGMENSHAN,CHINA

作　　者：王国芝[1] 刘树根[2] 

机构地区：[1]中国科学院地球化学研究所,贵州贵阳550002 [2]成都理工学院石油系,四川成都610059

出　　处：《矿物岩石》2001年第1期71-76,共6页Mineralogy and Petrology

基　　金：国土资源部攻关项目!"中国西部盆 -山系统的耦合关系及其动力学过程"

摘　　要：通过对变质带的空间分布特征、矿物组合的世代关系和同位素定年的综合研究表明 ,龙门山造山带的穹状递增变质作用为发生于燕山期的区域动热变质作用 ,所形成的递增变质带在空间上呈穹隆状 ,等变带围绕热中心呈环带状分布 ,热中心发育花岗岩 ,从热中心向四周变质程度依次递减。热中心花岗岩的侵位和上隆滞后于穹状递增变质作用 ,二者在成因上无直接的联系。其 p Td轨迹揭示出了盆山耦合过程中壳幔间相互作用过程和热历史演变。The comprehensive studies based on space distribution of metamorphic zone, generation relation of mineral asemblage and geochronology, suggest that the domal progressive metmorphism in Longmenshan orogen is regional dynamic thermal metamorphism which happened in Yanshan age. The progressive metamorphic zone displayed a shape of dome in space, granite intruded in the central metamorphism zone and isograde band distributed around thermal center as zonal, strength of metamorphism decrease gradually from thermal center to outside. The time of intrusion and uplift of granite located in the thermal center lag that of domal progressive metamorphism, there is no origin connection between metamorphism and igneous intrusion. The pTd path reveals that mutual process information between crust and mantle, and evolution of thermal history during Basin-Mountain coupling.

关 键 词：递增变质作用 pTd轨迹 岩石圈 造山带 热状态演变 同位素定年 

分 类 号：P588.3[天文地球—岩石学] P542.2[天文地球—地质学]