西藏同卡地区高压麻粒岩的发现、PT轨迹及其大地构造意义  

Discovery and P-T path of high-pressure granulite in Tongka area of Tibet and its tectonic significance

作　　者：张万平 王立全 强巴扎西 王保弟 刘伟 袁四化[3] 

机构地区：[1]成都地质调查中心,成都610082 [2]西藏地勘局区域地质调查大队,拉萨851400 [3]中国地质科学院地质研究所,北京100037

出　　处：《岩石学报》2010年第6期1915-1924,共10页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(2009CB421003)资助

摘　　要：在班公湖-怒江缝合带的同卡地区发现了高压麻粒岩,它经历了至少两期变质作用,即高压麻粒岩相和退变质角闪岩相变质作用。峰期高压麻粒岩相矿物组合为:石榴石-单斜辉石-斜长石,退变质角闪岩相矿物组合:角闪石-斜长石。地质温压计的计算结果表明高压麻粒岩相的温压条件为600～750℃,11.0～13.0kb;退变质角闪岩相的温压条件为500～600℃,6.0kb左右,高压麻粒岩具有顺时针退变质的P-T轨迹特点。The high-pressure granulite discovered in Tongka area of Bangong Co-Nujiang suture zone in Tibeten Plateau,went through at least two stage metamorphisms of high-pressure granulite phase and retrogressive-metamorphic amphibolite phase. Mineral assemblages of the high-pressure granulite phase in the peak stage were garnet-clinopyroxene-plagioclase while mineral assemblages of retrogressive-metamorphic amphibolite phase were amphibolite-plagioclase. Geological temperature-pressure indicator showed that the temperature-pressure conditions of high-pressure granulite phase were 600~750℃,11.0~13.0kb,while that of retrogressive-metamorphic amphibolite phase were 500~600℃,6.0kb and so the high-pressure granulite was of clockwise retrogersive-metamorphic P-T path characteristic.

关 键 词：同卡地区 班公湖-怒江结合缝合带 麻粒岩 P-T轨迹 

分 类 号：P588.347[天文地球—岩石学]