高级变质区变基性岩脉群的研究——以太平寨—金厂峪地区为例  

METABASIC DYKE SWARMS IN A HIGH-GRADE METAMORPHIC TERRANE——A CASE STUDY IN THE TAIPINGZHAIJINGCHANGYU AREA, EASTERN HEBEI PROVINCE

作　　者：陈曼云 

机构地区：[1]长春地质学院

出　　处：《地质学报》1990年第2期157-169,T001,共14页Acta Geologica Sinica

摘　　要：据地质和岩石学研究,冀东高级变质区内的太平寨—金厂峪地区有三期变基性岩脉。在第二、三期变基性岩脉中的石榴子石和角闪石分别聚集,形成两个矿物集中区,即gt+cpx+pl±hy和hb+cpx+pl±hy。岩石中的P_(H_2O)是控制形成这两个矿物集中区的主要因素,它们是在同一变质温度下同时形成的。第二期基性岩脉经受了辉石麻粒岩相(温度在825℃左右)变质作用的改造,尔后与第三期基性岩脉一起经受了角闪麻粒岩相(温度在750℃左右、压办在0.9 GPa)变质作用的改造。The rocks in the studied area consist mainly of charnockite, tonalite, trondhjemite and metagabbro with some meta-supercrustal rocks. According to geological and petrographic studies the metabasic dyke swarms can be divided into three phases. The metabasic dykes of the first phase occur as inclusions in charnockite, whose gneissosity assumes the same strike as the regional gneissosity. The metabasic dykes of the second and third phases cut the charnockite and regional gneissosity and exhibit distinct chilled borders, indicating that they were formed after the main-phase tectonism and early stage granulite facies metamorphism.In the metahasic dykes of the second and third phases, garnet and hornblende form different aggregate areas of minerals. The mineral assemblages of the aggregate areas containing garnet and hornblende are gt+cpx+pl±hy and hb+cpx+pl±hy respectively. P_(H_2O) in the rocks is the main factor for controlling the formation of the two aggregate areas. All of them were formed simultaneously at the same temperature.The basic dykes of the second phase have undergone proxene-granulite facies metamorphism. The temperature of metamorphism was about 825℃. Later they together with the basic dykes of the third phase were subjected to amphibole granulite facies metamorphism. The temperature of this metamorphism was about 750℃ and the pressure 0.9GPa.

关 键 词：变质 基性 岩脉 

分 类 号：P588.3[天文地球—岩石学]