鲁西花岗绿岩带和变质作用  

GRANITE-GREENSTONE BELT AND THE METAMORPHISM IN THE LUXI UPLIFT, SHANDONG

作　　者：徐惠芬[1] 

机构地区：[1]中国地质科学院地质研究所

出　　处：《山东地质》1990年第1期50-58,共9页Geology of Shandong

摘　　要：山东郯庐断裂以西的鲁西断块是我国较典型的晚太古代花岗绿岩带,同位素年龄资料表明,它的形成开始在近于2800Ma以前,约在2700—2500Ma间经历多期构造变形、变质作用和岩浆活动。发育有具喷发旋回和鬣刺结构的科马提岩、具枕状和杏仁构造的拉斑玄武岩,以及TTG演化系列的花岗质岩套,同时伴随有与绿岩带有关的铁、金等矿产。变质作用与构造变形紧密相关,变质等级属角闪岩相—绿片岩相,随时间的推移,变质等级逐渐降低,PTt轨迹显示鲁西花岗绿岩带主要是在地壳回返大陆抬升过程中形成的。空间上表现变质作用不均匀,尤其是晚太古末期,近东部雁翎关组泥质岩石出现红柱石等中温低压矿物、而西部柳杭组出现多硅白云母、黑硬绿泥石和硬绿泥石等低温高应变矿物。A Late Archearn granite-greenstone belt is located in the Luxi Uplift, east to the Tanlu Fault, Shandong. The belt is a typical one of the Archearn greenstone belts in China. New data of geochronology have shown that the belt formed at≥2800 Ma. ago and between about 2700-2500 Ma. underwent polygene tectonic deformation, magmatism and metamorphism. There are komatiites with volcanic lava cycle and split structure, tholeiites with pillow and amydaloidal structure, and TTG granitoids of the Archearn age. Some Fe and Au ore. deposits related to the greenstone belt have been discovered. Metamorphism can be related directly to the deformation. The P-T-t path which is based on the basic rocks suggests that the metamorphism occurred in the region belongs to amphibolite facies-greenschist fades, and the retrogresive metamorphism was evolved during the uplift of the Late Archearn Luxi crust.

关 键 词：花岗绿岩带 构造 变质作用 

分 类 号：P588.5[天文地球—岩石学]