胶东—鲁南早元古代双变质带及其地质意义

EASTERN SHANDONG—SOUTHERN SHANDONG PAIRED METAMORPHIC BELTS AND THEIR GEOLOGICAL SIGNIFICANCE

摘要:

本文作者描述了胶东—鲁南双变质带,从荣成、文登、威海经青岛、胶南、诸城、日照到莒南赋存于太古代至早元古代胶东群和/或胶南群变质杂岩中的C类榴辉岩带,代表了高压低温变质带;从胶东到鲁南的桃科期(早元古代)Ⅰ型花岗岩带及胶东莱西—安丘早元古代麻粒岩相岩石则代表了高温低压变质带。我们推测,这一双变质带,形成于早元古代华南板块向华北板块的俯冲期。在这次碰撞事件之后,胶东—鲁南地区发生角闪岩相变质作用,这次变质事件使得高压低温变质带发生了进变质作用,使C类榴辉岩平衡温度升高,同时使蓝闪石片岩消失;高温低压变质带则发生了退变质作用,Ⅰ型花岗岩发生混合岩化作用,麻粒岩相岩石遭受退化变质。胶东—鲁南双变质带,表明了华北—华南陆块的东部边界是从合肥、嘉山、响水、连云港经鲁南、青岛到胶东(荣成、威海)后而没入北黄海的。

Abstract:

In this paper the authors described the paired metamorphic belts in Eastern—Southern Shandong. The group C eclogite zone encompassed in metamorphic rocks of the Archaean—Proterozoic Jiaodong Group and/or Jiaonan Group Starts from Rongcheng, Wendeng and Weihai, passing through Qingdao, Jiaonan,Zhucheng and Rizhao,to Junan county,and represents the high-pressure and low-temperature metamorphic belt while the zone of I-type granites formed in the Taoke stage (Pt_1) from Eastern Shandong to Southern Shandong an...