鲁西地块早前寒武纪构造-岩浆活动区划及演化的新认识

以野外区域地质调查为基础，结合前人的岩石学和年代学成果，根据地壳构造层次划分、构造作用及岩浆活动特征，探讨了鲁西地块的前寒武纪构造演化格局。鲁西地块的构造-岩浆岩区可以划分为：西部的TTG类岩区和东部的片麻状二长花岗岩区。TTG类岩石是鲁西地块新太古代陆壳岩浆活动的产物，片麻状二长花岗岩是TTC类陆壳岩浆活动之后在新太古代晚期发生的大规模陆壳增生活动形成的。贯穿两个构造-岩浆岩区之间的多条北西向韧性剪切带表明鲁西地块在新太古代末发生的地壳加厚是两个岩区通过多条韧性剪切带挤压叠置实现的陆壳加厚作用所致。TTG岩区和片麻状二长花岗岩区内广泛发育的元古代未变形未变质的酸性岩脉和基性岩墙群表明鲁西地块在新太古代末两个岩区已经焊接在一起，进入元古代以后，鲁西地块完全克拉通化，具有刚性板块的特征。

New Comment on the Early Precambrian Tectono-Magmatic Subdivision and Evolution in the Western Shandong Block

The evolution of early Precambrian tectono-magmatic activities in the Western Shandong Block was studied by using the methods of field geology,petrology and geochronology. Two units can be subdivided: The TTG rocks in the west and gneissic adamellite in the east. The TTG rocks were the products of Late NeoArchean continental magmatic activity,and the geissoid adamellite rocks were the products of continental accretion activity after the TTG magmatic activity. The subdivision of tectono-magmatic units in the Western Shandong Block provided a good Precambrian tectonic section. The ductile transtensional zones between these two tectono-magmatic units show that the paleocrust was thickened by superimposition of these ductile transtensional zones. The Proterozoic sialic and diabase dike swarms extensively developed in these two units show that these units were joined together after the cratonization at the end of NeoArchean.This indicates that the Western Shandong Block was a part of the brittle craton in the Proterozoic time.