论文部分内容阅读
虽然苏鲁变质带北部的超高压变质岩石的类型及其特征与大别山超高压带相似，但是要划出与大别山相对应的岩石构造单元是困难的。详细的区域地质、岩石学、同位素年代学及地球化学的研究已将超高压带的西界大致圈定在牟平断裂至米山断裂的范围内。特别需要提出的是，在荣成超高压变质岩石分布区的南北两侧，出露有３ 种不同成因的麻粒岩，即榴辉岩化的麻粒岩；由超高压变质岩经高压升温变质作用生成的麻粒岩；以及未经过榴辉岩相变质的麻粒岩。它们有规律地成带分布。这些麻粒岩带以及在荣成地区出露的未经过麻粒岩相叠加变质的超高压变质带，各自都有着完全不同的变质历史，并且都以深大韧性剪切带为其边界。由此笔者将苏鲁变质带北部由南向北划分为海阳所变质地块（榴辉岩化扬子陆块基底变质单元）、荣成变质地块（超高压变质单元）、威海变质地块（麻粒岩相叠加变质的超高压构造岩片）、昆嵛山边界杂岩带。这些来源于地壳深层的结晶块体是超高压带形成和演化的产物，在后来的进一步碰撞挤压中，这些来源于深层而就位于中上地壳水平的结晶块体，有可能发生了与薄皮构造机制（ｔｈｉｎ－ｓｋｉｎ ｔｈｒｕｓｔ）类似的构造过程。它们有如一系列的推覆体挤压叠置，使华北和华南陆块最后挤压在一起。
Although the types and characteristics of UHP metamorphic rocks in the northern part of the Sulu metamorphic belt are similar to the UHP Dabie Mountains, it is difficult to draw rock structural units corresponding to the Dabie Mountains. Detailed regional geology, petrology, isotopic geochronology and geochemistry have roughly delineated the western boundary of the UHP zone within the Muping fault to the Mishan fault. In particular, it needs to be pointed out that three types of granulites of different origin, namely eclogite granulites, are exposed on both north and south sides of the Rongcheng UHP metamorphic rock distribution area; and they are degenerated by high-pressure metamorphic rocks Granulite formed by the action; and granulite not altered by eclogite. They are regularly distributed. These granulite rocks, as well as the UHPM metamorphic zones that have not been granulite-facies metamorphosed in the Junggar area, have completely different metamorphic history and are all characterized by deep ductile shear zones. Therefore, the author divides the northern part of the Sulu metamorphic belt from south to north into Haiyuan metamorphic block (eclogite-Yangdi block), Rongcheng metamorphic block (UHP metamorphic unit), Weihai metamorphic block Granulite superimposed metamorphic ultrahigh-pressure structural rocks), Kunyu Mountain Boundary Complex belt. These crystalline crusts, derived from the deep crust, are the products of the formation and evolution of the UHP. In the subsequent further crush-extrusion, these are derived from the deep, crystalline blocks located at the level of the upper crust, Similar constructional processes for thin-skin thrust. They are like a series of nappe crush superposition, so that the North China and South China Lands finally squeezed together.