山东诸城榴辉岩相长英质岩石变质特征

通过变质矿物及岩石学的特征确定出山东诸城地区含有榴辉岩块体的片麻岩经历了榴辉岩相到绿帘角闪岩相、绿片岩相的退变质过程。证据有:(1)在榴辉岩块体的边缘片麻岩与榴辉岩呈1-2cm宽的条带状相间排列;(2)硅质片岩中出现Ky-Zo-Q的高压矿物组合;(3)钠长石的矿物晶体内出现硬玉质辉石的残留体;(4)出现高度富Si的多硅白云母(Si=3.55);(5)镁钠闪石及与其共生的暗硬玉(Jd=21)的出现。

METAMORPHIC PETROLOGY OF FELSIC ROCKS SURROUNDING ECLOGITES IN THE ZHUCHENG AREA,SHANDONG

Mineralogical and petrological features indicate that gneisses containing eclogite lenses in the Zhucheng area, Shandong,have undergone eclogite, epidote-amphibolite and greenschist-facies metamorphism successively. The evidence is as follows- 1. eclogite lenses and gneisses on their edges occur alternately as 1 - 2-cm-wide bands; 2. the high-pressure mineral assemblage Ky-Zo-Q occurs in siliceous schists; 3. jadeitic augite relics are present in albite crystals; 4. phengite contains up to 3. 55 Si per formula unit; 5. magnesioriebeckite is associated with chloromelanite (jadeite=21).