Discovery of mantle and lower crust xenoliths from early Cretaceous volcanic rocks of southwestern Tianshan,Xinjiang  

作　　者：Baofu Han Xuechao Wang Guoqi He Tairan Wu Maosong Li Yulin Liu Shiguang Wang 

机构地区：[1]Peking Univ, Dept Geol, Beijing 100871, Peoples R China

出　　处：《Chinese Science Bulletin》1999年第12期1119-1123,共5页

摘　　要：In Tuoyun area of southwestern Tianshan, mantle and lower crust xenoliths are present In the volcanic rocks with ages of 101-123 Ma. Mantle xenoliths include mineral megacrysts such as kaersutite and pargasite, feldspar, biotite, and rare pyroxene and rock fragments such as perodotite, pyroxenite, amphibolite, and rare glimmerite. Lower crust xenoliths are mainly banded and massive granulite. The volcanic rocks were produced by within-plate magmatism. Occurrence of hydrous and volatile mineral megacrysts, amphibolite, and some pyroxenite containing hydrous and volatile minerals indicates that mantle metasomatism was intense. Undoubtedly, this discovery is very important to understanding of the crust-mantle structure and geodynamic background in depth in southwestern Tianshan and geological correlation with adjacent regions.In Tuoyun area of southwestern Tianshan, mantle and lower crust xenoliths are present in the volcanic rocks with ages of 101–123 Ma. Mantle xenoliths include mineral megacrysts such as kaersutite and pargasite, feldspar, biotite, and rare pyroxene and rock fragments such as perodotite, pyroxenite, amphibolite, and rare glimmerite. Lower crust xeno-liths are mainly banded and massive granulite. The volcanic rocks were produced by within-plate magmatism. Occurrence of hydrous and volatile mineral megacrysts, amphibolite, and some pyroxenite containing hydrous and volatile minerals indicates that mantle metasomatism was intense. Undoubtedly, this discovery is very important to understanding of the crust-mantle structure and geodynamic background in depth in southwestern Tianshan and geological correlation with adjacent regions.

关 键 词：MANTLE lower crust XENOLITH MEGACRYST volcanic rock southwestern Tianshan. 

分 类 号：P588.1[天文地球—岩石学] P[天文地球—地质学]