A Study of Contact Metamorphism of Late Paleozoic Strata in the Middle of Inner Mongolia
详细信息
- 责任者：Li Juan (Department of Earth Sciences ; Jilin University ; Changchun 130061 ; China) ; Zheng Changqing
- 刊名：Earth Science Frontiers
- 出版年：2011
- 卷期：18(2)
- 关键词：接触变质作用 ; contact metamorphism ; 粘土矿物 ; clay minerals ; 内蒙古 ; Inner Mongolia
- 页码：p.223-230
- 图表：5 illus., 3 tables, 34 refs.
- 分类号：0802
- 出版序号：20120176
- issnNo：ISSN1005-2321
- isbnNo：CN11-3370/P
摘要
Some of the Late Paleozoic strata in the middle Inner Mongolia developed zeolite- and/or prehnite-pumpellyite facies contact metamorphism due to the intrusion of Mesozoic magmas. Studies of clay minerals, illite crystallinity and vitrinite reflectance of typical profile indicate that 1) illite and chlorite are the dominant clay minerals, interlayered illite and smectite (I/S) or smectite are present in very few samples, and in most cases interlayered illite and chlorite (I/C) are rare; 2) illite crystallinity ranges from 0.22 to 0.40; and 3) the vitrinite reflectance values (Ro) are in the range of 1.5~4.0. The results suggest that only very low-grade contact metamorphism rather than large-scale greenschist facies regional metamorphism developed in the limited areas affected by the magmatic intrusion, and this low-grade metamorphism affected only sedimentary strata and oil resources formed before Late Permian.