Metamorphic Evolution of Early Precambrian Khondalite Series in oft-com:office:smarttags" />
详细信息
- 责任者：Wang Fang (Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Liu Fulai
- 刊名：Acta Petrologica Sinica
- 出版年：2010
- 卷期：26(7)
- 关键词：孔兹岩 ; khondalite ; 山东 ; Shandong Province
- 页码：p.2057-2072
- 图表：9 illus., 4 tables, 38 refs.
- 分类号：0802
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
///Early Precambrian khondalite series,which mainly consist of Al-rich schists and gneissic rocks with thin layers of marble,are widespread in north Shandong Province,SE Sino-Korean craton.Four stages of the metamorphic history have been recognized in mineral assemblages.The P-T conditions for each metamorphic stage were obtained using thermodynamically and experimentally calibrated geothermobarometers.Garent along with fine-grained inclusion minerals,defines a prograde assemblage（M1）garnet+biotite+plagioclase+quartz.The peak of metamorphism（M2）at about 760 ℃ and 10.0 kb is defined by kyanite-bearing granulite-facies mineral assemblage.Symplectite or coronas of cordierite surrounding relict garnet indicate garnet occurring breakdown reaction at conditions around 750~800 ℃ and 4.0~5.4 kb.Kelyphites of fine-grained biotite ±quartz around garnet formed during the cooling process（M4）at about 550~650 ℃ and4.0 kb.The results define a sequential P-T path containing near-isothermal decompression（ITD）and near-isobaric cooling（IBC）stages.The clockwise hybrid ITD and IBC P-T paths of the Early Precambrian khondalite series in North Shandong Province imply a model of thickening followed by rapid uplifting in a collisional orogen.