The blueschists in western Yunnan Province are distributed in Lancangjiang and Ailaoshan metamorphic belts and occur as interlayer in green schist and mica schist. Their protolith is basaltic and pelitic rocks with a ...The blueschists in western Yunnan Province are distributed in Lancangjiang and Ailaoshan metamorphic belts and occur as interlayer in green schist and mica schist. Their protolith is basaltic and pelitic rocks with a mineral assemblage of Cr (or Win)+Ab+Qz+Chl+Ph+Ep+Sph+Act and Gl+Ph+Tc+Ep+Alm+Qz+Do, respectively. The P-T conditions of blueschist metamorphism range from 170—443℃ at c. 4—6. 7 kbar. The origin of blue schist of the Lancangjiang belt is related to the subduction and the close of the paleo-Tethys oceanic basin. The Ailaoshan blueschist, however, may be related to the continent continent collision and the dynamic metamorphism.展开更多
The detailed study on petrochemistry and geochemistry shows that meta-volcanics from Huimin and meta-basalts from Suyi belong, respectively, to different volcanic series. The former is of non-alkalic volcanic series a...The detailed study on petrochemistry and geochemistry shows that meta-volcanics from Huimin and meta-basalts from Suyi belong, respectively, to different volcanic series. The former is of non-alkalic volcanic series and the latter is of straddle A-type alkslic series. Based on their geochemical characteristics of REE, LIL, HFS and Nd, Sr isotope elements, we suggest that Huimin volcanics were formed in an island arc setting and Suyi basalts were formed in a back-continental arc extensive setting. These two volcanic series have not petrogenic relationship.展开更多
With the continuing discoveries of coesite-bearing eclogite, the Dabie Mountainsnorthern Jiangsu-Eastern Shandong ultrahigh pressure metamorphic zone has become a hot spot to international geoscientists. So far, howev...With the continuing discoveries of coesite-bearing eclogite, the Dabie Mountainsnorthern Jiangsu-Eastern Shandong ultrahigh pressure metamorphic zone has become a hot spot to international geoscientists. So far, however, eclogites with real coesite were found on-展开更多
The Western Yunnan is just situated in juncture area of the Yangtze,Indosinia and Shan-Thai Microcontinents,with the geosuture zones among them marked by ophiolite suites and blue schists.Agreat number of petrological...The Western Yunnan is just situated in juncture area of the Yangtze,Indosinia and Shan-Thai Microcontinents,with the geosuture zones among them marked by ophiolite suites and blue schists.Agreat number of petrological data support systematic evidences for Paleo-Tethys occurring in the area,andaccording to them,the tectonic evolution is reconstructed.Paleo-Tethys might be a poly-island ocean duringthe Late Paleozoic,and relic oceanic basins developed in Triassic1 Neo-Tethys immigrated westwards intoBurma.The area is an orogenic belt experiencing complicated subduction and violent continent-continent col-lision,and reformed by the younger structures,specially the Himalayan movement.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘The blueschists in western Yunnan Province are distributed in Lancangjiang and Ailaoshan metamorphic belts and occur as interlayer in green schist and mica schist. Their protolith is basaltic and pelitic rocks with a mineral assemblage of Cr (or Win)+Ab+Qz+Chl+Ph+Ep+Sph+Act and Gl+Ph+Tc+Ep+Alm+Qz+Do, respectively. The P-T conditions of blueschist metamorphism range from 170—443℃ at c. 4—6. 7 kbar. The origin of blue schist of the Lancangjiang belt is related to the subduction and the close of the paleo-Tethys oceanic basin. The Ailaoshan blueschist, however, may be related to the continent continent collision and the dynamic metamorphism.
基金Project supported by the National Natural Science Foundation of China.
文摘The detailed study on petrochemistry and geochemistry shows that meta-volcanics from Huimin and meta-basalts from Suyi belong, respectively, to different volcanic series. The former is of non-alkalic volcanic series and the latter is of straddle A-type alkslic series. Based on their geochemical characteristics of REE, LIL, HFS and Nd, Sr isotope elements, we suggest that Huimin volcanics were formed in an island arc setting and Suyi basalts were formed in a back-continental arc extensive setting. These two volcanic series have not petrogenic relationship.
基金Project supported by the National Natural Science Foundation of China.
文摘With the continuing discoveries of coesite-bearing eclogite, the Dabie Mountainsnorthern Jiangsu-Eastern Shandong ultrahigh pressure metamorphic zone has become a hot spot to international geoscientists. So far, however, eclogites with real coesite were found on-
基金the National Natural Science Foundation of China.
文摘The Western Yunnan is just situated in juncture area of the Yangtze,Indosinia and Shan-Thai Microcontinents,with the geosuture zones among them marked by ophiolite suites and blue schists.Agreat number of petrological data support systematic evidences for Paleo-Tethys occurring in the area,andaccording to them,the tectonic evolution is reconstructed.Paleo-Tethys might be a poly-island ocean duringthe Late Paleozoic,and relic oceanic basins developed in Triassic1 Neo-Tethys immigrated westwards intoBurma.The area is an orogenic belt experiencing complicated subduction and violent continent-continent col-lision,and reformed by the younger structures,specially the Himalayan movement.
