Field observation showed that there are many irregular leucocratic intrusive rocks in pillow lavas in the Danfeng Group in the Xiaowangjian area, north Qinling orogenic belt. Photomicrographs indicated that the protol...Field observation showed that there are many irregular leucocratic intrusive rocks in pillow lavas in the Danfeng Group in the Xiaowangjian area, north Qinling orogenic belt. Photomicrographs indicated that the protoliths of those altered leucocratic intr展开更多
Cenxi Permian basalts are the late Palaeozoic island-arc type basalts first found in South China. REE and trace element characteristics and distribution patterns show that this volcanic formation, which has been isoto...Cenxi Permian basalts are the late Palaeozoic island-arc type basalts first found in South China. REE and trace element characteristics and distribution patterns show that this volcanic formation, which has been isotopically dated at 261 MaB.P. by the 39Ar/ 40Ar method, is of an active continental marginal island arc type, and that the tectonic environment at that time was an island-arc marginal sea or minor ocean basin related with the paleo-Tethyan tectonic belt in western Guangdong-eastern Guangxi.展开更多
Based on the geological mapping, it is suggested that the pillow lavas exposed in Jianshui area in southeastern Yunnan Province are emplaced into the western part of Shizong-Mile faults, the boundary between the Yangt...Based on the geological mapping, it is suggested that the pillow lavas exposed in Jianshui area in southeastern Yunnan Province are emplaced into the western part of Shizong-Mile faults, the boundary between the Yangtze and Cathaysian blocks, and mainly composed of tectonic massive of basalts and basaltic andsites. The geological and geochemical studies show that these lavas erupted in an island arc tectonic setting, which suggests that there existed the subduction of oceanic crust between the Yangtze and Cathaysian blocks. The paleontological fossils in the sedimentary interlayers between the volcanic rocks indicate that these pillow lavas erupted during Carboniferous-Permian. The geologic and geochemical evidence suggested that there existed an eastern branch of Paleo-Tethys between the Yangtze and Cathaysian blocks in southeastern Yunnan, South China.展开更多
基金the National Natural Science Foundation of China (Grant No. 40472119)the Programme of Excellent Young Scientists of the Ministry of Land and Resourcesof China+1 种基金the Ministry of Science and Technology of China (Grant Nos. 2002CB412608 and 2006BABOlAll)the China Geological Survey (Grant Nos. 1212010633601 and 1212010611807)
文摘Field observation showed that there are many irregular leucocratic intrusive rocks in pillow lavas in the Danfeng Group in the Xiaowangjian area, north Qinling orogenic belt. Photomicrographs indicated that the protoliths of those altered leucocratic intr
文摘Cenxi Permian basalts are the late Palaeozoic island-arc type basalts first found in South China. REE and trace element characteristics and distribution patterns show that this volcanic formation, which has been isotopically dated at 261 MaB.P. by the 39Ar/ 40Ar method, is of an active continental marginal island arc type, and that the tectonic environment at that time was an island-arc marginal sea or minor ocean basin related with the paleo-Tethyan tectonic belt in western Guangdong-eastern Guangxi.
文摘Based on the geological mapping, it is suggested that the pillow lavas exposed in Jianshui area in southeastern Yunnan Province are emplaced into the western part of Shizong-Mile faults, the boundary between the Yangtze and Cathaysian blocks, and mainly composed of tectonic massive of basalts and basaltic andsites. The geological and geochemical studies show that these lavas erupted in an island arc tectonic setting, which suggests that there existed the subduction of oceanic crust between the Yangtze and Cathaysian blocks. The paleontological fossils in the sedimentary interlayers between the volcanic rocks indicate that these pillow lavas erupted during Carboniferous-Permian. The geologic and geochemical evidence suggested that there existed an eastern branch of Paleo-Tethys between the Yangtze and Cathaysian blocks in southeastern Yunnan, South China.
