Nd-Sr isotopic compositions of 12 Mesozoic granitoids from Jiangxi Province have been reported. They show loe-ε<sub>ND</sub>（-13.8—- 8.3）, high-l<sub>sr</sub>（0.71069—0.73981） and old t&...Nd-Sr isotopic compositions of 12 Mesozoic granitoids from Jiangxi Province have been reported. They show loe-ε<sub>ND</sub>（-13.8—- 8.3）, high-l<sub>sr</sub>（0.71069—0.73981） and old t<sub>DM</sub> （2087—1635 Ma）. Comparison between the Sm-Nd isotopic compositions of the granitoids and those of the basement metamorphic rocks suggests that these granitoids were mainly derived from the metasedimentary rocks. There is an east-west trend Mesozoic granitoid zone with lowt<sub>DM</sub> from S. Jiangxi to S. Fujian. The origin of these granites was preliminarily discussed.展开更多
Nd isotopic compositions of 58 granitoids in South China have been reported in this paper; These data together with other published data reveal that granites with Nd model ages (tDM) greater than 1.8 Ga are distribute...Nd isotopic compositions of 58 granitoids in South China have been reported in this paper; These data together with other published data reveal that granites with Nd model ages (tDM) greater than 1.8 Ga are distributed mainly in three areas: southwestern Zhejiang-northwestern Fujian, two sides of the Wuyi Mountain and Wanyangshan-Zhuguangshan. These granites are believed to be derived from partial melting of old crust in these areas. The Mesozoic granites with (DM 【 1.6 Ga are distributed in three zones: the Gangang structural zone, Nanling latitudinal structural zone and Fujian-Zhejiang coastal zone. These zones may have been an extensional tectonic setting and mantle-derived components or magmas may have been involved to different extents in the granite formation. Based on Nd model ages of granites and published chronological data of mafic and ultramafic rocks, it is believed that the crust in South China experienced episodic accretions, among which the early-middle Proterozoic is the most important展开更多
文摘Nd-Sr isotopic compositions of 12 Mesozoic granitoids from Jiangxi Province have been reported. They show loe-ε<sub>ND</sub>（-13.8—- 8.3）, high-l<sub>sr</sub>（0.71069—0.73981） and old t<sub>DM</sub> （2087—1635 Ma）. Comparison between the Sm-Nd isotopic compositions of the granitoids and those of the basement metamorphic rocks suggests that these granitoids were mainly derived from the metasedimentary rocks. There is an east-west trend Mesozoic granitoid zone with lowt<sub>DM</sub> from S. Jiangxi to S. Fujian. The origin of these granites was preliminarily discussed.
文摘Nd isotopic compositions of 58 granitoids in South China have been reported in this paper; These data together with other published data reveal that granites with Nd model ages (tDM) greater than 1.8 Ga are distributed mainly in three areas: southwestern Zhejiang-northwestern Fujian, two sides of the Wuyi Mountain and Wanyangshan-Zhuguangshan. These granites are believed to be derived from partial melting of old crust in these areas. The Mesozoic granites with (DM 【 1.6 Ga are distributed in three zones: the Gangang structural zone, Nanling latitudinal structural zone and Fujian-Zhejiang coastal zone. These zones may have been an extensional tectonic setting and mantle-derived components or magmas may have been involved to different extents in the granite formation. Based on Nd model ages of granites and published chronological data of mafic and ultramafic rocks, it is believed that the crust in South China experienced episodic accretions, among which the early-middle Proterozoic is the most important
