【摘要】 SHRIMP锆石U Pb年龄测定结果表明 ,云南峨山、江西九岭和安徽许村等 3个岩体的形成年龄分别为818± 10Ma、818± 10Ma和 82 9± 11Ma ,与广西北部的本洞、三防、元宝山、湖北的黄陵岩体以及的广西北部的基性岩墙的年龄完全一致 ,表明在 82 0～ 830Ma期间 ,扬子克拉通在广大区域内几乎同时发生了广泛的地壳重熔和幔源基性岩浆活动。虽然这些花岗岩的类型不同 ,但它们的形成时代相当一致 ,表明这些不同类型的花岗岩应形成于相同或相关的构造环境 ,很可能是地幔柱活动导致下地壳重熔的产物。更多还原

【Abstract】 SHRIMP U-Pb zircon analysis gives 818±10 Ma, 818±10 Ma and 829±11 Ma for the Eshan Pluton in Yunnan, the Jiuling Pluton in Jiangxi and the Xuchun Pluton in Anhui, respectively. These new high-precision U-Pb ages are in good agreement with those for the Bendong, Snagfang and Yuanbaoshan in Guangxi, the Huangling in Hubei and the mafic dyke/sills in Guangxi, indicating that an extensive crustal anatexis associated with mantle-derived magmatism occurred at 820-830 Ma in a vast region in South China. Although these granitoids correspond to different petrogenetic types, they should have been formed contemporaneously in a coherent geodynamic setting.更多还原