论文部分内容阅读
四堡群为一套出露于桂北黔东南地区、变形强烈的浅变质、陆源碎屑岩火山岩、系,厚度大于5000 m,其下未见底,上被丹洲群(下江群相当地层)所覆盖。桂北四堡群自下而上划分为九小组、文通组和鱼西组3组。样品A20140731-3采自于文通组,岩性为灰绿色熔结火山岩,首次分选出600余粒岩浆型锆石,完成SHRIMP U-Pb定年测点15个,获得加权平均年龄(860±13)Ma。这表明四堡群主体属于新元古界,进而分析、讨论了江南造山带主要地层对比关系。
The Si Bao Group is a set of shallowly metamorphic and terrigenous clastic volcanic rocks exposed in the southeastern Guizhou area of northern Guangxi. The thickness is more than 5000 m, with no bottom underneath and is dominated by the Danzhou Group Strata) covered. Four groups of northern Guangxi are divided into nine groups from bottom to top, Wen Tong group and Yu West group. Sample A20140731-3 was collected from Wentong Formation and lithology was gray-green fused volcanic rock. Sixty grains of magmatic zircons were sorted out for the first time. Fifteen SHRIMP U-Pb dating points were completed, and the weighted average age (860 ± 13) Ma. This shows that the main Fort Si Bao group belongs to the Neoproterozoic, and then analyzed and discussed the main strata Jiangnan orogenic correlation.