地质学报2017，Vol.91Issue(2)：302-314,13.
南秦岭旬阳盆地东部晚泥盆世岩浆成因钠长岩及其构造意义
Late Devonian Magmtogenic Albitites in the Eastern Xunyang Basin of the South Qinling Orogen and Theire Tectonic Significance
摘要
Abstract
The albitites,distributed widely within the low-grade metamorphic strata of Lower Silurian and Devonian in the Xunyang-Baihe basin of the South Qinling orogen,are usually regarded as the product of hydrothermal sedimentation or hydrothermal metasomatism.The study conducted the geochemical and zircon U-Pb LA-ICP-MS dating analysis for the albitite intruding into the low-grade metamorphic rocks of the Lower Silurian Meiziya Formation in the Huanshiban area in the eastern part of the Xunyang basin.The geochemical analysis shows that the albitites are characterized by Na-rich,K-depleted,aluminum unsaturated,LILES-depleted such as K and Rb,and HFSE-riched such as Nb,Ta,Th,Hf,with negative Eu anomaly.The youngest U-Pb age of zircon from albitites is 364～376 Ma,and it should represent the formation age of the albitite,suggesting the Xunyang Basin in the South Qinling Orogen was in an intense extensional tectonic setting during Late Devonian.Results suggest that both the hydrothermal-related and magmtogenic albitites probably coexist in the Xunyang-Baihe basin.The Huangshiban magmtogenic abitites contain abundant xenocrysts zircons of Precambrian and Early Paleozoic,and the oldest zircon age (3291 Ma) has been obtained for the zircon xenocrysts in the South Qinling orogen and its adjacent areas.The dating data of zircon xenocrysts show that the South Qinling Orogen probably has marked affinity with Yangtze block from the Early Archean.关键词
南秦岭/旬阳盆地/晚泥盆世/钠长岩/伸展作用Key words
South Qinling Orogen/Xunyang basin/Late Devonian/abitite/extension引用本文复制引用
罗金海,周亚军,徐欢,尤佳,李亦飞,车自成..南秦岭旬阳盆地东部晚泥盆世岩浆成因钠长岩及其构造意义[J].地质学报,2017,91(2):302-314,13.基金项目
本文为陕西省自然科学基金项目(编号2014JM5206)资助成果. （编号2014JM5206）
