地质与资源2023，Vol.32Issue(6)：691-698,8.DOI:10.13686/j.cnki.dzyzy.2023.06.005
扬子板块西缘下志留统龙马溪组底部斑脱岩研究
BENTONITES IN THE BOTTOM OF LOWER SILURIAN LONGMAXI FORMATION ON THE WESTERN MARGIN OF YANGTZE PLATE:
摘要
Abstract
Bentonites are widely distributed and developed in several layers in the Ordovician-Silurian boundary,which is of great significance for the study of stratigraphic chronology,stratigraphic correlation,event stratigraphy and mass extinction in the period.The zircon U-Pb dating of bentonites in the bottom of Upper Ordovician-Lower Silurian Longmaxi Formation in Yongshan area on the western margin of Yangtze Plate yields the weighted average age of 443.5± 1.7 Ma,which defines the sedimentary age of the strata and provides a reliable basis for the study of Ordovician-Silurian volcanic eruption event and stratigraphic chronology on the western margin of Yangtze Plate,as well as basic information for the establishment of Ordovician-Silurian high-resolution stratigraphic framework on the periphery of Yangtze Plate.The trace element characteristics of zircon show the features of Ⅰ-type granite formed in magmatic arc or orogenic belt.The multi-stage and high-frequency volcanic activity in the Late Ordovician-Early Silurian is possibly the dominant factor causing the mass extinction.关键词
扬子板块/斑脱岩/锆石U-Pb年龄/微量元素/生物大灭绝Key words
Yangtze Plate/bentonite/zircon U-Pb age/trace element/mass extinction分类
天文与地球科学引用本文复制引用
王万能,庞占基,王浩宇,王东晖,于一帆..扬子板块西缘下志留统龙马溪组底部斑脱岩研究[J].地质与资源,2023,32(6):691-698,8.基金项目
中国地质调查局项目"滇中楚雄云龙镇等4幅1∶5万区域地质调查"(DD20220987). （DD20220987）
