岩石矿物学杂志2026，Vol.45Issue(2)：245-258,14.DOI:10.20086/j.cnki.yskw.2026.5007
滇东南建水晚古生代枕状熔岩年代学、地球化学特征及构造背景
Geochronology,geochemistry and tectonic setting of Late Paleozoic pillow lava in Jianshui,Southeastern Yunnan
摘要
Abstract
Based on the 1∶50 000 regional geological and mineral survey in Jianshui area of Yunnan Province,a set of pillow lava was determined in the study area,which was scattered on the Triassic clastic rock strata.The weighted average age of 14 zircons obtained by LA-ICP-MS zircon U-Pb dating is 352.3±5.9 Ma(MSWD=1.7),which belongs to the early period of Early Carboniferous and represents the eruption time of lava.The lava has the characteristics of high alkali(Na2O＞K2O,Na2O/K2O=2.93～65.7,average 23.1),high Al(Al2O3=11.43％～16.67％)and low Ti(TiO2=1.71％～2.62％,average 2.16％).It belongs to the subalkaline basalt series.The total amount of rare earth elements of the lava is low,∑REE=101.81×10-6～138.50×10-6,and it is enriched in large ion lithophile elements such as Rb,Ba,Th,K and high field strength elements such as Nb,Ta,etc.,show-ing the characteristics of the large uplift distribution pattern unique to the intraplate basalt,which is similar to the characteristics of OIB.The normalized rare earth element distribution pattern of lava shows a right-leaning distribu-tion pattern enriched in light rare earth elements,which is similar to the characteristics of intraplate basalt or ocean-ic island basalt.Combined with the regional geological background,this paper believes that the Jianshui pillow lava may be a product of the Yangtze and Cathaysian continental blocks controlled by the Paleo-Tethys multi-island ocean system under the early extension of the Late Paleozoic,along with the basic volcanic rocks in the northern section of Shizong-Mile,and the Early Carboniferous pillow basalts in the Longlin area of Jingxi,western Guangxi.关键词
枕状熔岩/锆石U-Pb年龄/地球化学/裂谷环境/古特提斯洋/滇东南建水Key words
pillow lava/zircon U-Pb age/geochemistry/rift valley/Paleo-Tethys/Jianshui area,Southeastern Yunnan分类
天文与地球科学引用本文复制引用
郭宏杰,刘德民,王涛,李金祥,李玉龙,于小亮,靳浩,林艳海,李永登,谈绍洁..滇东南建水晚古生代枕状熔岩年代学、地球化学特征及构造背景[J].岩石矿物学杂志,2026,45(2):245-258,14.基金项目
中国地质调查局地质调查项目(1212011220400) Project of China Geological Survey(1212011220400) （1212011220400）
