地质论评2024，Vol.70Issue(3)：1127-1138,12.DOI:10.16509/j.georeview.2023.11.055
冀西北地区中侏罗世玄武岩的首次发现及其地质意义
The first discovery of Middle Jurassic basalts in Northwestern Hebei Province and its geological significance
摘要
Abstract
This paper is the result of geological survey.Writers first discovered the basalt association at the bottom of the Middle—Upper Jurassic Tiaojishan Formation in the Xuanhua District—Zhuolu County area,Zhangjiakou City,whose age,geochemical properties,and geological significance requires to further research.This article conducts geological,petrological,geochemical,and isotopic chronological studies on the basalts.The SiO2 content of the basalt ranges from 39.49％to 49.74％,Mg # ranges from 28 to 65,and the Rittmann index(σ)ranging from 2.61 to 33.12.The basalt belongs to the alkaline basalt series and forms bimodal volcanic rock combination with the overlying trachyte,indicating that the early volcanic rocks of the Tiaojishan Formation were formed in a continental plate tensile environment.This set of basalts is a geological,petrological,and tectonic study of the basaltic magma underplating of the neutral volcanic rocks of the Tiaojishan Formation.关键词
冀西北/中侏罗世玄武岩/髫髻山组/底侵作用/板内拉张Key words
northwestern Hebei/Middle Jurassic basalts/Tiaojishan Formation/plate tension引用本文复制引用
白春东,许凡,李泽阳,孟家葆,朱本鸿..冀西北地区中侏罗世玄武岩的首次发现及其地质意义[J].地质论评,2024,70(3):1127-1138,12.基金项目
本文为河北省自然资源厅"河北省沙岭子、宣化县、深井镇、涿鹿县1∶5万区域地质调查"的成果. This paper is the result of the 1:50000 Regional Geological Survey of Shalingzi,Xuanhua County,Shenjing Town,and Zhuolu County in Hebei Province by the Department of Natural Resources of Hebei Province （）
