地质学报2026，Vol.100Issue(6)：2110-2128,19.DOI:10.19762/j.cnki.dizhixuebao.2025441
辉绿岩斜锆石侵位年龄对华北龙山组中元古界年代属性的限定
U-Pb baddeleyite ages of diabase dykes constrain the Mesoproterozoic chronostratigraphic attribution of the Longshan Formation,North China Craton
摘要
Abstract
One of the significant researchadvances in the Meso-Neoproterozoic strata in the Yanliao area of North China is the discovery of the Yanliao Large Igneous Province(YLIP;～1325 Ma).Previous studies have suggested that the YLIP was emplaced only within the Xiamaling Formation and did not intrude into the overlying stratigraphic horizons.However,the authors have recently discovered diabase sills intruding into the Longshan Formation in the Yanliao area.To clarify whether these diabases are genetically related to the YLIP and to constrain the chronostratigraphic attribution of the Longshan Formation,which has lacked reliable age constraints for over half a century,this study conducted U-Pb geochronological analyses on baddeleyite extracted from the diabases intruding the Longshan Formation using secondary ion mass spectrometry(SIMS)and sensitive high-resolution ion microprobe(SHRIMP)methods.The SIMS method yielded a weighted mean 207Pb/208Pb age of 1322±8 Ma,while the SHRIMP method obtained a weighted mean 207Pb/208Pb age of 1304±8 Ma.The results from both dating methods are highly consistent with the peak magmatic activity of the YLIP reported in previous studies.Based on these geochronological results,combined with a comprehensive investigation of spatiotemporal distribution,intrusive contact relationships,and rare earth element(REE)distribution patterns between the diabases intruding the Longshan Formation and the YLIP,this study concludes that the diabases intruding the Longshan Formation are part of the YLIP.Furthermore,these dating results define the stratigraphic age of the Longshan Formation as the Mesoproterozoic,predating 1322～1304 Ma.This research achieves a breakthrough in the study of the chronostratigraphic attribution of the"Meso-Neoproterozoic"Longshan Formation in North China,a long-standing puzzle that has persisted for more than half a century.It also provides new evidence and age constraints for understanding whether the evolution of eukaryotic microorganisms(including algae)during the Proterozoic follows the"Boring Billion"(1.8～0.8 Ga)evolutionary pattern.while simultaneously expanding the spatio-temporal scope of the YLIP.关键词
华北克拉通/辉绿岩/斜锆石 U-Pb定年/龙山组/地层时代厘定Key words
North China Craton/diabase/baddeleyite U-Pb dating/Longshan Formation/stratigraphic age definition引用本文复制引用
张运强,郝森,陈骁帅,旷红伟,柳永清,王玉冲,彭楠,陈钊鸿,周起凤,李瑞红,王志民..辉绿岩斜锆石侵位年龄对华北龙山组中元古界年代属性的限定[J].地质学报,2026,100(6):2110-2128,19.基金项目
本文为国家重点研发计划项目(编号2022YFF0800302)、国家自然科学基金项目(编号U2444209,42072135,42472150)和中国地质调查局项目(编号DD20230383,DD20240013,DD20221649)联合资助的成果. （编号2022YFF0800302）
