摘要
大黄峪岩体位于华北克拉通中部,是太行山中生代构造-岩浆活动带的重要组成部分。本次研究通过对大黄峪黑云母二长花岗岩进行锆石年代学、地球化学和成因矿物学等方面研究,解析了大黄峪岩体的成岩时代及构造背景并反演了岩浆演化的过程。研究发现,样品中的锆石颗粒长宽比1.31∶1~2.90∶1,晶体类型主要有S、P两种主型,具有壳幔混源特征。锆石U-Pb年龄为130.5 Ma,表明其侵位于早白垩世,与太行山北段其他岩体形成时代一致。Ti温度计计算锆石结晶温度为743~920℃(均值为849℃),锆石Ce氧逸度计结果显示lgfO_(2)为-14.80~-5.45(平均FMQ为3.44)。角闪石为镁角闪石,温压计计算结果显示其形成温度为771~789℃,压力为87~103 MPa,氧逸度(lgfO_(2))为-13.4~-13.2,平衡熔体含水量为4.4%~4.6%,形成深度为3.3~3.9 km。黑云母为富镁黑云母,形成温度为693~720℃,压力为43~58 MPa,氧逸度(logfO_(2))为-17.21~-16.28。锆石ε_(Hf)(t)值分布于下地壳与上地壳Hf同位素分异演化线之间(ε_(Hf)(t)=-20.14~-17.77,TDM_(2)=2304~2461 Ma)。综合研究认为,大黄峪黑云母二长花岗为地壳和地幔物质相互作用形成的。
The Dahuangyu pluton is located in the central part of the North China Craton and is an important component of the Mesozoic tectonic-magmatic belt in the Taihang Mountains.This study conducted research on the zircon geochronology,geochemistry,and petrogenesis of the Dahuangyu biotite monzogranite to determine its emplacement age and tectonic setting and to reconstruct the magmatic evolution process.The study found that the zircon grains in the samples have a length-to-width ratio of 1.31∶1 to 2.90∶1,and the main crystal types are S and P,indicating a mixed crust-mantle source.The zircon U-Pb age is 130.5 Ma,indicating that it was emplaced in the Early Cretaceous,consistent with the formation age of other plutons in the northern Taihang Mountains.The Ti thermometer calculation shows that the zircon crystallization temperature vary from 743 to 920℃(average 849℃),and the zircon Ce oxygen fugacity meter calculation shows that lgfO_(2)vary between-14.80 and-5.45(average FMQ 3.44).Amphibole is magnesian amphibole,and the thermobarometer calculation shows that its formation temperature is 771 to 789℃,pressure is 87 to 103 MPa,oxygen fugacity(lgfO_(2))is-13.4 to-13.2,equilibrium melt water content is 4.4%to 4.6%,and formation depth is 3.3 to 3.9 km.Biotite is magnesium-rich biotite,with a formation temperature of 693 to 720℃,pressure between 43 and 58 MPa,and oxygen fugacity(lgfO_(2))of-17.21 to-16.28.Theε_(Hf)(t)values of zircon are distributed between the lower crust and upper crust Hf isotopic differentiation and evolution lines(ε_(Hf)(t)=-20.14 to-17.77,TDM_(2)=2304 to 2461 Ma).The comprehensive study suggests that the Dahuangyu biotite monzogranite was formed by the interaction of crust and mantle.
作者
温雨菁
张聚全
郭子桤
张龙
吴晓贺
张乐民
WEN Yujing;ZHANG Juquan;GUO Ziqi;ZHANG Long;WU Xiaohe;ZHANG Lemin(Hebei GEO University,Shijiazhuang 052161,China;Key Laboratory of Strategic and Critical Mineral Resources of Hebei Province,Hebei GEO University,Shijiazhuang 052161,China;Collaborative Innovation Center for Strategic and Critical Mineral Resources of Hebei Province,Shijiazhuang 052161,China)
出处
《河北地质大学学报》
2025年第6期1-17,共17页
Journal of Hebei Geo University
基金
国家自然科学基金项目(U2444208)。
