渭北韩城-富平一带重磁异常特征及其地质找矿意义  

Gravagnetic Anomalies And Ore Prospecting In The Area From Hancheng To Fuping County At The Northern Side Of The Weihe River

作　　者：张焕侠 刘建利 屈挺 李飞 任乖雅 王庆国 于淑莉 Zhang Huanxia;Liu Jianli;Li Fei;Qu Ting;Ren Guaiya;Wang Qingguo;Yu Shuli(Shaanxi Geophysical and Geochemical Exploration Team Co.,LTD,Xi'an 710043)

机构地区：[1]陕西地矿物化探队有限公司,陕西西安710043

出　　处：《陕西地质》2023年第1期19-25,18,共8页Geology of Shaanxi

基　　金：陕西地矿集团有限公司科研专项资金项目(KY202109)。

摘　　要：铁矿石为大宗商品及战略物资,当前我国铁矿资源安全问题凸现。火山-沉积变质型铁矿是陕西省重要铁矿类型之一,涑水群为该类型铁矿的赋矿地层之一。渭北韩城-合阳-蒲城-富平航磁异常带幅值高、规模大,多个异常圈闭中心呈串珠状排列,地表主体为新生界地层。该磁异常带是否整体对应赋存磁铁矿的隐伏涑水群,如果存在,其展布形态如何,一直为陕西地质同行心中存疑。本文结合区域地质构造演化、航磁△T三维反演结果及1∶5万重、磁、电综合物探剖面反演解释结果,首次为该地区航磁异常带整体对应隐伏涑水群及其展布形态提出了推断依据,同时认为隐伏涑水群整体形似褶皱,NE-SW向展布,西北翼陡,东南翼缓。该认识推断有助于陕西省火山-沉积受变质型铁矿中阳山庄式铁矿的找矿预测,对陕西省铁矿找矿有着深远意义。Volcanic sedimentary metamorphic iron ore is one of the important types of iron ore and the Sushui Group is one of the host strata of this ore type in Shaanxi Province.The aeromagnetic anomaly zone along the counties of Hancheng,Heyang,Pucheng and Fuping in the northern side of the Weihe River is featured in high amplitude and large scale,appearing in multiple anomaly trap centers arranged in a string of beads,mainly composed of the Cenozoic strata at the ground surface.Whether this magnetic anomaly zone corresponds to the concealed Sushui Group where magnetite occurs as a whole,and if so,how about their distribution?Based on regional tectonics,three-dimensional inversion results of aeromagnetic△T and inversion interpretation results of gravity,magnetic and electrical integrated geophysical profiles at a scale of 1:50,000,the inference basis for the overall corresponding blind Sushui Group and its distribution shape along the aeromagnetic anomaly zone appearing at the counties of Hancheng,Heyang,Pucheng and Fuping is proposed in this paper for the first time.At the same time,the whole strata of the blind Sushui Group have shapes like a fold,with NE-SW spreading,steep angle at the northwest wing and slow southeast wing.The inference of this blind Sushui Group is helpful to the prospecting and prediction of the Yangshanzhuang type iron ore in the volcanic sedimentary metamorphic type of iron ore in Shaanxi Province.

关 键 词：渭北 重磁异常 三维反演 隐伏涑水群 硅铁质建造 

分 类 号：P31[天文地球—固体地球物理学] P611[天文地球—地球物理学] P631