大兴安岭战备村地区航磁特征及在地质调查中的应用

以大兴安岭战备村地区1∶5万区域地质矿产调查为例,阐述了磁法技术如何快速有效地指导和开展填图工作。研究区磁场可划分为:特高值磁场、高值磁场、紊乱磁场、条带状磁场、正负抖动磁场、平缓正磁场、平缓负磁场和环状磁场等8种。除玛尼吐组及燕山期侵入岩具有正的中等航磁异常外,基性和酸性火山岩既具有负的低磁异常,又具有正的高磁异常特征。基于此,结合区域地质,识别出了塔木兰沟组与梅勒图组的基性岩地层和火山机构、满克头鄂博组和白音高老组酸性火山岩地层及火山机构,建立了早侏罗统战备村组酸性火山岩地层,并得到了后期山地工程和岩石地球化学分析结果的验证。

Aeromagnetic characteristics and its application in regional geological survey from Zhanbeicun,Great Hinggan Mountain

Taking 1:50 000 regional geological survey in Zhanbeicun distict, Great Hinggan Mountain as an example, the authors described how to guide and carry out mapping work effectively and quickly by using magnetic method. The studied area can be divided into eight fields, including very high value magnetic, high value magnetic, disturbance of magnetic, strip magnetic, positive and negative jitter magnetic, gentle positive magnetic, gentle negative magnetic field and circular magnetic field. Except the Manitu Formation and Yanshan period intrusive rocks that are with positive medium aeromagnetic anomalies, the basic and acidic volcanic rocks not only have negative low magnetic anomaly, but also have positive high magnetic anomaly. Based on this, combined with regional geology, the authors identified the basic volcanic rock assemblages as well as volcanic structures of Tamulangou and Meiletu formations, the acid volcanic rock assemblages as well as volcanic structures of Manketouebo and Baiyingaolao formations, and also newly established Jurassic volcanic stratigraphy of Zhanbeicun Formation, which was later confirmed by mountain engineering and petrogeochemical analysis.