河北省承德县地区航磁异常特征及找矿前景分析

Characteristics of Aeromagnetic Anomaly in Chengde County,Hebei Province Analysis of mineral exploration prospects

河北省承德县地区地处华北陆块区晋冀古陆块的迁西陆核与燕山裂谷复合部位,中-新生代以来,其构造演化既受特提斯构造域影响,又受环太平洋构造域控制,经历了多期次的构造热事件,地质构造复杂,多金属成矿作用集中产出,成矿条件优越。在系统分析研究区地质背景的基础之上,采取水平一阶导数、垂向一阶导数以及Tilt梯度等技术方法对获取的1∶5万航磁数据进行各种位场转换与处理,根据磁异常分布特征,对区内已有的断裂和已知矿点进行了分析与研究,得到矿点与研究区内的断裂构造分布、磁性强弱分布密切相关。结合各种地质资料,利用Tilt梯度方法进一步完善了承德县地区的断裂构造,新推断断裂6条,依据化探异常与已知矿点航磁异常特征圈定找矿靶区共7处,为该区后续进一步研究地质构造背景和找矿提供借鉴。

The Chengde County area in Hebei Province is located in the composite area of the Qianxi Land Core and the Yanshan Rift of the Jin Ji Ancient Land Block in the North China Block.Since the Mesozoic and Cenozoic eras,its tectonic evolution has been influenced by both the Tethys tectonic domain and the Pacific Rim tectonic domain,experiencing multiple stages of tectonic thermal events.The geological structure is complex,and polymetallic mineralization is concentrated,resulting in superior mineralization conditions.On the basis of systematic analysis of the geological background of the study area,various potential field transformations and processing were carried out on the 1∶50000 aeromagnetic data obtained using techniques such as horizontal first derivative,vertical first derivative,and Tilt gradient.Based on the distribution characteristics of magnetic anomalies,existing faults and known mineral points in the area were analyzed and studied,and it was found that the distribution of fault structures and magnetic strength in the study area are closely related to the distribution of mineral points.By combining various geological data and using the Tilt gradient method,the fault structure in Chengde County area has been further improved.Six new faults have been inferred,and a total of seven prospecting target areas have been delineated based on the characteristics of geochemical anomalies and known ore point aeromagnetic anomalies.This provides reference for further research on geological structure background and prospecting in the area.