河北小山火山的地磁场分布特征及其地质意义

Geomagnetic Field Distribution Characteristics of Xiaoshan Volcano and Its Geological Significance

河北小山火山地处渤海之滨,是渤海西岸地壳活动最直接的证据,其典型性、多样性和自然性在国内非常罕见,具有独特的科学研究意义。该火山地质遗迹保护区基本全被第四系覆盖,而高精度磁测方法可研究第四系覆盖区地质特征,是寻找火山遗迹边界、区内典型地质构造的必要手段。本研究主要分析了小山火山地质遗迹保护区的磁场分布特征;通过对磁异常进行化极、向上延拓等处理,基本查明保护区内岩浆岩和沉积地层的分布范围,圈定了火山遗迹的边界,并推断存在多条断裂。本研究可为小山火山地质遗迹的保护工作提供可靠的基础资料,对地质遗迹景观点的划分、保护区的整体合理规划等具有重要的参考价值。

Located on the Bohai seashore,the Xiaoshan volcano is the direct evidence of crustal activity on the western Bohai seacoast.The area is famous for its typicality,diversity and naturalness.With its unique scienti-fic significance,it is very rare in China.Due to the extensive Quaternary cover on the volcanic rocks,high-precision magnetic measurement was used to delineate the boundary of volcanic relics and to study typical geological structures.In this study,we described the magnetic field distribution characteristics of the Xiaoshan volcanic geological relics protected zone.Distribution range of the magmatic and sedimentary rocks in the zone was identified and their boundaries were delineated,and a number of faults were inferred.This is achieved through analyzing magnetic anomaly of the pole,upward extension,and the search for derivative and other processing methods.Our findings support that the high-precision magnetic method is effective to study the geological characteristics beneath the overburden area.The study of the magnetic field distribution features provides detailed and reliable basic data for the Xiaoshan volcano geological relics,and has important implications for the division of the geological relic landscape and for sensible planning of the protected zone.