Abstract
The gravity and magnetic measurements have been obtained from 34 stations with 50m intervals along the survey line positioned between Jangtanri and sindapri for studying subsurface geology and structures of the volcanic rocks in Yeoncheon area. The Bouguer gravity and magnetic anomaly values were evaluated from the reduction of the field observation, and then interpreted by Nettleton's method and maximum-pepth rules, are approximately 160m based on magnetic data and 135m based on gravity data. High Bouguer gravity anomaly zone between 0m in Jangtanri and 900m along the survery line, is caused by thick and high density, older dasalt which is positioned beneath jijangbong tuff breccia, and this result corresponds to the interpretation result based on magnetic anomly. Lower gravity and magnetic anomaly zones ariund 900m are caused by between 1300m and 1550m are caused by high density of Quarternary basalt exposed in the surface, and lower gravity and magnetic anomalies at 200m and 1250m are caused by faults.