Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

In geothermal aspects, we have estimated the Curie point depth on the aero-magnetic data acquired in the Gyeongsang Basin. The result shows that the shallowest Curie point depth of 11.4 km appears in the area of Masan-Changwon-Milyang, whereas the deepest depth of 14 km appears in the northwestern part of the Gyeongsang basin. Utilizing the estimated Curie point depth distribution and assuming the temperature at which the rocks, mainly of the magnetite in the rocks, lose the magnetization(Curie point) to be 550℃, the maximum temperature gradient calculated from the Curie point depth at the shallowest center, that is, Masan-Changwon-Milyang area is about 49℃/km, which is much higher than that of the global mean 40.3℃/km. In the meantime, by applying various data processing methods to the original aero-magnetic data, we could derive major magnetic lineaments in the direction of NNE-SSE in the middle and southern part of the study area, and those in the direction of NWW-SEE in the northern part. Especially a small area in the southern part, known as Milyang sub-basin, we could derive a lot of magnetic circular features, many of which correspond to some well known calderas and cauldrons, and which seem to be directly or indirectly related to the magnetic lineaments of the study area. From the Curie point depth estimation and the magnetic lineaments analysis in the study area together with some review of the heat flow analysis data already published on the Korean Peninsula, we could derive that the deep volcanic activities took place mainly in the southern part of the Gyeongsang basin, i.e., Masan-Changwon-Milyang area. From these aspects, in the Masan-Changwon-Milyang, the possibility of the existence of the remnant geothermal potentials would be high, and it seems that the geothermal energy will transfer to the surface through the weak linear structures by the convection system. As there exist the sediments on the surface doing the role of cap rocks masking the heat dispersion to the surface by the convection system in the southern part of the Gyeongsang basin, we could expect high feasibility of the development of the geothermal energy for hot spring and local heating.