Crustal Temperature and Geothermal Systems in the Northeastern Part of China

Abstract

Cenozoic basaltic rocks are distributed widely in the northeastern part of China. However, active geothermal systems are very rare except that of Changbaishan volcano at the border of China and North Korea where high temperature hot spring activities exist. In this paper, we firstly clarified the crust and upper mantle temperature based on the heat flow data. As a result, it is shown that the crustal temperature is not high enough to generate basaltic magma in the crust. The basaltic magmas generate only in the upper mantle. This is the reason why the geothermal systems generally do not develop in the Cenozoic basaltic region of the northeastern part of China. The reconnaissance geophysical and geochemical surveys were conducted around the hot spring activities at the flank of Changbaishan volcano. As a result, a preliminary conceptual thermal model with supply of magmatic fluid is constructed. The hot spring activities at Changbaishan volcano may relate to another type of magmatic activity (silicic trachyte magma) in the Quaternary.