A conceptual model of the Tianjin Geothermal system based on isotopic studies

摘要

The isotopic technique is an effective measure to set uu the conceptual model of a hydrothermal system. A deep circular geothermal system exists in Tianjin, including the semi-open and semi-closed karst geothermal subsystem in the bedrock and closed porous water subsystem in the elastic rocks. The geothermal water is originated from the ancient precipitation of 21 - 10 kaBP. Since Holocene epoch, the geothermal water is sealed for heating up.