Geodynamic correlation between the Hainan plume and the heat flow along the Southeast Coast of China: Numerical simulation

Abstract

The relationship between surface heat flow, geothermal resources, and the mantle plume has always been a hot topic in geothermics. Based on the latest heat flow data analysis, we find that away from the Hainan plume, the heat flow demonstrates an increasing trend toward the northeast, and the southeast China coast is a high heat flow belt. Additionally, there is a thin crustal belt that coincides with the high heat flow belt along the southeast China coast, along which a series of mantle plume-derived basalts have developed, and the age of these basalts gradually increases as away from the Hainan plume. To explain the correlation between the Hainan plume and the heat flow along the southeast China coast, we propose a dynamic model to simulate the thermal evolution process of the South China Block as it moved above the Hainan plume since 80 Ma. The modeling results show that a lithospheric high-temperature zone began to be formed in Fujian Province when it was located above the Hainan plume at 80 Ma. Subsequently, the South China Block moved to the northeast at a rate of 1.8 cm/year, and the lithospheric high-temperature zone was also gradually away from the Hainan plume, resulting in the current heat flow showing an increasing trend from Hainan Province to Fujian Province. Our results provide a novel explanation for the correlation between the Hainan plume and the heat flow along the southeast China coast, which might shed light on exploring geothermal resources along the southeast China coast.