Terrestrial heat flow of continental China: Updated dataset and tectonic implications

Abstract

Terrestrial heat flow is a crucial parameter to indicate the thermal state within the Earth, containing integrated information of the ground temperature, thermal conductivity, and crustal/mantle heat flow. We present an updated heat flow dataset and map in continental China. The data increases from 862 to 1230 observations since the year 1999 and the sites cover the major tectonic units, although their spatial distribution remains uneven. Excluding the local anomalies related to hydrothermal activities, the background heat flow values display a range from 30 to 140 mW m–2 with a mean of 60.4 ± 12.3 mW m–2. The updated heat flow map exhibits a heat flow pattern consisted of four heat flow provinces in continental China: eastern mantle-induced high flow province, southwestern crust-induced high heat flow province, central normal heat flow province and northwestern low heat flow province. The major heat flow provinces correspond to the Cenozoic lithosphere-scale tectonic units. The heat flow shows good correlation with crustal thickness and elevation, agreeing with the thermal isostasy. The heat flow distribution also corresponds with the Meso-Cenozoic tectonic activities. The present heat flow-tectonic pattern in continental China is formed by the Meso-Cenozoic geodynamic processes, including the Cenozoic India-Eurasian collision and the Mesozoic-Cenozoic western subduction of the Pacific Plate.