Study On Crustal Heat Production And Estimation Of Hot Dry Rock Resources Potential In South China

Based on the geochemical map of mainland China,the content of U,Th and K₂O on the surface of South China is digitized based on a 0.25°×0.25°grid and integrated into two data specifications,1°×1°grid and South China tectonic unit.According to the heat generation formula,the results are as follows:the surface heat generation of each tectonic unit in South China exceeds1.57?Wm^-3;the Southeast Coastal Magmatic Arc(inner zone),the Southeast Coastal Magmatic Arc(outer zone)and Hainan Island are widely exposed with granites and the surface heat generation exceeds 2.76?Wm^-3,while the Southeast Coastal Magmatic Arc(inner zone)has a surface heat generation of 3?Wm^-3;the surface heat generation of the tectonic units in South China is at an intermediate level compared with the average surface heat generation of the tectonic units in North America,Australia and South Africa.According to the stratification of the crust and the surface heat flow as a constraint condition,the Monte Carlo method was used to invert the heat production of the upper,middle and lower crust of each tectonic unit in South China,showing a phenomenon that the upper crust inversion results are better.The average crustal heat generation is weighted according to the thickness of the upper,middle and lower crust,and the average crustal heat generation of each tectonic unit in South China is 0.47?1.38?Wm^-3;it is assumed that the surface heat generation calculated according to the heat generation formula is the upper crustal heat generation and divided by the average crustal heat generation obtained from the inversion to obtain the crustal differentiation index,the crustal differentiation index of each tectonic unit in South China is 1.14?3.42.The calculated geothermal depth is 0-10 km,with an interval of 0.1 km,and is divided into upper and lower layers with a boundary of 3 km.Two heat generation models are used to calculate the deep temperature,and then the volume method is used to evaluate the Hot Dry Rock Resources in the 1°×1°grid of each tectonic unit in South China(1°×1°grid that meets the ground temperature conditions greater than 180?).The following 1°×1°grids are used to calculate the ground temperature by using two heat generation models to estimate the heat storage,no matter the ground temperature conditions are suitable or the burial depth is shallow,they all become more favorable potential areas for Hot Dry Rock Resources.These 1°×1°grids(identified by the center point of the grid)are:(25.5 N,100.5 E)in the northwest of Kunming,Yunnan Province and(25.5N,102.5 E)in the northeast of Kunming;(22.5 N,111.5 E)near Guangzhou,(26.5 N,115.5 E)in the northeast of Ganzhou,Jiangxi Province and(26.5 N,118.5 E)in the northwest of Fuzhou,Fujian Province;(29.5 N,121.5 E)near Ningbo City,Zhejiang Province.