Distributive Characteristics of Hot Dry Rocks in Sedimentary Basins of China: A Study Based on Vitrinite Reflectance of Hydrocarbon Source Rocks

Abstract

AbstractGeothermal resources as a type of renewable clean energy are highly contributive to sustainable development. In this study, the geothermal resources in some sedimentary basins of China were characterized, and sedimentary basins from different eras and of different types were discussed. On this basis, the major influence factors on the geothermal resources of different regions were elaborated. The geothermal resource potentials in major sedimentary basins of China were evaluated. The geothermal resources in the sedimentary basins of China are extensively distributed and diverse, which are geologically different from East to West China. The target strata of faulted basins in East China, superimposed basins in Central China, and cratonic basins in West China are mainly Cenozoic strata, Mesozoic strata, and Paleozoic strata, respectively. These target strata experienced different types of thermal events in geological historical periods. The Cenozoic faulted basins in East China are mostly heat basins. The Cenozoic sediments are superthick and largely differ in thickness among regions. The effects of Cenozoic geothermal events and the major controlling factors both differed among regions, and the causes of differences included thermal subsidence activities and magmatic activities. These basins are major potential zones for exploitation of hot dry rocks in China. The Mesozoic superimposed basins in Central China are mostly temperate basins, and the ground temperatures nowadays are mainly controlled by thermal subsidence. The potential target zones of hot dry rocks in these basins are the Paleozoic strata in the southwest of basins, which can develop into medium-temperature geothermal resources. In the Paleozoic cratonic basins in West China, the Paleozoic marine sedimentary strata are the major target strata of hot dry rocks. The Paleozoic volcanic events little affected the formation of hot dry rocks, and the formation of major hot dry rocks relied on superthick sedimentary strata, where middle- to low-temperature geothermal resources developed.