Distribution Characteristics and Genetic Mechanisms of Geothermal Radon Mineral Water in Shandong Province

Abstract

This study systematically investigates the concentration of ²²²Rn in geothermal fluids and the distribution of geothermal radon mineral water in Shandong Province, with the aim of elucidating formation mechanisms and influencing factors. The findings indicate that the overall abundance of ²²²Rn in geothermal fluids across the region is relatively low. Geothermal radon mineral water is primarily located within banded thermal reservoirs associated with bedrock fracture structures in the Ludong and Luxi uplift geothermal zones. The study reveals that the ionic composition, radioactivity intensity, and extent of water-rock interactions exert only effects in the concentration of ²²²Rn in geothermal fluids. The formation of geothermal radon mineral water is predominantly governed by “fracture-controlled” mechanisms, with thermal reservoir lithology, fracture tectonics, and seismic activity serving as key determinants. Additionally, the enrichment of ²²²Rn in geothermal fluids is influenced by factors such as geothermal fluid temperature, depth of occurrence, cap rock thickness, and alteration processes. The genetic mechanisms of geothermal radon mineral water can be categorized into two types: ‘native’ and ‘composite’. These findings provide critical insights into the exploration and development of geothermal radon mineral water resources in Shandong and similar regions.