U–Pb dating integrated with geothermometry: an approach to recognize and reconstruct ancient hydrothermal fluid flow

Understanding ancient hydrothermal fluid flow is critical for predictive models of geoenergy resources, including critical raw materials, oil and gas, geothermal energy, natural hydrogen, and fluid disposal reservoirs. This study proposes a novel approach, integrating U–Pb dating and fluid-inclusion geothermometry, to distinguish hydrothermal heating from the palaeo-ambient burial temperature (PABT) in palaeogeothermometric records. Our approach combines fluid-inclusion geothermometry with absolute age and burial history to quantify if the palaeotemperature exceeded the PABT. Applied to the shelf of the Anadarko and Arkoma basins, we analysed three calcite cement samples from Mississippian-aged carbonate host rocks with ages of 318.2 ± 18.1, 305.0 ± 10.5 and 308.6 ± 2.5 Ma. Our results demonstrate temperature anomalies 44–144°C above PABTs of 41, 27 and 27°C, revealing prolonged Carboniferous–Permian hydrothermal fluid flow. Combined with regional data, we interpret the hydrothermal fluid flow as originating from recharge on the Ouachita and Ancestral Rocky mountains, leading to gravity-driven fluid flow into the hot foredeep of the Anadarko and Arkoma basins, and out through regional stratigraphic aquifers with structural damage.