Serpentine Hot Springs consists of two thermal areas (Serpentine Hot Springs proper and Arctic Hot Springs) located on Hot Springs Creek. The waters of Serpentine and Arctic Hot Springs are likely fed by the same source because they have virtually identical chemical compositions and similar maximum subsurface temperatures of 127+/-3°C (260+/-5.4°F). Based on hydrogen and oxygen isotopes, the thermal waters are primarily meteoric (derived from precipitation) in origin. The thermal waters also contain a saline component, interpreted to be a product of bedrock leaching or a ~7% seawater component.
Most of the geothermal features in northern Alaska, including Serpentine Hot Springs, are not associated with recent volcanism, but are instead associated with granitic plutons.(Figure 1. Map of hot springs and granitic plutons) 33 of the 36 thermal springs north of the Alaska Range occur within 5 km (3 mi) of a granitic pluton margin. Serpentine Hot Springs occurs above a 70 km2 (27 mi2) Late Cretaceous (69.2 ± 2 to 80.2 ± 3 million years ago) biotite granite stock called the Oonatut Granite Complex. Based on the geochemistry and geology of northern Alaska thermal springs, the heat is being derived from deep circulation of meteoric water through fractures in the granitic plutons. As the water percolates down through the fractures, it heats up due to the geothermal gradient (increase of temperature with depth), and then moves back up to the surface along the fractured and faulted margins of the plutons. Subsurface temperature estimates for Serpentine Hot Springs as well as 25 other thermal springs in west-central Alaska indicate that the thermal waters circulate to depths of 3.3-5.3 km (2.1-3.3 mi). This circulation depth was determined using a geothermal gradient of 30 °C/km to 50 °C/km; however, if magma underlies the springs and is contributing heat to the system these depths could be shallower.