ABSTRACT
This chapter focuses on select geothermal systems and their relationships to the tectonic environment in which they formed. An overview of two main geologic types of geothermal systems-magmatic and amagmatic-and the geologic and geochemical characteristics of each begins the chapter. The tectonic settings and geologic types of geothermal systems exert a clear inuence on the physicochemical characteristics of geothermal resources and on how those resources might ultimately be developed. The discussion here generally follows earlier ideas of occurrence models of geothermal systems proposed by previous workers (Erdlac et al., 2008; Mufer, 1976; Walker et al., 2005) and recently extended to characterizing geothermal resources as play concepts similar to the oil industry (Moeck, 2014). The effort here is to move toward a classication system that removes arbitrary boundaries, such as temperature or enthalpy to distinguish geothermal systems, and focuses on fundamental geological parameters that dictate the characteristics of geothermal resources and how those resources might best be found and developed.
