Economic geology of the geothermal deposits of Mexico
In a general sense, geothermal refers to the natural heat of the Earth’s interior, independent of the factors involved in its surface manifestations. This heat flows directly through the rocks or is transported by fluids that rise along fractures to more or less deep zones and form the geothermal reservoirs. The heat source—the fluid—and the zone in the crust where the fluid is stored or circulates, together make up the geothermal system.
The term geothermal field implies considerations as to the feasibility of economic development. To benefit from geothermal energy implies developing the heat that underlies the Earth’s surface. Energy production uses the water that comes into contact with subsurface rocks. In some areas the high heat generates steam, but in most geothermal fields the water remains in liquid form. Trapped in subsurface reservoirs, this water may be extracted by drilling wells.