geothermal resource potential of the safford-san simon basin, arizona

500 m interval, while 1.2 HFU is reported for the 950 to 1,050 m interval
in this hole (Reiter and Shearer, 1979).
The temperature-versus-depth profile
of this well (Figure 13) shows a temperature inversion below 500 m which is
consistent with the heat flow data.
Lateral flow of thermal water entering
the drill hole at about 600 m is a possible explanation for the temperature
profile below 500 m.
The "Laramide" rocks believed to be encountered in this
hole are inferred to have fracture permeability and have potential as a deep
geotherma1 reserV01r. 'Th' 1S we 11,whose b0ttom hIt 0 e emperat ure 1S . about 7Z o C,
implies that the thermal anomaly associated with the Buena Vista thermal wells
is more extensive and includes a larger area than is encompassed by the wells
at Buena Vista.
Available information points toward a deep geothermal system in the
fractured and sheared "Laramide" volcanic sequence and in the major Basin and
Range fault zones transecting the subsurface in the Buena Vista area.
Because
no Quaternary volcanism is known in the Buena Vista region, the origin of the
thermal anomaly is probably deep circulation of water through hot rock at depth
which is heated by regional crustal heat flux.
Additional geochemical and
detailed heat flow studies are needed to adequately assess the extent and
temperatures of the inferred, deep (1 to 2 km) geothermal system in the Buena
Vista area.
The known shallow, low-temperature geothermal reservoir at Buena
Vista area has significant direct-use potential in agriculture, aquaculture,
and space heating using 40 to 50 0 C water.
49