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

the area less than one mile north of the Buena Vista thermal wells.
Core descriptions
by E.S. Davidson of the U.S. Geological Survey from well D-6-27-35CBB
suggest that this well is very near the fault zone (files, USGS,
Tucson).
Davidson describes a conglomerate between 171 and 210 m whose bedding dips 30 0
"from vertical" (files, USGS, Tucson).
The bedding orientation is interpreted
as either evidence of drag on the hanging wall of the Butte fault zone or talus
below a paleo-escarpment.
Fanglomerate depositional dip is ruled out because
the'observed dip is probably too steep.
While conglomerates, predating highangle
Basin and Range faulting, commonly have monoclinal geometry in Bonita
Creek and in Eagle Creek, both east of Buena Vista, these sediments do not
contain red granite clasts.
Instead, they are angularly unconformable with
overlying flat-bedded conglomerate, which consists of basaltic. and red granite
clasts (Heindl, 1958).
The younger bimodal gravels are post and syntectonic
high-angle Basin and Range faulting such that they fill contemporary structural
basins.
Tilted gravels in D-6-27-35CBB, which contain red granite, are
included in the younger suite of sediment that fill contemporary basins;
therefore, the apparently anomalous bedding orientation of gravels in D-6-27­
35CBB may indicate deformation proximal to a fault, albeit the Butte Fault.
Below the tilted gravels in well D-6-27-35CBB, volcanic rock and volcanoclastic
sediments are encountered at 211 m depth, while at 275 m depth, probable
Laramide andesite is encountered.
The andesite is epidotized and mineralized
with copper (files, USGS, Tucson). Another well, 1.5 miles south of
D-6-27-35CBB, also is believed to bottom in bedrock. This well, D-7-27-2CDB,
reaches "red granite" at 213 m depth (files, USGS, Tucson). This "red granite"
is interpreted by the writer as a red stained "Laramide" silicic tuff or a
stained quartz monzonite intrusion like those exposed in the Gila Mountains
near the Lone Star mine.
This "red granite" is not believed to be lithology
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