Proven and potential geothermal resources are shown by the outlined areas on the 1:1,000,000 map of Arizona. The areas are numbered by county. They outline known hot wells and springs and appropriate geologic setting. Approximately 85% to 90% of the known geothermal occurrences are listed in the computer printout. All of the areas except Greenlee 1 occur in sediment-filled basins. Isolated single occurrences of hot water (>30 degrees C) are shown on the map as dots. (64 pages)

The Tucson basin, located in southeastern Arizona, underlies a rapidly growing metropolitan area. Because of Tucson's rapid growth and because it's economy relies heavily upon the aerospace, agriculture, defense, education, electronics, mining, and tourism industries, significant opportunities exist for direct-heat utilization of geothermal water. Geothermal energy could have economic impact by stabilizing energy costs to resource users. The purpose of this report is to outline known occurrences of thermal (>300 degree C) water around Tucson. Identification of the main geologic and geohydrologic features which determine the temperature distribution beneath Tucson provides a basis to formulate geologic models which have use in exploration and evaluation of area resources. (66 pages)

Willcox, Arizona, established in 1880 when the Southern Pacific Railroad was built, lies on the east edge of the Willcox Playa at the northwest base of the Dos Cabezas Mountains in the Sulphur Springs Valley of southeastern Arizona (Fig. 1). The Sulphur Springs Valley, named for the no longer flowing springs at the base of low hills south of the playa, is underlain by the sediment filled Willcox basin. While sulphurous springs are frequently thermal and may indicate significant geothermal energy potential, the namesake springs in the valley are not believed to have been thermal. However, several wells drilled for irrigation and domestic water supplies have encountered thermal water (>30 degrees C). This report summarizes and discusses these occurrences in context to their geologic and geohydrologic settings. An additional goal of this study is to identify areas in the Willcox basin, which have geothermal resource potential. Because the Willcox area has a large agricultural economic base and has relatively cool nights in the winter, significant opportunities exist for direct use of geothermal heat. Agricultural and space heating applications best utilize lower temperature resources. Possible development of geothermal resources in the Willcox area may be advantageous in saving energy and conserving ground water. Many forms of geothermal agriculture such as greenhouses use far less ground water per acre for irrigation than conventional crops such as cotton. (39 pages)

Numerous artesian wells in the Safford basin, southeast Arizona, discharge thermal water (30 to 500 degrees C) contained in sand and gravel aquifers stacked within and below an extensive silt and clay aquaclude. The artesian geothermal resource appears to be characterized chiefly by a conductive thermal regime in basin fill sediments, although hydrothermal convective systems apparently exist below the silt and clay in a few areas. A probable hydrothermal system is located 18 km south of Safford adjacent to U.S. 666 (Fig. 1). This system, the Artesia anomaly, is characterized by high soil mercury and high apparent heat flow (>167 mW/m 2) in a 3 km2) area. The Artesia anomaly is the subject of this report. (51 pages)

The San Carlos-Safford-Duncan Nonpoint-Source Management Zone (Figure 1) is known to contain significant quantities of geothermal energy resources. Following the energy crisis in the 1970s, these resources were studied in detail. This report includes references pertaining to geothermal energy resources, hot springs and wells, heat flow measurements, and geothermal gradients. Two geothermal reservoirs are located in Greenlee County. One ofArizona's most important Known Geothermal Resource Areas (KGRA) is at Clifton. References pertaining to geothermal resource evaluations for Greenlee County and the Clifton KGRA include Witcher (1979a), Arizona Geothermal Commercialization Team( 1979), Witcher and Stone (1980), Witcher (1981), and Hahman (1979a, b). The Safford basin, in Graham County, contains at least four proven and potential geothermal reservoirs of less than 1.2 km depth and three inferred moderate to high-temperature reservoirs less than 2.5 kIn depth (Arizona Geothermal Commercialization Team, 1979). Studies by Witcher, 1979b, 1981, 1982) Rahman, (1979a) and Halnnan and others (1979) focused on characterizing the nature and extent ofgeothermal anomalies in the Safford area. (7 pages)

This report details geothermal resource exploration done for Arizona Public Service and the U.S. Department of Energy. Arizona Public Services (APS) of Phoenix, Arizona, retained David Brown & Associates (DBA) in 2005 to evaluate the geothermal resources of the Clifton Hot Springs area in Greenlee County, eastern Arizona for electric power production. Project Management was provided by T2 & Associates of Sacramento, California. The intent of the evaluation was to determine the local geologic controls of the geothermal system and, using publicly available data and original mapping performed for this project, to recommend locations for Controlled Source Audiomagnetotelluric (CSAMT) cross sections. The results of the geophysics were then combined with the geologic mapping to site three gradient holes, two of which were drilled to depths of 635 feet and 1,000 feet, respectively. This work was done with funding from the US Department of Energy under their Geothermal Resource Exploration and Development III (GRED III) program and co-funding from APS. Grant number was DE-FC36- 04GO14346.