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 Big Sandy Valley is a north-trending valley located south and east of Kingman, Mohave County, Arizona (Figure I-1). Interstate 93 between Phoenix and Kingman travels along the axis of the Big Sandy Valley. This road provides major access to several small communities located in and adjacent to the valley. Well maintained dirt roads also lead to many of the ranches and mines in the area. Three springs have temperatures in excess of 30 degrees C and most wells have simple temperature gradients in excess of 30 degrees C/km. Higher gradients are found along the coarse of the Big Sandy River as well as in the southern portion of the valley. Current data indicate reservoir temperatures in excess of 150°C may be achieved at depths in excess of 3 kilometers. Desalting operations are unlikely in most of the valley. The best area for such use lies in the southern portion of the area. Direct use applications appear to be more likely. (26 pages)

The geologic history of Arizona can be found in the record of its rocks, the five periods of geologic time, the Younger Precambrian, the Older Precambrian, the Paleozoic, the Mesozoic and the Cenozoic tell the story of Arizona's past. Part of the story they relate is the ancient lifeforms of the state. Long before man discovered the New World for the first time life was abundant, there were ground sloths, camels, bison and when an ancient sea ruled part of the state there were mollusks, jellyfish and other forms of marine life. This bibliography is meant to be used as a guide to some of the literature on the ancient life of Arizona. It is not a comprehensive listing, but it is the most complete bibliography on this topic to date and as such will be useful to both students of geology and geologists. (46 pages)

Scale at 1:50,000. 18 p. Text and Sheet.

Structural measurements of deformation fabrics in Paleoproterozoic rocks within the map area were plotted on stereonets using Rick Allmendinger’s Stereonet software provided on his Cornell University website (www.geo.cornell.edu/geology/faculty/RWA/programs.html). One map sheet and a second sheet with geochemical data and plots, structural stereonets and three cross-sections.

These geologic map sheets and report encompass the proposed State Route 95 Relocation Corridor in Mohave Valley, western Arizona, between the Black Mountains on the east and the Colorado River on the west (Figure 1). The maps were developed through compilation of existing geologic mapping and extensive new geologic mapping. The map area includes a portion of the historical floodplain of the Colorado River, a broad swath of the piedmont east of the river, parts of western flank of the Black Mountains, the channels and terraces of Sacramento Wash, and the northernmost piedmont of the Mohave Mountains (the Powell Mountain area). The corridor is predominantly covered with late Miocene and younger alluvium deposited by local tributary washes and the Colorado River. Deposits range in age from modern to at least 8 Ma (millions of years ago), and deposit characteristics and composition vary substantially depending on whether they were emplaced by the modern Colorado River, older versions of the river, or tributary washes derived from the Black Mountains or the northern end of the Mohave Mountains. The northern, northeastern, and southernmost parts of the map include a variety of bedrock types ranging in age from early Proterozoic to middle Miocene. This map and report describe the physical characteristics of geologic units of different ages and sources, the mapped extent of various geologic units, and potential geologic resource and geologic hazard implications of this mapping. These maps include modified versions of portions of several published maps that have been completed in this area since 1997 (Howard et al., 1997; Howard et al., 1999; Faulds et al., 2001; Murphy et al., 2004; Pearthree and House, 2005; Pearthree, 2007; Spencer et al., 2007; Malmon, in review). Extensive new surficial geologic mapping and bedrock mapping was done where needed.

The eastern Black Canyon City 7 ½' Quadrangle and the western Squaw Creek Mesa 7 ½' Quadrangle includes the Interstate 17 corridor where it passes through Black Canyon City and Rock Springs and continues north up the steep grade on the southwest slope of Black Mesa (Figure 1). The distribution of surfaces of different ages and sources in the Black Canyon City quadrangle is associated with the Agua Fria River and Quaternary landslides in the southern and northern halves of the quadrangle, respectively. The southern half of the quadrangle is dominated by the incised Agua Fria River and its tributaries (Little Squaw Creek and Moore Gulch). The Agua Fria River has incised up to 60 m into Paleoproterozoic bedrock (Xs) in the 11 southwestern quarter of the quadrangle. The Little Squaw Creek and Moore Gulch have incised up to 20 m into Chalk Canyon Formation (Tc, Tcl, Tcs) in the southern half of the quadrangle. The northern half of the quadrangle is dominated by Quaternary landslides (Figure 2, 3) ranging from relatively fresh Holocene landslides (Qylsd) to degraded Pleistocene landslides (Qlso). Several older landslide deposits contain younger landslides, indicating that younger mass-wasting events have occurred on older landslide deposits.

The Boundary Cone 7 ½' Quadrangle includes part of the Black Mountains and most of the piedmont between the Colorado River floodplain and the Black Mountains southeast of Bullhead City, Arizona. Production of this new geologic map continues the Arizona Geological Survey mapping program in the rapidly developing lower Colorado River corridor, and complements geologic mapping to the northwest and west of this quadrangle (Figure 1). This mapping was done under the joint State-Federal STATEMAP program, as specified in the National Geologic Mapping Act of 1992, and was jointly funded by the Arizona Geological Survey and the U.S. Geological Survey under STATEMAP Program Contract award number 05HQAG0078. Mapping was compiled digitally using ESRI ArcGIS software.

The Needles NE 7 ½' Quadrangle includes the modern and historical floodplain of the Colorado River and the lower piedmont between the river and the Black Mountains to the east. This quadrangle is completely covered with late Cenozoic surficial deposits laid down by the Colorado River or its tributaries. Deposits range in age from modern to several million years old, and deposit characteristics and composition vary substantially depending on whether they were emplaced by the modern Colorado River, older versions of the river, or tributary washes derived from the Black Mountains. This map and report describe the physical characteristics of deposits of different ages and sources, the mapped extent of various deposits, and potential geologic resource and geologic hazard implications of this mapping.

The geology of the Davis Dam SE quadrangle reflects the complex interplay of the Colorado River and piedmont drainages that flow from the Black Mountains to join the river. The history of the Colorado River in this area begins with the influx of water and sediment from the north about 5.5 Ma (House et. al., 2002). The first deposits associated with the river contain only locally-derived sediment from the northern part of Mohave Valley. These deposits are succeeded by the fine-grained Bouse Formation, which was probably deposited in a series of lakes as the developing Colorado River spilled over successive divides (Spencer and Patchette, 1997; House et al, 2002; Spencer and Pearthree, 2001). After the Colorado River was integrated through Mohave Valley, it entered a major phase of aggradation which resulted in the accumulation of about 800 feet of river sand and gravel that interfingers with tributary gravel and sand. By 3.3 Ma, the river had begun to incise into the valley fill and tributary deposits were cut into the uppermost part of the old river deposits. The river downcut to a level close to the modern river level by the early Quaternary, but subsequently there were at least 2 major aggradation events during the middle to late Quaternary. The modern channel is quite narrow and most of the historical floodplain has been developed, either as part of Bullhead City or as agricultural fields in the Fort Mohave Indian Reservation.