Seven sinkholes surround the city of Sedona in Coconino and Yavapai Counties, Arizona. They occur in surface bedrock of Permian age Esplanade Sandstone, Hermit formation, and Schnebly Hill Sandstone, but the causative source is from the collapse of subsurface water-filled caves in Mississippian Redwall Limestone that underlies those formations. The original Mississippian-age Redwall karst surface has undergone two additional phases of dissolution enlargement in later geologic time. The first occurred after the Laramide uplift of the Mogollon Highlands when northeast flowing streams penetrated the exposed Redwall Limestone erosion surface, and the second took place following the generation of the Verde graben ~10 million years ago when regional drainage reversal took place. Pre-graben Miocene basalt lava flows that overlie eroded Paleozoic strata are present on either side of, and faulted within, the Verde graben closed depression. Post-graben erosion generated the Mogollon Rim escarpment in the northern portion of the Verde Valley and allowed surface streams to erode the broad Dry Creek and Margs Draw valleys. Oak Creek fault, and the erosion of its canyon, is much younger than the faulting that generated the Verde graben.

Over time, water flow through the Sedona area evolved from surface flow to dominantly groundwater flow, mainly due to leakage through abundant northwest-southeast oriented rock joints and permeable fault zones into underlying cavernous Redwall Limestone. USGS oxygen isotope studies show that water recharge entering the northeastern part of the Upper Verde watershed, and passing beneath the greater Sedona area, originated high on the Colorado Plateau above 6900 feet before discharging at a rate of ~15 millions of gallons per day at artesian springs in the Page Springs area to the southwest of Sedona. Dissolution caves in the underlying Redwall Limestone have now enlarged to the point where their sandstone roof rocks have collapsed into limestone caves over the past several thousand years. Devils Kitchen sinkhole has historic records of collapse in the 1880s, 1989 and 1995, and it will continue to collapse in future years.

Six additional sinkholes are in various stages of collapse from modern time and possibly to the end of the last Ice Age. While the danger of future collapse is probably minimal to humans, unregulated septic leakage into hidden sinkhole breccias within the town limits could contaminate groundwater being tapped for municipal use or the contamination of the Page Springs outflow. The report contains geologic maps, cross sections, photographs and individual features of the sinkholes as of the end of 2009.

At the request of the U.S. Forest Service to Red Rock Jeep Tours of Sedona a geologic report on the condition of the Devils Kitchen sinkhole was required for the safe continuation of Jeep visits to the site (Fig. 1). Mark Avery of the jeep company contacted me to study the site and write up my findings. The study of sinkholes in the Sedona area has been of interest to the writer for some time and the present study is hoped to shed some light on these fascinating geologic features. This report is offered as a public contribution at the cost of publication and without fee.

To help commemorate Arizona’s centennial on February 14, 2012, a centennial project was begun to inventory and promote the protection of historic cemeteries throughout the state. Historic cemeteries were chosen as the focus of a centennial project because they are important irreplaceable resources many of which are in danger of being lost through neglect, natural erosion, and vandalism. As the Arizona Centennial approached, it seemed appropriate that an organized statewide effort be undertaken to locate, inventory and provide guidance for the conservation and maintenance of these significant properties.

Alameda-Stone Cemetery, commonly called the National cemetery, was used as Tucson's first cemetery from about 1860 to 1875. It was the direct successor of the cemetery inside the Tucson Presidio. The City of Tucson closed the cemetery in 1875 in anticipation of the coming of the railroad and the sale of the cemetery land for residential and commercial uses. In 1881, the city directed that all burials be removed from the National Cemetery and re-interred at the Court Street Cemetery. However, many burials were not removed before the land was subdivided and developed. These volumes document the archaeological investigation of the area from 2006-2008 before construction of a new court building.

This summary report overviews a State of Arizona and U. S. Department of Energy funded drilling project to determine if near-term hot dry rock (HDR) geothermal potential exists in the eastern portion of the White Mountains region of Arizona. A 4,505 feet deep slim-hole exploratory well, Alpine1/Federal, was drilled within the Apache-Sitgreaves National Forest at Alpine Divide near the Alpine Divide camp ground about 5 miles north of Alpine, Arizona in Apache County (Figure 1). A comprehensive technical report, in two parts, details the results of the project. Part 1, Alpine1/Federal, Drilling Report, discusses the drilling operations,
logging program, permitting and site selection for the hole. Part 2, Temperature Gradients, Geothermal Potential, and Geology, summarizes the temperature gradients, heat flow, geothermal potential, and subsurface geology.