Early Navajo land use in northwestern New Mexico: Big Bead Mesa in regional perspective

Big Bead Mesa (LA 12351) is the most famous Navajo archaeological site ever investigated and has played an important role in the interpretation of Navajo culture history. It remains a sacred place to the Navajo, both for historical and spiritual reasons. Pioneering work by Dorothy L. Keur resulted in the publication of the first Society for American Archaeology Memoir and brought Navajo archaeology national recognition. James Hester used Big Bead Mesa as the type site for his Cabezon Phase, although he conducted no research at the site. Big Bead Mesa is not the only Early Navajo site in the Rio Puerco Valley; however, the surrounding area has never been adequately investigated or reported. This paper documents a variety of Navajo sites in the Rio Puerco Valley and indicates that Big Bead Mesa was only a small part of a much larger Navajo occupation that extended to the north, west, and south.     

Joint controlled fluid flow patterns and iron mass transfer in Jurassic Navajo Sandstone,Southern Utah,USA

The Jurassic Navajo Sandstone of Grand Staircase Escalante National Monument (GSENM), Utah, exhibits a broad range of iron oxide/oxyhydroxide concretionary geometries that record a complex paragenetic history of the reservoir. The concretionary geometries are as follows: (i) common macroconcretions (>5 mm in diameter), (ii) ubiquitous microconcretions (<5 mm in diameter), (iii) localized iron oxide/oxyhydroxide‐lined northeast‐striking joints, and (iv) loopy asymmetrical mineralization and banded precipitation patterns (Liesegang bands) associated with the joints. Spheroidal concretion geometries typically indicate diffusive mass transfer, whereas asymmetrical mineralization represents advective directional flow. Liesegang bands parallel to asymmetrical mineralization denote a diffusive mass transfer component perpendicular to the principal flow direction. Careful study of concretionary geometries and their cross‐cutting relationships establishes a relative timing of precipitation and mobilization events. Macroconcretions formed post‐Laramide (<55 Ma), prior to and independent of the Miocene joints. The joints provided conduits for later oxidizing fluids that precipitated iron oxide/oxyhydroxide lining on the joint faces. Advective mass transfer overprinted the area with preferentially cemented flow lines (asymmetrical mineralization) less than 10 Ma, coincident with development of a hydraulic low to the southeast of the region (Colorado River downcutting). Certain trace elements are genetically tied to concretion formation, and evaluation of trace elements establishes precursor mineral phases. Enriched uranium concentrations in concretions (relative to the host rock) and low/undetectable sulfur concentrations in both host rock and concretions suggest that iron oxyhydroxide was a primary precipitate rather than a reduced iron mineral (i.e., pyrite or siderite) that later oxidized. Enrichment of Ni and As in concretions functions as fingerprints for diagenetic concretion formation when determining genesis of ambiguous iron oxide/oxyhydroxide spherules such as the remotely sensed ‘blueberries’ on Mars. Similarities between Mars and Utah spherules such as geometry, in situ spacing and volumetric density suggest that Mars spherules precipitated via a geochemically self‐organized nucleation pattern in diffusive chemical reaction fronts.     

Technologies of compliance: Surveillance of self‐administration of tuberculosis treatment, 1956–1966

The development of antibiotics for tuberculosis in the 1950s liberated patients from prolonged hospitalization and enabled physicians to bring treatment to underserved populations. However, outpatient treatment programs could only be as effective as the reliability with which patients self‐administered medications. This anxiety with non‐compliance quickly became ubiquitous in medicine. Several physicians, treating tuberculosis among the Navajo, attempted to use technologies of surveillance to overcome this limitation. They used fluorescent tracers, urine testing, and radioactive pill dispensers to expose non‐compliance. Although successful, these techniques threatened patient‐doctor relationships with secrecy and distrust. Physicians turned instead to personal surveillance through directly observed therapy.     

Iron precipitation in a natural CO2 reservoir: Jurassic Navajo Sandstone in the northern San Rafael Swell,UT, USA

Diagenetic iron (oxyhydr)oxide minerals are common precipitates expected in CO₂ reservoirs, and these minerals record fluid flow for application to carbon capture and sequestration (CSS). Multiple mineralogy and spectroscopy analyses on a pore to meter scale characterize a well‐exposed, lithologically controlled, iron (oxyhydr)oxides reaction front in the Jurassic Navajo Sandstone. Dolomite is the most prevalent cement (up to 23 area%), followed by only several percent or less of iron (oxyhydr)oxides, kaolinite, illite, and gypsum cements. Bulk geochemistry based on diagenetic mineralogies in the reaction front is compared with the water chemistry from nearby modern spring effluent emanating from the Navajo Sandstone to conclude that similar fluids (i.e., CO₂‐charged, saline waters containing hydrocarbons) are responsible for the precipitation. A second comparison of bulk geochemistry and diagenetic mineralogies of the reaction front with data from other abundant Navajo Sandstone concretions in the Spencer Flat region (in south central Utah) shows that reservoir fluids likely vary spatially and temporally in the porous and permeable Navajo Sandstone. CO₂ injection into porous and permeable, quartz arenite, saline aquifers will likely result in minor clay and abundant dolomite precipitation that will significantly decrease porosity.     

Characteristics of CO2‐driven cold‐water geyser,Crystal Geyser in Utah: experimental observation and mechanism analyses

Geologic carbon capture and storage (CCS) is an option for reducing CO₂ emissions, but leakage to the surface is a risk factor. Natural CO₂ reservoirs that erupt from abandoned oil and gas holes leak to the surface as spectacular cold geysers in the Colorado Plateau, United States. A better understanding of the mechanisms of CO₂‐driven cold‐water geysers will provide valuable insight about the potential modes of leakage from engineered CCS sites. A notable example of a CO₂‐driven cold‐water geyser is Crystal Geyser in central Utah. We investigated the fluid mechanics of this regularly erupting geyser by instrumenting its conduit with sensors and measuring pressure and temperature every 20 sec over a period of 17 days. Analyses of these measurements suggest that the timescale of a single‐eruption cycle is composed of four successive eruption types with two recharge periods ranging from 30 to 40 h. Current eruption patterns exhibit a bimodal distribution, but these patterns evolved during past 80 years. The field observation suggests that the geyser's eruptions are regular and predictable and reflect pressure and temperature changes resulting from Joule–Thomson cooling and endothermic CO₂ exsolution. The eruption interval between multiple small‐scale eruptions is a direct indicator of the subsequent large‐scale eruption.