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Aftermath of Miracle When the crowds leave, we're left With the excess-- oily fish, baskets of bread-- Too much to cart across the desert. We never asked for this. Our [...]

The unconformity-related uranium (URU) deposits in the Proterozoic Athabasca Basin (Canada) represent the richest, and one of the most important, uranium endowments in the world. Most of the URU deposits are associated with pre-existing graphitic basement faults that were reactivated after the formation of the basin. These graphite-rich structures have been widely used as a vector for exploration, but the nature of the association of the URU deposits with graphitic basement faults has been debated for over four decades. Proposed roles of graphite include: (1) as a direct reducing agent to reduce U6+to U4+and precipitate uraninite; (2) as a precursor of hydrocarbons (mainly CH4) produced in situ or nearby and then used as a reducing agent for uraninite precipitation; (3) as a precursor of hydrocarbons produced at depth that were remobilized to the site of mineralization and acted as a reducing agent for uraninite precipitation; and (4) as a lubricant facilitating faulting and fluid flow that led to uranium mineralization. This paper uses the Phoenix uranium deposit in the southeastern Athabasca Basin as a case study to address these uncertainties. Petrographic studies indicate that there is no direct contact between graphite and uraninite at microscopic scales, and the content of graphite in the graphitic metapelite along the ore-controlling WS Shear Zone does not show a systematic change with the distance from the unconformity surface. Raman spectroscopic studies of graphite suggest that the degree of structural disorder of graphite, expressed by various parameters related to the D bands and G band ratios, does not change systematically with the distance from the unconformity surface either. The minor irregularities in these parameters near the unconformity are better explained by paleo-weathering related to the unconformity and/or diagenetic processes than by hydrothermal activity related to uranium mineralization. Based on these observations and interpretations, the role of graphite as an in situ reducing agent, either directly or as a provider of hydrocarbons, is discounted. It is proposed that hydrocarbons derived from graphite at depth, tapped by episodic reactivation or seismicity of the basement faults that was facilitated by graphite as a lubricant, were responsible for URU mineralization.

Background: Magnetic sphincter augmentation (MSA) is a surgical treatment for gastroesophageal reflux disease using a ring of titanium beads to improve the function of the lower esophageal sphincter. Prior to implantation, a comprehensive preoperative esophageal workup is required to determine patient candidacy in an effort to reduce the dysphagia, dilation, and explantation rate of the device. This study was designed to assess the best predictors for these endpoints. Methods: A prospectively maintained IRB-approved database was retrospectively reviewed for patients undergoing MSA implantation. Patients were divided into 3 groups, those that needed no intervention, those that needed medical intervention with oral steroids for reported dysphagia, and surgical intervention, which included endoscopic dilation and/or surgical explantation. Primary endpoints included preoperative objective and subjective testing from a comprehensive esophageal workup including intraoperative notation of number of beads on the device. Results: There were 99 patients eligible for the study with a mean age of 52 and mean follow-up of 10.2 months. Mean BMI was 27 and 59% were female. The no-intervention group had 59 patients, medical intervention group had 25 patients, and surgical intervention group had 15 patients. Preoperative esophageal manometry findings, pH testing off medications, endoscopic and radiologic evaluation showed no difference between the 3 groups. No differences were seen in preoperative subjective evaluations based on GERD-HRQL or RSI scores. There was no difference in average number of beads on the device between the 3 groups. Conclusion: A comprehensive esophageal workup is important to confirm the presence of gastroesophageal reflux disease and rule out other esophageal pathology. However, this study shows that a preoperative comprehensive esophageal workup does not predict which patients will develop dysphagia or require either medical or surgical interventions following MSA implantation.

Fruit of the vine Rainbow or no rainbow, I'd have gotten drunk too, more than a year lost, an ark full of animals, the whole earth renewed. What better cause [...]

Infrared (Visible-Near Infrared-Shortwave Infrared (VNIR-SWIR)) spectroscopy is a cost-effective technique for mineral identification in the field. Modern hand-held spectrometers are equipped with on-board spectral libraries that enable rapid, qualitative analysis of most minerals and facilitate recognition of key alteration minerals for exploration. Spectral libraries can be general or customized for specific mineral deposit environments. To this end, careful collection of spectra in a controlled environment on pure specimens of key minerals was completed using the National Mineral Reference Collection (NMC) of the Geological Survey of Canada. The spectra collected from specimens in the ‘Kodama Clay Collection’ were processed using spectral plotting software and each new example was validated before being added to a group of spectra considered for incorporation into the on-board library of the handheld ASD-TerraSpec Halo near-infrared (NIR) mineral identification instrument. Spectra from an additional suite of mineral samples of the NMC containing REE, U, Th, and/or Nb are being prepared for a new, publicly available spectral library. These minerals commonly occur in carbonatite or alkali intrusive deposits, and as such will assist in the exploration for critical metals.

The article determines base cases for the remaining technically recoverable gas resources, potential future drilling activity, and total-field estimated ultimate recovery, which are dependent on natural gas prices. It mentions that reduced natural gas prices have declined the development of the Haynesville shale in east Texas and southwest Louisiana. Also, it summarizes a research made by the Bureau of Economic Geology (BEG) of the Haynesville's resource and production potential.

This study estimates reservoir quality and free-gas storage capacity of the Barnett Shale in the main natural-gas producing area of the Fort Worth basin by mapping log-derived thickness, porosity, and porosity-feet. In the Barnett Shale, the density porosity (DPHI) log curve is a very useful tool to quantitatively assess shale gas resources, and gamma-ray (GR) and neutron porosity log curves are important factors in identifying the shale gas reservoir. The key data were digital logs from 146 wells selected based on the availability of GR and density log curves, log quality, and good spatial distribution. The Barnett Shale pay zone was determined on the basis of (1) DPHI >5%, (2) high GR values (commonly >~90 API units), (3) no significant intercalated carbonate-rich beds, and (4) individual pay zones being thick enough to be commercially successful for the current design of horizontal wells. In the study area, the Barnett Shale pay zone varies from about 165 ft (50 m) to 420 ft (128 m) in thickness (H). Average DPHI values of individual wells for the pay zone vary from 8.5 to 14.0%. Porosity-feet maps of the pay zone show that areas of high DPHI-H values coincide with areas of high natural gas production, indicating that log-derived porosity-feet maps are a good method for evaluating reservoir quality and assessing natural gas resource in the Barnett Shale play. A limitation to this method is shown in the northwestern corner of the study area, which is located in the liquids-rich window with lower thermal maturity. [ABSTRACT FROM AUTHOR]

An analysis of 31 whole cores (~ 1600 ft, ~490 m) and closely spaced wireline logs (,~500 wells) penetrating the Lower Cretaceous (Cenomanian) lower Woodbine Group in the mature East Texas field and adjacent areas indicates that depositional origins and complexity of the sandstone-body architecture in the field vary from those inferred from previous studies. Heterogeneity in the lower Woodbine Group is controlled by highstand, fluvial-dominated deltaic depositional architecture, with dip-elongate distributary-channel sandstones pinching out over short distances (typically < 500 ft [ < 150 m]) into delta-plain and interdistributary-bay siltstones and mudstones. This highstand section is truncated in the north and west parts of the field by a thick (maximum of 140 ft [43 m]) lowstand, incised-valley-fill succession composed of multistoried, coarse-gravel conglomerate and coarse sandstone beds of bed-load fluvial systems. In some areas of the field, this valley fill directly overlies distal-delta-front deposits, recording a fall in relative sea level of at least 215 ft (65 m). Correlation with the Woodbine succession in the East Texas Basin indicates that these highstand and lowstand deposits occur in the basal three fourth-order sequences of the unit, which comprises a maximum of 14 such cycles. Previous studies of the Woodbine Group have inferred meanderbelt sandstones flanked by coeval flood-plain mudstones and well-connected, laterally continuous sheet sandstones of wave-dominated deltaic and barrier-strand-plain settings. This model is inappropriate, and a full assessment of reservoir compartmentalization, fluid flow, and unswept mobile oil in East Texas field should include the highstand, fluvial-dominated deltaic and lowstand valley-fill sandstone-body architecture. [ABSTRACT FROM AUTHOR]

The article looks at the future share of unconventional natural gas supply in the U.S. The need for liquefied natural gas will be lessened by the continuing growth of unconventional gas supplies. More wells are required to produce unconventional gas because their resources are generally low-grade compared to conventional gas. Coalbed methane also contributes to the supply of unconventional gas in the U.S. while shale gas has impact on unconventional gas production.

A digital x-ray imaging system was designed for small-animal studies. This system is a fiber-optics taper-coupled imaging system with two CCD arrays uniquely jointed. The x-ray source of the system has a small focal spot of 20 µm. This digital imaging system contains specially designed shelves to provide magnification levels, ranging from 1.5× to 5×. The system is characterized in terms of its properties of spatial resolution. An observer-based spatial resolution measurement was conducted with a line-pair target and a sector test pattern. The modulation transfer function of the system, with different magnifications, was studied by use of a 10-µm lead slit. The average resolutions at 50% and 5% modulations at 1× magnification were measured as 3.9 and 8.4 lp/mm, respectively, where lp indicates line pairs. With 5× magnification, the 50% and the 5% modulations provided 13.2- and 29.9-lp/mm, respectively, average spatial resolutions. The measurements showed consistency between the two individual CCD arrays; the difference in resolution between the two CCDs is less than 1%, even at high magnifications.

Letters to the editor are presented in response to articles in previous issues including "Why Gitmo Will Never Close," by Michael Crowley, about the U.S. Naval Station at Guantanamo Bay, Cuba, "Faith and the Campus" by Karl Vick and Ashraf Khali, about al-Azhar University, and "Per Favore, Put the Euro to a Vote," about the Euro currency, in the June 10, 2013 issue.

The article presents the poem "Evensong," by Eric Potter. First Line: The sails of evening wink discreet farewells; Last Line: She lights a yellow candle, smiles and turns.

Presents the poem "What Is Essential," by Eric Potter. First Line: Dead trees know, being; Last Line: It costs them everything.