GEOLOGY AND GEOCHRONOLOGY OF THE EAST DOME COMPLEX WITHIN THE HOG HEAVEN VOLCANIC FIELD, FLATHEAD COUNTY, MONTANA

This study describes the style and timing of volcanic activity and mineralization in the East Dome Complex (EDC) of the 55-km2 Eocene-Oligocene Hog Heaven Volcanic Field (~36-30 Ma; HHVF) located in northwestern Montana. The HHVF consists of three NE-aligned, predominantly high-K rhyodacitic dome complexes (1.8-4.9 wt. % K2O; 63.2-72.9 wt. % SiO2) formed near the crest the Purcell Anticlinorium, a major Cordilleran fold-thrust belt structure deforming metasedimentary rocks of the Mesoproterozoic Belt Supergroup. Dome emplacement was controlled by a NE-striking fault associated with a pull-apart basin formed between two overlapping, NW-trending dextral oblique-slip faults. The objective of this study is to describe the volcanism and mineralization in the EDC with new 1:12,000-scale geologic mapping, bulk geochemical data, U-Pb zircon ages, and a new 40Ar/39Ar date for hydrothermal alunite. The EDC consists of an 18.3 km2 vent complex cut by a 0.64 km2 maar-diatreme. Silicified breccia, tuff rings, and moat deposits mark the contact between the EDC and Mesoproterozoic Belt Supergroup rocks to define the larger vent complex, which is interpreted as a caldera. New U-Pb zircon ages for EDC rhyodacite domes and flows within and adjacent to the caldera vent range in age from about 35 to 32 Ma. The maar diatreme cuts a 31.1 Ma ignimbrite recognized throughout HHVF. Maar-diatreme vent breccia contains sulfide and volcanic clasts of the EDC rhyodacite and quartzite and argillite from the Revett formation of the Belt Supergroup. A vuggy silica alteration halo encloses the diatreme in plan view. HHVF mineral deposits have unusually high Ag:Au compared to most high-sulfidation epithermal systems worldwide. The only mining district in the HHVF is centered on the EDC where zoned, polymetallic base and precious metal (Ag-Pb-Zn-Cu-Au) mineralization occurs in lode veins, stratabound deposits, and disseminated in the diatreme breccia. This study reports a new 40Ar/39Ar age of about 32.0 Ma for alunite in the maar-diatreme. This new age coupled with a previously reported K-Ar age of 30 Ma for alunite in altered rock near the EDC suggests that the mineral deposits formed before, during, and after the caldera-forming ignimbrite eruption at 31.1 Ma. The style and composition of magmatism and mineralization within the HHVF may reflect an advanced stage of crustal extension in northwestern Montana ca. 36-30 Ma

The Isolated Photon Cross Section in p pbar Collisions at sqrt(s) = 1.8 TeV

We report a new measurement of the cross section for the production of isolated photons, with transverse energies (ET) above 10 GeV and pseudorapidities |eta| < 2.5, in p pbar collisions at sqrt{s} = 1.8 TeV. The results are based on a data sample of 107.6 pb-1 recorded during 1992--1995 with the D0 detector at the Fermilab Tevatron collider. The background, predominantly from jets which fragment to neutral mesons, was estimated using the longitudinal shower shape of photon candidates in the calorimeter. The measured cross section is in good agreement with the next-to-leading order (NLO) QCD calculation for ET > 36 GeV.Comment: 12 pages, 4 figures, LaTeX. Submitted to Physical Review Letter

A Strategic Model For Accounting Education

The need for significant changes in accounting education has been discussed for more than a decade, but this challenge has been unmet by educators and the profession.&nbsp; The purpose of this article is to discuss (1) the need for change in education (2) a model for accounting education, and (3) examples of how to improve accounting education.&nbsp; Accounting programs that adopt significant changes that provide students with the necessary skills will thrive in the future and continue to supply the profession with a sufficient supply of qualified graduates

Implementing Curricula To Meet The Needs Of Financial Professionals

Major changes in the financial profession warrant assessment of current practices and strategic planning for the future education of such professionals.&nbsp; This article discusses the core competencies, obtained from numerous studies, of accounting and finance professionals.&nbsp; After common core competencies are identified for the both accounting and finance professions, the need for change in accounting and finance curricula are discussed.&nbsp; Next, a combined undergraduate curriculum for both the accounting and finance students, which incorporates the common core competencies, is proposed.&nbsp; Finally, the authors issue a call for further research

Sintering-Induced Nucleation and Growth of Noble Metal Nanoparticles for Plasmonic Resonance Ceramic Color

This study demonstrates the formation of nanoparticles (NPs) from metal salts within ceramic glazes, such that the use of this colorant technology is more accessible to artisans, employs less metal content, is less environmentally harmful, and allows for the use of traditional kilns. Gold NPs have been demonstrated to possess a specific, low material loading use as a ceramic glaze colorant via plasmon resonance. Pre-synthesized gold NPs that are added to ceramic glazes have been found to significantly change in size after firing in both reductive and oxidative atmospheres, but still maintain some size relationships and color properties. Unfortunately, it is not viable for the art community to fabricate and employ gold NP systems with high precision in a studio setting; however, the use of noble metal salts or metal oxides are realistic. To that end, this work investigates spontaneous gold and silver NP synthesis by the firing-induced development of NPs from metallic salts included within the glaze materials. Glaze samples with gold and silver salts are fired in reductive and oxidative environments, yielding a range of surface plasmon coloring effects for ceramic coloring. Additionally, the use of gold NP waste (precipitated Au NPs waste) was added to wet ceramic glazes to investigate firing effects on NPs precipitate and potential use as an alternative colorant. Sintering-induced NP nucleation and growth was observed after firing in both oxidation and reduction environments, although to differing degrees. The direct noble metal salt application process eliminates the need for preliminary gold NP synthesis, thus allowing for more practical and environmentally friendly methods in creating plasmonic resonance ceramic coloring, potentially reflective of the processes employed in ancient nanoparticle glasses

Measurement of the W boson mass using large rapidity electrons

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.62.092006.We present a measurement of the W boson mass using data collected by the DØ experiment at the Fermilab Tevatron during 1994–1995. We identify W bosons by their decays to eν final states where the electron is detected in a forward calorimeter. We extract the W boson mass M(W) by fitting the transverse mass and transverse electron and neutrino momentum spectra from a sample of 11 089 W⃗ eν decay candidates. We use a sample of 1687 dielectron events, mostly due to Z⃗ ee decays, to constrain our model of the detector response. Using the forward calorimeter data, we measure M(W)=80.691±0.227 GeV. Combining the forward calorimeter measurements with our previously published central calorimeter results, we obtain M(W)=80.482±0.091 GeV

A CASE FOR COMMUNITY-BASED TEACHER EDUCATION: THE CRITICAL SPACE BETWEEN SOCIAL JUSTICE-ORIENTED TEACHING AND LEARNING

A case-study analysis is used to examine the relationship between community partners and in-service public high school teachers who co-constructed a culturally responsive informal learning experience. An analysis of a summer literacy and character development camp for adolescent males of color provides a supportive argument for developing the Community-Based Teacher (Murrell, 2001). Culturally responsive informal learning experiences of public school students are the centerpiece of this case study as well as the shared experiential education instruction provided by community partners. Implications for teacher education programs, both traditional and Alternative Routes to Certification (ARCs) that purport mission statements integrating social justice are discussed. Community partners are integral practice of community-based teachers and the case study is used to reinforce this idea as well as claim the importance of community partners in the development of a pre-service community-based teacher

Limits on quark compositeness from high energy jets in p-bar p collisions at 1.8 TeV

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.62.031101.Events in p-bar p collisions at s√=1.8TeV with total transverse energy exceeding 500 GeV are used to set limits on quark substructure. The data are consistent with next-to-leading order QCD calculations. We set a lower limit of 2.0 TeV at 95% confidence on the energy scale ΛLL for compositeness in quarks, assuming a model with a left-left isoscalar contact interaction term. The limits on ΛLL are found to be insensitive to the sign of the interference term in the Lagrangian

Search for first-generation scalar and vector leptoquarks

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.64.092004.We describe a search for the pair production of first-generation scalar and vector leptoquarks in the eejj and eνjj channels by the DØ Collaboration. The data are from the 1992–1996 pp-bar run at s√=1.8 TeV at the Fermilab Tevatron collider. We find no evidence for leptoquark production; in addition, no kinematically interesting events are observed using relaxed selection criteria. The results from the eejj and eνjj channels are combined with those from a previous DØ analysis of the ννjj channel to obtain 95% confidence level (C.L.) upper limits on the leptoquark pair-production cross section as a function of mass and of β, the branching fraction to a charged lepton. These limits are compared to next-to-leading-order theory to set 95% C.L. lower limits on the mass of a first-generation scalar leptoquark of 225, 204, and 79 GeV/c(2) for β=1, 12, and 0, respectively. For vector leptoquarks with gauge (Yang-Mills) couplings, 95% C.L. lower limits of 345, 337, and 206 GeV/c(2) are set on the mass for β=1, 12, and 0, respectively. Mass limits for vector leptoquarks are also set for anomalous vector couplings