The process of pyrite oxidation at the surface of mine waste may produce acidic water that is gradually neutralized as it drains away from the waste, depositing different Febearing secondary minerals in roughly concentric zones that emanate from mine-waste piles. These Fe-bearing minerals are indicators of the geochemical conditions under which they form. Airborne and orbital imaging spectrometers can be used to map these mineral zones because each of these Fe-bearing secondary minerals is spectrally unique. In this way, imaging spectroscopy can be used to rapidly screen entire mining districts for potential sources of surface acid drainage and to detect acid producing minerals in mine waste or unmined rock outcrops. Spectral data from the AVIRIS instrument were used to evaluate mine waste at the California Gulch Superfund Site near Leadville, CO. Laboratory leach tests of surface samples show that leachate pH is most acidic and metals most mobile in samples from the inner jarosite zone and that leachate pH is near-neutral and metals least mobile in samples from the outer goethite zone.

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This paper presents a detailed study of the mineralogical, microscopic, thermal, and spectral characteristics of jarosite and natrojarosite minerals. Systematic mineralogic and chemical examination of a suite of 32 natural stoichiometric jarosite and natrojarosite samples from diverse supergene and hydrothermal environments indicates that there is only limited solid solution between Na and K at low temperatures, which suggests the presence of a solvus in the jarosite-natrojarosite system at temperatures below about 140°C. The samples examined in this study consist of either end members or coexisting end-member pairs of jarosite and natrojarosite. Quantitative electron-probe microanalysis data for several natural hydrothermal samples show only end-member compositions for individual grains or zones, and no detectable alkali-site deficiencies, which indicates that there is no hydronium substitution within the analytical uncertainty of the method. In addition, there is no evidence of Fe deficiencies in the natural hydrothermal samples. Hydronium-bearing jarosite was detected in only one relatively young supergene sample suggesting that terrestrial hydronium-bearing jarosites generally are unstable over geologic timescales.Unit-cell parameters of the 20 natural stoichiometric jarosites and 12 natural stoichiometric natrojarosites examined in this study have distinct and narrow ranges in the a-and c-cell dimensions. There is no overlap of these parameters at the 1r level for the two end-member compositions. Several hydrothermal samples consist of fine-scale (2-10 lm) intimate intergrowths of jarosite and natrojarosite, which could have resulted from solid-state diffusion segregation or growth zoning due to variations in the Na/K activity ratio of hydrothermal solutions. Published by Elsevier Ltd.

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Strategies to predict metal mobility in surficial mining environments Email alerting services cite this article to receive free e-mail alerts when new articles www.gsapubs.org/cgi/alerts click Subscribe Geology to subscribe to Reviews in Engineering www.gsapubs.org/subscriptions/ click Permission request to contact GSA http://www.geosociety.org/pubs/copyrt.htm#gsa click viewpoint. Opinions presented in this publication do not reflect official positions of the Society. positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political article's full citation. GSA provides this and other forums for the presentation of diverse opinions and articles on their own or their organization's Web site providing the posting includes a reference to the science. This file may not be posted to any Web site, but authors may post the abstracts only of their unlimited copies of items in GSA's journals for noncommercial use in classrooms to further education and to use a single figure, a single table, and/or a brief paragraph of text in subsequent works and to make GSA, employment. Individual scientists are hereby granted permission, without fees or further requests to

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We developed a statistically based strategy for sampling the surficial material of mine-waste dumps for use in screening and prioritizing historic dumps on abandoned mine lands. This sampling strategy entails the collection of a representative composite sample from individual dumps and allows for regional or watershed-based assessments. One 30-increment dump-composite sample collected using this sampling strategy contains as much information, relative to average value, as 30 individual grab samples at l/x of the analytical cost INTRODUCTIONThe mine-waste dump sampling strategy discussed in this paper was developed during the U.S. Geological Survey, Mineral Resources Program Solid-Phase Sampling Workshop, March 24-26, 1997, in Denver, Colorado, taught by Charles Ramsey. Workshop participants made valuable contributions to the development of this sampling strategy. Many discussions in this paper originate from the workshop notes prepared by Charles Ramsey, which are based on Pitard (1993).There are thousands of mine-waste dumps present on abandoned mine lands. Since they are historic dumps, most are relatively small. We sought to develop a cost-effective sampling strategy that could provide the foundation for screening and prioritizing these dumps on a regional or watershed basis. In screening, one is interested in the average behavior and potential environmental effects of a waste dump. Leaching tests are one of our main screening procedures to evaluate and prioritize the dumps. Because we are concerned with average properties of mine-waste dumps, our sampling strategy entails collection of a composite sample from each dump. The U.S. Environmental Protection Agency states that "composite samples reflect a physical rather than a mathematical mechanism for averaging. Therefore, compositing should be generally avoided if population parameters other than a mean are of interest (e.g., percentiles or standard deviations)" (U.S. Environmental Protection Agency, 1996). In other words, compositing is an acceptable sampling procedure when average properties are of interestThe sampling strategy presented herein is appropriate for screening purposes. When more detailed site characterization is required, other sampling strategies may be employed depending on the objectives of the work (e.g.

Objective: To understand perspectives of stakeholders during initial district-wide implementation of a Breakfast in the Classroom (BIC) model of the School Breakfast Program. Design: Qualitative data were collected from twenty-nine focus groups and twenty interviews with stakeholders in a school district early in the process of implementing a BIC model of the School Breakfast Program. Setting: Ten elementary schools within a large, urban school district in the USA that served predominantly low-income, racial/ethnic minority students. Subjects: Purposively selected stakeholders in elementary schools that had implemented BIC for 3-6 months: students (n 85), parents/guardians (n 86), classroom teachers (n 44), cafeteria managers (n 10) and principals (n 10). Results: Four primary themes emerged, which were interpreted based on the Diffusion of Innovations model. School staff had changed their perceptions of both the relative disadvantages and costs related to time and effort of BIC over time; the majority of each stakeholder group expressed an appreciation for BIC; student breakfast consumption varied from day to day, related to compatibility of foods with child preferences; and stakeholders held mixed and various impressions of BIC's potential impacts. Conclusions: The study underscores the importance of engaging school staff and parents in discussions of BIC programming prior to its initiation to pre-emptively address concerns related to cost, relative disadvantages and compatibility with child preferences and school routines/workflow. Effectively communicating with stakeholders about positive impacts and nutritional value of the meals may improve support for BIC. These findings provide new information to policy makers, districts and practitioners that can be used to improve implementation efforts, model delivery and outcomes.