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Sample records for mining district san

  1. Mercury in the gold mining district of San Martin de Loba, South of Bolivar (Colombia).

    PubMed

    Olivero-Verbel, Jesus; Caballero-Gallardo, Karina; Turizo-Tapia, Alexi

    2015-04-01

    Gold mining is responsible for most Hg pollution in developing countries. The aims of this study were to assess the levels of total Hg (T-Hg) in human hair, fish, water, macrophyte, and sediment samples in the gold mining district of San Martin de Loba, Colombia, as well as to determine fish consumption-based risks for T-Hg ingestion. T-Hg levels were measured by electrothermal atomization and atomic absorption spectroscopy. The overall mean T-Hg level in hair for humans in the mining district of San Martin de Loba was 2.12 μg/g, whereas for the reference site, Chimichagua, Cesar, it was 0.58 μg/g. Mean T-Hg levels were not different when considered within localities belonging to the mining district but differed when the comparison included Chimichagua. T-Hg levels in examined locations were weakly but significantly associated with age and height, as well as with fish consumption, except in San Martin de Loba. High T-Hg concentrations in fish were detected in Pseudoplatystoma magdaleniatum, Caquetaia kraussii, Ageneiosus pardalis, Cyrtocharax magdalenae, and Triportheus magdalenae, whereas the lowest appeared in Prochilodus magdalenae and Hemiancistrus wilsoni. In terms of Hg exposure due to fish consumption, only these last two species offer some guarantee of low risk for Hg-related health problems. Water, floating macrophytes, and sediments from effluents near mining sites also had high Hg values. In mines of San Martin de Loba and Hatillo de Loba, for instance, the geoaccumulation index (I(geo)) for sediments reached values greater than 6, indicating extreme pollution. In short, these data support the presence of a high Hg-polluted environment in this mining district, with direct risk for deleterious effects on the health of the mining communities.

  2. Upper Animas Mining District

    EPA Pesticide Factsheets

    Web page provides narrative of What's New?, Site Description, Site Risk, Cleanup Progress, Community Involvement, Next Steps, Site Documents, FAQ, Contacts and LInks for the Upper Animas Mining District site in San Juan County, Colorado.

  3. 33 CFR 165.1103 - Security Zone; Naval Mine Anti Submarine Warfare Command; San Diego Bay, San Diego, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Submarine Warfare Command; San Diego Bay, San Diego, CA. 165.1103 Section 165.1103 Navigation and Navigable... Eleventh Coast Guard District § 165.1103 Security Zone; Naval Mine Anti Submarine Warfare Command; San... the Naval Mine Anti Submarine Warfare Command, bound by the following coordinates: 32°43′40.9″ N,...

  4. Arsenic content in groundwater from the southern part of the San Antonio-El Triunfo mining district, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Wurl, Jobst; Mendez-Rodriguez, Lía; Acosta-Vargas, Baudilio

    2014-10-01

    The San Antonio-El Triunfo mining district is located in a mountain region 60 km southeast of La Paz, the capital of the Mexican state of Baja California Sur. Mining activities, focused on gold and silver extraction, which began in the second half of the 18th century; the main activity took place between 1878 and 1911. The minerals were treated through the cyanide method, burned, and smelted. In effect between 800,000 and 1 million tons of mine waste materials were scattered in an area of approximately 350-400 km2. This area contains today several byproducts as a result from arsenopyrite oxidation, such as arsenolite (As2O3). The aim of this study was to analyze groundwater composition in order to define the actual concentrations of relevant parameters to detect ore mining contaminations, especially in respect to arsenic. In the autumn of 2010, 29 groundwater samples were obtained using flow-through bailer or down-hole pump methods, and a total of 37 variables were measured in each sample. Arsenic (dissolved) exceeded the values established by the World Health Organization (WHO, 2011) (0.01 mg/L) in 41% of the monitored sites. The maximum concentration of arsenic found in one observation well was 0.45 mg/L. Four water samples, which were characterized by elevated concentration of boron (max. conc. 9.5 mg/L), fluoride (max. conc. 3.25 mg/L) and alkaline pH values (>9), showed a composition typical for hydrothermal water. Because all four samples had arsenic concentration under 0.008 mg/L, we conclude that no significant impact of arsenic from hydrothermal fluids is found in the study area.

  5. Grants Mining District

    EPA Pesticide Factsheets

    The Grants Mineral Belt was the focus of uranium extraction and production activities from the 1950s until the late 1990s. EPA is working with state, local, and federal partners to assess and address health risks and environmental effects of the mines

  6. Concentration, distribution, and translocation of mercury and methylmercury in mine-waste, sediment, soil, water, and fish collected near the Abbadia San Salvatore mercury mine, Monte Amiata district, Italy.

    PubMed

    Rimondi, Valentina; Gray, John E; Costagliola, Pilario; Vaselli, Orlando; Lattanzi, Pierfranco

    2012-01-01

    The distribution and translocation of mercury (Hg) was studied in the Paglia River ecosystem, located downstream from the inactive Abbadia San Salvatore mine (ASSM). The ASSM is part of the Monte Amiata Hg district, Southern Tuscany, Italy, which was one of the world's largest Hg districts. Concentrations of Hg and methyl-Hg were determined in mine-waste calcine (retorted ore), sediment, water, soil, and freshwater fish collected from the ASSM and the downstream Paglia River. Concentrations of Hg in calcine samples ranged from 25 to 1500 μg/g, all of which exceeded the industrial soil contamination level for Hg of 5 μg/g used in Italy. Stream and lake sediment samples collected downstream from the ASSM ranged in Hg concentration from 0.26 to 15 μg/g, of which more than 50% exceeded the probable effect concentration for Hg of 1.06 μg/g, the concentration above which harmful effects are likely to be observed in sediment-dwelling organisms. Stream and lake sediment methyl-Hg concentrations showed a significant correlation with TOC indicating considerable methylation and potential bioavailability of Hg. Stream water contained Hg as high as 1400 ng/L, but only one water sample exceeded the 1000 ng/L drinking water Hg standard used in Italy. Concentrations of Hg were elevated in freshwater fish muscle samples and ranged from 0.16 to 1.2 μg/g (wet weight), averaged 0.84 μg/g, and 96% of these exceeded the 0.3 μg/g (methyl-Hg, wet weight) USEPA fish muscle standard recommended to protect human health. Analysis of fish muscle for methyl-Hg confirmed that >90% of the Hg in these fish is methyl-Hg. Such highly elevated Hg concentrations in fish indicated active methylation, significant bioavailability, and uptake of Hg by fish in the Paglia River ecosystem. Methyl-Hg is highly toxic and the high Hg concentrations in these fish represent a potential pathway of Hg to the human food chain.

  7. Concentration, distribution, and translocation of mercury and methylmercury in mine-waste, sediment, soil, water, and fish collected near the Abbadia San Salvatore mercury mine, Monte Amiata district, Italy

    USGS Publications Warehouse

    Rimondi, V.; Gray, J.E.; Costagliola, P.; Vaselli, O.; Lattanzi, P.

    2012-01-01

    The distribution and translocation of mercury (Hg) was studied in the Paglia River ecosystem, located downstream from the inactive Abbadia San Salvatore mine (ASSM). The ASSM is part of the Monte Amiata Hg district, Southern Tuscany, Italy, which was one of the world’s largest Hg districts. Concentrations of Hg and methyl-Hg were determined in mine-waste calcine (retorted ore), sediment, water, soil, and freshwater fish collected from the ASSM and the downstream Paglia River. Concentrations of Hg in calcine samples ranged from 25 to 1500 μg/g, all of which exceeded the industrial soil contamination level for Hg of 5 μg/g used in Italy. Stream and lake sediment samples collected downstream from the ASSM ranged in Hg concentration from 0.26 to 15 μg/g, of which more than 50% exceeded the probable effect concentration for Hg of 1.06 μg/g, the concentration above which harmful effects are likely to be observed in sediment-dwelling organisms. Stream and lake sediment methyl-Hg concentrations showed a significant correlation with TOC indicating considerable methylation and potential bioavailability of Hg. Stream water contained Hg as high as 1400 ng/L, but only one water sample exceeded the 1000 ng/L drinking water Hg standard used in Italy. Concentrations of Hg were elevated in freshwater fish muscle samples and ranged from 0.16 to 1.2 μg/g (wet weight), averaged 0.84 μg/g, and 96% of these exceeded the 0.3 μg/g (methyl-Hg, wet weight) USEPA fish muscle standard recommended to protect human health. Analysis of fish muscle for methyl-Hg confirmed that > 90% of the Hg in these fish is methyl-Hg. Such highly elevated Hg concentrations in fish indicated active methylation, significant bioavailability, and uptake of Hg by fish in the Paglia River ecosystem. Methyl-Hg is highly toxic and the high Hg concentrations in these fish represent a potential pathway of Hg to the human food chain.

  8. Neogene geomorphic and climatic evolution of the central San Juan Mountains, Colorado: K/Ar age and stable isotope data on supergene alunite and jarosite from the Creede mining district

    USGS Publications Warehouse

    Rye, Robert O.; Bethke, Philip M.; Lanphere, Marvin A.; Steven, Thomas A.

    2000-01-01

    K/Ar age determinations or supergene alunite and jarosite, formed during Neogene weathering of the epithermal silver and base-metal ores of the Creede mining district, have been combined with geologic evidence to estimate the timing of regional uplift of the southern Rocky Mountains and related canyon cutting. In addition, oxygen and hydrogen isotopic studies suggest climate changes in the central San Juan Mountains during the past 5 m.y. Alunite [ideally (K,Na)Al3(SO4)2(OH)6] and jarosite [ideally KFe3(SO4)2(OH)6] can be dated by K/Ar or 40Ar/39Ar techniques and both contain OH and SO4 sites that enable four stable isotope analyses (δD, δ18OOH, and δ34S) to be made. This supergene alunite and jarosite formed by weathering of sulfide-rich ore bodies may record the evolution of the chemical and hydrologic processes affecting ancient oxidized acid ground water, as well as details of climate history and geomorphic evolution. Fine-grained (1-10 μm) supergene alunite and jarosite occur in minor fractures in the upper, oxidized parts of the 25 Ma sulfide-bearing veins of the Creede mining district, and jarosite also occurs in adjacent oxidized Ag-bearing clastic sediments. K/Ar ages for alunite range from 4.8 to 3.1 Ma, and for jarosite range from 2.6 to 0.9 Ma. The δD values for alunite and jarosite show opposite correlations with elevation, and values for jarosite correlate with age. Calculated δDH2O values of alunite fluids approach but are larger than those of present-day meteoric water. Calculated δDH2O values for jarosite fluids are more variable; the values of the youngest jarosites are lowest and are similar to those of present-day meteoric water in the district. The narrow δD-δ18OSO4 values of alunites reflects oxidation of sulfide below the water table. The greater range in these values for jarosites reflects oxidation of sulfide under vadose conditions. The ages of alunite mark the position of the paleo-water table at the end of a period of moderate

  9. San Mateo Creek Basin

    EPA Pesticide Factsheets

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  10. San Diego Community College District Student Satisfaction Survey, 2001.

    ERIC Educational Resources Information Center

    San Diego Community Coll. District, CA. Research and Planning.

    The San Diego Community College District (SDCCD), California, conducted a student satisfaction survey at three colleges during fall 2002. The survey instrument includes the following three parts: (1) Service Areas: students were asked to rate the levels of importance and satisfaction for 22 services; (2) Survey Themes: seventy-six statements were…

  11. Healthy Schools Initiative: Implementation Study in Four San Mateo County School Districts

    ERIC Educational Resources Information Center

    Westrich, Lisa; Sanchez, Monika; Strobel, Karen; Duong, Nina

    2012-01-01

    The Sequoia Healthcare District (SHD), in collaboration with four local school districts--Belmont-Redwood Shores School District (BRSSD), Redwood City School District (RCSD), San Carlos School District (SCSD), and Sequoia Union High School District (SUHSD)--launched the Healthy Schools Initiative (HSI) in August 2010. This three-year initiative is…

  12. EPA, San Diego County Air District to Unveil Air Monitor in San Ysidro

    EPA Pesticide Factsheets

    LOS ANGELES - On Tuesday, U.S. EPA Regional Administrator Jared Blumenfeld, along with representatives from the San Diego County Air Pollution Control District (SDAPCD), U.S. Customs and Border Protection and the U.S. General Services Administration, will

  13. San Jose/Evergreen Community College District: Governing Board's Strategic Master Plan.

    ERIC Educational Resources Information Center

    San Jose/Evergreen Community Coll. District, San Jose, CA.

    This report presents San Jose/Evergreen Community College District Governing Board's Strategic Master Plan. This report summarizes the district's mission statement, goal statements, and board priorities. The San Jose/Evergreen Community College District is committed to providing open access and opportunity for success to its multi-ethnic…

  14. Developing Early Warning Indicators for the San Francisco Unified School District. Youth Data Archive Issue Brief

    ERIC Educational Resources Information Center

    John W. Gardner Center for Youth and Their Communities, 2011

    2011-01-01

    San Francisco's Bridge to Success (BtS) initiative brings together the City and County of San Francisco, the San Francisco Unified School District (SFUSD), the City College of San Francisco (CCSF), and key community organizations to promote postsecondary success for underrepresented students. Partners agree that the first step in achieving this…

  15. San Francisco Bay Sand Mining Resource Evaluation and Impact Analysis

    NASA Astrophysics Data System (ADS)

    Fenical, S.; Tirindelli, M.; Sicular, D.; Gragg, J.; Huitt, C.

    2012-12-01

    This paper presents results of the evaluation of potential future sand resources within certain Central San Francisco Bay (Central Bay) sand mining lease areas, as well as the potential impacts of further mining these areas for a ten-year period. The study consisted of morphological analysis using field measurements and hydrodynamic modeling, and covered a wide spectrum of physical processes including tidal and river circulation, salinity, sediment transport, and morphology. The study was conducted within the framework of an Environmental Impact Report (EIR) prepared by the California State Lands Commission (CSLC) as part of the discretionary approval process for issuing new mining leases. The results of the morphological analysis indicate a measurable depletion of sand resources in the Central Bay lease areas during the period 1997-2008, and that for the purposes of the proposed ten-year mining lease renewal, sand mining resources in Central Bay are largely limited to material already in place. The morphological analysis results also indicate that the proposed additional ten years of sand mining in the Central Bay lease areas are not likely to cause a significant impact on sediment transport and budgets in areas outside the vicinity of the lease areas, such as the San Francisco Bar, Ocean Beach, etc. Numerical modeling results, including particle tracking exercises, do indicate a net seaward transport of sand, and that a linkage exists between the mining areas and offshore areas (San Francisco Bar, Ocean Beach, etc). However, the modeling results demonstrate that the linkage is weak, and that any measurable changes in hydrodynamics, salinity and sediment transport/morphology caused by the mining activities are likely to be confined to the vicinity of the mining areas.

  16. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Cooperation between superintendent and district mining... MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY § 215.23 Cooperation between superintendent and district mining supervisor. (a) The district mining supervisor of the Miami field...

  17. Seismic activity in the Sunnyside mining district, Utah, during 1967

    USGS Publications Warehouse

    Barnes, Barton K.; Dunrud, C. Richard; Hernandez, Jerome

    1969-01-01

    A seismic monitoring network near Sunnyside, Utah, consisting of a triangular array of seismometer stations that encompasses most of the mine workings in the district, recorded over 50,000 local earth tremors during 1967. About 540 of the tremors were of sufficient magnitude to be accurately located. Most of these were located within 2-3 miles of mine workings and were also near known or suspected faults. The district-wide seismic activity generally consisted of two different patterns--a periodic increase in the daily number of tremors at weekly intervals, and also a less regular and longer term increase and decrease of seismic activity that occurred over a period of weeks or even months. The shorter and more regular pattern can be correlated with the mine work week and seems to result from mining. The longer term activity, however, does not correlate with known mining causes sad therefore seems to be .caused by natural stresses.

  18. Capistrano unified school district works with San Onofre NGS

    SciTech Connect

    Osterfield, M.A. ); Cramer, E.N. )

    1992-01-01

    A unique arrangement has the science coordinator for Capistrano Unified School District's (CUSD) grades kindergarten through eight (K-8) as a part-time contract employee at San Onofre Nuclear Generating Station (SONGS). The purpose is to assess the science capabilities at SONGS useful to CUSD teachers and to assist in making them available. This is different from the usual single-teacher renewal program or from part-time employment. This creates several unique situations for SONGS and the 23 K-8 schools in CUSD, supplementing the existing program of optional science field trips to SONGS. This approach also interests the developing mind in science before being turned off by uninteresting, user-unfriendly, bookish approaches.

  19. English Articulation between the San Francisco Unified School District and the City College of San Francisco. Youth Data Archive Issue Brief

    ERIC Educational Resources Information Center

    Gurantz, Oded

    2012-01-01

    San Francisco's Bridge to Success (BtS) initiative brings together the City and County of San Francisco, the San Francisco Unified School District (SFUSD), the City College of San Francisco (CCSF), and key community organizations to promote postsecondary success for underrepresented students. Various working groups, each comprised of staff from…

  20. 78 FR 37130 - Revisions to the California State Implementation Plan, San Diego Air Pollution Control District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Diego Air Pollution... taking direct final action to approve a revision to the San Diego Air Pollution Control District (SDAPCD... Part 52 Environmental protection, Air pollution control, Incorporation by reference,...

  1. 78 FR 37176 - Revisions to the California State Implementation Plan, San Diego Air Pollution Control District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Diego Air Pollution... proposing to approve a revision to the San Diego Air Pollution Control District (SDAPCD) portion of the... sources under the Clean Air Act (CAA or the Act). DATES: Any comments on this proposal must arrive by...

  2. 76 FR 39091 - San Luis Obispo Flood Control and Water Conservation District; Notice of Effectiveness of Surrender

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-05

    ... for a Conduit Hydroelectric Project \\1\\ to the San Luis Obispo Flood Control and Water Conservation District (District) for the Lopez Water Treatment Plant Hydropower Generation Unit Project No. 4804. The... Energy Regulatory Commission San Luis Obispo Flood Control and Water Conservation District; Notice...

  3. Asturian mercury mining district (Spain) and the environment: a review.

    PubMed

    Ordóñez, A; Álvarez, R; Loredo, J

    2013-11-01

    Mercury is of particular concern amongst global environmental pollutants, with abundant contaminated sites worldwide, many of which are associated with mining activities. Asturias (Northwest of Spain) can be considered an Hg metallogenic province with abundant epithermal-type deposits, whose paragenetic sequences include also As-rich minerals. These mines were abandoned long before the introduction of any environmental regulations to control metal release from these sources. Consequently, the environment is globally affected, as high metal concentrations have been found in soils, waters, sediments, plants, and air. In this paper, a characterization of the environmental affection caused by Hg mining in nine Asturian mine sites is presented, with particular emphasis in Hg and As contents. Hg concentrations found in the studied milieu are similar and even higher than those reported in previous studies for other mercury mining districts (mainly Almadén and Idrija). Furthermore, the potential adverse health effects of exposure to these elements in the considered sites in this district have been assessed.

  4. Undersea safety mining of the large gold deposit in Xinli District of Sanshandao Gold Mine

    NASA Astrophysics Data System (ADS)

    Liu, Zhi-xiang; Dang, Wen-gang; He, Xian-qun

    2012-07-01

    The exploration of undersea resources becomes popular as land resources decrease. Researches were conducted with emphasis on the safety and efficiency of undersea mining of the large gold deposit in Xinli District of Sanshandao Gold Mine. A series of tests for the physical and mechanical characteristics of rock mass were carried out, and the three-dimensional geo-stress distribution was tested in the mining area. Further, a similar experimental simulation platform, which revealed the mechanism of water inrush and ascertained the reasonable thickness of the safety isolate layer, was established for the undersea mining. Meanwhile, the feasibility of cancelling the ore pillars and the safety conditions was checked by numerical simulation. The simulation results show that it is safe to exploit the ore body below the -85 m level (presently, the exploitation level is below -160 m in Xinli District), and the ore pillars can be cancelled below the -560 m level. Furthermore, a novel backfill method was designed to reduce the rock strata disturbance and settlement, and the settlement of roof strata was monitored during the mining process. Engineering practice shows that the settlement of roof strata was small and that no disaster happened. This indicates that the undersea safety mining technology of the large gold deposit is achieved in Xinli District.

  5. Mercury pollution issues in mining districts (Armenia)

    NASA Astrophysics Data System (ADS)

    Saghatelyan, Armen; Sahakyan, Lilit; Belyaeva, Olga; Torosyan, Nver

    2015-04-01

    The issue of mercury (Hg) due to its chemical and geochemical peculiarities and a negative impact it produces on human health has a long history. Existence of international projects devoted to Hg research (AMAP Technical Background Report, 2013) and elaboration on a new convention to combat Hg pollution (http://www.mercuryconvention.org/Home/tabid/3360/Default.aspx) prove that Hg has already become a global concern. Presently, data on Armenia's area pollution with Hg available in international literature sources and reports are scarce and cover pollution sources only. According to published data (AMAP Technical Background Report, 2013), in 2009 summary emission of Hg on the entire territory of the Republic of Armenia made 222,723 kg, considerable shares of which fell on primary copper production (88,057 kg), cement production (57,094 kg), production of gold from large mines (46,728 kg), waste and other losses due to breakage and disposal in landfill (29,995 kg); besides, some quantities originated from amalgams, combustion of different-type fuel and garbage, and so on. One should mind, that these are calculated statistical data, which reflect neither a complete list of Hg pollution sources nor a realistic picture of levels of Hg pollution of different environmental compartments and risks. Local monitoring data on Hg pollution are not sufficient either. This abstract is aimed at revealing of Hg pollution problems in some of Armenia's mining regions through generalization of data on complex investigations implemented at the Center for Ecological-Noosphere Studies NAS RA between 2005 and 2011, and is focused on Hg pollution of different environmental compartments: water - atmosphere - soil - farm produce - atmospheric precipitation - human bio-substrates. The obtained data indicate that as a result of ore mining and processing Hg enters onto the surface, travels through air and water migration streams and finally brings to pollution of all environmental compartments

  6. Mercury speciation in the Mt. Amiata mining district (Italy): interplay between urban activities and mercury contamination

    USGS Publications Warehouse

    Rimondi, Valentina; Bardelli, Fabrizio; Benvenuti, Marco; Costagliola, Pilario; Gray, John E.; Lattanzi, Pierfranco

    2014-01-01

    A fundamental step to evaluate the biogeochemical and eco-toxicological significance of Hg dispersion in the environment is to determine speciation of Hg in solid matrices. In this study, several analytical techniques such as scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), sequential chemical extractions (SCEs), and X-ray absorption spectroscopy (XANES) were used to identify Hg compounds and Hg speciation in samples collected from the Mt. Amiata Hg mining district, southern Tuscany, Italy. Different geological materials, such as mine waste calcine (retorted ore), soil, stream sediment, and stream water suspended particulate matter were analyzed. Results show that the samples were generally composed of highly insoluble Hg compounds such as sulphides (HgS, cinnabar and metacinnabar), and more soluble Hg halides such as those associated with the mosesite group. Other moderately soluble Hg compounds, HgCl2, HgO and Hg0, were also identified in stream sediments draining the mining area. The presence of these minerals suggests active and continuous runoff of soluble Hg compounds from calcines, where such Hg compounds form during retorting, or later in secondary processes. Specifically, we suggest that, due to the proximity of Hg mines to the urban center of Abbadia San Salvatore, the influence of other anthropogenic activities was a key factor for Hg speciation, resulting in the formation of unusual Hg-minerals such as mosesite.

  7. New perspectives on a 140-year legacy of mining and abandoned mine cleanup in the San Juan Mountains, Colorado

    USGS Publications Warehouse

    Yager, Douglas B.; Fey, David L.; Chapin, Thomas; Johnson, Raymond H.

    2016-01-01

    The Gold King mine water release that occurred on 5 August 2015 near the historical mining community of Silverton, Colorado, highlights the environmental legacy that abandoned mines have on the environment. During reclamation efforts, a breach of collapsed workings at the Gold King mine sent 3 million gallons of acidic and metal-rich mine water into the upper Animas River, a tributary to the Colorado River basin. The Gold King mine is located in the scenic, western San Juan Mountains, a region renowned for its volcano-tectonic and gold-silver-base metal mineralization history. Prior to mining, acidic drainage from hydrothermally altered areas was a major source of metals and acidity to streams, and it continues to be so. In addition to abandoned hard rock metal mines, uranium mine waste poses a long-term storage and immobilization challenge in this area. Uranium resources are mined in the Colorado Plateau, which borders the San Juan Mountains on the west. Uranium processing and repository sites along the Animas River near Durango, Colorado, are a prime example of how the legacy of mining must be managed for the health and well-being of future generations. The San Juan Mountains are part of a geoenvironmental nexus where geology, mining, agriculture, recreation, and community issues converge. This trip will explore the geology, mining, and mine cleanup history in which a community-driven, watershed-based stakeholder process is an integral part. Research tools and historical data useful for understanding complex watersheds impacted by natural sources of metals and acidity overprinted by mining will also be discussed.

  8. Geology and ore deposits of the Section 23 Mine, Ambrosia Lake District, New Mexico

    USGS Publications Warehouse

    Granger, H.C.; Santos, E.S.

    1982-01-01

    The section 23 mine is one of about 18 large uranium mines opened in sandstones of the fluvial Westwater Canyon Member of the Jurassic Morrison Formation in the Ambrosia Lake mining district during the early 1960s. The Ambrosia Lake district is one of several mining districts within the Grants mineral belt, an elongate zone containing many uranium deposits along the southern flank of the San Juan basin. Two distinct types of ore occur in the mine. Primary ore occurs as peneconcordant layers of uranium-rich authigenic organic matter that impregnates parts of the reduced sandstone host rocks and which are typically elongate in an east-southeast direction subparallel both to the sedimentary trends and to the present-day regional strike of the strata. These are called prefault or trend ores because of their early genesis and their elongation and alinement. A second type of ore in the mine is referred to as postfault, stacked, or redistributed ore. Its genesis was similar to that of the roll-type deposits in Tertiary rocks of Wyoming and Texas. Oxidation, related to the development of a large tongue of oxidized rock extending from Gallup to Ambrosia Lake, destroyed much of the primary ore and redistributed it as massive accumulations of lower grade ores bordering the redox interface at the edge of the tongue. Host rocks in the southern half of sec. 23 (T. 14 N., R. 10 W.) are oxidized and contain only remnants of the original, tabular, organic-rich ore. Thick bodies of roll-type ore are distributed along the leading edge of the oxidized zone, and pristine primary ore is found only near the north edge of the section. Organic matter in the primary ore was derived from humic acids that precipitated in the pores of the sandstones and fixed uranium as both coffinite and urano-organic compounds. Vanadium, molybdenum, and selenium are also associated with the ore. The secondary or roll-type ores are essentially free of organic carbon and contain uranium both as coffinite and

  9. Mapping Mineralization in the Monitor Pass Mining District

    NASA Astrophysics Data System (ADS)

    Shoffner, J. D.; Calvin, W. M.

    2007-12-01

    The Leviathan Mine, located in the Monitor Pass mining district in Alpine county California, was previously an open pit sulfur mine that supplied a nearby operation in Yerington, Nevada with sulfur for copper oxide leaching. The area was first mined underground in the mid 1800s and by the 1950s became an open pit operation. A decade later, the sulfur became uneconomic to extract, leaving the company bankrupt. By the 1980s, the EPA had declared Leviathan Mine a Superfund site due to acid mine drainage into Leviathan creek. Remediation continues today, but high sulfur soils and the potential for acid generation is abundant in the Monitor Pass area. This discovery of iron sulfate on Mars motivated the acquisition of airborne and spaceborne data similar to datasets available for Mars. In addition, high spatial resolution mineral mapping could help identify high priority remediation targets within the mine site. Low resolution (30m per pixel) spaceborne data from ALI and ASTER sensors were combined into a 13-filter dataset to locate areas of interest and as an overview of the area. Initial results were promising, showing evidence for iron oxides and clay mineralization, with some areas suggesting sulfates. The combination of thermal infrared and shortwave infrared datasets optimizes the potential for mineral identification. Therefore, we planned dual hyperspectral acquitions. SEBASS thermal data (7-15μm) at 2m per pixel was acquired on July 16, 2007. ProSpecTIR V-S (0.43- 2.45μm) was acquired on August 17, 2007, also at 2m per pixel. Field spectra were collected concurrently with the SpecTIR flight. The high resolution data will be used to confirm and refine the findings from spaceborne results and be presented at the meeting.

  10. Mines, prospects, mining claims, and sample localities of the Dark Canyon Instant Study Area and vicinity, San Juan County, Utah

    USGS Publications Warehouse

    Light, Thomas D.

    1981-01-01

    In conjunction with studies conducted by the U.S. Geological Survey, the U.S. Bureau of Mines conducted a mineral survey in 1979 of known mines, prospect workings, and mineralized zones in the Dark Canyon Instant Study Area, San Juan County, Utah.  This map is a supplement to the Mineral Resources of the Dark Canyon Instant Study Area (Weitz and Light, 1981)., and depicts the locations of mines, prospects, mining claims and sample localities for the area examined by the U.S. Bureau of Mines.

  11. Mining pollution: The case of the Baguio mining district, the philippines

    NASA Astrophysics Data System (ADS)

    Briones, Nicomedes D.

    1987-07-01

    Environmental problems caused by improper mine tailings disposal in the Baguio district include pollution of the Lower Agno River system and its watershed and siltation of irrigation canals in the Pangasinan plains. Direct economic losses are from reduced agricultural production due to siltation of irrigation works and farmlands. To check the adverse ecological effects of improper mine tailings disposal, government regulations have been imposed on mining firms. Several disposal schemes have been proposed, including the use of the reservoir of a multipurpose project to be sited in the watershed where the mines are located. Because of siltation problems, however, trapping the tailings in the reservoir will diminish the economic benefits that can be derived from the project.

  12. Geology and Ore Deposits of the Uncompahgre (Ouray) Mining District, Southwestern Colorado

    USGS Publications Warehouse

    Burbank, Wilbur Swett; Luedke, Robert G.

    2008-01-01

    The Uncompahgre mining district, part of the Ouray mining district, includes an area of about 15 square miles (mi2) on the northwestern flank of the San Juan Mountains in southwestern Colorado from which ores of gold, silver, copper, lead, and zinc have had a gross value of $14 to 15 million. Bedrock within the district ranges in age from Proterozoic to Cenozoic. The oldest or basement rocks, the Uncompahgre Formation of Proterozoic age, consist of metamorphic quartzite and slate and are exposed in a small erosional window in the southern part of the district. Overlying those rocks with a profound angular unconformity are Paleozoic marine sedimentary rocks consisting mostly of limestones and dolomites and some shale and sandstone that are assigned to the Elbert Formation and Ouray Limestone, both of Devonian age, and the Leadville Limestone of Mississippian age. These units are, in turn, overlain by rocks of marine transitional to continental origin that are assigned to the Molas and Hermosa Formations of Pennsylvanian age and the Cutler Formation of Permian age; these three formations are composed predominantly of conglomerates, sandstones, and shales that contain interbedded fossiliferous limestones within the lower two-thirds of the sequence. The overlying Mesozoic strata rest also on a pronounced angular unconformity upon the Paleozoic section. This thick Mesozoic section, of which much of the upper part was eroded before the region was covered by rocks of Tertiary age, consists of the Dolores Formation of Triassic age, the Entrada Sandstone, Wanakah Formation, and Morrison Formation all of Jurassic age, and the Dakota Sandstone and Mancos Shale of Cretaceous age. These strata dominantly consist of shales, mudstones, and sandstones and minor limestones, breccias, and conglomerates. In early Tertiary time the region was beveled by erosion and then covered by a thick deposit of volcanic rocks of mid-Tertiary age. These volcanic rocks, assigned to the San Juan

  13. A jewel in the desert: BHP Billiton's San Juan underground mine

    SciTech Connect

    Buchsbaum, L.

    2007-12-15

    The Navajo Nation is America's largest native American tribe by population and acreage, and is blessed with large tracks of good coal deposits. BHP Billiton's New Mexico Coal Co. is the largest in the Navajo regeneration area. The holdings comprise the San Juan underground mine, the La Plata surface mine, now in reclamation, and the expanding Navajo surface mine. The article recounts the recent history of the mines. It stresses the emphasis on sensitivity to and helping to sustain tribal culture, and also on safety. San Juan's longwall system is unique to the nation. It started up as an automated system from the outset. Problems caused by hydrogen sulfide are being tackled. San Juan has a bleederless ventilation system to minimise the risk of spontaneous combustion of methane and the atmospheric conditions in the mine are heavily monitored, especially within the gob areas. 3 photos.

  14. Geochemistry of placer gold, Koyukuk-Chandalar mining district, Alaska

    USGS Publications Warehouse

    Mosier, E.L.; Cathrall, J.B.; Antweiler, J.C.; Tripp, R.B.

    1989-01-01

    The Koyukuk-Chandalar mining district of the Brooks Range mineral belt in north-central Alaska contains numerous placer gold deposits but few known lode gold sources. Gold grains, collected from 46 placer localities and 6 lode gold sites in the district, were analyzed for Ag and 37 trace elements utilizing direct current-arc optical emission spectroscopy. When possible, several measurements were made on each sample and averaged. Gold content was calculated by the summation of the 38 elements determined and subtracting from 100. The objectives of our study were to characterize the deposits by defining the type and number of distinct geochemical characteristics for the Au, to determine relationships of Au in placer deposits to possible lode sources (placer and lode), to identify possible primary sources of placer gold, and to study processes of placer formation. Interpretation of results emphasize that the Au grains are almost invariably ternary (Au-Ag-Cu) alloys. The average Cu content is 0.040% and the average Ag content and fineness [(Au/Au+Ag)??1,000] are 10.5% and 893 parts per thousand, respectively, for the 46 placer localities. Six geochemically distinct types of placer gold can be identified in the Koyukuk-Chandalar mining district based on Ag and Cu values. One type with an average Ag content of 21.2%, an average Cu content of 0.007%, and 786 average fineness is found only in the eastern part of the district. Placer gold grains that have an average Ag content of 6.0%, an average Cu content of 0.276%, and 940 average fineness were found in the western part of the district. Four intermediate types generally occur in order across the district. Variations in the chemistry of the placer gold can be related to variable depositional environments at the primary gold sources. Placer gold geochemistry is important in determining the origin and depositional environment of the primary Au sources and could add to the knowledge of the thermal history of the southcentral

  15. San Jose Unified School District Health & Safety Guide for Facilities and Construction.

    ERIC Educational Resources Information Center

    2001

    This guide from the San Jose Unified School District describes recommended procedures to promote and maintain a healthy and safe school environment during maintenance, modernization, or construction. Guidelines are presented in the following areas: (1) construction safety; (2) communication; (3) material selection; (4) heating, ventilation, and…

  16. San Jose/Evergreen Community College District: Information Systems Technology Planning.

    ERIC Educational Resources Information Center

    San Jose/Evergreen Community Coll. District, San Jose, CA.

    This report presents the San Jose/Evergreen Community College District information systems technology plan. It outlines the following five global objectives: (1) develop an information technology infrastructure to support and facilitate administration, instruction, and student services; (2) establish electronic communications as the basis for…

  17. Evaluation Report of the San Marcos Independent School District's Bilingual Education Program.

    ERIC Educational Resources Information Center

    Harrison, Helene W.

    The San Marcos Independent School District's Bilingual Education Program for 1972-73 was evaluated in this report. The program consisted of 684 students in grades K-5 in 4 elementary schools. The majority of these students were Mexican American with only 18% monolingual English speakers. The program's objectives were, first, to provide bilingual…

  18. Energy Conservation in the San Diego Community College District: Initial Study.

    ERIC Educational Resources Information Center

    San Diego Community Coll. District, CA. Research Office.

    This four-part report presents the findings of a study conducted by the San Diego Community College District (SDCCD) to assess methods of effecting savings in energy usage at college facilities, to determine curricular areas in which energy-related instruction could be increased, and to examine ways of saving energy through scheduling and…

  19. Hydrologic data from wells at or in the vicinity of the San Juan coal mine, San Juan County, New Mexico

    USGS Publications Warehouse

    Stewart, Anne M.; Thomas, Nicole

    2015-01-01

    In 2010, in cooperation with the Mining and Minerals Division (MMD) of the State of New Mexico Energy, Minerals and Natural Resources Department, the U.S. Geological Survey (USGS) initiated a 4-year assessment of hydrologic conditions at the San Juan coal mine (SJCM), located about 14 miles west-northwest of the city of Farmington, San Juan County, New Mexico. The mine produces coal for power generation at the adjacent San Juan Generating Station (SJGS) and stores coal-combustion byproducts from the SJGS in mined-out surface-mining pits. The purpose of the hydrologic assessment is to identify groundwater flow paths away from SJCM coal-combustion-byproduct storage sites that might allow metals that may be leached from coal-combustion byproducts to eventually reach wells or streams after regional dewatering ceases and groundwater recovers to predevelopment levels. The hydrologic assessment, undertaken between 2010 and 2013, included compilation of existing data. The purpose of this report is to present data that were acquired and compiled by the USGS for the SJCM hydrologic assessment.

  20. San Jose Unified School District, 2010-2013: Building a Culture of Evidence-Based Practice around College Readiness

    ERIC Educational Resources Information Center

    Kless, Lambrina

    2013-01-01

    In 2012-2013, leaders and staff of the San Jose Unified School District (SJUSD) focused on accomplishing the district's new mission: to aggressively pursue solutions to close the opportunity gap and ensure that all students leave SJUSD with twenty-first-century skills, prepared to participate in a global society. The district's participation in…

  1. Master Contract: San Joaquin Delta College Teachers Association/CTA/NEA and San Joaquin Delta Community College District, July 1987-June 1990.

    ERIC Educational Resources Information Center

    San Joaquin Delta Community Coll. District, CA.

    The collective bargaining agreement between the San Joaquin Delta Community College District Board of Trustees and the San Joaquin Delta College Teachers Association/California Teachers Association/National Education Association is presented. This contract, covering the period from July 1987 through June 1990, deals with the following topics:…

  2. Spreading of pollutants from alkaline mine drainage. Rodalquilar mining district (SE Spain).

    PubMed

    González, V; García, I; del Moral, F; de Haro, S; Sánchez, J A; Simón, M

    2012-09-15

    In the Rodalquilar mining district of SE Spain, a total of 46 soil samples that were between 0 and 20 cm in depth were taken from the tailings dump, stream sediments, and surfaces that were presumably were unaffected by mining. In each soil sample, organic carbon content, pH, particle size distribution and total and soluble trace element content were analysed. Pollutants were scattered by runoff from two source areas: tailings from Au mining (Sn, Sb, As and Se) and wastes from Pb mining (Pb, Cu and Zn). Sn, Pb, and Sb were spread mostly in the solid phase of the runoff, while Cu, Zn, As and Se were spread in both the solid and soluble phases of the runoff. The pollutants with the highest soluble concentrations were As and Se, which were scattered at greater distances from the source. Some evidence suggests that tailings from Au mining could also be scattered by wind, but no farther than 1500 m from the source.

  3. Uranium minerals from the San Marcos District, Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Reyes-Cortés, Manuel; Fuentes-Cobas, Luis; Torres-Moye, Enrique; Esparza-Ponce, Hilda; Montero-Cabrera, María Elena

    2010-05-01

    The mineralogy of the two uranium deposits (Victorino and San Marcos I) of Sierra San Marcos, located 30 km northwest of Chihuahua City, Mexico, was studied by optical microscopy, powder X-ray diffraction with Rietveld analysis, scanning electron microscopy with energy dispersive X-ray analysis, inductively coupled plasma spectrometry, and gamma spectrometry. At the San Marcos I deposit, uranophane Ca(UO2)2Si2O7·6(H2O) (the dominant mineral at both deposits) and metatyuyamunite Ca(UO2)(V2O8)·3(H2O) were observed. Uranophane, uraninite (UO2+x), masuyite Pb(UO2)3O3(OH)·3(H2O), and becquerelite Ca(UO2)6O4(OH)6 ·(8H2O) are present at the Victorino deposit. Field observations, coupled with analytical data, suggest the following sequence of mineralization: (1) deposition of uraninite, (2) alteration of uraninite to masuyite, (3) deposition of uranophane, (4) micro-fracturing, (5) calcite deposition in the micro-fractures, and (6) formation of becquerelite. The investigated deposits were formed by high-to low-temperature hydrothermal activity during post-orogenic evolution of Sierra San Marcos. The secondary mineralization occurred through a combination of hydrothermal and supergene alteration events. Becquerelite was formed in situ by reaction of uraninite with geothermal carbonated solutions, which led to almost complete dissolution of the precursor uraninite. The Victorino deposit represents the second known occurrence of becquerelite in Mexico, the other being the uranium deposits at Peña Blanca in Chihuahua State.

  4. Geo-environmetal characterization of dry riverbeds affected by mine tailings in the Mazarrón district, Murcia (Spain)

    NASA Astrophysics Data System (ADS)

    Martín-Crespo, Tomás.; Gómez-Ortiz, David; Martínez-Pagán, Pedro; Martín-Velázquez, Silvia; de Ignacio, Cristina; Lillo, Javier; Faz, Angel

    2010-05-01

    Mine tailings constitute an environmental issue of public concern because they represent accumulations and emission sources of heavy metals and acid mine drainage by sulphide oxidation. In this work, two geophysical methods, electrical resistivity tomography (ERT) and ground-penetrating radar (GPR), as well as mineralogical and geochemical techniques have been used in order to obtain a geo-environmental characterization of two dry riverbeds in a mining district. The abandoned San Cristóbal and Los Perules mining group (Mazarrón, Murcia) has generated a huge amount of sludge from the Ag, Pb and Zn extraction operations. These tailings were piled up in ponds or directly dumped to the San Cristóbal dry riverbed located at the mining site, and Las Moreras dry riverbed, where San Cristóbal flows into a few meters downstream. Furthermore, Las Moreras watercourse flows into the Mediterranean Sea five kilometres downstream. Samples from two boreholes have been analyzed in order to obtain thickness, mineralogical and chemical composition of tailings and watercourse sedimentary materials affected by them. San Cristóbal sampling point shows a thickness of 3,5 m of mine tailings, 2 m of sedimentary materials, and the in situ volcanic rocks to 5,5 m depth. Las Moreras site shows a thickness of 2 m of a mine tailings deposit, 4 m of sedimentary materials, and the in situ metamorphic rocks 6 m depth. In both sites, significant amounts of pyrite (15-20 wt %), sphalerite (10-15 wt %) and galena (5-10 wt %) have been determined, and secondary oxides (hematite) and sulphates (gypsum, jarosite) minerals have been also identified. Ag, As, Cd, Co, Cu, Sb, V, Pb and Zn contents are also significant in all studied samples from tailings samples, and acid mine drainage has been clearly detected affecting the San Cristóbal dry riverbed. Regarding the alluvial materials from the riverbeds, pyrite, sphalerite and galena have been only identified in the San Cristóbal sampling point

  5. Geochemistry of selected mercury mine-tailings in the Parkfield Mercury District, California

    USGS Publications Warehouse

    Rytuba, James J.; Kotlyar, Boris B.; Wilkerson, Gregg; Olson, Jerry

    2001-01-01

    The Parkfield mercury district is located in the southern part of the California Coast Range mercury mineral belt and contains three silica-carbonate-type mercury deposits that have had significant mercury production. Mercury was first produced in the district in 1873, but the main period of production occurred from 1915-1922. Total production from the district is about 5,000 flasks of mercury (a flask equals 76 pounds of mercury) with most production coming from the Patriquin mine (1,875 flasks), and somewhat less from the King (1,600 flasks) and Dawson (1,470 flasks) mines. Several other small prospects and mines occur in the district but only minor production has come from them. In 1969, Phelan Sulphur Company carried out mineral exploration at the King mine and announced the discovery of 55,000 tons of mercury ore with an average grade of 5.2 pounds per ton. The King mine is located on federal land administered by the U.S. Bureau of Land Management. Several other parcels of federal land are present adjacent to other mines and prospects in the Parkfield district. An environmental assessment of mine sites on and adjacent to federal land was carried out to determine the amount of mercury and other trace metals present in mine wastes and in sediments from streams impacted by past mining.

  6. Remote sensing evaluation of the Klondike Mining District, Nevada. Part 1: Geology, photography and infrared

    NASA Technical Reports Server (NTRS)

    Brennan, P. A.; Chapman, P. E.; Chipp, E. R.

    1971-01-01

    During August of 1970 Mission 140 was flown with the NASA P3A aircraft over the Klondike Mining District, Nevada. High quality metric photography, thermal infrared imagery, multispectral photography and multichannel microwave radiometry were obtained. Geology and ground truth data are presented and relationships of the physical attributes of geologic materials to remotely sensed data is discussed. It is concluded that remote sensing data was valuable in the geologic evaluation of the Klondike Mining District and would be of value in other mining districts.

  7. Detecting areas disturbed by mining activities through Landsat images, San Luis Potosi City, Mexico

    NASA Astrophysics Data System (ADS)

    Torres-Vera, M.-A.

    2009-04-01

    Mining history in San Luis Potosí (Mexico) goes back to more than four centuries, and the accumulation of mining waste poses an important problem to ecological risk prevention. Epithermal deposits are the most common in this region and the impact of mining exploitation must be evaluated to propose sustainable development of the natural resources, which have a strong contribution of the national economy. The state San Luis Potosi is situated in the central part of Mexico between parallels 21°11' and 24°34' of north latitude and 98°23' and 102°14' of west longitude, 424 km northeast from Mexico City. Today is a sprawling city with more than half a million residents. The aim of this study was to analyse land cover and vegetation changes between 1972 and 2000 in San Luis Potosi Valley, using satellite image data. Since large changes in land cover and vegetation are taking place in the Valley and there is a lack of good data, such as maps, statistics and aerial photographs, it was appropriate to use satellite data for assessment of land cover and vegetation to estimate the environmental impact of the mining industry. Field data samples were used to evaluate the change results obtained with the multispectral satellite images. The results show that land cover change in the San Luis Potosi Valley has occurred in the past decade as a result of both natural forces and human activities, which have in turn impacted on the regional sustainable development of the mining resources.

  8. Pitchblende deposits at the Wood and Calhoun mines, Central City mining district, Gilpin County, Colorado

    USGS Publications Warehouse

    Moore, Frank R.; Butler, C.R.

    1952-01-01

    Pitchblende has been mined in commercial quantities from four gold- and silver-bearing pyrite-sphalerite-galena veins that occur in an area about one-half mile square on the south side of Quartz Hill, Central City district, Gilpin County, Colo. These veins are the Kirk, the German-Belcher, the Wood, and the Calhoun. Two of these veins, the Wood and the Calhoun, were studied in an attempt to determine the geologic factors favorable for pitchblende deposition. All accessible workings at the Wood and East Calhoun mines were mapped by tape and compass, and the distribution of radioactivity was studied in the field. Channel and chip samples were taken for chemical assay to compare radioactivity with uranium content. The pitchblende-bearing veins cat both pre-Cambrian granite gneiss and quartz-biotite schist; however, the gneiss was the more favorable host rock. Two bostonite porphyry dikes of Tertiary(?) age were crosscut by the Wood and Calhoun veins. The pitchblende occurs in lenses erratically distributed along the veins and in stringers extending outward from the veins. In the lenses it forms hard'. masses, but elsewhere it is Soft and powdery. The pitchblende is contemporaneous with the pyrite bat earlier than the sphalerite and galena in the same vein. All the observed pitchblende was at depths of less than 400 ft. The veins probably cannot be mined profitably for the pitchblende alone under present conditions.

  9. What's weathering? Mineralogy and field leach studies in mine waste, Leadville and Montezuma mining districts, Colorado

    USGS Publications Warehouse

    Diehl, S.F.; Hageman, Phil L.; Smith, Kathleen S.

    2006-01-01

    Weathering is important in the development of rock fabrics that control porosity in mine-waste materials, and in turn, porosity affects metal transport through and from mine-waste piles into watersheds. Mine-waste piles are dynamic physical and chemical systems as evidenced by remnant Fe-oxide boxwork structures after sulfide minerals, development of alteration rinds and etch pits on grains, and precipitation of secondary minerals under low temperature conditions. These microscale changes in the mine-waste materials are the result of partial to total dissolution of sulfide and other minerals. Mine-waste materials from the Dinero, Lower Chatauqua, and Saints John sites, Leadville and Montezuma mining districts, Colorado, exhibit rock fabrics that indicate that weathering products, e.g., Fe oxyhydroxides, jarosite, and clays, have been transported in suspension through the waste piles and deposited in voids and as coatings on rock fragments. Microscale characterization of weathered, partially dissolved minerals lends insight into the source of leachable metals in these mine-waste sites. Mineralogic studies show that galena in the Lower Chatauqua waste is enriched in Ag. Qualitative and semiquantitative microanalysis of weathered, altered galena grains from all three sites show that the Ag-bearing galena is more susceptible to dissolution. It is not surprising, then, that solutions experimentally leached from Lower Chatauqua waste are higher in Pb (2310 ppb) compared to leachates from the Dinero (31 ppb) and Saints John (1360 ppb) wastes. The mobility of metals is increased at acidic pH. Using the USGS Field Leach Test protocol, leachate derived from the Dinero waste has a pH of 3 and high concentrations of Al (443 ppb), Fe (441 ppb), and Zn (7970 ppb). Leachate from Sts. John tailings has a pH about 4 and high concentrations of Mn (1520 ppb), Zn (2240 ppb), and Pb (1360 ppb). Leachate from the Lower Chatauqua waste has an intermediate pH of 5, but in addition to the

  10. Caldera-related gold mineralization of the El Limón mining district, western Nicaragua

    NASA Astrophysics Data System (ADS)

    Malone, Gary B.; Stoiber, Richard E.

    1987-08-01

    The town of El Limón, the center of a small gold mining district, lies 36 km northeast of León, Nicaragua. This paper reports on the sequence of volcanic rocks in the district, the structures in these volcanics and the relationship of the gold veins to them.

  11. The Goldfield mining district, Nevada: an acid sulfate bonanza gold deposit

    USGS Publications Warehouse

    Rockwell, Barnaby W.

    2000-01-01

    This paper provides an introduction to the geology, ore deposits, and fluid geochemistry of the Goldfield mining district, Esmerelda and Nye Counties, Nevada. Also included is a brief interpretation of mineral maps of the western half of the district which were recently produced from remotely sensed imagery acquired by the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) systems operated by NASA JPL.

  12. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Cooperation between superintendent and district mining... MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY § 215.23 Cooperation between... technical advice as may be necessary or appropriate to the most efficient cooperation in the conduct of...

  13. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Cooperation between superintendent and district mining... MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY § 215.23 Cooperation between... technical advice as may be necessary or appropriate to the most efficient cooperation in the conduct of...

  14. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Cooperation between superintendent and district mining... MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY § 215.23 Cooperation between... technical advice as may be necessary or appropriate to the most efficient cooperation in the conduct of...

  15. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Cooperation between superintendent and district mining... MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY § 215.23 Cooperation between... technical advice as may be necessary or appropriate to the most efficient cooperation in the conduct of...

  16. Acid Mine Drainage and Metal Sulfate Minerals in the Shasta Mining District, California

    NASA Astrophysics Data System (ADS)

    Livingston, J. D.; Murphy, W. M.; Miller, R. M.; Ayars, E. J.

    2005-12-01

    Metal sulfate minerals were collected at four surface water drainage sites during September and October of 2004 in the Shasta Mining District, southern Klamath Mountains, Shasta County, California and analyzed by X-ray fluorescence, atomic absorption spectroscopy, and X-ray diffraction to determine elements present, quantities of Fe, Cu, and Zn, and mineralogy. The Shasta Mining District produced major quantities of Cu, Zn, and pyrite (S) with minor amounts of Au, Ag, and Fe from massive sulfide bodies (Kinkel et al., 1956). Three study sites are located on Iron Mountain and one study site is at Bully Hill. Although mining occurred during a period of just over 100 years, it is estimated that acid mine drainage (AMD) will continue from Iron Mountain for over 3,200 years (Nordstrom and Alpers, 1998). AMD at the study sites produces blooms of metal sulfates during California's Mediterranean climate summer. The minerals readily dissolve in the "first flush" of seasonal rain creating runoff water of low pH with high amounts of dissolved metals (Bayless and Olyphant, 1993; Jambor et al., 2000). Data were examined for mineralogical changes in time and space and for zoning of minerals on a scale of centimeters. Sulfate mineral samples are complex with some samples composed of over a dozen different minerals. Site 1 is located on Spring Creek downstream from the Iron Mountain superfund remediation site, so levels of Fe, Cu, and Zn in the sulfates at this site are lower than at the other sites. Two site 1 samples from the same location taken a month apart show Ca, Fe, Cu, Sr, Y, and Sn, and the first sample also has detectable Br. The metal sulfates identified from the first visit are celestine, cesanite, chessexite, hectorfloresite, and ungemachite, and the mineralogy of the second visit is bilinite, epsomite, millosevichite, and anhydrite. The Fe bearing sulfate mineral during the first visit is ungemachite, but bilinite was the Fe bearing mineral at the time of the second

  17. Stratigraphy of Slick Rock district and vicinity, San Miguel and Dolores Counties, Colorado

    USGS Publications Warehouse

    Shawe, Daniel R.; Simmons, George C.; Archbold, Norbert L.

    1968-01-01

    The Slick Rock district covers about 570 square miles in western San Miguel and Dolores Counties, in southwestern Colorado. It is at the south edge of the salt-anticline region of southwestern Colorado and southeastern Utah and of the Uravan mineral belt.Deposition of Paleozoic sedimentary rocks in the district and vicinity was principally controlled by development of the Paradox Basin, and of Mesozoic rocks by development of a depositional basin farther west. The Paleozoic rocks generally are thickest at the northeast side of the Paradox Basin in a northwest- trending trough which seems to be a wide graben in Precambrian igneous and metamorphic basement rocks; Mesozoic rocks generally thicken westward and southwestward from the district.Sedimentary rocks rest on a Precambrian basement consisting of a variety of rocks, including granite and amphibolite. The surface of the Precambrian rocks is irregular and generally more than 2,000 feet below sea level and 7,000-11,000 feet below the ground surface. In the northern part of the district the Precambrian surface plunges abruptly northeastward into the trough occupying the northeast side of the Paradox Basin, and in the southern part it sags in a narrow northeasterly oriented trough. Deepening of both troughs, or crustal deformation in their vicinity, influenced sedimentation during much of late Paleozoic and Mesozoic time.The maximum total thickness of sedimentary rocks underlying the district is 13,000 feet, and prior to extensive erosion in the late Tertiary and the Quaternary it may have been as much as about 18,000 feet. The lower 5,000 feet or more of the sequence of sedimentary rocks consists of arenaceous strata of early Paleozoic age overlain by dominantly marine carbonate rocks and evaporite beds interbedded with lesser amounts of clastic sediments of late Paleozoic age. Overlying these rocks is about 4,500 feet of terrestrial clastic sediments, dominantly sandstone with lesser amounts of shale, mudstone

  18. Seismic activity in the Sunnyside mining district, Carbon and Emery Counties, Utah, during 1968

    USGS Publications Warehouse

    Dunrud, C. Richard; Maberry, John O.; Hernandez, Jerome H.

    1970-01-01

    More than 20,000 local earth tremors were recorded by the seismic monitoring network in the Sunnyside mining district during 1968. This is about 40 percent of the number of tremors recorded by the network in 1967. In 1968 a total of 281 tremors were of sufficient magnitude to be located accurately--about 50 percent of the number of tremors in 1967 that were located accurately. As in previous years, nearly all the earth tremors originated near, or within a few thousand feet of, the mine workings. This distribution indicates that mine-induced stress changes caused most of the seismic activity. However, over periods of weeks and months there were significant changes in the distribution of seismic activity caused by tremors that were not directly related to mining but probably were caused by adjustment of natural stresses 6r by a complex combination of both natural and mine-induced stress changes. In 1968 the distribution of tremor hypocenters varied considerably with time, relative to active mining areas and to faults present in the mine workings. During the first 6 months, most tremors originated along or near faults that trend close to or through the active mine workings. However, in the last 6 months, the tremor hypocenters tended to concentrate in the rock mass closer to, or around, the active mining areas. This shift in concentration of seismic activity with time has been noted throughout the district many times since recording began in 1963, and is apparently caused by spontaneous releases of stored strain energy resulting from mine-induced stress changes. These spontaneous releases of strain energy, together with rock creep, apparently are the mechanism of adjustment within the rock mass toward equilibrium conditions, which are continually disrupted by mining. Although potentially hazardous bumps were rare in the Sunnyside mining district during 1968, smaller bumps and rock falls were more common in a given active mining area whenever hypocenters of larger

  19. Complete Analytical Data for Samples of Jurassic Igneous Rocks in the Bald Mountain Mining District, Nevada

    USGS Publications Warehouse

    du Bray, Edward A.

    2009-01-01

    This report presents all petrographic, major oxide, and trace element data for a set of 109 samples collected during an investigation of Jurassic igneous rocks in the Bald Mountain mining district, Nevada. Igneous rocks in the district include the Bald Mountain stock, quartz-feldspar porphyry dikes, basaltic andesite dikes, aplite sills, and rare lamprophyre dikes. These rocks, although variably altered near intrusion-related mineral deposits, are fresh in many parts of the district. Igneous rocks in the district are hosted by Paleozoic sedimentary rocks.

  20. Mercury-contaminated hydraulic mining debris in San Francisco Bay

    USGS Publications Warehouse

    Bouse, Robin M.; Fuller, Christopher C.; Luoma, Samuel N.; Hornberger, Michelle I.; Jaffe, Bruce E.; Smith, Richard E.

    2010-01-01

    Mercury concentrations in pre-Gold Rush sediment range between 0.03 and 0.08 μg g-1. In core sediments that have characteristics of the gold deposits and were deposited during the time of hydraulic mining, mercury concentrations can be up to 0.45 μg/g. Modern sediment (post-1952 deposition) contains mercury concentrations up to 0.79 μg/g and is likely a mix of hydraulic mining mercury and mercury introduced from other sources.

  1. Hydrology and Ground-Water Quality in the Mine Workings within the Picher Mining District, Northeastern Oklahoma, 2002-03

    USGS Publications Warehouse

    DeHay, Kelli L.; Andrews, William J.; Sughru, Michael P.

    2004-01-01

    The Picher mining district of northeastern Ottawa County, Oklahoma, was a major site of mining for lead and zinc ores in the first half of the 20th century. The primary source of lead and zinc were sulfide minerals disseminated in the cherty limestones and dolomites of the Boone Formation of Mississippian age, which comprises the Boone aquifer. Ground water in the aquifer and seeping to surface water in the district has been contaminated by sulfate, iron, lead, zinc, and several other metals. The U.S. Geological Survey, in cooperation with the Oklahoma Department of Environmental Quality, investigated hydrology and ground-water quality in the mine workings in the mining district, as part of the process to aid water managers and planners in designing remediation measures that may restore the environmental quality of the district to pre-mining conditions. Most ground-water levels underlying the mining district had similar altitudes, indicating a large degree of hydraulic connection in the mine workings and overlying aquifer materials. Recharge-age dates derived from concentrations of chlorofluorocarbons and other dissolved gases indicated that water in the Boone aquifer may flow slowly from the northeast and southeast portions of the mining district. However, recharge-age dates may have been affected by the types of sites sampled, with more recent recharge-age dates being associated with mine-shafts, which are more prone to atmospheric interactions and surface runoff than the sampled airshafts. Water levels in streams upstream from the confluence of Tar and Lytle Creeks were several feet higher than those in adjacent portions of the Boone aquifer, perhaps due to low-permeability streambed sediments and indicating the streams may be losing water to the aquifer in this area. From just upstream to downstream from the confluence of Tar and Lytle Creeks, surface-water elevations in these streams were less than those in the surrounding Boone aquifer, indicating that

  2. Mercury pollution by mining activities in Rayo Rojo mining district, Apolobamba (Bolivia)

    NASA Astrophysics Data System (ADS)

    Teran-Mita, T.; Faz Cano, A.; Muñoz, M.; Millán, R.; Salvador, F.

    2009-04-01

    In Bolivia, metal mining activities since historical times have been one of the most important causes of the environmental degradation. This is the case of the Natural Integrated Management Area of Apolobamba (Department of La Paz, Bolivia), where intense gold mining activities have been carried out from former times to present days, with very little gold extraction and very scarce mineral processing technology. In Apolobamba mercury is still being used in the amalgam processes and this might conduct to high Hg contents. Inhabitants of this area consume fish from lakes and rivers, and use the waters for the livestock, domestic use, and irrigation. The aim of this work was to evaluate mercury impact into the soil-plant-water system. The Technical University of Cartagena, Spain, through the Research Group "Sustainable Use, Management and Reclamation of Soil and Water", carried out a research, in the most intense affected gold extraction zones in Apolobamba, among them Rayo Rojo, where mining activity is mainly gold extraction, although the extracted mineral volume and technology used is low. Rayo Rojo is located in the central part of ANMI - Apolobamba (in the andean region), inside of Pelechuco municipality; the area belongs biogeographically to the Altoandina and Puna. This district, located in Apolobamba mountain-range, where altitudes above 5.000 m.a.s.l are reached. Water, soil, sediment and plant samples were taken around the operations mining sites and total mercury analysed. Mercury content was determined by AMA-254 model, based on the thermal decomposition of the sample and collection of the Hg vapour on a gold amalgamator. The analysis is performed from solid samples without any further preparation. Samples are initially dried at 125°C and then thermally decomposed at the temperature of 550°C. Mercury vapour is then trapped on the gold amalgamator. AMA-254 method certificated standards were BCR 62-BCR 281. Preliminary results show high Hg concentrations

  3. Effect of mining activities in biotic communities of Villa de la Paz, San Luis Potosi, Mexico.

    PubMed

    Espinosa-Reyes, Guillermo; González-Mille, Donaji J; Ilizaliturri-Hernández, César A; Mejía-Saavedra, Jesús; Cilia-López, V Gabriela; Costilla-Salazar, Rogelio; Díaz-Barriga, Fernando

    2014-01-01

    Mining is one of the most important industrial activities worldwide. During its different stages numerous impacts are generated to the environment. The activities in the region have generated a great amount of mining residues, which have caused severe pollution and health effects in both human population and biotic components. The aim of this paper was to assess the impact of mining activities on biotic communities within the district of Villa de la Paz. The results showed that the concentrations of As and Pb in soil were higher than the national regulations for urban or agricultural areas. The bioavailability of these metals was certified by the presence of them in the roots of species of plants and in kidneys and livers of wild rodents. In regard to the community analysis, the sites that were located close to the mining district of Villa de la Paz registered a lower biological diversity, in both plants and wild rodents, aside from showing a change in the species composition of plant communities. The results of this study are evidence of the impact of mining on biotic communities, and the need to take into account the wildlife in the assessment of contaminated sites.

  4. Effect of Mining Activities in Biotic Communities of Villa de la Paz, San Luis Potosi, Mexico

    PubMed Central

    Espinosa-Reyes, Guillermo; González-Mille, Donaji J.; Ilizaliturri-Hernández, César A.; Mejía-Saavedra, Jesús; Cilia-López, V. Gabriela; Costilla-Salazar, Rogelio; Díaz-Barriga, Fernando

    2014-01-01

    Mining is one of the most important industrial activities worldwide. During its different stages numerous impacts are generated to the environment. The activities in the region have generated a great amount of mining residues, which have caused severe pollution and health effects in both human population and biotic components. The aim of this paper was to assess the impact of mining activities on biotic communities within the district of Villa de la Paz. The results showed that the concentrations of As and Pb in soil were higher than the national regulations for urban or agricultural areas. The bioavailability of these metals was certified by the presence of them in the roots of species of plants and in kidneys and livers of wild rodents. In regard to the community analysis, the sites that were located close to the mining district of Villa de la Paz registered a lower biological diversity, in both plants and wild rodents, aside from showing a change in the species composition of plant communities. The results of this study are evidence of the impact of mining on biotic communities, and the need to take into account the wildlife in the assessment of contaminated sites. PMID:24592381

  5. Mines and Prospects, Idaho Springs District, Clear Creek and Gilpin Counties, Colorado - Descriptions and Maps

    USGS Publications Warehouse

    Moench, Robert Hadley; Drake, Avery Ala

    1966-01-01

    The Idaho Springs mining district forms an important segment of the Front Range mineral belt, a northeast-trending zone of coextensive intrusive rocks and hydrothermal ore deposits of early Tertiary age. This belt, which is about 50 miles long, extends from the region just west of Boulder southwestward across the Front Range. From 1859, when placer gold was discovered in Idaho Springs and lode gold in Central City, through 1959, ores valued at about $200 million were shipped from a 50-square-mile area that includes the Idaho Springs and adjacent districts to the north, west, and southwest. The adjacent Central City district, which produced ores valued at more than $100 million, is clearly the most important district in the mineral belt. The Idaho Springs district from 1860 to 1959 produced ores valued at about $65 million, and the districts to the west and southwest produced smaller amounts. Gold has accounted for about 60 percent of the value of the ore, but in some areas silver provides the chief values, and copper, lead, and zinc add value to the ores in most areas. Mining activity in the Idaho Springs and adjacent districts was at its 'heyday' in the late 1800's, it declined sharply after 1914, it was somewhat renewed during the 1930's, and it greatly declined during World War II. In the 1950's uranium prospecting stimulated some mining activity. No uranium was produced, however, and at the close of the decade only one mine--the Bald Eagle--was being worked for its precious- and base-metal ores. In this report, 135 mines and prospects are described. The mines and prospects described are those that were accessible at the time of this study, as well as a few inaccessible properties for which some information was available. Most of the data for the inaccessible or unimportant properties were obtained from Bastin and Hill (1917) and Spurr, Garrey, and Ball (1908). The following list shows, in alphabetical order, the names of about 325 openings of mines and

  6. Western Molybdenum Company mine, Chewelah District, Stevens County, Washington

    USGS Publications Warehouse

    Cooper, John R.

    1954-01-01

    The Western Molybdenum Co. mine was opened many years ago to obtain copper. The only production was several carloads of crude copper ore shipped during World War I. An unsuccessful attempt to produce molybdenum was made in 1939-1941.

  7. San Diego's Big Boom: District Bureaucracy Supports Culture of Learning. A Research Report. Document R-02-2

    ERIC Educational Resources Information Center

    Hightower, Amy M.

    2002-01-01

    This paper contributes to an emerging body of literature on school districts as active partners in education reform. Using qualitative methods, it details the first three years of a major districtwide initiative in San Diego City Schools as reformers sought to orient central office bureaucracy around an instructional agenda. This paper both…

  8. Modernizing "San Antonio Independent School District v. Rodriguez": How Evolving Supreme Court Jurisprudence Changes the Face of Education Finance Litigation

    ERIC Educational Resources Information Center

    Saleh, Matthew

    2011-01-01

    This article aims to "modernize" the current legal debate over inequitable public school funding at the state and local level. The 1973 Supreme Court case of "San Antonio Independent School District v. Rodriguez" established precedent, allowing for property-tax based education funding programs at the state-level--a major source…

  9. A Successful University-School District Partnership to Help San Francisco's K-12 Students Learn About Science and Medicine.

    ERIC Educational Resources Information Center

    Clark, Margaret R.

    1996-01-01

    The Science and Health Education Partnership was established in 1987 at the University of California, San Francisco, to support local school district efforts to improve science education. Components include instructional assistance to teachers and direct work with students. Emphasis has evolved from helping teachers and students to supporting…

  10. Hydrogeochemical Investigations of Historic Mining Districts, Central Western Slope of Colorado, Including Influence on Surface-Water Quality

    USGS Publications Warehouse

    Nash, J. Thomas

    2002-01-01

    This report describes reconnaissance hydrogeochemical investigations of 22 mining districts on the Western Slope of Colorado in the Gunnison and Uncompahgre National Forests and adjacent public lands administered by the Bureau of Land Management. Sources and fates of contaminants from historic mines, mine waste, and mill tailings are interpreted from chemical analyses for 190 samples of surface waters; 185 samples of mined rocks, mill tailings, and altered rocks; and passive leach analyses of 116 samples of those mineralized materials. Short reaches of several headwater streams show relatively low level effects of historic mining; the headwaters of the Uncompahgre River are highly contaminated by mines and unmined altered rocks in the Red Mountain district. There is encouraging evidence that natural processes attenuate mine-related contamination in most districts.

  11. Trace elements biomonitoring in a historical mining district (les Malines, France).

    PubMed

    Saunier, Jean-Baptiste; Losfeld, Guillaume; Freydier, Rémi; Grison, Claude

    2013-11-01

    The aim of this study is to investigate the trace elements (TE) contents of potential biomonitors in a historical Zn-Pb mining district: apiary products (honey, royal-jelly and beeswax) lichen and moss were sampled and analysed. In spite of high TE concentrations in mining waste and soil, apiary products are free of TE contamination originating from historical mining. Lichen/moss show high TE levels, which suggest atmospheric input of local dust. Pb isotopes analysis proved the origin of TE found in lichen/moss to be mainly mining waste. These results help discuss the choice of relevant organisms for monitoring TE in the environment and bring additional data on the potential impacts of brownfields left after mining, especially on food products from apiaries.

  12. Mercury speciation and microbial transformations in mine wastes, stream sediments, and surface waters at the Almaden Mining District, Spain

    USGS Publications Warehouse

    Gray, John E.; Hines, Mark E.; Higueras, Pablo L.; Adatto, Isaac; Lasorsa, Brenda K.

    2004-01-01

    Speciation of Hg and conversion to methyl-Hg were evaluated in mine wastes, sediments, and water collected from the Almade??n District, Spain, the world's largest Hg producing region. Our data for methyl-Hg, a neurotoxin hazardous to humans, are the first reported for sediment and water from the Almade??n area. Concentrations of Hg and methyl-Hg in mine waste, sediment, and water from Almade??n are among the highest found at Hg mines worldwide. Mine wastes from Almade??n contain highly elevated Hg concentrations, ranging from 160 to 34 000 ??g/g, and methyl-Hg varies from <0.20 to 3100 ng/g. Isotopic tracer methods indicate that mine wastes at one site (Almadenejos) exhibit unusually high rates of Hg-methylation, which correspond with mine wastes containing the highest methyl-Hg concentrations. Streamwater collected near the Almade??n mine is also contaminated, containing Hg as high as 13 000 ng/L and methyl-Hg as high as 30 ng/L; corresponding stream sediments contain Hg concentrations as high as 2300 ??g/g and methyl-Hg concentrations as high as 82 ng/g. Several streamwaters contain Hg concentrations in excess of the 1000 ng/L World Health Organization (WHO) drinking water standard. Methyl-Hg formation and degradation was rapid in mines wastes and stream sediments demonstrating the dynamic nature of Hg cycling. These data indicate substantial downstream transport of Hg from the Almade??n mine and significant conversion to methyl-Hg in the surface environment.

  13. Economic significance of revised age relations of rocks in the Cornucopia mining district, Elko County, Nevada

    USGS Publications Warehouse

    Coats, Robert Roy

    1967-01-01

    Recent geologic work in the Cornucopia mining district, a small silver-gold mining district in northwestern Elko County, Nev., has resulted in significant revision of the geological interpretation. Rocks formerly thought to be premineralization in age, but unmineralized, are now known to be postmineral extrusives, resting unconformably on the altered andesite in which the ore bodies are found. Extensions of the known productive veins may be expected at shallow depth beneath the younger volcanic rocks, and are separated from the mined part of the veins by postmineral high-angle faults that have brought the younger volcanic rocks into fault contact with the mineralized andesite. Some veins are apparently terminated against premineral faults.

  14. Geochemical characterization of slags, other mines wastes, and their leachates from the Elizabeth and Ely mines (Vermont), the Ducktown mining district (Tennessee), and the Clayton smelter site (Idaho)

    USGS Publications Warehouse

    Piatak, Nadine M.; Seal, Robert R., II; Hammarstrom, Jane M.; Meier, Allen L.; Briggs, Paul H.

    2003-01-01

    Waste-rock material produced at historic metal mines contains elevated concentrations of potentially toxic trace elements. Two types of mine waste were examined in this study: sintered waste rock and slag. The samples were collected from the Elizabeth and Ely mines in the Vermont copper belt (Besshi-type massive sulfide deposits), from the Copper Basin mining district near Ducktown, Tennessee (Besshi-type massive sulfide deposits), and from the Clayton silver mine in the Bayhorse mining district, Idaho (polymetallic vein and replacement deposits). The data in this report are presented as a compilation with minimal interpretation or discussion. A detailed discussion and interpretation of the slag data are presented in a companion paper. Data collected from sintered waste rock and slag include: (1) bulk rock chemistry, (2) mineralogy, (3) and the distribution of trace elements among phases for the slag samples. In addition, the reactivity of the waste material under surficial conditions was assessed by examining secondary minerals formed on slag and by laboratory leaching tests using deionized water and a synthetic solution approximating precipitation in the eastern United States.

  15. 248 mine, Terlingua quicksilver district, Brewster County, Texas

    USGS Publications Warehouse

    Yates, Robert G.; Thompson, George A.

    1944-01-01

    The 248 quicksilver mine is in Section 248, Block G-4, 2 miles east of Terlingua and 86 miles by dirt road from Alpine, Tex., the nearest railway shipping point (see accompanying maps). Cinnabar, the quicksilver mineral, was discovered before 1902. By 1934 there were only about 700 feet of subsurface workings, but in recent years the Esperado Mining Co., which has the property under lease, has greatly extended exploratory workings and has built a Herreshoff furnace rated at 40 tons per day. At the present time there are 1 1/3 miles of underground workings and 800 feet of surface trenches.

  16. Distribution of gaseous Hg in the Mercury mining district of Mt. Amiata (Central Italy): a geochemical survey prior the reclamation project.

    PubMed

    Vaselli, Orlando; Higueras, Pablo; Nisi, Barbara; María Esbrí, José; Cabassi, Jacopo; Martínez-Coronado, Alba; Tassi, Franco; Rappuoli, Daniele

    2013-08-01

    The Mt. Amiata volcano is the youngest and largest volcanic edifice in Tuscany (central-northern Italy) and is characterized by a geothermal field, exploited for the production of electrical energy. In the past Mt. Amiata was also known as a world-class Hg district whose mining activity was mainly distributed in the central-eastern part of this silicic volcanic complex, and particularly in the municipality of Abbadia San Salvatore. In the present work we report a geochemical survey on Hg(0) measurements related to the former mercury mine facilities prior the reclamation project. The Hg(0) measurements were carried out by car for long distance regional surveys, and on foot for local scale surveys by using two LUMEX (915+ and M) devices. This study presents the very first Hg(0) data obtained with this analytical technique in the Mt. Amiata area. The facilities related to the mining areas and structures where cinnabar was converted to metallic Hg are characterized by high Hg values (>50,000ngm(-3)), although the urban center of Abbadia San Salvatore, few hundred meters away, does not appear to be receiving significant pollution from the calcine area and former industrial edifices, all the recorded values being below the values recommended by the issuing Tuscany Region authorities (300ngm(-3)) and in some cases approaching the Hg background levels (3-5ngm(-3)) for the Mt. Amiata area.

  17. Analysis of exceptionally large tremors in two gold mining districts of South Africa

    USGS Publications Warehouse

    McGarr, A.; Bicknell, J.; Sembera, E.; Green, R.W.E.

    1989-01-01

    An investigation of ground motion, recorded using broad-band, wide dynamic-range digital seismographs, of large mine tremors from two South African mining districts with different geologic settings, reveals some essential differences in both seismic source and ground motion parameters. In the Klerksdorp district where the strata are offset by major throughgoing normal faults, the largest tremors, with magnitudes ranging as high as 5.2, tend to be associated with slip on these pre-existing faults. Moreover, the seismic source and ground motion parameters are quite similar to those of natural crustal earthquakes. In the Carletonville district, by contrast, where substantial faults do not exist, the large-magnitude tremors appear to result from the failure of relatively intact rock and cause seismic stress drops and ground motion parameters higher than normally observed for natural shocks. Additionally, there appears to be an upper magnitude limit of about 4 in the Carletonville district. Detailed analyses of an exceptionally large event recorded locally from each of these districts serve to highlight these contrasts. ?? 1989 Birkha??user Verlag.

  18. Hydrologic conditions in the coal mining district of Indiana and implications for reclamation of abandoned mine lands

    SciTech Connect

    Olyphant, G.A.; Harper, D.

    1998-12-31

    Bedrock strata of the mining district of Indiana (Indiana Coal Mining District, ICMD) include numerous coalbeds of economic importance, together with underclays, roof shales, limestones, and sandstones of Pennsylvanian age. These are typically poor aquifers with low hydraulic conductivities and specific yields. Surficial materials include loess, till, alluvium, and other deposits of pleistocene age. The loess and till also have low hydraulic conductivities, so that very few shallow aquifers exist in the vicinities of abandoned mine land (AML) sites, except where they are close to the alluvial fill of large bedrock valleys. The hydrologic cascade at AML sites in Indiana is strongly conditioned by the existence of elevated deposits of coarse-grained coal-preparation refuse and flooded underground mine workings. Flooded mines are the principal conduits of groundwater flow in the area, but their boundaries, flowpaths, and mechanisms of recharge and discharge are very different from those of natural aquifers and are poorly understood. Acidic mine drainage often emerges as seepages and springs on the edges of the elevated refuse deposits, but the low permeability of the natural surficial materials and bedrock inhibits the development of off-site groundwater contaminant plumes. The water balance across the surface of the refuse deposits is critical to reclamation planning and success. Enhancing runoff through reduction of infiltration capacity has the beneficial effect of reducing recharge through the acid-generating refuse, but the excess runoff may be accompanied by soil erosion that can lead to reclamation failure. Furthermore, during cool seasons and stormy periods, a well vegetated surface promotes recharge through increased infiltration, resulting in greater rates of acidic baseflow seepage. Passive Anoxic Limestone Drains (PALDs) have been successfully coupled with wetland treatment systems to improve surface waters that discharge from AML sites. Storm runoff from

  19. The plumbotectonics of the West Shasta mining district, eastern Klamath Mountains, California ( USA).

    USGS Publications Warehouse

    Doe, B.R.; Delevaux, M.H.; Albers, J.P.

    1985-01-01

    The tectonic setting comprising the West Shasta mining district has often been compared with that of primitive island arcs. Concentrations of U, Th, and Pb and Pb isotope compositions were determined for Devonian ores and rocks of the West Shasta district, E Klamath Mountains, California, to help evaluate the tectonic classification. The lead isotope pattern is found to be complex. From comparison of the data with those on younger ores and rocks in the region and with those isotopic patterns found in modern tectonic terranes, however, a number of conclusions are described in detail. -after Authors

  20. Cadmium Accumulation in Periphyton from an Abandoned Mining District in the Buffalo National River, Arkansas.

    PubMed

    McCauley, Jacob R; Bouldin, Jennifer L

    2016-06-01

    The Rush Mining District along the Buffalo River in Arkansas has a significant history of zinc and lead mining operations. The tails and spoils of these operations deposit heavy amounts of raw ore into streams. One element commonly found in the earth's crust that becomes a minor constituent of the deposition is cadmium. Periphyton samples from Rush Creek and Clabber Creek, two creeks within the Rush Mining District were measured for cadmium as well as two creeks with no history of mining, Spring Creek and Water Creek. Periphyton samples from Rush and Clabber Creek contained mean cadmium concentrations of 436.6 ± 67.3 and 93.38 ± 8.67 µg/kg, respectively. Spring Creek and Water Creek had a mean cadmium concentration of 40.49 ± 3.40 and 41.78 ± 3.99 µg/kg within periphyton. The results indicate increased metal concentrations in algal communities from mined areas. As periphyton is the base of the aquatic food chain, it acts as a conduit for movement of cadmium in the food web.

  1. State of remediation and metal toxicity in the Tri-State Mining District, USA.

    PubMed

    Johnson, Aaron W; Gutiérrez, Mélida; Gouzie, Douglas; McAliley, L Rex

    2016-02-01

    Mining operations in the Tri-State Mining District of Kansas, Missouri and Oklahoma (TSMD), once one of the major lead and zinc mining areas in the world, had completely ceased by 1970. As mining companies moved out, the land was left with underground tunnels and mine shafts and the surface with abandoned tailings piles, which progressively contaminated groundwater and soil. Despite remedial actions undertaken in the 1980's, areas within the TSMD still contain Cd, Pb, and Zn concentrations exceeding safe levels. Because of the large area and highly dispersed occurrence of wastes, environmental studies generally have been confined either to a stream basin or to a single state. Studies also have differed in their approach and analytical methodologies. An overview of the totality of the TSMD and its present state of contamination is presented here. Data show that metal content in sediments have the following common features: (1) a wide range of Pb and Zn concentrations, up to three orders of magnitude, (2) median values for Cd, Pb and Zn content in sediments and soils were similar among studies, (3) median values for most studies were at or above the guidelines recommended for aquatic habitats, and (4) highest content of Pb and Zn were closely associated with the geographical location of former mining and smelting centers. The above observations imply that mine wastes remain a problem and further remediation is needed. Cost-effective remedial alternatives for this area's geology, climate, and land use, are discussed.

  2. Geographies of displacement: Latina/os, oral history, and the politics of gentrification in San Francisco's Mission District.

    PubMed

    Mirabal, Nancy Raquel

    2009-05-01

    During the 1990s and early 2000s, working-class and poor neighborhoods in San Francisco underwent dramatic economic and racial changes. One of the most heavily gentrified neighborhoods was the Mission District. As a result of local politics, housing and rental policies, real estate speculation, and development, thousands of Latina/o families were displaced. Using oral historical and ethnographic methodologies, print media, archival sources, and policy papers, this article traces the gentrification of the Mission District from the perspective of the Latina/o community. It also examines how gentrification was articulated as a positive turn within the larger public discourse on space and access.

  3. Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District.

    PubMed

    Beyer, W Nelson; Franson, J Christian; French, John B; May, Thomas; Rattner, Barnett A; Shearn-Bochsler, Valerie I; Warner, Sarah E; Weber, John; Mosby, David

    2013-10-01

    Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000-3,200 mg Pb/kg. Analyses of earthworms [33-4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11-3.0 (reference) and 1.3-30 (contaminated) and American robin (Turdus migratorius) = 0.43-8.5 (reference) and 7.6-72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32%) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9%) with systemic toxic effects, and 4 (12%) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58-82% in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

  4. Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District

    USGS Publications Warehouse

    Beyer, W. Nelson; Franson, J. Christian; French, John B.; May, Thomas; Rattner, Barnett A.; Shearn-Bochsler, Valerie I.; Warner, Sarah E.; Weber, John; Mosby, David

    2013-01-01

    Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000–3,200 mg Pb/kg. Analyses of earthworms [33–4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11–3.0 (reference) and 1.3–30 (contaminated) and American robin (Turdus migratorius) = 0.43–8.5 (reference) and 7.6–72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32 %) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9 %) with systemic toxic effects, and 4 (12 %) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58–82 % in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

  5. Participation among San Francisco Unified School District Students in Programs Offered by the Department of Children, Youth, and Their Families. Youth Data Archive Issue Brief

    ERIC Educational Resources Information Center

    Williams, Imeh

    2013-01-01

    For the past year, the San Francisco Department of Children, Youth, and their Families (DCYF), San Francisco Unified School District (SFUSD), and the John W. Gardner Center for Youth and Their Communities at Stanford University (Gardner Center) have collaborated to examine SFUSD student participation in DCYF-funded programs. This analysis utilizes…

  6. Forest ecosystem development in post-mining landscapes: a case study of the Lusatian lignite district

    NASA Astrophysics Data System (ADS)

    Hüttl, Reinhard F.; Weber, Edwin

    2001-08-01

    The restoration of surface mining landscapes requires the (re)creation of ecosystems. In Lusatia (eastern Germany), large-scale open-cast lignite mining operations generated spoil dumps widely consisting of acidified, phytotoxic substrates. Amelioration and rehabilitation measures have been developed and applied to these substrates since the 1950s. However, it is still not clear whether these approaches are sustainable. This paper reports on collaborative research work into the ecological potential of forest ecosystem development on typical minesites in the Lusatian lignite district. At first sight, pine stands on minesites along a chronosequence comprising about 35 years did not show differences when compared with stands on non-mined sites of the general region. Furthermore, with some modification, conceptual models for flora and fauna succession in forest stands on non-mined sites seem to be applicable, at least for the early stages of forest ecosystem development. For example, soil organism abundance and activity at minesites had already reached levels typical of non-mined sites after about 20-30 years. In contrast, mine soils are very different from non-mined soils of the test region. Chemically, mine soil development is dominated by processes originating from pyrite oxidation. Geogenic, i.e. lignitic, soil organic carbon was shown to substitute for some functions of pedogenic soil organic matter. Rooting was hampered but not completely impeded in strongly acidified soil compartments. Roots and mycorrhizae are apparently able to make use of the characteristic heterogeneity of young mine soils. Considering these recent results and the knowledge accumulated during more than 30 years of research on minesite rehabilitation internationally, it can be stated that minesite restoration might be used as an ideal case study for forest ecosystem development starting at "point zero" on " terra nova".

  7. Land disposal of San Luis drain sediments, Panoche Water District, South Dos Palos, California

    SciTech Connect

    Zawislanski, Peter; Benson, Sally; TerBerg, Robert; Borglin, Sharon

    2002-07-01

    Lawrence Berkeley National Laboratory (LBNL), LFR Levine-Fricke (LFR), the U.S. Bureau of Reclamation (USBR) and the Panoche Water District, have completed a pilot-scale test of the viability of land application of selenium- (Se-) enriched San Luis Drain (SLD) sediments. The project was initiated in October 1998 by LBNL. LFR assumed the role of primary subcontractor on the project in July 2001. Substantial portions of this report, describing work performed prior to November 2000, were previously prepared by LBNL personnel. The data set, findings, and recommendations are herein updated with information collected since November 2000. Local land disposal is an attractive option due to its low cost and the proximity of large areas of available land. Two modes of disposal are being tested: (1) the application to a nearby SLD embankment, and (2) the application to and incorporation with nearby farm soils. The study of these options considers the key problems that may potentially arise from this approach. These include disturbance of SLD sediments during dredging, resulting in increased downstream Se concentrations; movement of the land-applied Se to groundwater; reduced productivity of farm crops; and Se uptake by wild and crop plants. This report describes field and laboratory activities carried out from 1998 through February 2002, and results of these investigations.

  8. Soil geochemistry of Mother Lode-type gold deposits in the Hodson mining district, central California, U.S.A.

    USGS Publications Warehouse

    Chaffee, M.A.; Hill, R.H.

    1989-01-01

    The Hodson mining district is in the westernmost foothills of the Sierra Nevada in California, about 17 km west of the town of Angels Camp. This district is part of the West Gold Belt, which lies about 12-16 km west of, and generally parallel to, the better known Mother Lode Gold Belt in central California. The district produced several million dollars worth of Au between about 1890 and 1940. ?? 1989.

  9. Minor and trace-elements in apiary products from a historical mining district (Les Malines, France).

    PubMed

    Losfeld, Guillaume; Saunier, Jean-Baptiste; Grison, Claude

    2014-03-01

    The trace-elements (TE) contents of honey, royal-jelly and beeswax from a historical Zn-Pb mining district have been investigated to assess potential contamination. In spite of high levels of heavy metal (As, Cd, Tl, Pb) in wastes left after mining stopped, apiary products appear to be relatively free of TE contamination. For honey, the following average levels (±standard error) were observed: Zn 571±440μgkg(-1), Pb 26±20μgkg(-1), Tl 13±10μgkg(-1), Cd 7±6μgkg(-1) and As 3±4μg.kg(-1). These results bring additional data to the potential impact of brownfields left after mining on apiary products. They also bring new data to assess potential risks linked with honey consumption and discuss legal TE contents in honey and other food products from apiaries.

  10. The Power of a Good Idea: How the San Francisco School District Is Building a PreK-3rd Grade Bridge

    ERIC Educational Resources Information Center

    Nyhan, Paul

    2015-01-01

    In 2008 the San Francisco Unified School District (SFUSD) confronted a problem that has been growing for decades. It boasted the highest academic performance of any large urban district in California, yet its achievement gap was widening, as too many African American, Latino, and low-income students fell far behind their classmates. The…

  11. 78 FR 72025 - Security Zones; Naval Base Point Loma; Naval Mine Anti Submarine Warfare Command; San Diego Bay...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA87 Security Zones; Naval Base Point Loma; Naval Mine Anti.... SUMMARY: The Coast Guard is increasing a portion of an existing San Diego Bay security zone at Naval Base... permission of the Captain of the Port, the Commander of Naval Base Point Loma, the Commander of the...

  12. The Nation's Report Card Mathematics 2013 Trial Urban District Snapshot Report. San Diego Unified School District. Grade 8, Public Schools

    ERIC Educational Resources Information Center

    National Center for Education Statistics, 2013

    2013-01-01

    The National Assessment of Educational Progress (NAEP), in partnership with the National Assessment Governing Board and the Council of the Great City Schools (CGCS), created the Trial Urban District Assessment (TUDA) in 2002 to support the improvement of student achievement in the nation's large urban districts. NAEP TUDA results in mathematics…

  13. The Nation's Report Card Reading 2013 Trial Urban District Snapshot Report. San Diego Unified School District. Grade 8, Public Schools

    ERIC Educational Resources Information Center

    National Center for Education Statistics, 2013

    2013-01-01

    The National Assessment of Educational Progress (NAEP), in partnership with the National Assessment Governing Board and the Council of the Great City Schools (CGCS), created the Trial Urban District Assessment (TUDA) in 2002 to support the improvement of student achievement in the nation's large urban districts. NAEP TUDA results in mathematics…

  14. The Nation's Report Card Reading 2013 Trial Urban District Snapshot Report. San Diego Unified School District. Grade 4, Public Schools

    ERIC Educational Resources Information Center

    National Center for Education Statistics, 2013

    2013-01-01

    The National Assessment of Educational Progress (NAEP), in partnership with the National Assessment Governing Board and the Council of the Great City Schools (CGCS), created the Trial Urban District Assessment (TUDA) in 2002 to support the improvement of student achievement in the nation's large urban districts. NAEP TUDA results in mathematics…

  15. Mass loads of dissolved and particulate mercury and other trace elements in the Mt. Amiata mining district, Southern Tuscany (Italy)

    USGS Publications Warehouse

    Rimondi, V.; Costagliola, P.; Gray, J.E.; Lattanzi, P.; Nannucci, M.; Paolieri, M.; Salvadori, A.

    2014-01-01

    Total dissolved and particulate mercury (Hg), arsenic (As), and antimony (Sb) mass loads were estimated in different seasons (March and September 2011 and March 2012) in the Paglia River basin (PRB) (central Italy). The Paglia River drains the Mt. Amiata Hg district, one of the largest Hg-rich regions worldwide. Quantification of Hg, As, and Sb mass loads in this watershed allowed (1) identification of the contamination sources, (2) evaluation of the effects of Hg on the environment, and (3) determination of processes affecting Hg transport. The dominant source of Hg in the Paglia River is runoff from Hg mines in the Mt. Amiata region. The maximum Hg mass load was found to be related to runoff from the inactive Abbadia San Salvatore Mine (ASSM), and up to 30 g day−1 of Hg, dominantly in the particulate form, was transported both in high and low flow conditions in 2011. In addition, enrichment factors (EFs) calculated for suspended particulate matter (SPM) were similar in different seasons indicating that water discharge controls the quantities of Hg transported in the PRB, and considerable Hg was transported in all seasons studied. Overall, as much as 11 kg of Hg are discharged annually in the PRB and this Hg is transported downstream to the Tiber River, and eventually to the Mediterranean Sea. Similar to Hg, maximum mass loads for As and Sb were found in March 2011, when as much as 190 g day−1 each of As and Sb were measured from sites downstream from the ASSM. Therefore, the Paglia River represents a significant source of Hg, Sb, and As to the Mediterranean Sea.

  16. Automated realtime detection of mining induced seismicity in the Ruhr coal mining district, Germany, using master waveforms

    NASA Astrophysics Data System (ADS)

    Fischer, Kasper D.; Wlecklik, Dennis; Friederich, Wolfgang; Wehling-Benatelli, Sebastian

    2016-04-01

    The exploitation of the subsurface by mining, geothermal or petroleum production causes seismic events in the surrounding areas. Shallow focal depths can lead to perceptible ground motions in densely populated areas and in rare cases to damages even for small events (magnitude smaller than 3.5). Thus, the monitoring of this kind of activities is necessary and increasingly requested by governmental agencies. A reliable detection and localisation of small events generally requires a dense and therefore expensive local seismic station network. At the end of 2014 and beginning of 2015, a dense seismic network of 12 stations was set up as a test case in the area of the black coal mine Prosper-Haniel in the Ruhr district, Germany. This network was capable of detecting almost 400 events within 4 weeks. A cluster analysis identified 135 events of magnitude -0.7 or higher, which could be located. This cluster analysis was also used to construct master events for running a real-time single-station cross-correlation detector in the Seiscomp3 software. The results of the real-time cross-correlation detector are compared to the results of the cluster analysis with respect to the number, magnitudes and locations of the events. This two-step monitoring of the source area provides a cost efficient way for long term monitoring of the mining activity.

  17. Factors controlling localization of uranium deposits in the Dakota Sandstone, Gallup and Ambrosia Lake mining districts, McKinley County, New Mexico

    USGS Publications Warehouse

    Pierson, Charles Thomas; Green, Morris W.

    1977-01-01

    Geologic studies were made at all of the uranium mines and prospects in the Dakota Sandstone of Early(?) and Late Cretaceous age in the Gallup mining district, McKinley County, New Mexico. Dakota mines in the adjacent Ambrosia Lake mining district were visited briefly for comparative purposes. Mines in the eastern part of the Gallup district, and in the Ambrosia Lake district, are on the Chaco slope of the southern San Juan Basin in strata which dip gently northward toward the central part of the basin. Mines in the western part of the Gallup district are along the Gallup hogback (Nutria monocline) in strata which dip steeply westward into the Gallup sag. Geologic factors which controlled formation of the uranium deposits in the Dakota Sandstone are: (1) a source of uranium, believed to be uranium deposits of the underlying Morrison Formation of Late Jurassic age; (2) the accessibility to the Dakota of uranium-bearing solutions from the Morrison; (3) the presence in the Dakota of permeable sandstone beds overlain by impermeable carbonaceous shale beds; and (4) the occurrence within the permeable Dakota sandstone beds of carbonaceous reducing material as bedding-plane laminae, or as pockets of carbonaceous trash. Most of the Dakota uranium deposits are found in the lower part of the formation in marginal-marine distributary-channel sandstones which were deposited in the backshore environment. However, the Hogback no. 4 (Hyde) Mine (Gallup district) occurs in sandy paludal shale of the backshore environment, and another deposit, the Silver Spur (Ambrosia Lake district), is found in what is interpreted to be a massive beach or barrier-bar sandstone of the foreshore environment in the upper part of the Dakota. The sedimentary depositional environment most favorable for the accumulation of uranium is that of backshore areas lateral to main distributary channels, where levee, splay, and some distributary-channel sandstones intertongue with gray carbonaceous shales and

  18. Environmental assessment of mining industry solid pollution in the mercurial district of Azzaba, northeast Algeria.

    PubMed

    Seklaoui, M'hamed; Boutaleb, Abdelhak; Benali, Hanafi; Alligui, Fadila; Prochaska, Walter

    2016-11-01

    To date, there have been few detailed studies regarding the impact of mining and metallogenic activities on solid fractions in the Azzaba mercurial district (northeast Algeria) despite its importance and global similarity with large Hg mines. To assess the degree, distribution, and sources of pollution, a physical inventory of apparent pollution was developed, and several samples of mining waste, process waste, sediment, and soil were collected on regional and local scales to determine the concentration of Hg and other metals according to their existing mineralogical association. Several physico-chemical parameters that are known to influence the pollution distribution are realized. The extremely high concentrations of all metals exceed all norms and predominantly characterize the metallurgic and mining areas; the metal concentrations significantly decrease at significant low distances from these sources. The geo-accumulation index, which is the most realistic assessment method, demonstrates that soils and sediments near waste dumps and abandoned Hg mines are extremely polluted by all analyzed metals. The pollution by these metals decreases significantly with distance, which indicates a limited dispersion. The results of a clustering analysis and an integrated pollution index suggest that waste dumps, which are composed of calcine and condensation wastes, are the main source of pollution. Correlations and principal component analysis reveal the important role of hosting carbonate rocks in limiting pollution and differentiating calcine wastes from condensation waste, which has an extremely high Hg concentration (˃1 %).

  19. Evidence of Mercurial Contamination and Denundation Downstream of New Idria Mercury Mine, San Benito County, California

    NASA Astrophysics Data System (ADS)

    Letsinger, H. E.; Sharma, R. K.; Weinman, B.

    2014-12-01

    California's Central Valley water quality and soils are essential to the survival of the valley's communities and agriculture. Therefore, detection of possible contaminants within the valley streams and soils are paramount to the protection of this land and the people that depend upon it. Here we explore the impact of the contaminated stream beds near the New Idria Mercury Mine site, San Benito County, California. Previous work by Ganguli et al. (2000) has been done in this area to determine the mercury levels associated with the water that flows near the ghost town of New Idria. We performed geochemical analyses on the finer bed sediments from channels draining the area, as well as the coarser sediments taken from along the channel banks, to determine mercury transport downriver from the source. Using a novel application of tau, a mass transfer coefficient typically used in critical zone studies or soil production and weathering rates, we determine downstream weathering, accumulation, and transport of mercury. Our initial geochemical data showed higher tau values upstream as well as within the banks of the contaminated streambed and a greater accumulation of mercury near the pollution source (i.e., mine tailings, (τ ~ 103)). Tau results also show elevated mercurial levels existing downstream, with accumulations in mid- (τ ~ 102) and down-stream (τ ~ 10) reaches. Combining tau results with more traditional indices of chemical weathering (CIA) support consistent overall Hg-weathering processes with low levels of chemical weathering and higher dominance of coupled physical-anthropogenic weathering.

  20. Environmental impact of mine tailings in Redi mines, Sindhudurg District, Maharashtra (India).

    PubMed

    Sawant, Arun D; Thakur, Vikas A

    2011-07-01

    Redi mine contains Fe, Mn as major elements, Al, Si as minor elements and also contains traces of Cr, Zn, Pb, Ni, Cu and P. The toxic trace elements present in the ore have also contributed to the contamination of the environment. Various operations of mining, the machinery used, transportation, the metallurgy and kind of waste management practices used are the significant factors of contributing to the nature of tailings of mine. The studies of tailings have revealed that, in addition to elemental contaminations, the operations create acidic environment around the area (pH-6.2 to 6.3 ), as water samples around showed acidic to slightly basic (pH 5.1 to 7.3) nature while soil samples were found acidic to the slightly basic (pH 6.1 to 7.4). In the samples of ore, tailings and soil, the most abundant elements found are Fe, Mn, Si and Al. In water samples, in addition to presence of Fe, Mn, Si, Al, P, significant quantities of Ni, Zn are also found. Ore, tailings and soil samples were analysed by X-Ray Diffraction technique and have shown the presence of goethite, gibbsite, kaolinite, quartz and mica alongwith haematite in the overall composition of ore.

  1. Progress report on the Happy Jack mine, Which Canyon area, San Juan county, Utah

    USGS Publications Warehouse

    Trites, Albert F.; Chew, Randall T.

    1954-01-01

    The Happy Jack mine is in the White Canyon area, San Juan county, Utah. Production is from high-grade uranium deposits in the Shinarump conglomerate of the Triassic age. In this area the Shinarump beds range from about 16 to 40 feet in thickness and the lower part of these beds fills an east-trending channel this is note than 750 feet wide and 10 feet deep. The Shinarump conglomerate consists of beds of coarse- to fine-grained quartzose sandstone, conglomerate, siltstone, and claystone. Carbonized wood is abundant in these beds, and in the field it was classified as mineral charcoal and coal. Intra-Shinarump channels, cross-stratification, current lineation, and slumping and compaction structures have been recognized in the mine. Steeply dipping fractures have dominant trends in four directions -- N 65°W, N 60°E, N 85°E, and due north. Uranium occurs as bedded deposits, as replacement bodies in accumulations of "trash", and as replacements of larger fragments of wood. An "ore shoot" is formed where the three types of uranium deposits occur together; these ore shoots appear to be elongate masses with sharp boundaries. Uranium minerals include uraninite, sooty pitchblende(?), and the sulfate--betazippeite, johannite, and uranopilite. Associated with the uraninite are the sulfide minerals covellite, bornite, chalcopyritw, and pyrite. Galena and sphalerite have been found in close association with uranium minerals. The gaunge minerals include: limonite and hematite present in most of the sandstone beds throughout the deposit, jarosite that impregnates much of the sandstone in the outer parts of the mine workings, gypsum that fills many of the fractures, and barite that impregnates the sandstone in at least one part of the mine. Secondary copper minerals, mainly copper sulfates, occur throughout the mine, but most abundant near the adits in the outermost 30 feet of the workings. The minerals comprising the bulk of the country rock include quartz, feldspar, and clay

  2. Geology and ore deposits of the Whitepine area, Tomichi mining district, Gunnison County, Colorado

    USGS Publications Warehouse

    Robinson, Charles Sherwood

    1956-01-01

    The Tomichi mining district is on the western slope of the Continental Divide near the southern end of the Sawatch Range in southeastern Gunnison County, Colorado. The most productive part of the Tomichi district was the Whitepine area. It is estimated that since the discovery of ore in 1879 the area has produced approximately $7,000,000, principally in lead and zinc, with lesser amounts of silver, copper, and gold. Geologically, the Whitepine area is a faulted syncline of Paleozoic rocks that was intruded by Tertiary igneous rocks. The oldest rock of the area is the Silver Plume granite of pre-Cambrian age. Deposited upon this successively were the Sawatch quartzite (Late Cambrian), Manitou dolomite (Early Ordovician), Harding quartzite (Middle Ordovician), Fremont dolomite (Lade Ordovician), Chaffee formation (Late Devonian), Leadville limestone (Late Mississippian), and Beldon shale (Late Pennsylvanian); a total thickness of about 1,450 feet. During the Laramide Revolution, the sedimentary rocks were folded into a broad northward-plunging syncline, faulted, and intruded by a series of igneous rocks. The igneous rocks, in order of relative age from oldest to youngest, are: a rhyolite stock, the Princeton quartz monzonite batholith, quartz monzonite or quartz latite porphyry dikes, and rhyolite or pitchstone porphyry dikes. The ore deposits of the Whitepine area may be classified into replacement deposits, vein deposits, and contact metamorphic deposits. The replacement deposits may be further subdivided into deposits along faults and bedded deposits. Of the types of deposits, the most productive have been the replacement deposits along faults. The major replacement deposits along faults are those of the Akron, Morning Star, and Victor mines. The ore deposits of these mines are in the foot wall of the Star faults in the Akron mine in the Manitou dolomite and in the Morning Star and Victor mines in the Leadville limestone. The chief bedded replacement deposits are

  3. Geochemistry and mineralogy of the carbonates of the Creede mining district, Colorado

    USGS Publications Warehouse

    Wetlaufer, Pamela Heald

    1977-01-01

    This paper describes the results of a study of the carbonate gangue in the silver-base metal ore deposit of the Creede mining district, located in Tertiary volcanic rocks of the central San Juan Mountains, southwestern Colorado. Two carbonate stages can be distinguished and defined on the basis of mineral association, compositional range and position in the sequence of ore deposition. Electron microprobe analyses show that the early pre-ore carbonate stage is comprised of rhodochrosite with a compositional range of 68 to 93 mole percent MnCO3, 7 to 32 mole percent FeCO3, 2 to 15 mole percent CaCO3, and 0.5 to 4 mole percent MgCO3. The later intra-ore carbonate stage is made up of siderite-manganosiderite with a broad range of iron content (33 to 94 mole percent FeCO3; 6 to 67 mole percent MnCO3; 1 to 13 mole percent CaCO3; and 1 to 10 mole percent MgCO3). Both carbonate stages are spatially restricted within the vein system, the rhodochrosite limited to the southern third and the siderite limited to the northern two-thirds. The two stages have not been found at the same sample locality. The two stages of carbonate define two of the five main depositional stages in the history of the Creede hydrothermal system and thereby document broad scale variations within the depositing, and continually evolving fluids. However, the complexity of the textural and mineralogical variations within each carbonate stage limits their usefulness in unraveling the finer details of the character of the ore fluids. The frequently massive rhodochroslte has undergone several periods of leaching and regrowth which, except at one locality, cannot be resolved by compositional, textural or color variations. Although some compositionally zoned siderite rhombs have been documented, the siderite, too, has had a complicated history of leaching and regrowth. The zoning indicates (i) an early low-calcium siderite + hematite growth followed by (2) relatively high-calcium siderite depositlon (without

  4. Surface water monitoring in the mercury mining district of Asturias (Spain).

    PubMed

    Loredo, Jorge; Petit-Domínguez, María Dolores; Ordóñez, Almudena; Galán, María Pilar; Fernández-Martínez, Rodolfo; Alvarez, Rodrigo; Rucandio, María Isabel

    2010-04-15

    Systematic monitoring of surface waters in the area of abandoned mine sites constitutes an essential step in the characterisation of pollution from historic mine sites. The analytical data collected throughout a hydrologic period can be used for hydrological modelling and also to select appropriate preventive and/or corrective measures in order to avoid pollution of watercourses. Caudal River drains the main abandoned Hg mine sites (located in Mieres and Pola de Lena districts) in Central Asturias (NW Spain). This paper describes a systematic monitoring of physical and chemical parameters in eighteen selected sampling points within the Caudal River catchment. At each sampling station, water flow, pH, specific conductance, dissolved oxygen, salinity, temperature, redox potential and turbidity were controlled "in situ" and major and trace elements were analysed in the laboratory. In the Hg-mineralised areas, As is present in the form of As-rich pyrite, realgar and occasionally arsenopyrite. Mine drainage and leachates from spoil heaps exhibit in some cases acidic conditions and high As contents, and they are incorporated to Caudal River tributaries. Multivariate statistical analysis aids to the interpretation of the spatial and temporary variations found in the sampled areas, as part of a methodology applicable to different environmental and geological studies.

  5. Study on Association between Spatial Distribution of Metal Mines and Disease Mortality: A Case Study in Suxian District, South China

    PubMed Central

    Song, Daping; Jiang, Dong; Wang, Yong; Chen, Wei; Huang, Yaohuan; Zhuang, Dafang

    2013-01-01

    Metal mines release toxic substances into the environment and can therefore negatively impact the health of residents in nearby regions. This paper sought to investigate whether there was excess disease mortality in populations in the vicinity of the mining area in Suxian District, South China. The spatial distribution of metal mining and related activities from 1985 to 2012, which was derived from remote sensing imagery, was overlapped with disease mortality data. Three hotspot areas with high disease mortality were identified around the Shizhuyuan mine sites, i.e., the Dengjiatang metal smelting sites, and the Xianxichong mine sites. Disease mortality decreased with the distance to the mining and smelting areas. Population exposure to pollution was estimated on the basis of distance from town of residence to pollution source. The risk of dying according to disease mortality rates was analyzed within 7–25 km buffers. The results suggested that there was a close relationship between the risk of disease mortality and proximity to the Suxian District mining industries. These associations were dependent on the type and scale of mining activities, the area influenced by mining and so on. PMID:24135822

  6. Mercury and other metal(oid)s from mining activities in sediments from the Almadén district

    NASA Astrophysics Data System (ADS)

    García-Ordiales, Efrén; Esbrí, José M.; Higueras, Pablo; Loredo, Jorge

    2015-04-01

    Almadén (South Central Spain) is worldwide famous because of mercury mining. But besides, the area has also been the site of other types of mining, in particular exploitation of Pb-Zn sulphides, with variable contents of other economic metals such as Ag, as well as others with high pollution potential such as As, Cd, Sb, etc. These exploitations were in activity in different historic periods, since Romans times to the 20th Century, and most of them were abandoned with no reclamation measures at all, acting as important sources of contamination in surrounding soils. In this work, we present a preliminary assessment of the affection of sediments for the streams of Almadén mine district, considering other potential pollutants in addition to mercury. Sampling was carried out during the period 2010-2013, and involved the collection of 65 samples of stream sediments in the main river of the district (Valdeazogues River) and main subsidiaries. Samples were air-dried, sieved to <2mm to discard gravel fraction, milled to <63μm and analysed in certified laboratory (ACME Labs Canada) by ICP-AES and ICP-MS after hot acid digestion. Results showed that sediments suffer a significant metal accumulation within the district, being specially concern at the areas close to mines. Most studied samples exceed the heavy metals and metalloids reference values for uncontaminated sites as well as those fitted to protect the aquatic life. Element by element, mercury contents are widely disperse in the district because of mining activities and it can be considered as the main pollutant of the district. Concentrations of other potentially harmful elements such as Pb, Zn and As show also important concentrations, which may be attributed to anthropogenic sources, specially to decommissioned mines. Comparing concentrations from the different surveyed areas, two different zones were identified: One located in the upper part of the district, where the intense mining activities related with four

  7. 77 FR 10472 - San Bernardino National Forest, Mountaintop Ranger District, California, Mitsubishi South Quarry...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ... environmental impact statement. SUMMARY: Mitsubishi Cement Corporation is submitting to the San Bernardino... 440 acres of unpatented claims owned by Mitsubishi Cement Corporation on the San Bernardino National Forest with approximately 6.6 acres of the haul road located on Mitsubishi Cement Corporation fee...

  8. Geochemical data from waters in Prospect Gulch, San Juan County, Colorado, that span pre- and post-Lark Mine remediation

    USGS Publications Warehouse

    Johnson, Raymond H.; Yager, Douglas B.; Johnson, Hugh D.

    2011-01-01

    In San Juan County, Colorado, the effects of historical mining continue to contribute dissolved metals to groundwater and surface water. Water samples in Prospect Gulch near Silverton, Colorado, were collected at selected locations that span pre- and post-reclamation activities at the Lark Mine, located in the Prospect Gulch watershed. Geochemical results from those water samples are presented in this report. Water samples were analyzed for specific conductance, pH, temperature, and dissolved oxygen with handheld field meters, and metals were analyzed using inductively coupled plasma-mass spectrometry.

  9. Physiography and Quaternary geology of the San Juan Mountains, Colorado

    USGS Publications Warehouse

    Atwood, Wallace W.; Mather, Kirtley F.

    1932-01-01

    appeared from time to time as folios"' of the Geologic Atlas and reports on the economic geology of the mining districts, published by the United States Geological Survey between 1899 and 1910. Gradually the concept of the geologic problems was changed. Instead of considering individual mining districts as the units of investigation it became apparent that the San Juan region must itself be the unit. In 1908 Mr. Cross drafted plans for the completion of the San Juan studies on this enlarged basis. His aim was to arrange for the publication of papers on different subjects rather than one huge monograph on the region as a whole.

  10. Potential effects of anticipated coal mining on salinity of the Price, San Rafael, and Green Rivers, Utah

    USGS Publications Warehouse

    Lindskov, K.L.

    1986-01-01

    The impact of anticipated coal mining in Utah on the salinity of the Price, San Rafael, and Green Rivers is to be addressed in the repermitting of existing mines and permitting of new mines. To determine the potential impacts, mathematical models were developed for the Price and San Rafael River basins. Little impact on the quantity and quality of streamflow is expected for the Price and San Rafael Rivers. The increase in mean monthly flow of the Price River downstream from Scofield Reservoir is projected as 3.5 cu ft/sec, ranging from 1.7% in June to 140% in February. The potential increase in dissolved solids concentration downstream from Scofield Reservoir would range from 10.4% in June and July (from 202 to 223 mg/L) to 97.0% in February (from 202 to 398 mg/L). However, the concentration of the mixture of mine water with the existing flow released from Scofield Reservoir would contain less than 500 mg/L of dissolved solids. At the mouth of the Price River, the potential increase in mean monthly flow is projected as 12.6 cu ft/sec, ranging from 3.7% in May to 37.7% in January. The potential changes in dissolved solids concentration would range from a 20.7% decrease in January (from 3,677 to 2,917 mg/L) to a 1.3% increase in June (from 1,911 to 1,935 mg/L). At the mouth of the San Rafael River , the potential increase in mean monthly flow ranges from 2.9 cu ft/sec in February to 6.7 cu ft/sec in May, with the increase ranging from 0.8% in June to 12.6% in November. The potential changes in dissolved solids concentration would range from a 5.3 % decrease in March (from 2,318 to 2,195 mg/L) to a 0.6% increase in May (from 1,649 to 1,659 mg/L). The anticipated mining in the Price and San Rafael River basins is not expected to cause a detectable change in the quantity and quality of streamflow in the Green River. The projected peak increase in flow resulting from discharge from the mines is less than 0.3% of the average flow in the Green River. (Author 's abstract)

  11. Remote Detection and Mapping of Supergene Iron Oxides in the Cripple Creek Mining District, Colorado

    NASA Technical Reports Server (NTRS)

    Taranik, D. L.; Kruse, F. A.; Goetz, A. F. H.; Atkinson, W. W.

    1990-01-01

    The Geophysical and Environmental Research Imaging Spectrometer (GERIS) was flown over the Cripple Creek mining district in south-central Colorado to improve the geological understanding of the district. As part of the study, an airborne mapping technique was developed for the discrimination of the ferric iron minerals hematite, goethite, and jarosite, minerals often important indicators of the distribution of economic mineralization. A software technique was developed which uses the binary encoding of spectral slopes to identify the mineral hematite from the group goethite/jarosite. Mixtures of hematite and goethite can also be detected with GERIS data. The study included district-wide field mapping and spectral measurements to evaluate the accuracy of the image classifications. The ARC/INFO geographic information system (GIS) was a useful tool which allowed quantitative comparison of the field mapping and GERIS image data sets. The study results demonstrate the ability to discriminate individual iron minerals using imaging spectroscopy, and the development of a rapid mapping technique useful in the reconnaissance stage of minerals exploration.

  12. Estimation of potential pollution from mine tailings in the San Pedro River (1993-2005), Mexico-US border

    NASA Astrophysics Data System (ADS)

    Gómez-Alvarez, Agustín; Meza-Figueroa, Diana; Villalba-Atondo, Arturo I.; Valenzuela-García, Jesús Leobardo; Ramírez-Hernández, Jorge; Almendariz-Tapia, Javier

    2009-06-01

    The San Pedro River (SPR) is located in northern Sonora (Mexico) and southeastern Arizona (USA). SPR is a transboundary river that develops along the Sonora (Mexico) and Arizona (USA) border, and is considered the main source of water for a variety of users (human settlements, agriculture, livestock, and industry). The SPR originates in the historic Cananea mining area, which hosts some of the most important copper mineralizations in Mexico. Acid mine drainage derived from mine tailings is currently reaching a tributary of the SPR near Cananea City, resulting in the contamination of the SPR with heavy metals and sulfates in water and sediments. This study documents the accumulation and distribution of heavy metals in surface water along a segment of the SPR from 1993 to 2005. Total concentrations of Cd, Cu, Fe, Mn, Pb, and Zn in surface waters are above maximum permissible levels in sampling sites near mine tailing deposits. Nevertheless, a significant decrease in the Fe and SO4 2- in surface water (SO4 2-: 7,180-460.39 mg/L; Fe: 1,600-9.51 mg/L) as well as a gradual decrease in the heavy and transition metal content were observed during the period from 1994 to 2005. Approximately 2.3 km downstream of the mine tailings, the heavy metal content of the water drops quickly following an increase in pH values due to the discharging of wastewater into the river. The attenuation of the heavy metal content in surface waters is related to stream sediment precipitation (accompanied by metal coprecipitation and sorption) and water dilution. Determining the heavy metal concentration led to the conclusion that the Cananea mining area and the San Pedro River are ecosystems that are impacted by the mining industry and by untreated wastewater discharges arising from the city of Cananea (Sonora, Mexico).

  13. Pollution by Arsenic, Mercury and other Heavy Metals in Sunchulli mining district of Apolobamba (Bolivia)

    NASA Astrophysics Data System (ADS)

    Terán Mita, Tania; Faz Cano, Angel; Muñoz, Maria Angeles; Millán Gómez, Rocio; Chincheros Paniagua, Jaime

    2010-05-01

    In Bolivia, metal mining activities since historical times have been one of the most important sources of environmental pollution. This is the case of the National Area of Apolobamba Integrated Management (ANMIN of Apolobamba) in La Paz, Bolivia, where intense gold mining activities have been carried out from former times to the present, with very little gold extraction and very primitive mineral processing technology; in fact, mercury is still being used in the amalgam processes of the gold concentration, which is burned outdoors to recover the gold. Sunchullí is a representative mining district in ANMIN of Apolobamba where mining activity is mainly gold extraction and its water effluents go to the Amazonian basin; in this mining district the productivity of extracted mineral is very low but the processes can result in heavy-metal contamination of the air, water, soils and plants. Due to its high toxicity, the contamination by arsenic and mercury create the most critical environmental problems. In addition, some other heavy metals may also be present such as lead, copper, zinc and cadmium. These heavy metals could be incorporated in the trophic chain, through the flora and the fauna, in their bio-available and soluble forms. Inhabitants of this area consume foodcrops, fish from lakes and rivers and use the waters for the livestock, domestic use, and irrigation. The aim of this work was to evaluate the heavy metals pollution by gold mining activities in Sunchullí area. In Sunchullí two representative zones were distinguished and sampled. Zone near the mining operation site was considered as affected by mineral extraction processes, while far away zones represented the non affected ones by the mining operation. In each zone, 3 plots were established; in each plot, 3 soil sampling points were selected in a random manner and analysed separately. In each sampling point, two samples were taken, one at the surface, from 0-5 cm depth (topsoil), and the other between 5

  14. Preliminary report on part of the Oat Hill quicksilver mine, Mayacmas district, Napa County, California

    USGS Publications Warehouse

    Fix, Philip Forsyth

    1955-01-01

    Oat Hill quicksilver mine, located in the Mayacmas district of northern California, and credited with having produced more than 160,000 flasks of quicksilver, was sampled cooperatively by the Buray of Mines and Geological Survey during 1944. 28 diamond drill holes totaling 8,120 feet were drilled by the Bureau of Mines in four of the six principal veins to sample virgin low-grade reserves and stope fill, and reserves in the other two veins were estimated from existing underground workings and by inferences from drill holes in nearby veins. The writer estimates a total of 10,220 flasks of quicksilver in indicated and inferred reserves totaling 320,000 tons. Indicated reserves minable under 1943 conditions are estimated at 1,960 flasks of quicksilver in 75,000 tons averaging 3.0 lbs Hg per ton. Inferred reserves minable under 1943 conditions are estimated at 4,640 flasks of quicksilver in 109,920 tons averaging about 3.2 lbs Hg per ton. Inferred reserves believed minable only under economic conditions much more favorable than even those of 1943 are estimated at 2,620 flasks of quicksilver in 135,080 tons averaging a little less than 1.5 lbs Hg per ton. About two-thirds of the indicated reserves are accessible in underground workings. All other reserves are estimated approximately without access underground. Several areas not sampled may possibly contain reserves.

  15. Sultan Mountain mine, western San Juan Mountains, Colorado: A fluid inclusion and stable isotope study

    SciTech Connect

    Musgrave, J.A. ); Thompson, T.B. . Dept. of Earth Resources)

    1991-01-01

    The Sultan Mountain (SM) mine, in the western San Juan Mountains of Colorado, has produced Cu-Pb-Zn-Ag-Au ores from the mid-1870s until the 1950s. Production was from veins filling faults and fissures along the southern margin of the Silverton caldera. The principal host rock to the veins is a quartz monzonite stock. Five periods of hypogene mineralization have been recognized: (1) early quartz-pyrite; (2) quartz-pyrite; (3) rhodochrosite-siderite; (4) main ore-stage chalcopyrite, tetrahedrite, galena, sphalerite, and gold; and (5) quartz-fluorite. Evidence of open-space filling (banding, crustification, vugs) is widespread. Heating studies of fluid inclusions in quartz, rhodochrosite-siderite, sphalerite, and fluorite indicate temperatures were approximately 200 C for stages 1 to 4 and 186 C for stage 5. Stages 1, 2, and 4 show evidence of boiling. Crushing studies indicate that high-pressure gas, probably CO[sub 2], is present in the fluid inclusions. Freezing point depression estimates of salinity, corrected for CO[sub 2], indicate a range of 13.6 to 1.3 wt percent NaCl equiv. These data together with P-V-T data for saline solutions and P[sub CO[sub 2

  16. Selected Metals in Sediments and Streams in the Oklahoma Part of the Tri-State Mining District, 2000-2006

    USGS Publications Warehouse

    Andrews, William J.; Becker, Mark F.; Mashburn, Shana L.; Smith, S. Jerrod

    2009-01-01

    The abandoned Tri-State mining district includes 1,188 square miles in northeastern Oklahoma, southeastern Kansas, and southwestern Missouri. The most productive part of the Tri-State mining district was the 40-square mile part in Oklahoma, commonly referred to as 'the Picher mining district' in north-central Ottawa County, Oklahoma. The Oklahoma part of the Tri-State mining district was a primary producing area of lead and zinc in the United States during the first half of the 20th century. Sulfide minerals of cadmium, iron, lead, and zinc that remained in flooded underground mine workings and in mine tailings on the land surface oxidized and dissolved with time, forming a variety of oxide, hydroxide, and hydroxycarbonate metallic minerals on the land surface and in streams that drain the district. Metals in water and sediments in streams draining the mining district can potentially impair the habitat and health of many forms of aquatic and terrestrial life. Lakebed, streambed and floodplain sediments and/or stream water were sampled at 30 sites in the Oklahoma part of the Tri-State mining district by the U.S. Geological Survey and the Oklahoma Department of Environmental Quality from 2000 to 2006 in cooperation with the U.S. Environmental Protection Agency, and the Quapaw and Seneca-Cayuga Tribes of Oklahoma. Aluminum and iron concentrations of several thousand milligrams per kilogram were measured in sediments collected from the upstream end of Grand Lake O' the Cherokees. Manganese and zinc concentrations in those sediments were several hundred milligrams per kilogram. Lead and cadmium concentrations in those sediments were about 10 percent and 0.1 percent of zinc concentrations, respectively. Sediment cores collected in a transect across the floodplain of Tar Creek near Miami, Oklahoma, in 2004 had similar or greater concentrations of those metals than sediment cores collected at the upstream end of Grand Lake O' the Cherokees. The greatest concentrations of

  17. Soil eco-physiological indicators from a coal mining area in El Bierzo District (Spain).

    NASA Astrophysics Data System (ADS)

    Díaz Puente, Fco. Javier; Mejuto Mendieta, Marcos; Cardona García, Ana Isabel; Rodríguez Gallego, Vergelina; García Álvarez, Avelino

    2010-05-01

    CIEMAT. Avda. Complutense, 22. 28040 Madrid. Spain. The El Bierzo carboniferous basin (León, N.W. of Spain) is placed in a tenth of the surface of this district, in the area called "Bierzo Alto". Coal has been mined in El Bierzo from the late XVIII century, having been intensely exploited during the XX century. The mining activity has left a heritage of withdrawed mining structures. Nowadays some mining activity remains in the area, and new exploitations based on open pit processes, cause the burial of natural soil with overlaying mine tailings. Characterization and study of the edaphic landscapes in the area is a necessary activity within the framework of its overall restoration planning, also providing fundamental information for the design and monitoring of waste coal recovery activities. For this work eight zones were chosen, representing the spatial variability within the upper basin of the Rodrigatos river, into the Bierzo Alto, including reference areas not affected by mining activities. In addition three mine tailings outside the area are included in this work to cover the variability of restoration processes. After a first study, based on physical, physico-chemical and chemical characteristics of soils, we have continued the study including some eco-physiological parameters. The objective of this work is to identify potential soil disruption, its extent and causes. Soil microbial activity is influenced by a wide set of soil characteristics. Eco-physiological parameters analysed in this work are: • Microbial Biomass carbon • Basal Respirometry • Maximum respiratory rate Microbial biomass carbon was analysed according the Substrate Induced Respirometry (SIR) method. Relational parameters such as metabolic quotient (CO2-C/Cmic) and the Cmic/Corg ratio have been obtained from these variables. Our results shown that soil microbial biomass carbon is strongly influenced by the water holding capacity (WHC) of the samples (R=0,895) as well as by organic

  18. Effects of an agricultural drainwater bypass on fishes inhabiting the Grassland Water District and the lower San Joaquin River, California

    USGS Publications Warehouse

    Saiki, M.K.; Martin, B.A.; Schwarzbach, S.E.; May, T.W.

    2001-01-01

    The Grassland Bypass Project, which began operation in September 1996, was conceived as a means of diverting brackish selenium-contaminated agricultural drainwater away from canals and sloughs needed for transporting irrigation water to wetlands within the Grassland Water District (the Grasslands), Merced County, California. The seleniferous drainwater is now routed into the San Luis Drain for conveyance to North Mud Slough and eventual disposal in the San Joaquin River. The purpose of this study was to determine the extent to which the Grassland Bypass Project has affected fishes in sloughs and other surface waters within and downstream from the Grasslands. During September-October 1997, 9,795 fish representing 25 species were captured at 13 sampling sites. Although several species exhibited restricted spatial distributions, association analysis and cluster analysis failed to identify more than one fish species assemblage inhabiting the various sites. However, seleniferous drainwater from the San Luis Drain has influenced selenium concentrations in whole fish within North Mud Slough and the San Joaquin River. The highest concentrations of selenium (12-23 ??g/g, dry weight basis) were measured in green sunfish Lepomis cyanellus from the San Luis Drain where seleniferous drainwater is most concentrated, whereas the second highest concentrations occurred in green sunfish (7.6-17 ??g/g) and bluegills Lepomis macrochirus (14-18 ??g/g) from North Mud Slough immediately downstream from the drain. Although there was some variation, fish in the San Joaquin River generally contained higher body burdens of selenium when captured immediately below the mouth of North Mud Slough (3.1-4.8 ??g/g for green sunfish, 3.7-5.0 ??g/g for bluegills) than when captured upstream from the mouth (0.67-3.3 ??g/g for green sunfish, 0.59-3.7 ??g/g for bluegills). Waterborne selenium was the single most important predictor of selenium concentrations in green sunfish and bluegills, as judged by

  19. Evaluation of Color and Color Infrared Photography from the Goldfield Mining District, Esmerelda and Nye Countries, Nevada

    NASA Technical Reports Server (NTRS)

    Ashley, R. P.

    1970-01-01

    The determination of geological features characteristic of the Goldfield epithermal ore deposits is considered and which of them can be identified from color and color infrared aerial photography. The Goldfield mining district in the western part of the Basin and Range Province is the area of study, located in desert terrain of relatively low relief.

  20. Evaluation of the environmental contamination at an abandoned mining site using multivariate statistical techniques--the Rodalquilar (Southern Spain) mining district.

    PubMed

    Bagur, M G; Morales, S; López-Chicano, M

    2009-11-15

    Unsupervised and supervised pattern recognition techniques such as hierarchical cluster analysis, principal component analysis, factor analysis and linear discriminant analysis have been applied to water samples recollected in Rodalquilar mining district (Southern Spain) in order to identify different sources of environmental pollution caused by the abandoned mining industry. The effect of the mining activity on waters was monitored determining the concentration of eleven elements (Mn, Ba, Co, Cu, Zn, As, Cd, Sb, Hg, Au and Pb) by inductively coupled plasma mass spectrometry (ICP-MS). The Box-Cox transformation has been used to transform the data set in normal form in order to minimize the non-normal distribution of the geochemical data. The environmental impact is affected mainly by the mining activity developed in the zone, the acid drainage and finally by the chemical treatment used for the benefit of gold.

  1. Risk: For Whom? Representations of Mining Activity by Different Social Actors in the Molango Manganese District of Hidalgo, Mexico.

    PubMed

    Catalán-Vázquez, Minerva; Riojas-Rodríguez, Horacio; Pelcastre-Villafuerte, Blanca Estela

    2014-01-01

    Previous studies have shown high levels of manganese exposure and neurocognitive damage in the population living in the mining zone in Molango, Mexico. One of the objectives of the Intersectoral Group on Environmental Management for the mining district has been to provide public participation in the risk management plan. To achieve this, it is important to know how the different social actors represent the mining activity. The objectives of this study were to characterize the social representations of the mining activity by different social actors. A qualitative design was used based on in-depth interviews of residents, public officials, and a mining company representative. The analysis was conducted according to themes for each group of actors. Essentially, distinct social representations of the different mining activities were identified. Residents viewed mining activities as synonymous with contamination and, therefore, as having affected all areas of their environment, health, and daily life. These activities were seen as a collective risk. The public officials and the mining company held that there was no evidence of harm and saw mining activities as a generator of regional development. Harm to health and the environment were seen as a stance taken by the communities in order to obtain economic benefits from the company. These images of the "other" are shaped by social, political, and cultural factors. They make it difficult for the actors to reach cooperative agreements and thereby affect progress on the risk management plan. Decisionmakers need to take these differences into account when promoting social participation.

  2. Engineers at the Golden Gate: A History of the San Francisco District U.S. Army Corps of Engineers 1866-1980

    DTIC Science & Technology

    1980-01-01

    long-distance, endurance horse ride. A rather unique activity is the special observance of Native American Day, held to pay tribute to the Porno ...by San Francisco District in conjunction with the Mendocino Porno Council, a Native-American organization, to promote American Indian heritage and

  3. Quantifying natural source mercury emissions from the Ivanhoe Mining District, north-central Nevada, USA

    NASA Astrophysics Data System (ADS)

    Engle, Mark A.; Gustin, Mae Sexauer; Zhang, Hong

    In order to assess the importance of mercury emissions from naturally enriched sources relative to anthropogenic point sources, data must be collected that characterizes mercury emissions from representative areas and quantifies the influence of various environmental parameters that control emissions. With this information, we will be able to scale up natural source emissions to regional areas. In this study in situ mercury emission measurements were used, along with data from laboratory studies and statistical analysis, to scale up mercury emissions for the naturally enriched Ivanhoe Mining District, Nevada. Results from stepwise multi-variate regression analysis indicated that lithology, soil mercury concentration, and distance from the nearest fault were the most important factors controlling mercury flux. Field and lab experiments demonstrated that light and precipitation enhanced mercury emissions from alluvium with background mercury concentrations. Diel mercury emissions followed a Gaussian distribution. The Gaussian distribution was used to calculate an average daily emission for each lithologic unit, which were then used to calculate an average flux for the entire area of 17.1 ng Hg m -2 h -1. An annual emission of ˜8.7×10 4 g of mercury to the atmosphere was calculated for the 586 km 2 area. The bulk of the Hg released into the atmosphere from the district (˜89%) is from naturally enriched non-point sources and ˜11% is emitted from areas of anthropogenic disturbance where mercury was mined. Mercury emissions from this area exceed the natural emission factor applied to mercury rich belts of the world (1.5 ng m -2 h -1) by an order of magnitude.

  4. Geology and mining history of the Southeast Missouri Barite District and the Valles Mines, Washington, Jefferson, and St. Francois Counties, Missouri

    USGS Publications Warehouse

    Mugel, Douglas N.

    2017-03-09

    The Southeast Missouri Barite District and the Valles Mines are located in Washington, Jefferson, and St. Francois Counties, Missouri, where barite and lead ore are present together in surficial and near-surface deposits. Lead mining in the area began in the early 1700’s and extended into the early 1900’s. Hand mining of lead in the residuum resulted in widespread pits (also called shafts or diggings), and there was some underground mining of lead in bedrock. By the 1860’s barite was recovered from the residuum by hand mining, also resulting in widespread diggings, but generally not underground mines in bedrock. Mechanized open-pit mining of the residuum for barite began in the 1920’s. Barite production slowed by the 1980’s, and there has not been any barite mining since 1998. Mechanized barite mining resulted in large mined areas and tailings ponds containing waste from barite mills.The U.S. Environmental Protection Agency (EPA) has determined that lead is present in surface soils in Washington and Jefferson Counties at concentrations exceeding health-based screening levels. Also, elevated concentrations of barium, arsenic, and cadmium have been identified in surface soils, and lead concentrations exceeding the Federal drinking-water standard of 15 micrograms per liter have been identified in private drinking-water wells. Potential sources of these contaminants are wastes associated with barite mining, wastes associated with lead mining, or unmined natural deposits of barium, lead, and other metals. As a first step in helping EPA determine the source of soil and groundwater contamination, the U.S. Geological Survey (USGS), in cooperation with the EPA, investigated the geology and mining history of the Southeast Missouri Barite District and the Valles Mines.Ore minerals are barite (barium sulfate), galena (lead sulfide), cerussite (lead carbonate), anglesite (lead sulfate), sphalerite (zinc sulfide), smithsonite (zinc carbonate), and chalcopyrite (copper

  5. Coal mine bumps as related to geologic features in the northern part of the Sunnyside District, Carbon County, Utah

    USGS Publications Warehouse

    Osterwald, Frank W.; Dunrud, C. Richard; Collins, Donley S.

    1993-01-01

    Coal mine bumps, which are violent, spontaneous, and often catastrophic disruptions of coal and rock, were common in the Sunnyside coal mining district, Utah, before the introduction of protective-engineering methods, modern room-and-pillar retreat mining with continuous mining machines, and particularly modern longwall mining. The coal at Sunnyside, when stressed during mining, fails continuously with many popping, snapping, and banging noises. Although most of the bumps are beneficial because they make mining easier, many of the large ones are dangerous and in the past caused injuries and fatalities, particularly with room- and-pillar mining methods used in the early mining operations. Geologic mapping of underground mine openings revealed many types of deformational features, some pre-mine and some post-mine in age. Stresses resulting from mining are concentrated near the mine openings; if openings are driven at large angles to small pre-mine deformational features, particularly shatter zones in coal, abnormal stress buildups may occur and violent bumps may result. Other geologic features, such as ripple marks, oriented sand grains, intertongued rock contacts, trace fossils, and load casts, also influence the occurrence of bumps by impeding slip of coal and rocks along bedding planes. The stress field in the coal also varies markedly because of the rough ridge and canyon topography. These features may allow excessively large stress components to accumulate. At many places, the stresses that contribute to deformation and failures of mine openings are oriented horizontally. The stratigraphy of the rocks immediately above and below the mined coal bed strongly influences the deformation of the mine openings in response to stress accumulations. Triaxial compressive testing of coal from the Sunnyside No.1 and No.3 Mines indicates that the strength of the coal increases several times as the confining (lateral) stress is increased. Strengths of cores cut from single

  6. Structural reinterpretation of the Ajo mining district, Pima County, Arizona, based on paleomagnetic and geochronologic studies.

    USGS Publications Warehouse

    Hagstrum, J.T.; Cox, D.P.; Miller, R.J.

    1987-01-01

    The Ajo mining district of southern Arizona is divided into two main structural blocks by the Gibson Arroyo fault. The eastern Camelback Mountain block contains the Late Cretaceous-early Tertiary porphyry copper deposit which has been previously thought to be associated with the displaced apex of a large intrusion exposed by deeper erosion in the western Cardigan Peak block. However, unpublished U-Pb data support a mid-Tertiary age for the western intrusion. The following sequence of mid-Tertiary events in the district are indicated: 1) emplacement of the western intrusion, 2) movement along the Gibson Arroyo fault, 3) unroofing and perhaps tilting of the pluton approx 70o to the south along with the Camelback Mountain block, 4) syntectonic depositions of the Locomotive Fanglomerate and the Ajo Volcanics, 5) continued uplift and tilting to the south totaling 40o to 60o, 6) intrusion of the youngest dikes with attendant alteration and remagnetization of the host rocks, and 7) minor (?) oblique movement along the Gibson Arroyo fault.-from Authors

  7. Geology and ore deposits of the South Silverton mining area, San Juan County, Colorado

    USGS Publications Warehouse

    Varnes, David J.

    1963-01-01

    The South Silverton mining area is immediately southeast of the town of Silverton, San Juan County, in southwestern Colorado (fig. 1). The town of Silverton itself lies in a relatively flat and open reach of the Animas Valley, called Bakers Park, in the western part of the San Juan Mountains. (See figs. 2 and 8.) The roughly circular area of the geologic map map (pl. 1) includes about 18½ square miles of the mountainous country southeast of Silverton. It is bounded on the west and north by the Animas River, on the east by Cunningham Creek, and on the south by Mountaineer Creek and Deer Park Creek. Altitudes range from 9,125 feet above sea level in the canyon of the Animas, at the southwest corner of the area, to 13,451 feet on Kendall Peak, 2¾ miles to the northeast.Within this area nearly a dozen horn-like peaks and sharp ridges separated by deep glacial cirques rise to altitudes of 13,000 feet or more. (See figs. 3, 7, 10, and 24.) Exposures are excellent along the crests and upper flanks of the ridges, but the bedrock along the lower parts of the valley walls and floors of the cirques is largely concealed by accumulations of talus. The timbered slopes along the south side of the Animas Valley are extensively covered with glacial moraine. Several of the high basins within the cirques hold ponds or small lakes; the largest is Silver Lake (fig. 23).Roads skirt the northern and eastern edges of the area but none give good access into the interior. Silverton is adjacent to U.S. Highway 550, which passes over the mountains by way of Red Mountain Pass from Ouray, 24 miles to the north, to Durango, 53 miles to the south. The community is also served by the narrow-gage line of the Denver and Rio Grande Western Railroad that follows the Animas River upstream from Durango. A gravel road, State Highway 110, follows the Animas River upstream, eastward from Silverton. From this highway a side road branches off to Cunningham Gulch as far as the Highland Mary mill, and

  8. Structural geology mapping using PALSAR data in the Bau gold mining district, Sarawak, Malaysia

    NASA Astrophysics Data System (ADS)

    Pour, Amin Beiranvand; Hashim, Mazlan

    2014-08-01

    The application of optical remote sensing data for geological mapping is difficult in the tropical environment. The persistent cloud coverage, dominated vegetation in the landscape and limited bedrock exposures are constraints imposed by the tropical climate. Structural geology investigations that are searching for epithermal or polymetallic vein-type ore deposits can be developed using Synthetic Aperture Radar (SAR) remote sensing data in tropical/sub-tropical regions. The Bau gold mining district in the State of Sarawak, East Malaysia, on the island of Borneo has been selected for this study. The Bau is a gold field similar to Carlin style gold deposits, but gold mineralization at Bau is much more structurally controlled. Geological analyses coupled with the Phased Array type L-band Synthetic Aperture Radar (PALSAR) remote sensing data were used to detect structural elements associated with gold mineralization. The PALSAR data were used to perform lithological-structural mapping of mineralized zones in the study area and surrounding terrain. Structural elements were detected along the SSW to NNE trend of the Tuban fault zone and Tai Parit fault that corresponds to the areas of occurrence of the gold mineralization in the Bau Limestone. Most of quartz-gold bearing veins occur in high-angle faults, fractures and joints within massive units of the Bau Limestone. The results show that four deformation events (D1-D4) in the structures of the Bau district and structurally controlled gold mineralization indicators, including faults, joints and fractures are detectable using PALSAR data at both regional and district scales. The approach used in this study can be more broadly applicable to provide preliminary information for exploration potentially interesting areas of epithermal or polymetallic vein-type mineralization using the PALSAR data in the tropical/sub-tropical regions.

  9. Preparatory work required for a long-term district recirculation test in a gassy underground metal-non metal mine

    SciTech Connect

    Pritchard, C.J.

    1995-12-31

    Federal mine safety regulations prohibit the recirculation of face air In a gassy Class III metal-non metal mine. Tg Soda Ash, Inc, operates a 2.0M ton/yr (2.2 million st/yr) underground gassy Class III trona mine in southwest Wyoming, currently liberating approximately 5,700 m{sup 3}/day (200,000 ft{sup 3}/day) of methane. Because of the low methane emissions and the incombustibility of trona, it was decided that Tg would be an excellent environment to test recirculation at a U.S. gassy mine, for possible future use by industry. A research program was begun with the cooperation of MSHA, the U.S. Bureau of Mines, the University of Utah, and Tg. Initial testing centered around re-using shop air underground. Next, conduct a continuous miner section recirculation test to see how the face contamination was affected by 305m (1,000 ft) and 610m (2,000 ft) recirculation distances. A district test followed to examine the effects of the critical parameter - respirable dust. Finally, a long-term program to study respirable trona dust transportation and deposition In mine airways to plan for district fan siting and effects on face air dust levels.

  10. The Sweet Home rhodochrosite specimen mine, Alma District, Central Colorado: the porphyry molybdenum-fluorine connection

    NASA Astrophysics Data System (ADS)

    Bartos, Paul J.; Nelson, Eric P.; Misantoni, Dean

    2007-02-01

    Intermediate sulfidation veins containing quartz-sphalerite-tetrahedrite-rhodochrosite-fluorite in the Sweet Home Mine, Alma District, Colorado were originally mined for silver starting in 1873. For the last 13 years up until 2004, however, the mine has produced world-class rhodochrosite specimens. Some of these specimens are considered to be among the finest mineral specimens ever produced and the finest of their species with values well over 1 million US dollars. The extraction, preparation, and marketing techniques pioneered at the Sweet Home operation have revolutionized the minerals specimen industry. The Sweet Home deposit is interpreted as a single pulse variant of a Climax-type hydrothermal system. Evidence for this includes (1) an age of mineralization (25.8 ± 0.3 Ma) that coincides with the age of the end stages of mineralization of the Climax molybdenum deposit approximately 7.5 km to the northeast; (2) a geochemical (Mn, W, F) and mineralogical (topaz, fluorite, hubnerite, greisen muscovite) signature typically associated with Climax-type systems; (3) the presence of porphyry rhyolite dikes, a breccia dike, and local quartz-molybdenite veins in the nearby area; (4) a small pegmatite within the mine with an age (25.9 ± 0.3 Ma) coincident with mineralization, which also contains minor amounts of disseminated molybdenite; and (5) the presence of similar-appearing gemmy, red rhodochrosites at Climax and other high-silica rhyolite systems. A significant difference is that unlike Climax-type systems, the Sweet Home hydrothermal system appears to have consisted of a single, relatively small pulse of magmatic fluid that slowly cooled and diluted with groundwater. This is inferred to have occurred at moderate depths in the order of 1.5-2.5 km below the surface. The fluids that formed the Sweet Home veins were dilute (salinity in the order of 2-4 wt% NaCl equivalent), high-temperature (temperatures of homogenization up to 370°C), and initially of magmatic

  11. Environmental control on water quality; cases studies from Battle Mountain mining district, north-central Nevada. Chapter A.

    USGS Publications Warehouse

    Tuttle, Michele L.W.; Wanty, Richard B.; Berger, Byron R.; Stillings, Lisa L.

    2003-01-01

    The environmental controls on water quality were the focus of our study in a portion of the Battle Mountain mining district, north-central Nevada. Samples representing areas outside known mineralized areas, in undisturbed mineralized areas, and in mined areas were chemically and isotopically analyzed. The results are related to geologic, hydrologic, and climatic data. Streams in background areas outside the mineralized zones reflect normal weathering of volcanically derived rocks. The waters are generally dilute, slightly alkaline in pH, and very low in metals. As these streams flow into mineralized zones, their character changes. In undisturbed mineralized areas, discharge into streams of ground water through hydrologically conductive fractures can be traced with chemistry and, even more effectively, with sulfur isotopic composition of dissolved sulfate. Generally, these tracers are much more subtle than in those areas where mining has produced adits and mine-waste piles. The influence of drainage from these mining relicts on water quality is often dramatic, especially in unusually wet conditions. In one heavily mined area, we were able to show that the unusually wet weather in the winter and spring greatly degraded water quality. Addition of calcite to the acid, metalrich mine drainage raised the stream pH and nearly quantitatively removed the metals through coprecipitation and (or) adsorption onto oxyhydroxides. This paper is divided into four case studies used to demonstrate our results. Each addresses the role of geology, hydrology, mining activity and (or) local climate on water quality. Collectively, they provide a comprehensive look at the important factors affecting water quality in this portion of the Battle Mountain mining district.

  12. Metals in riparian wildlife of the lead mining district of southeastern Missouri

    USGS Publications Warehouse

    Niethammer, K.R.; Atkinson, R.D.; Baskett, T.S.; Samson, F.B.

    1985-01-01

    Five species of riparian vertebrates (425 individuals) primarily representing upper trophic levels were collected from the Big River and Black River drainages in two lead mining districts of southeastern Missouri, 1981?82. Big River is subject to metal pollution via erosion and seepage from large tailings piles from inactive lead mines. Black River drains part of a currently mined area. Bullfrogs (Rana catesbeiana), muskrats (Ondatra zibethicus), and green-backed herons (Butorides striatus) collected downstream from the source of metal contamination to Big River had significantly (ANOVA, P<0.05) higher lead and cadmium levels than specimens collected at either an uncontaminated upstream site or on Black River. Northern water snakes (Nerodia sipedon) had elevated lead levels below the tailings source, but did not seem to accumulate cadmium. Levels of lead, cadmium, or zinc in northern rough-winged swallows (Stelgidopteryx serripennis) were not related to collecting locality. Carcasses of ten bank swallows (Riparia riparia) collected from a colony nesting in a tailings pile along the Big River had lead concentrations of 2.0?39 ppm wet weight. Differences between zinc concentrations in vertebrates collected from contaminated and uncontaminated sites were less apparent than differences in lead and cadmium. There was little relationship between metal concentrations in the animals studied and their trophic levels. Bullfrogs are the most promising species examined for monitoring environmental levels of lead, cadmium, and zinc. Downstream from the source of tailings, bullfrogs had markedly higher levels of these metals in most of their tissues. The species is also widely distributed in North America, easily caught, and relatively sedentary.

  13. Geologic, geochemical, and geophysical investigations in the northern part of the Gilmore mining district, Lemhi County, Idaho

    USGS Publications Warehouse

    Ruppel, Edward Thompson; Watts, K.C.; Peterson, Donald L.

    1970-01-01

    Geologic, geochemical, and geophysical investigations in the northern part of the Gilmore (Texas) mining district, Lemhi County, Idaho, indicate an area of anomalous concentrations of lead and silver in glacial deposits. These deposits overlie the probable extensions of the main veins as them are projected northward from the central part of the district. The anomalous area is underlain by the Jefferson Formation, which is the most favorable host rock for mineral deposits in the district, and by quartz diorite and granodiorite of the Gilmore stock. The stock also appears to underlie part of the gravel-covered area east of the district, which suggests that this area is of possible interest for geochemical and geophysical prospecting.

  14. Zinc and lead poisoning in wild birds in the Tri-State Mining District (Oklahoma, Kansas, Missouri)

    USGS Publications Warehouse

    Beyer, W.N.; Dalgam, J.; Dudding, S.; French, J.B.; Mateo, R.; Miesner, J.; Sileo, L.; Spann, J.

    2004-01-01

    contaminated with Pb, Cd, and Zn from mining, milling and smelting. Metals have been dispersed heterogeneously throughout the District in the form of milled mine waste ('chat'), as flotation tailings and from smelters as aerial deposition or slag. This study was conducted to determine if the habitat has been contaminated to the extent that the assessment populations of wild birds are exposed to toxic concentrations of metals. American robins (Turdus migratorius), northern cardinals (Cardinalis cardinalis), and waterfowl had increased Pb tissue concentrations (p < 0.05) compared with Pb tissue concentrations from reference birds, and the exposure of songbirds to Pb was comparable with that of birds observed at other sites severely contaminated with Pb. Mean activities of the Pb-sensitive enzyme delta-aminolevulinic acid dehydratase (ALAD) were decreased by >50% in red blood cells in these birds (p < 0.05). Several birds had tissue concentrations of Pb that have been associated with impaired biological functions and external signs of poisoning. Cadmium was increased in kidneys of songbirds (p < 0.05), but no proximal tubule cell necrosis associated with Cd poisoning was observed. Zinc concentrations in liver and kidney of waterfowl were significantly higher (p < 0.05) than reference values. The increased environmental concentrations of Zn associated with mining in the District accounted for the pancreatitis previously observed in five waterfowl from the District. The District is the first site at which free-flying wild birds have been found to be suffering severe effects of Zn poisoning.

  15. The role of static stress transfer in mining induced seismic events occurrence, a case study of the Rudna mine in the Legnica-Glogow Copper District in Poland

    NASA Astrophysics Data System (ADS)

    Orlecka-Sikora, B.

    2010-08-01

    Seismicity accompanying mining exploitation results from changes in the stress field in the rock mass near the mining excavations caused by human activity. Many studies of the temporal and spatial distribution of mining induced seismicity have provided evidence for interrelations among events. Although a variety of techniques have been applied to quantify the interdependences of mining induced seismic events, the physical mechanism of interactions has not been unequivocally identified. Based on the premise that one possible cause of interactions among seismic events can be static stress transfer, we have verified statistically the role of Coulomb stress transfer in the generation process of mining induced seismicity using a series of seismic events that occurred in the Rudna mine in the Legnica-Głogów Copper District in Poland. We quantify the triggering and inhibiting effect by the proportion of events in the series, whose locations are consistent with the stress increased and stress decreased zones, respectively. We have found that more than 60 per cent of the analysed seismic events occurred in areas where stress was enhanced due to the occurrence of previous events. The statistical significance of these results is tested by comparing them with the same proportions obtained for 2000 random permutations of the original series of events. The test has indicated that the locations in positive stress changes areas are preferred statistically significantly when the stress changes exceed 0.05 bar. This result turns out to be robust to the errors of the nodal planes determination.

  16. Summary of seismic activity and its relation to geology and mining in the Sunnyside mining district, Carbon and Emery Counties, Utah, during 1967-1970

    USGS Publications Warehouse

    Dunrud, C. Richard; Osterwald, Frank W.; Hernandez, Jerome

    1973-01-01

    In the Sunnyside mining district, Utah, coal is mined under thick and variable overburden which is locally weakened by faults and other structural discontinuities. Stress changes and local stress concentrations produced by mining under these conditions often cause sudden and violent ruptures in the coal and surrounding rock mass. The strain energy released by this type of failure, which can produce shock waves and may discharge coal and rock with explosive force, is often a serious threat to life and property. These releases of strain energy are called bumps or bounces by miners if they occur in the coal, and rock bursts if they occur in the surrounding rock mass. Many of these releases are so violent that they generate seismic waves that can be felt, or at least detected by seismic instruments, miles from the site of the rupture, whereas others are smaller and can be detected only by those sensitive seismic instruments within a few thousand feet of the site of the rupture. In 1969 and 1970, about 27,000 and about 15,000 earth tremors, respectively, were recorded by the five-station seismic monitoring network that is located at the surface and encompasses most of the mine workings in the district. Of these totals, 512 and 524 earth tremors, respectively, were of sufficient magnitude (greater than 1. 5 on the Richter scale) so that the hypocenters could be accurately located. In 1968 about 20,000 tremors were recorded, with 281 large enough to plot, but in 1967 over 50,000 were recorded, of which 540 were plotted. In this report we discuss the way in which seismic activity, geology, and mining are related or seem to be related for the period 1967 through 1970, with emphasis on the period 1969-70. We also suggest certain mining procedures which, based on studies during the period, might increase the safety and efficiency of mining operations in the Sunnyside district. A complete tabulation of the larger magnitude earth tremors which occurred during 1969-70 and

  17. Epithermal mineralization controlled by synextensional magmatism in the Guazapares Mining District of the Sierra Madre Occidental silicic large igneous province, Mexico

    NASA Astrophysics Data System (ADS)

    Murray, Bryan P.; Busby, Cathy J.

    2015-03-01

    We show here that epithermal mineralization in the Guazapares Mining District is closely related to extensional deformation and magmatism during the mid-Cenozoic ignimbrite flare-up of the Sierra Madre Occidental silicic large igneous province, Mexico. Three Late Oligocene-Early Miocene synextensional formations are identified by detailed volcanic lithofacies mapping in the study area: (1) ca. 27.5 Ma Parajes formation, composed of silicic outflow ignimbrite sheets; (2) ca. 27-24.5 Ma Témoris formation, consisting primarily of locally erupted mafic-intermediate composition lavas and interbedded fluvial and debris flow deposits; (3) ca. 24.5-23 Ma Sierra Guazapares formation, composed of silicic vent to proximal ignimbrites, lavas, subvolcanic intrusions, and volcaniclastic deposits. Epithermal low-to intermediate-sulfidation, gold-silver-lead-zinc vein and breccia mineralization appears to be associated with emplacement of Sierra Guazapares formation rhyolite plugs and is favored where pre-to-synvolcanic extensional structures are in close association with these hypabyssal intrusions. Several resource areas in the Guazapares Mining District are located along the easternmost strands of the Guazapares Fault Zone, a NNW-trending normal fault system that hosts most of the epithermal mineralization in the mining district. This study describes the geology that underlies three of these areas, which are, from north to south: (1) The Monte Cristo resource area, which is underlain primarily by Sierra Guazapares formation rhyolite dome collapse breccia, lapilli-tuffs, and fluvially reworked tuffs that interfinger with lacustrine sedimentary rocks in a synvolcanic half-graben bounded by the Sangre de Cristo Fault. Deposition in the hanging wall of this half-graben was concurrent with the development of a rhyolite lava dome-hypabyssal intrusion complex in the footwall; mineralization is concentrated in the high-silica rhyolite intrusions in the footwall and along the

  18. Geochemical evidence of chemical and physical weathering of mine waste downriver from the New Idria Mercury Mine, San Benito County, California

    NASA Astrophysics Data System (ADS)

    Sharma, R. K.; Weinman, B.

    2014-12-01

    Soil, river bank, and sediment samples were collected from Panoache Creek's mine tailings and its drainages in the Mendota Pool area of California's Central Valley. The samples were collected in order to understand the transport mechanisms of mercury and other heavy metals from the abandoned New Idria Mercury Mine (NIMM) in San Banito County, CA. It is generally thought that materials weathered from the NIMM site flow down gradient into the San Carlos Creek, which then joins Silver Creek and Panoche Creek, before finally ending up in the Valley's Mendota pool and San Joaquin River (SJR). While we know that factors like geology, anthropogenic activities, and weathering can accelerate heavy metal accumulation at downgradient reaches (Chakravarty and Patgiri, 2009), it is unclear how this part of the SJR has responded to the mine's abandonment since the 1970s. To investigate how mercury and other heavy metals are weathering and being transported through this portion of the SJR drainage, gains and losses using "enrichment factors" (EF) were calculated and compared along a gradient downstream. Overall, EF of fine and bank sediments show Hg is being enriched and stored within bank sediments. For example, Hg in banks sediments are up to 5% enriched compared to the bed sediments. There is also an enrichment gain trending downstream, as sediments settling in the Mendota pool have comparatively higher EF for Hg (0.94 ppm to 6.91 ppm) relative to background concentrations. Along with other geochemical indices, which can be used to more highly resolve exactly how mine contaminants like Hg are chemically and physically being weathered, (i.e., Igeo, PLI, and CIA) the overall enrichment trend is interpreted to be the physical transport of erosion material during runoff events from the stream banks of SJR tributaries. This interpretation is also supported by depleted Sr and enriched Rb/Sr ratios, which further support physical transport as a dominating factor in contaminant

  19. Mineral investigations in the Colville Mining District and Southern National Petroleum Reserve in Alaska. Open file report (Final)

    SciTech Connect

    Kurtak, J.M.; Hicks, R.W.; Werdon, M.B.; Meyer, M.P.; Mull, C.G.

    1995-12-31

    The U.S. Bureau of Mines conducted a five-year mineral resource assessment of the 16.6 million acre Colville Mining District in northern Alaska, which includes part of the National Petroleum Reserve in Alaska. During fieldwork, 1593 rock, soil, and stream sediment samples were collected and four bulk samples taken for beneficiation studies. A total of 40 mineral occurrences were documented, including 27 which were previously undescribed. Moderate potential exists for development of zinc-lead-silver, barite, and phosphate deposits.

  20. Geology of the Wood and East Calhoun mines, Central City District, Gilpin County, Colorado

    USGS Publications Warehouse

    Drake, Avery Ala

    1955-01-01

    The Wood-East Calhoun mine area is underlain by complexly folded Precambrian gneiss and pegmatite. The major fold in the area is an anticline that trends about N. 60° E. The Precambrian rocks are intruded by bostonite porphyry dikes of Tertiary age. All the rocks are cut by east- to northeast - trending faults that have been filled by precious metal-sulfide veins which have been worked chiefly for gold. The Wood vein occurs in an east-trending fault; the Calhoun vein occurs in a northeast-trending fault. Much of the uranium production of the Central City district has come from the Wood vein on Quartz Hill. The veins consist chiefly of quartz; pyrite is the chief metallic mineral and chalcopyrite is next in abundance. Sphalerite, galena, tetrahedrite-tennantite, and pitchblende are locally present. Deposition began with alteration-stage quartz and pyrite followed in order by pitchblend, light-yellow pyrite, massive quartz, yellow pyrite, shalerite, comb quartz, chalcopyrite, tetrahedrite-tennantite, galena, chalcopyrite, pyrite, and gray to light-brown fine-grained quartz. The veins of the Central City district are zoned, with quartz-pyrite veins near the center and galena-sphalerite veins on the periphery. The known pitchblende bodies are in the transition between these, but paragenetically, the pitchblende is earlier than all other metallic minerals. A trace element study of the ore indicates an association of zirconium and molybdenum with uranium, of bismuth, antimony, and arsenic with copper, and of cadmium with zinc. The pitchblende and other ore minerals are concentrated in ore shoots. The shoots are in open spaces controlled by the competency of the wall rocks, the presence of a prevailing direction of weakness in the rocks, and changes in strike and dip of the vein. The pitchblende is thought to be a local constituent of the quartz-pyrite ores and to owe its origin to residual solutions from the quartz bostonite magma.

  1. Mercury isotope fractionation during ore retorting in the Almadén mining district, Spain

    USGS Publications Warehouse

    Gray, John E.; Pribil, Michael J.; Higueras, Pablo L.

    2013-01-01

    Almadén, Spain, is the world's largest mercury (Hg) mining district, which has produced over 250,000 metric tons of Hg representing about 30% of the historical Hg produced worldwide. The objective of this study was to measure Hg isotopic compositions of cinnabar ore, mine waste calcine (retorted ore), elemental Hg (Hg0(L)), and elemental Hg gas (Hg0(g)), to evaluate potential Hg isotopic fractionation. Almadén cinnabar ore δ202Hg varied from − 0.92 to 0.15‰ (mean of − 0.56‰, σ = 0.35‰, n = 7), whereas calcine was isotopically heavier and δ202Hg ranged from − 0.03‰ to 1.01‰ (mean of 0.43‰, σ = 0.44‰, n = 8). The average δ202Hg enrichment of 0.99‰ between cinnabar ore and calcines generated during ore retorting indicated Hg isotopic mass dependent fractionation (MDF). Mass independent fractionation (MIF) was not observed in any of the samples in this study. Laboratory retorting experiments of cinnabar also were carried out to evaluate Hg isotopic fractionation of products generated during retorting such as calcine, Hg0(L), and Hg0(g). Calcine and Hg0(L) generated during these retorting experiments showed an enrichment in δ202Hg of as much as 1.90‰ and 0.67‰, respectively, compared to the original cinnabar ore. The δ202Hg for Hg0(g) generated during the retorting experiments was as much as 1.16‰ isotopically lighter compared to cinnabar, thus, when cinnabar ore was roasted, the resultant calcines formed were isotopically heavier, whereas the Hg0(g) generated was isotopically lighter in Hg isotopes.

  2. Characterization of a Strain Rate Transient Along the San Andreas and San Jacinto Faults Following the October 1999 Hector Mine Earthquake.

    NASA Astrophysics Data System (ADS)

    Hernandez, D.; Holt, W. E.; Bennett, R. A.; Dimitrova, L.; Haines, A. J.

    2006-12-01

    We are continuing work on developing and refining a tool for recognizing strain rate transients as well as for quantifying the magnitude and style of their temporal and spatial variations. We determined time-averaged velocity values in 0.05 year epochs using time-varying velocity estimates for continuous GPS station data from the Southern California Integrated GPS Network (SCIGN) for the time period between October 1999 and February 2004 [Li et al., 2005]. A self-consistent model velocity gradient tensor field solution is determined for each epoch by fitting bi-cubic Bessel interpolation to the GPS velocity vectors and we determine model dilatation strain rates, shear strain rates, and the rotation rates. Departures of the time dependent model strain rate and velocity fields from a master solution, obtained from a time-averaged solution for the period 1999-2004, with imposed plate motion constraints and Quaternary fault data, are evaluated in order to best characterize the time dependent strain rate field. A particular problem in determining the transient strain rate fields is the level of smoothing or damping that is applied. Our current approach is to choose a damping that both maximizes the departure of the transient strain rate field from the long-term master solution and achieves a reduced chi-squared value between model and observed GPS velocities of around 1.0 for all time epochs. We observe several noteworthy time-dependent changes. First, in the Eastern California Shear Zone (ECSZ) region, immediately following the October 1999 Hector Mine earthquake, there occurs a significant spatial increase of relatively high shear strain rate, which encompasses a significant portion of the ECSZ. Second, also following the Hector Mine event, there is a strain rate corridor that extends through the Pinto Mt. fault connecting the ECSZ to the San Andreas fault segment in the Salton Trough region. As this signal slowly decays, shear strain rates on segments of the San

  3. An assessment of AVIRIS data for hydrothermal alteration mapping in the Goldfield Mining District, Nevada

    NASA Technical Reports Server (NTRS)

    Carrere, Veronique; Abrams, Michael J.

    1988-01-01

    Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data were acquired over the Goldfield Mining District, Nevada, in September 1987. Goldfield is one of the group of large epithermal precious metal deposits in Tertiary volcanic rocks, associated with silicic volcanism and caldera formation. Hydrothermal alteration consists of silicification along fractures, advanced agrillic and argillic zones further away from veins and more widespread propylitic zones. An evaluation of AVIRIS data quality was performed. Faults in the data, related to engineering problems and a different behavior of the instrument while on-board the U2, were encountered. Consequently, a decision was made to use raw data and correct them only for dark current variations and detector read-out-delays. New software was written to that effect. Atmospheric correction was performed using the flat field correction technique. Analysis of the data was then performed to extract spectral information, mainly concentrating on the 2 to 2.45 micron window, as the alteration minerals of interest have their distinctive spectral reflectance features in this region. Principally kaolinite and alunite spectra were clearly obtained. Mapping of the different minerals and alteration zones was attempted using ratios and clustering techniques. Poor signal-to-noise performance of the instrument and the lack of appropriate software prevented the production of an alteration map of the area. Spectra extracted locally from the AVIRIS data were checked in the field by collecting representative samples of the outcrops.

  4. Clay minerals on Mars: Riotinto mining district (Huelva, Spain) as Earth analogue for acidic alteration pathways

    NASA Astrophysics Data System (ADS)

    Mavris, C.; Cuadros, J.; Bishop, J. L.; Nieto, J. M.; Michalski, J. R.

    2015-12-01

    Combined satellite and in-situ measurements of Mars surface have detected mineral assemblages indicating processes for which Earth analogues exist. Among them, aluminous clay-sulfate assemblages have been observed, which suggest alteration by acidic fluids. The Riotinto mining district (SW Spain) provides an Earth analogue site for such Martian processes. The parent rocks belong to an Upper Palaeozoic (Late Famennian-Tournaisian) volcano-sedimentary complex including siliciclastic sediments and mafic and felsic volcanics, all of which underwent hydrothermal alteration. The oxidation of an extensive pyrite-rich orebody provided mild to extreme acidic fluxes that leached the surrounding rocks for over 20 million years. The mineral assemblages are strongly dependent on their acidic alteration intensity. The observed mineralogical parageneses and leaching conditions for our sites at Riotinto are consistent with three alteration sequences: i) Mild: containing a range of clay minerals from vermiculite to kaolinite, with a wide variety of crystal order and mixed-layering; ii) Intermediate: containing smectite to kaolinite with jarosite-group phases; iii) Advanced: containing kaolinite, jarosite-group phases, and iron oxides. Our findings suggest that, even within this general scheme, the specific alteration pathways can be different.

  5. Geology of epithermal silver-gold bulk-mining targets, bodie district, Mono County, California

    USGS Publications Warehouse

    Hollister, V.F.; Silberman, M.L.

    1995-01-01

    The Bodie mining district in Mono County, California, is zoned with a core polymetallic-quartz vein system and silver- and gold-bearing quartz-adularia veins north and south of the core. The veins formed as a result of repeated normal faulting during doming shortly after extrusion of felsic flows and tuffs, and the magmatic-hydrothermal event seems to span at least 2 Ma. Epithermal mineralization accompanied repeated movement of the normal faults, resulting in vein development in the planes of the faults. The veins occur in a very large area of argillic alteration. Individual mineralized structures commonly formed new fracture planes during separate fault movements, with resulting broad zones of veinlets growing in the walls of the major vein-faults. The veinlet swarms have been found to constitute a target estimated at 75,000,000 tons, averaging 0.037 ounce gold per ton. The target is amenable to bulkmining exploitation. The epithermal mineralogy is simple, with electrum being the most important precious metal mineral. The host veins are typical low-sulfide banded epithermal quartz and adularia structures that filled voids created by the faulting. Historical data show that beneficiation of the simple vein mineralogy is very efficient. ?? 1995 Oxford University Press.

  6. [Project for the Creation of a Medical or Hospital Ethical Committee at a Local Level in the San Miguel Arcangel Hospital, District of San Miguelito, Province of Panama. Year 2013].

    PubMed

    Díaz Rivera, Yashiro A

    2015-01-01

    The next project was based on the design on the creation of a medical ethical Committee at a hospital. It was developed at the San Miguel Arcangel Hospital, District of San Miguelito, Province of Panama, in 2013. Insomuch as the creation of social projects requires unified international parameters, format is taken from the Unesco's guides for the establishing and working of bioethics committees; adapted to the socio-economic, political and cultural context of the San Miguelito District, Panama Province. Furthermore to adapting to socio-ecological aspect where the research project is carried out, the theoretical aspect includes from the ontological personalistic bioethics, where the cornerstone is the dignity of the human person. A study of perceptions of medical staff and nursing was developed on the management of the most common ethical dilemmas in the Hospital San Miguel Arcángel. The instrument used was a previously validated perception survey through a pilot test. Reliability was measured using Cronbach's alpha coefficient, and validity was obtained from the content. Satisfactory statistical results, that verify the working hypotheses on the recognition of the importance of autonomy, confidentiality, protection of vulnerable population, occupational health staff welfare and integration of bioethics at the institutional agenda, were obtained. However, there were particular aspects that indicate some doubt as to the management of some realities that are presented in the context of health care.

  7. 76 FR 35396 - Black Hills National Forest, Mystic Ranger District, South Dakota, Section 30 Limestone Mining...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... Mining Project AGENCY: Forest Service, USDA. ACTION: Corrected Notice of intent to prepare an... the purpose of mining for chemical grade limestone within mining claims on National Forest System land... publication dates. A Notice of Availability for the Section 30 Limestone Mining Project Draft EIS...

  8. Mercury dispersion in soils of an abandoned lead-zinc-silver mine, San Quintín (Spain)

    NASA Astrophysics Data System (ADS)

    Esbrí, José Maria; Martín-Crespo, T.; Gómez-Ortiz, D.; Monescillo, C. I.; Lorenzo, S.; Higueras, P.

    2010-05-01

    The mine considered on this work, namely San Quintín, is a filonian field with hydrothermal ores exploited during almost fifty years (1887-1934), producing 550.000Tm of galena, 550Tm of silver and 5.000 of sphalerite. Some rewashing works of tailings muds was achieved in recent times (1973-1985), including flotation tests of cinnabar ore from Almadén mines. The main problems remaining on the site are an active acid mine drainage (with pH ~ 2) and heavy metal dispersion on soils including gaseous mercury emissions. We present here results of a survey including soils sampling with mercury analysis and other pedological parameters, as well as determinations of mercury inmission in the atmosphere, using a common sampling grid. Analysis of soils samples has been carried out using an atomic absorption spectrometer AMA254, while air determinations were made by the same technique, using a Lumex RA-915+. The maps have been obtained by means of SURFER 8 software, as well as by ArcGIS software, and puts forward dispersion of mercury from cinnabar ore dump (108 ?g×g-1) to nearby soils (0.3 ?g×g-1 at 700 m of distance). The dispersion of mercury vapor exceed WHO level for chronic exposure (200 ng×m-3) in a small area (250 meters from cinnabar dump).

  9. Arsenic partitioning among particle-size fractions of mine wastes and stream sediments from cinnabar mining districts.

    PubMed

    Silva, Veronica; Loredo, Jorge; Fernández-Martínez, Rodolfo; Larios, Raquel; Ordóñez, Almudena; Gómez, Belén; Rucandio, Isabel

    2014-10-01

    Tailings from abandoned mercury mines represent an important pollution source by metals and metalloids. Mercury mining in Asturias (north-western Spain) has been carried out since Roman times until the 1970s. Specific and non-specific arsenic minerals are present in the paragenesis of the Hg ore deposit. As a result of intensive mining operations, waste materials contain high concentrations of As, which can be geochemically dispersed throughout surrounding areas. Arsenic accumulation, mobility and availability in soils and sediments are strongly affected by the association of As with solid phases and granular size composition. The objective of this study was to examine phase associations of As in the fine grain size subsamples of mine wastes (La Soterraña mine site) and stream sediments heavily affected by acid mine drainage (Los Rueldos mine site). An arsenic-selective sequential procedure, which categorizes As content into seven phase associations, was applied. In spite of a higher As accumulation in the finest particle-size subsamples, As fractionation did not seem to depend on grain size since similar distribution profiles were obtained for the studied granulometric fractions. The presence of As was relatively low in the most mobile forms in both sites. As was predominantly linked to short-range ordered Fe oxyhydroxides, coprecipitated with Fe and partially with Al oxyhydroxides and associated with structural material in mine waste samples. As incorporated into short-range ordered Fe oxyhydroxides was the predominant fraction at sediment samples, representing more than 80% of total As.

  10. Cadmium Bioaccumulation in European Flat Oysters (Ostrea Edulis) from Middle Adriatic Sea (San Benedetto Del Tronto District, Italy)

    PubMed Central

    Semeraro, Angela Marisa; Aliventi, Alessandra; Di Trani, Vittoria; Capocasa, Piero

    2014-01-01

    Bivalve molluscs represent an important source of cadmium exposure in humans, in particular oysters, because of their high filter feeding capability and high concentration of metal-binding metallothionein in tissues. In this study the authors investigated the difference in cadmium bioaccumulation in European flat oysters harvested from production areas in the district of San Benedetto del Tronto (Ascoli Piceno province, Italy), as a function of their origin (farming or natural beds) and the time of gathering. The beds lie 3 nm off-shore at a depth of 20-40 m and are collected by dredging. In the farms, baskets are suspended in the water column 2.5-3 nm offshore at a depth of 4 m. The authors analysed the results of cadmium monitoring plan carried out in oyster natural beds for a total of 15 samples collected from 2004 to 2012 and in two oyster farms for a total of 11 samples from 2009 to 2012. Although the few data did not allow to find a significant statistical association, they suggested two findings: i) cadmium concentration in oysters from natural beds seemed to be lower than in farmed oysters; and ii) in farmed oysters cadmium concentration even exceeded allowed maximum level for human consumption, in particular in autumn. The vertical stratification in the water column of phytoplankton and a cadmium dilution at oyster gonadal maturation might cause changes in oyster cadmium accumulation. PMID:27800338

  11. Analysis of the Transport and Fate of Metals Released From the Gold King Mine in the Animas and San Juan Rivers

    EPA Science Inventory

    This project’s objectives were to provide analysis of water quality following the release of acid mine drainage in the Animas and San Juan Rivers in a timely manner to 1) generate a comprehensive picture of the plume at the river system level, 2) help inform future monitoring eff...

  12. Characteristics and origin of coarse gold in Late Pleistocene sediments of the Cariboo placer mining district, British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Eyles, N.

    1995-02-01

    The Cariboo placer mining district (1000 km 2) sited in the Interior Plateau of central British Columbia, Canada, is the premier placer gold mining district of the Province. Gold is recovered from three Late Pleistocene sedimentary facies: postglacial fluvial gravels (< 10 Ka), Late Wisconsin till (ca. 25-10 Ka), and "older" fluvial gravels (>25 Ka). This study reports the morphology (size, roundness, sphericity) of 1636 gold grains, ranging in size from 0.25 to 17 mm, recovered from 19 placer mines. Older gravels contain the smallest gold grains (mean grani size 1.53 mm), grains of intermediate size occur in till (2.23 mm) and the coarsest gold occurs in postglacial gravels (2.34 mm) with a mean of 1.93 mm for the mining district as a whole. The most common grain shapes are sub-rounded, discoidal (14.73% of the grain population), sub-angular, discoidal (10.88%), and sub-rounded, sub-discoidal (9.59%); the most angular grains occur in postglacial gravels. In-situ growth of coarse, angular grains is indicated by a "composite" grain structure, consisting of aggregates of gold particles welded together by high-grade (Ag = < 2%) filamentous gold; in-situ coarsening may be reliant on organic complexing agents produced below a dense forest cover. An evolutionary sequence of grain form, from angular aggregates to rounded "pumpkin seed" grains, is suggested. Rounded grains commonly show a crystalline structure which may result from the cold hammering of gold during transport; fracturing along crystal boundaries is common. Gold grains may undergo cycles of coarsening, rounding, diagenesis and breakup in response to repeated recycling through Pleistocene sedimentary environments.

  13. Alteration and geochemical zoning in Bodie Bluff, Bodie mining district, eastern California

    USGS Publications Warehouse

    Herrera, P.A.; Closs, L.G.; Silberman, M.L.

    1993-01-01

    Banded, epithermal quartz-adularia veins have produced about 1.5 million ounces of gold and 7 million ounces of silver from the Bodie mining district, eastern California. The veins cut dacitic lava flows, pyroclastic rocks and intrusions. Sinter boulders occur in a graben structure at the top of Bodie Bluff and fragments of sinter and mineralized quartz veins occur in hydrothermal breccias nearby. Explosive venting evidently was part of the evolution of the ore-forming geothermal systems which, at one time, must had reached the paleosurface. Previous reconnaissance studies at Bodie Bluff suggested that the geometry of alteration mineral assemblages and distribution of some of the major and trace elements throughout the system correspond to those predicted by models of hot-spring, volcanic rock hosted precious metal deposits (Silberman, 1982; Silberman and Berger, 1985). The current study was undertaken to evaluate these sugestions further. About 500 samples of quartz veins and altered rocks, including sinter, collected over a vertical extent of 200 meters within Bodie Bluff were petrographically examined and chemically analyzed for trace elements by emission spectrographic and atomic absorption methods. Sixty-five samples were analyzed for major elements by X-ray fluorescence methods. The results of these analyses showed that, in general, alteration mineral assemblage and vertical geochemical zoning patterns follow those predicted for hot-spring deposits, but that geochemical zoning patterns for sinter and quartz veins (siliceous deposits), and altered wall rocks are not always similar. The predicted depth-concentration patterns for some elements, notably Au, Ag, Hg, and Tl in quartz veins, and Hg, As and Ag in wall rocks were not as expected, or were perturbed by the main ore producing zone. For both quartz veins and altered wall rocks, the main ore zone had elevated metal contents. Increased concentration of many of these elements could indicate proximity to this

  14. Long term fluctuations of groundwater mine pollution in a sulfide mining district with dry Mediterranean climate: Implications for water resources management and remediation.

    PubMed

    Caraballo, Manuel A; Macías, Francisco; Nieto, José Miguel; Ayora, Carlos

    2016-01-01

    Water resources management and restoration strategies, and subsequently ecological and human life quality, are highly influenced by the presence of short and long term cycles affecting the intensity of a targeted pollution. On this respect, a typical acid mine drainage (AMD) groundwater from a sulfide mining district with dry Mediterranean climate (Iberian Pyrite Belt, SW Spain) was studied to unravel the effect of long term weather changes in water flow rate and metal pollutants concentration. Three well differentiated polluting stages were observed and the specific geochemical, mineralogical and hydrological processes involved (pyrite and enclosing rocks dissolution, evaporitic salts precipitation-redisolution and pluviometric long term fluctuations) were discussed. Evidencing the importance of including longer background monitoring stage in AMD management and restoration strategies, the present study strongly advise a minimum 5-years period of AMD continuous monitoring previous to the design of any AMD remediation system in regions with dry Mediterranean climate.

  15. Mercury ores from the New Idria Mining District, California: Geochemical and stable isotope studies

    NASA Astrophysics Data System (ADS)

    Boctor, N. Z.; Shieh, Y. N.; Kullerud, G.

    1987-06-01

    The mercury ores of the New Idria Mining District are composed of metacinnabar and cinnabar with minor amounts of stibnite and iron disulfides. Metacinnabar from the main ore zone at the New Idria Mine contains Fe as a major impurity (0.96 to 2.80 wt.%), whereas that from the CO veins contains both Se (0.30 to 6.15 wt.%) and Fe (0.13 to 1.18 wt.%) in solid solution. The impurity content varies within the same specimen and within individual crystals as well and demonstrates lack of chemical equilibrium. Impurities tend to concentrate at the interfaces between metacinnabar and cinnabar in partly transformed crystals, thus increasing the barrier to nucleation of cinnabar and retarding or prohibiting any further transition of metacinnabar. Most of the pyrite and marcasite crystallized earlier than cinnabar and in rare cases contain nuclei of framboidal pyrite. Pyrite and marcasite crystallized as discrete phases and the latter does not show evidence of transition to pyrite. Dolomite shows normal marine carbonate δ 18O (24.6 to 29.7‰) and δ 13C (-1.7 to 2.5‰) values. Quartz displays δ 18O ranging from 18.5 to 21.5‰, distinctly lower than the associated dolomites, suggesting that the two minerals may have formed at two different stages. The range of δ 34S values for metacinnabar (0.0 to 3.2‰) overlaps with that of cinnabar (1.3 to 4.4‰). The δ 34S for pyrite ranges from 3.1 to 13.0‰; pyrite with framboidal nuclei shows the highest δ 34S values. The sulfur isotope data also suggest the lack of isotopic equilibrium. The source of C in the ore-forming fluids was marine carbonates leached from the Franciscan sediments. The source of S is uncertain because of lack of knowledge of the isotopic composition of total sulfur. It is likely that mixed sources of sulfur leached from sulfides in the host rocks and magmatic sulfur are involved.

  16. Bald Mountain gold mining district, Nevada: A Jurassic reduced intrusion-related gold system

    USGS Publications Warehouse

    Nutt, C.J.; Hofstra, A.H.

    2007-01-01

    The Bald Mountain mining district has produced about 2 million ounces (Moz) of An. Geologic mapping, field relationships, geochemical data, petrographic observations, fluid inclusion characteristics, and Pb, S, O, and H isotope data indicate that An mineralization was associated with a reduced Jurassic intrusion. Gold deposits are localized within and surrounding a Jurassic (159 Ma) quartz monzonite porphyry pluton and dike complex that intrudes Cambrian to Mississippian carbonate and clastic rocks. The pluton, associated dikes, and An mineralization were controlled by a crustal-scale northwest-trending structure named the Bida trend. Gold deposits are localized by fracture networks in the pluton and the contact metamorphic aureole, dike margins, high-angle faults, and certain strata or shale-limestone contacts in sedimentary rocks. Gold mineralization was accompanied by silicification and phyllic alteration, ??argillic alteration at shallow levels. Although An is typically present throughout, the system exhibits a classic concentric geochemical zonation pattern with Mo, W, Bi, and Cu near the center, Ag, Pb, and Zn at intermediate distances, and As and Sb peripheral to the intrusion. Near the center of the system, micron-sized native An occurs with base metal sulfides and sulfosalts. In peripheral deposits and in later stages of mineralization, Au is typically submicron in size and resides in pyrite or arsenopyrite. Electron microprobe and laser ablation ICP-MS analyses show that arsenopyrite, pyrite, and Bi sulfide minerals contain 10s to 1,000s of ppm Au. Ore-forming fluids were aqueous and carbonic at deep levels and episodically hypersaline at shallow levels due to boiling. The isotopic compositions of H and O in quartz and sericite and S and Pb in sulfides are indicative of magmatic ore fluids with sedimentary sulfur. Together, the evidence suggests that Au was introduced by reduced S-bearing magmatic fluids derived from a reduced intrusion. The reduced

  17. The magmatic history of the Vetas-California mining district, Santander Massif, Eastern Cordillera, Colombia

    NASA Astrophysics Data System (ADS)

    Mantilla Figueroa, Luis C.; Bissig, Thomas; Valencia, Víctor; Hart, Craig J. R.

    2013-08-01

    The Vetas-California Mining District (VCMD), located in the central part of the Santander Massif (Colombian Eastern Cordillera), based on U-Pb dating of zircons, records the following principal tectono-magmatic events: (1) the Grenville Orogenic event and high grade metamorphism and migmatitization between ˜1240 and 957 Ma; (2) early Ordovician calc-alkalic magmatism, which was synchronous with the Caparonensis-Famatinian Orogeny (˜477 Ma); (3) middle to late Ordovician post-collisional calc-alkalic magmatism (˜466-436 Ma); (4) late Triassic to early Jurassic magmatism between ˜204 and 196 Ma, characterized by both S- and I-type calc-alkalic intrusions and; (5) a late Miocene shallowly emplaced intermediate calc-alkaline intrusions (10.9 ± 0.2 and 8.4 ± 0.2 Ma). The presence of even younger igneous rocks is possible, given the widespread magmatic-hydrothermal alteration affecting all rock units in the area. The igneous rocks from the late Triassic-early Jurassic magmatic episodes are the volumetrically most important igneous rocks in the study area and in the Colombian Eastern Cordillera. They can be divided into three groups based on their field relationships, whole rock geochemistry and geochronology. These are early leucogranites herein termed Alaskites-I (204-199 Ma), Intermediate rocks (199-198 Ma), and late leucogranites, herein referred to as Alaskites-II (198-196 Ma). This Mesozoic magmatism is reflecting subtle changes in the crustal stress in a setting above an oblique subduction of the Panthalassa plate beneath Pangea. The lower Cretaceous siliciclastic Tambor Formation has detrital zircons of the same age populations as the metamorphic and igneous rocks present in the study area, suggesting that the provenance is related to the erosion of these local rocks during the late Jurassic or early Cretaceous, implying a local supply of sediments to the local depositional basins.

  18. A marketing plan for health care in the financial district of San Francisco.

    PubMed

    Evans, S

    1987-01-01

    The development of a corporate health marketing program for the Medical Pavilion was based on three assumptions. 1. Medical Pavilion will contribute positively to health care cost containment for employers by providing convenient, quality medical care which will help to reduce employee time lost from work due to physician visits, and through health screening, early diagnosis, and out-patient procedures, decrease unnecessary hospitalization. 2. The level of awareness among chief executive officers, benefits directors, corporate medical directors, and employees will be positively related to utilization of health services at the Medical Pavilion. 3. The Medical Pavilion will be organized on a private practice model; although special programs related to employer coverage and specific benefits may be considered separately. The recommended goals of the corporate health program of the Medical Pavilion were as follows: 1. To develop demographic profiles based on current utilization of medical services in a random sample to corporations in the Financial District. 2. To design a survey of corporate leadership to determine a needs assessment strategy for the development of preventive health services programs to be offered at the Medical Pavilion. 3. To select an advertising and public relations agency; and determine the marketing bridges, for the first year and the following five year period. 4. To evaluate effectiveness of the corporate health marketing plan referral data collected through the Management Information System to be established at the Medical Pavilion.

  19. Observed and simulated ground motions in the San Bernardino basin region for the Hector Mine, California, earthquake

    USGS Publications Warehouse

    Graves, R.W.; Wald, D.J.

    2004-01-01

    During the MW 7.1 Hector Mine earthquake, peak ground velocities recorded at sites in the central San Bernardino basin region were up to 2 times larger and had significantly longer durations of strong shaking than sites just outside the basin. To better understand the effects of 3D structure on the long-period ground-motion response in this region, we have performed finite-difference simulations for this earthquake. The simulations are numerically accurate for periods of 2 sec and longer and incorporate the detailed spatial and temporal heterogeneity of source rupture, as well as complex 3D basin structure. Here, we analyze three models of the San Bernardino basin: model A (with structural constraints from gravity and seismic reflection data), model F (water well and seismic refraction data), and the Southern California Earthquake Center version 3 model (hydrologic and seismic refraction data). Models A and F are characterized by a gradual increase in sediment thickness toward the south with an abrupt step-up in the basement surface across the San Jacinto fault. The basin structure in the SCEC version 3 model has a nearly uniform sediment thickness of 1 km with little basement topography along the San Jacinto fault. In models A and F, we impose a layered velocity structure within the sediments based on the seismic refraction data and an assumed depth-dependent Vp/Vs ratio. Sediment velocities within the SCEC version 3 model are given by a smoothly varying rule-based function that is calibrated to the seismic refraction measurements. Due to computational limitations, the minimum shear-wave velocity is fixed at 600 m/sec in all of the models. Ground-motion simulations for both models A and F provide a reasonably good match to the amplitude and waveform characteristics of the recorded motions. In these models, surface waves are generated as energy enters the basin through the gradually sloping northern margin. Due to the basement step along the San Jacinto fault, the

  20. Hydrogeochemical effects of a bulkhead in the Dinero mine tunnel, Sugar Loaf mining district, near Leadville, Colorado

    USGS Publications Warehouse

    Walton-Day, Katherine; Mills, Taylor J.

    2015-01-01

    The Dinero mine drainage tunnel is an abandoned, draining mine adit near Leadville, Colorado, that has an adverse effect on downstream water quality and aquatic life. In 2009, a bulkhead was constructed (creating a mine pool and increasing water-table elevations behind the tunnel) to limit drainage from the tunnel and improve downstream water quality. The goal of this study was to document changes to hydrology and water quality resulting from bulkhead emplacement, and to understand post-bulkhead changes in source water and geochemical processes that control mine-tunnel discharge and water quality. Comparison of pre-and post-bulkhead hydrology and water quality indicated that tunnel discharge and zinc and manganese loads decreased by up to 97 percent at the portal of Dinero tunnel and at two downstream sites (LF-537 and LF-580). However, some water-quality problems persisted at LF-537 and LF-580 during high-flow events and years, indicating the effects of the remaining mine waste in the area. In contrast, post-bulkhead water quality degraded at three upstream stream sites and a draining mine tunnel (Nelson tunnel). Water-quality degradation in the streams likely occurred from increased contributions of mine-pool groundwater to the streams. In contrast, water-quality degradation in the Nelson tunnel was likely from flow of mine-pool water along a vein that connects the Nelson tunnel to mine workings behind the Dinero tunnel bulkhead. Principal components analysis, mixing analysis, and inverse geochemical modeling using PHREEQC indicated that mixing and geochemical reactions (carbonate dissolution during acid weathering, precipitation of goethite and birnessite, and sorption of zinc) between three end-member water types generally explain the pre-and post-bulkhead water composition at the Dinero and Nelson tunnels. The three end members were (1) a relatively dilute groundwater having low sulfate and trace element concentrations; (2) mine pool water, and (3) water that

  1. Mercury pollution from the artisanal mining in Yani gold district, Northern Bolivia

    NASA Astrophysics Data System (ADS)

    Alfonso, Pura; Freixas, Anna; Bascompta, Marc; María Aranibar, Ana; Villegas, Karla; María García-Noguero, Eva; Higueras, Pablo; Cielito Saraiva, Angela

    2016-04-01

    Artisanal gold mining is the main economic activity in the Yani district, Northern Bolivia. In this area abundant orogenic gold deposits constituted by quartz veins hosted in paleozoic turbiditic series that contain either free gold or associated with pyrite. Gold is recovered in processing plants by gravimetric methods using shaking tables in several communities of this district. Previously, miners ground the mineral in ball mills together with mercury. The present study aims to evaluate the effect of mercury used in the gold recovering process to the environment and human health in the Yani district. The assessment was based on the analysis of human hair, sediments and water from the river nearby the processing plant and drinking water from the fountain that supplies these communities. 47 samples of hair from miners and other people from the Yani and Señor de Mayo communities were obtained in 2014 and 52 samples in 2015. All were analysed to evaluate the mercury exposure in these places. The results from the 2014 sampling show a wide range of Hg concentration in hair, especially in Señor de Mayo, with values up to 136 μg/g THg. However, in 2015 among the 43 residents in Señor de Mayo, 29 (67%) exhibit concentrations higher than 2 μg/g THg, with an average value of 5.36 μg/g THg. On the other hand, in Yani only 40% have concentrations above 2 μg/g THg, with an average value of 2.34 μg/g THg. The content in Hg in most of the hair samples exhibit values above the tolerable limits established by the US Environmental Protection Agency (1 μg/g Hg) and the World Health Organisation (WHO, 2 μg/g Hg). These high Hg concentrations are found not only in miners but also in the other members of the community, in spite of low fish consumption in this area. Part of the hair was analysed before and after cleaning. Usually in the second case the content of Hg is reduced, but still show high Hg levels, then probably the atmosphere is polluted with Hg and population is

  2. U.S. EPA Statement on San Juan River Data from Gold King Mine Release

    EPA Pesticide Factsheets

    SHIPROCK, NEW MEXICO - Today, U.S. EPA released additional water quality data from Aug. 7 to Aug. 9, 2015, on the San Juan River between Farmington and Shiprock, New Mexico. The August 7 data was collected for baseline purposes to understand river c

  3. Stream-sediment geochemistry in mining-impacted streams: Prichard, Eagle, and Beaver creeks, northern Coeur d'Alene Mining District, northern Idaho

    USGS Publications Warehouse

    Box, Stephen E.; Wallis, John C.; Briggs, Paul H.; Brown, Zoe Ann

    2005-01-01

    This report presents the results of one aspect of an integrated watershed-characterization study that was undertaken to assess the impacts of historical mining and milling of silver-lead-zinc ores on water and sediment composition and on aquatic biota in streams draining the northern part of the Coeur d?Alene Mining District in northern Idaho. We present the results of chemical analyses of 62 samples of streambed sediment, 19 samples of suspended sediment, 23 samples of streambank soil, and 29 samples of mine- and mill-related artificial- fill material collected from the drainages of Prichard, Eagle, and Beaver Creeks, all tributaries to the North Fork of the Coeur d?Alene River. All samples were sieved into three grain-size fractions (<0.063, 0.063?0.25, and 0.25?1.0 mm) and analyzed for 40 elements after four-acid digestion by inductively coupled plasma atomic-emission spectrometry and for mercury by continuous- flow cold-vapor atomic-absorption spectrometry in the U.S. Geological Survey laboratory in Denver, Colo. Historical mining of silver-lead-zinc ores in the headwater reaches of the Prichard Creek, Eagle Creek, and Beaver Creek drainages has resulted in enrichments of lead, zinc, mercury, arsenic, cadmium, silver, copper, cobalt, and, to a lesser extent, iron and manganese in streambed sediment. Using samples collected from the relatively unimpacted West Fork of Eagle Creek as representative of background compositions, streambed sediment in the vicinity of the mines and millsites has Pb and Zn contents of 20 to 100 times background values, decreasing to 2 to 5 times background values at the mouth of the each stream, 15 to 20 km downstream. Lesser enrichments (<10 times background values) of mercury and arsenic also are generally associated with, and decrease downstream from, historical silver-lead-zinc mining in the drainages. However, enrichments of arsenic and, to a lesser extent, mercury also are areally associated with the lode gold deposits along

  4. Prevalence of Vitamin D Insufficiency and Deficiency among Young Physicians at University District Hospital in San Juan, Puerto Rico.

    PubMed

    Ramírez-Vick, Margarita; Hernández-Dávila, Leticia; Rodríguez-Rivera, Nixzaliz; López-Valentín, Mariel; Haddock, Lillian; Rodríguez-Martínez, Renil; González-Bossolo, Alex

    2015-06-01

    Vitamin D has been attracting increased attention because of higher prevalences of vitamin D insufficiency and deficiency than expected in areas with sufficient sun exposure. Even though sunlight exposure and diet are the main determinants of vitamin D status, other factors, such as age, race, the use (or not) of sunscreen, medications, and malabsorptive conditions, also affect vitamin D levels. Recent studies have found high prevalences of vitamin D deficiency and insufficiency in different populations. However, there are limited data regarding the prevalence of vitamin D deficiency and insufficiency in Puerto Rico. To shed more light on the subject, we evaluated a sample of 51 internal medicine residents and research fellows, aged from 25 to 39 years at the University District Hospital in San Juan, Puerto Rico, doing so by means of a questionnaire that explored basic socio demographic and lifestyle characteristics and collected anthropometric data; in addition, we obtained blood samples in order to determine 25-hydroxyvitamin D levels. The median 25-hydroxyvitamin D level was 21 ng/mL (range, 7-38 ng/mL). Forty-five participants (88.2%) had 25-hydroxyvitamin D concentrations of lower than 30 ng/mL. We found vitamin D deficiencies in 43.1% of the population and insufficiencies in 45.1%. Contributory factors to our findings include limited exposure to sunlight during periods of high sun intensity, increased body mass index, and a limited area of the body being exposed to sunlight. A relationship between reduced physical activity levels and hypovitaminosis D was also found. Both calcium intake and vitamin D intake, which were markedly below recommended daily allowances, were positively correlated with 25-hydroxy vitamin D levels, but with a weak association.

  5. Gangue mineral textures and fluid inclusion characteristics of the Santa Margarita Vein in the Guanajuato Mining District, Mexico

    NASA Astrophysics Data System (ADS)

    Moncada, Daniel; Bodnar, Robert

    2012-06-01

    Successful exploration for mineral deposits requires tools that the explorationist can use to distinguish between targets with high potential for mineralization and those with lower economic potential. In this study, we describe a technique based on gangue mineral textures and fluid inclusion characteristics that has been applied to identify an area of high potential for gold-silver mineralization in the epithermal Ag-Au deposits at Guanajuato, Mexico. The Guanajuato mining district in Mexico is one of the largest silver producing districts in the world with continuous mining activity for nearly 500 years. Previous work conducted on the Veta Madre vein system that is located in the central part of this district identified favorable areas for further exploration in the deepest levels that have been developed and explored. The resulting exploration program discovered one of the richest gold-silver veins ever found in the district. This newly discovered vein that runs parallel to the Veta Madre was named the Santa Margarita vein. Selected mineralized samples from this vein contain up to 249 g/t of Au and up to 2,280 g/t Ag. Fluid inclusions in these samples show homogenization temperatures that range from 184 to 300°C and salinities ranging from 0 to 5 wt.% NaCl. Barren samples show the same range in homogenization temperature, but salinities range only up to 3 wt.% NaCl. Evidence of boiling was observed in most of the samples based on fluid inclusions and/or quartz and calcite textures. Liquid-rich inclusions with trapped illite are closely associated with high silver grades. The presence of assemblages of vapor-rich-only fluid inclusions, indicative of intense boiling or "flashing", shows the best correlation with high gold grades.

  6. Geochemistry of rare earth elements in minesoils from São Domingos mining district (Iberian Pyrite Belt)

    NASA Astrophysics Data System (ADS)

    Delgado, Joaquin; Perez-Lopez, Rafael; Nieto, Jose Miguel; Ayora, Carles

    2010-05-01

    The São Domingos mine is one of the most emblematic mining districts in the lower part of the Guadiana River Basin (SW of Iberian Peninsula). It is located in Portugal (about 5 km from the Spanish border), in the northern sector of the Iberian Pyrite Belt (IPB), one of the largest metallogenetic provinces of massive sulphides in the world. Although mining activity has ceased at present, the large-scale exploitation of this deposit between the second half of the XIX century and the first half of the XX century, has favoured the production of enormous waste dumps, where oxidation of pyrite and associated sulphides is resulting in the production of acid mine drainage (AMD). Mining wastes, minesoils, and acid mine drainage have been analyzed for their major ions and rare earth elements (REE) with the aim of understanding the REE mobility during sulphide weathering so that lanthanoid series can be used both as a proxy for the extent of water-rock interaction and as a tool for identifying impacts of AMD on natural ecosystems. Chemical speciation of REE in extracts from minesoils indicates that REE sulphate complexes (mainly LnSO4+) are the primary aqueous form (60-90%), and free ionic species (Ln3+, 10-40%) are the next most abundant form of soil water-soluble fraction and controls the REE speciation model. The REE from this fraction have NASC-normalized patterns with middle-REE (MREE) enriched signature compared to the light-REE (LREE) and heavy-REE (HREE), showing convex MREE-signatures and convexity index values of +1.29 +/- 1.13. These results are consistent with the typical REE fractionation patterns reported for AMD. Poorly crystalline iron oxyhydroxysulphates act as a source of labile MREE by dissolution and/or desorption processes and could explain the MREE-enriched signatures in solution.

  7. Blood lead concentrations in wild birds from a polluted mining region at Villa de La Paz, San Luis Potosi, Mexico.

    PubMed

    Chapa-Vargas, Leonardo; Mejia-Saavedra, Jose J; Monzalvo-Santos, Karina; Puebla-Olivares, Fernando

    2010-01-01

    This investigation was undertaken to determine the concentrations of lead in bird blood samples from a mining region in central Mexico and to compare concentrations among several different feeding guilds. The study took place in the Mexican state of San Luis Potosi in a region known as "Villa de la Paz." This is one of the most intensely exploited mining regions in central Mexico and has been actively mined for over four centuries. Lead concentrations from bird blood samples taken from four polluted sites were significantly higher than those from a control, unpolluted site (F = 6.3, P < 0.0002). Similarly, mean blood lead concentrations in birds from a highly polluted site were higher than those from a site that has intermediate pollution levels (P < 0.05). In addition, samples from insectivorous birds had significantly lower lead concentrations compared to granivores, frugivores-insectivores, and omnivores (F = 4.86, P = 0.004), and a large proportion of all individuals had blood lead concentrations indicative of low, sub-lethal toxic effects. Finally, in two polluted sites, remarkably small numbers of insectivore-frugivores, and granivores were trapped, and in one polluted site a large number of insectivores was trapped (X(2) = 29.9, P = 0.03), and no differences in proportions of migrants and non-migrants were found among sampling sites (X(2) = 0.6, P = 0.96). To date, it has not been determined to what extent constant exposure to these levels of pollution can influence health at the individual level, lifespan, and, therefore, population demography of birds from this region.

  8. Characterisation of sulphide-bearing waste-rock dumps using electrical resistivity imaging: the case study of the Rio Marina mining district (Elba Island, Italy).

    PubMed

    Mele, Mauro; Servida, Diego; Lupis, Domenico

    2013-07-01

    Sulphide-bearing mine dumps are potential sources of pollution when acid mine drainage (AMD) occurs. Because the generation of AMD depends on the volume and composition of waste materials, their characterisation is crucial for the evaluation of geochemical hazards and for the design of remediation strategies to minimise their environmental impact. In this paper, a cost-effective strategy for the characterisation of an inactive mine dump in the Rio Marina mining district (Elba Island, Italy) using earth resistivity imaging (ERI) is presented. As no information regarding the nature of waste rocks is found in reports for the mine, five ERI profiles were acquired at the top of the waste pile. The results show that waste rocks are heterogeneous with a maximum thickness of 30 m. Due to the large amounts of dispersed sulphide minerals, the waste rocks are characterised by an electrically conductive geophysical signature in comparison to the surrounding resistive metamorphic bedrock. A geostatistical approach was adopted to estimate the elevation of the edges of the mine dump, and the net volume of the waste rocks was computed through a raster analysis of the elevations of the upper and lower boundaries of the mine dump. High-conductivity anomalies were detected within the core of the mine dump. The integration of the hydrogeological, geochemical and geological framework of the Rio Marina mining district suggests that these anomalies could be a geophysical signature of subsurface regions where AMD is currently generated or stored, thus representing sources of environmental pollution.

  9. Uranium deposits at the Jomac mine, White Canyon area, San Juan County, Utah

    USGS Publications Warehouse

    Trites, A.F.; Hadd, G.A.

    1955-01-01

    azurite, and chalcanthite occur locally with the uranium minerals. Principal ore guides at the Jomac mine are channels, and scours at the bottom of these channels coal-bearing sandstone or conglomerate at the base of the Shinarump conglomerate, coal, and jarosite.

  10. Mercury methylation influenced by areas of past mercury mining in the Terlingua district, Southwest Texas, USA

    USGS Publications Warehouse

    Gray, J.E.; Hines, M.E.; Biester, H.

    2006-01-01

    Speciation and microbial transformation of Hg was studied in mine waste from abandoned Hg mines in SW Texas to evaluate the potential for methyl-Hg production and degradation in mine wastes. In mine waste samples, total Hg, ionic Hg2+, Hg0, methyl-Hg, organic C, and total S concentrations were measured, various Hg compounds were identified using thermal desorption pyrolysis, and potential rates of Hg methylation and methyl-Hg demethylation were determined using isotopic-tracer methods. These data are the first reported for Hg mines in this region. Total Hg and methyl-Hg concentrations were also determined in stream sediment collected downstream from two of the mines to evaluate transport of Hg and methylation in surrounding ecosystems. Mine waste contains total Hg and methyl-Hg concentrations as high as 19,000 ??g/g and 1500 ng/g, respectively, which are among the highest concentrations reported at Hg mines worldwide. Pyrolysis analyses show that mine waste contains variable amounts of cinnabar, metacinnabar, Hg0, and Hg sorbed onto particles. Methyl-Hg concentrations in mine waste correlate positively with ionic Hg2+, organic C, and total S, which are geochemical parameters that influence processes of Hg cycling and methylation. Net methylation rates were as high as 11,000 ng/g/day, indicating significant microbial Hg methylation at some sites, especially in samples collected inside retorts. Microbially-mediated methyl-Hg demethylation was also observed in many samples, but where both methylation and demethylation were found, the potential rate of methylation was faster. Total Hg concentrations in stream sediment samples were generally below the probable effect concentration of 1.06 ??g/g, the Hg concentration above which harmful effects are likely to be observed in sediment dwelling organisms; whereas total Hg concentrations in mine waste samples were found to exceed this concentration, although this is a sediment quality guideline and is not directly applicable

  11. Geologic map of the Kechumstuk fault zone in the Mount Veta area, Fortymile mining district, east-central Alaska

    USGS Publications Warehouse

    Day, Warren C.; O’Neill, J. Michael; Dusel-Bacon, Cynthia; Aleinikoff, John N.; Siron, Christopher R.

    2014-01-01

    This map was developed by the U.S. Geological Survey Mineral Resources Program to depict the fundamental geologic features for the western part of the Fortymile mining district of east-central Alaska, and to delineate the location of known bedrock mineral prospects and their relationship to rock types and structural features. This geospatial map database presents a 1:63,360-scale geologic map for the Kechumstuk fault zone and surrounding area, which lies 55 km northwest of Chicken, Alaska. The Kechumstuk fault zone is a northeast-trending zone of faults that transects the crystalline basement rocks of the Yukon-Tanana Upland of the western part of the Fortymile mining district. The crystalline basement rocks include Paleozoic metasedimentary and metaigneous rocks as well as granitoid intrusions of Triassic, Jurassic, and Cretaceous age. The geologic units represented by polygons in this dataset are based on new geologic mapping and geochronological data coupled with an interpretation of regional and new geophysical data collected by the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys. The geochronological data are reported in the accompanying geologic map text and represent new U-Pb dates on zircons collected from the igneous and metaigneous units within the map area.

  12. Reconstructing the history of mining and remediation in the Coeur d'Alene, Idaho Mining District using lake sediments.

    PubMed

    Morra, Matthew J; Carter, Meghan M; Rember, William C; Kaste, James M

    2015-09-01

    Mining that began in the late 1800s intensified during World War II contaminating Lake Coeur d'Alene sediments with potentially toxic elements. We used 80y of the sediment record to reconstruct metal(loid) loadings to the lake and quantitatively evaluate the effectiveness of tailings management. Sediment core analysis for pollen, chronological markers, and metal(loid)s permitted stratigraphic reconstruction showing that contaminant loading decreased after tailings pond construction, but that most metal(loid) concentrations exceed recommended limits. Arsenic concentrations (250-450 mg kg(-)(1)) at the sediment-water interface are potentially toxic; however, low P concentrations in recent sediments (1.0-1.4 mg kg(-)(1)) inhibit eutrophication and the concomitant release of soluble As. Zinc (3 g kg(-)(1)), Cd (10 mg kg(-)(1)), Ag (10 mg kg(-)(1)), and Cu (90 mg kg(-)(1)) concentrations are now lower than in sediments deposited during active mining, but remain an environmental concern. Sedimentary Cr and Pb concentrations have not changed in the last 50y, because tailings continue to enter the lake. Although modern Cr concentrations (40 mg kg(-)(1)) are unlikely to cause toxicity, current Pb concentrations (4 g kg(-)(1)) exceed acceptable limits, creating challenges for remediation. Strategies to manage other mining-contaminated watersheds should include consideration of elemental differences when evaluating remediation effectiveness.

  13. Initial studies for the phytostabilization of a mine tailing from the Cartagena-La Union Mining District (SE Spain).

    PubMed

    Conesa, Héctor M; Faz, Angel; Arnaldos, Raquel

    2007-01-01

    Mine tailings are one of the main environmental problems in post-mining landscapes and their removal is often complicated due to their high heavy metal content and dimensions. In this sense, using plant species for in situ stabilization may be an interesting and low cost option. Moreover, there are some plant species that have adapted to these conditions and are usually present at these contaminated sites. In this study, a mine tailing located in South-East Spain was investigated in order to establish lines for further phytostabilization research. A plot sampling design was carried out in order to characterize the soil properties. In addition, two plant species that have naturally colonized some parts of the tailing, Hyparrhenia hirta and Zygophyllum fabago, were sampled, including the analyses of their respective rhizospheric soils. The results of plot soil samples showed pH values from ultra acid to slightly alkaline. The electrical conductivity values were around 4dSm(-1) in plots with vegetation and 8dS m(-1) in the plot without vegetation. Total metal concentrations were high (4000 mg kg(-1) for Pb, 9000-15000 mg kg(-1) for Zn). DTPA- and water-extractable Zn were 5% and 3% of the total, respectively. H. hirta accumulated around 150 mg kg(-1) Pb in both shoots and roots. Zn concentration was 750 mg kg(-1) in Z. fabago shoots. DTPA-extractable Zn and Cu were positively correlated to plant uptake.

  14. Metals from mine waste as potential cause of oxidative stress in burrowing crab Neohelice granulata from San Antonio bay.

    PubMed

    Giarratano, Erica; Gil, Mónica N; Marinho, Carmen H; Malanga, Gabriela

    2016-10-01

    The Natural Protected Area San Antonio bay is of particular importance for its congregation of migratory shorebirds and it has been declared one of the Western Hemisphere Shorebird Reserve Network International site (WHSRN). Present study represents the first assessment of variation on oxidative stress biomarkers in male crab Neohelice granulata from San Antonio bay (Río Negro, Argentina) under field conditions, associated mainly to metal contamination coming from passive mining wastes. Three sites were sampled once every three months from November 2012 to August 2013 within this sea inlet (Pile, Fishery and Port) and a control site at the southeast of the bay (Punta Perdices). Accumulation of Ni, Zn, Cr and Al varied only with seasons although without a constant trend, meanwhile Cd, Cu and Pb also varied among sites being highest in Pile and Port. Biochemical results indicated that variations in catalase activity was only site specific being maximum in Pile; meanwhile lipid radical, α-tocopherol and metallothioneins were only seasonal specific being higher in autumn and winter. Seasonal variation was also found for total thioles, being the content higher in summer and autumn than in winter. Correlation analysis revealed that malondialdehyde and α-tocopherol have a positive association with Al and negative with Ni, meanwhile GST has a positive association with Fe. Crabs from the closest area to the waste pile did not exhibit a differentiated oxidative pressure despite the higher accumulation of metals. It is possible that crabs from contaminated areas have developed a tolerance to metals, indicating a strong ecotoxicological selective pressure. More studies are needed to assess whether there is a transfer of metals through the food chain.

  15. Review of the Proposed San Ramon Valley Center of the Contra Costa Community College District. Higher Education Update.

    ERIC Educational Resources Information Center

    California State Postsecondary Education Commission, Sacramento.

    The report evaluates a proposed San Ramon Valley Center community college and responds to California legislative requirements that the California Postsecondary Education Commission (CPEC) advise the legislature and governor regarding new institutions and campuses of public higher education. The report concludes that the San Ramon Valley Center…

  16. Sr, Nd and Pb isotopic compositions of Adakitic magma from the Wakurayama Dacite in San-in district, SW Japan

    NASA Astrophysics Data System (ADS)

    Sato, D.; Shibata, T.; Matsumoto, I.

    2011-12-01

    The Wakuraya Dacite, San-in district, SW Japan was described as Adakite (Defant and Drummond, 1990, Nature) by Sato et al. (2011, JGS). Adakitic rocks are characterized by higher Al2O3 and Sr, and lower MgO, K2O, Y and Yb. Many Quaternary silicate volcanoes in Southwest Japan are considered to be adakitic magmas that have been generated by partial melting of the subducted Philippine Sea plate (e.g. the Daisen volcano; Morris, 1995, Geology). The Wakurayama Dacite is distributed within a 5 km radius in Shimane prefecture, Southwest Japan. The Wakurayama Dacite was erupted in the Late Miocene to Pliocene (ca. 5 Ma; Morris et al., 1990, JSAES), the activity in advance of the Daisen volcano. We present major and trace elements and isotopic compositions (Sr, Nd and Pb) to discuss the origin of the end-members that are related to magma genesis of the Wakurayama Dacite. The chemical characteristics of these rocks, which have higher Al2O3 (17.6-19.7 wt.%) and Sr (552-799 ppm), and lower MgO (0.28-2.14 wt.%), K2O (1.26-1.48 wt.%), Y (5-15 ppm) and Yb (0.4-0.7 ppm) contents, are similar to typical adakite. The isotopic compositions of the Wakurayama Dacite show similar to those of the Daisen volcano (Tamura et al., 2003, J. Petrol.). According to Defant and Drummond (1990), adakites are characterized by similar low 87Sr/86Sr ratios (usually < 0.7040) to those of MORB, but the Wakurayama Dacite and the Daisen volcano have higher 87Sr/86Sr ratio (ca. 0.7046 to 0.7052). Kimura et al. (2005) proposed that the origin of Daisen adakitic magmas have been primarily created by mixing between subducted oceanic crust and its associated sediments from the Philippine Sea plate. The isotopic compositions (Sr, Nd and Pb) of the Wakurayama Dacite are shown the two component-mixing curve between oceanic crust (Shikoku basin basalt; Hicky-Vargas, 1991, EPSL) and sediments (the Nankai Trough terrigenous sediments; Shimoda et al., 1998, EPSL). Above results suggest that the partial melting of

  17. Application of techniques to identify coal-mine and power-generation effects on surface-water quality, San Juan River basin, New Mexico and Colorado

    USGS Publications Warehouse

    Goetz, C.L.; Abeyta, Cynthia G.; Thomas, E.V.

    1987-01-01

    Numerous analytical techniques were applied to determine water quality changes in the San Juan River basin upstream of Shiprock , New Mexico. Eight techniques were used to analyze hydrologic data such as: precipitation, water quality, and streamflow. The eight methods used are: (1) Piper diagram, (2) time-series plot, (3) frequency distribution, (4) box-and-whisker plot, (5) seasonal Kendall test, (6) Wilcoxon rank-sum test, (7) SEASRS procedure, and (8) analysis of flow adjusted, specific conductance data and smoothing. Post-1963 changes in dissolved solids concentration, dissolved potassium concentration, specific conductance, suspended sediment concentration, or suspended sediment load in the San Juan River downstream from the surface coal mines were examined to determine if coal mining was having an effect on the quality of surface water. None of the analytical methods used to analyzed the data showed any increase in dissolved solids concentration, dissolved potassium concentration, or specific conductance in the river downstream from the mines; some of the analytical methods used showed a decrease in dissolved solids concentration and specific conductance. Chaco River, an ephemeral stream tributary to the San Juan River, undergoes changes in water quality due to effluent from a power generation facility. The discharge in the Chaco River contributes about 1.9% of the average annual discharge at the downstream station, San Juan River at Shiprock, NM. The changes in water quality detected at the Chaco River station were not detected at the downstream Shiprock station. It was not possible, with the available data, to identify any effects of the surface coal mines on water quality that were separable from those of urbanization, agriculture, and other cultural and natural changes. In order to determine the specific causes of changes in water quality, it would be necessary to collect additional data at strategically located stations. (Author 's abstract)

  18. Paleomagnetic and mineral magnetic constraints on Zn-Pb ore genesis in the Pend Oreille Mine, Metaline district, Washington, USA

    USGS Publications Warehouse

    Pannalal, S.J.; Symons, David T. A.; Leach, D.L.

    2007-01-01

    Zinc-lead mineralization in the Metaline mining district of northeastern Washington, USA, is hosted by the Cambrian Metaline Formation and is classified into Yellowhead-type (YO) and Josephine-type (JO) ore based on texture and mineralogy. Paleomagnetic results are reported for four Cambrian Metaline Formation sites, one Ordovician Ledbetter slate site, 12 YO and 13 JO (including two breccia sites) mineralization sites in the Pend Oreille Mine, and eight sites from the nearby Cretaceous Kaniksu granite batholith. Thermal and alternating field step demagnetization, saturation isothermal remanence analysis, and synthetic specimen tests show that the remanence in the host carbonates and Zn-Pb mineralization is carried mostly by pseudosingle (PSD) to single domain (SD) pyrrhotite and mostly by PSD to SD magnetite in the Kaniksu granite. Based on thermomagnetic measurements, sphalerite and galena concentrates and tailings from the mine's mill contain hexagonal and monoclimc pyrrhotite. The postfolding characteristic remanent magnetization (ChRM), known thermal data, and paleoarc method of dating suggest that the Zn-Pb mineralization carries a primary chemical remanent magnetization (CRM), and Metaline Formation carbonates a secondary CRM that were acquired during the Middle Jurassic (166 ??6 Ma) during the waning stages of the Nevadan orogeny. A paleomagnetic breccia test favours a solution-collapse origin for the Josephine breccia. Finally, the Kaniksu paleopole is concordant with the North American Cretaceous reference paleopole, suggesting the Kootenay terrane has not been rotated since emplacement of the batholith at ???94 Ma. ?? 2007 NRC Canada.

  19. DNA methylation changes in Mexican children exposed to arsenic from two historic mining areas in San Luis potosí.

    PubMed

    Alegría-Torres, Jorge Alejandro; Carrizales-Yánez, Leticia; Díaz-Barriga, Fernando; Rosso-Camacho, Fernando; Motta, Valeria; Tarantini, Letizia; Bollati, Valentina

    2016-12-01

    Arsenic is a carcinogen and epimutagen that threatens the health of exposed populations worldwide. In this study, we examined the methylation status of Alu and long interspersed nucleotide elements (LINE-1) and their association with levels of urinary arsenic in 84 Mexican children between 6 and 12 years old from two historic mining areas in the State of San Luis Potosí, Mexico. Urinary arsenic levels were determined by atomic absorption spectrophotometry and DNA methylation analysis was performed in peripheral blood leukocytes by bisulfite-pyrosequencing. The geometric mean of urinary arsenic was 26.44 µg/g Cr (range 1.93-139.35). No significant differences in urinary arsenic or methylation patterns due to gender were observed. A positive correlation was found between urinary arsenic and the mean percentage of methylated cytosines in Alu sequences (Spearman correlation coefficient r = 0.532, P < 0.001), and a trend of LINE-1 hypomethylation was also observed (Spearman correlation coefficient r = -0.232, P = 0.038) after adjustment for sex and age. A linear regression model showed an association with log-normalized urinary arsenic for Alu (β = 1.05, 95% CI: 0.67; 1.43, P < 0.001) and LINE-1 (β = -0.703, 95% CI: -1.36; -0.38, P = 0.038). Despite the low-level arsenic exposure, a subtle epigenetic imbalance measured as DNA methylation was detected in the leukocytes of Mexican children living in two historic mining areas. Environ. Mol. Mutagen. 57:717-723, 2016. © 2016 Wiley Periodicals, Inc.

  20. Heavy metal concentrations in shallow marine sediments affected by submarine tailings disposal and artisanal gold mining, Buyat-Ratototok district, North Sulawesi, Indonesia

    NASA Astrophysics Data System (ADS)

    Edinger, Evan N.; Siregar, P. Raja; Blackwood, George M.

    2007-04-01

    Trace element concentrations in shallow marine sediments of the Buyat-Ratototok district of North Sulawesi, Indonesia, are affected by submarine disposal of industrial gold mine tailings and unregulated dumping of tailings and wastewater from small-scale gold mining using mercury amalgamation. Industrial mine tailings contained 590 690 ppm arsenic, 490 580 ppm antimony, and 0.8 5.8 ppm mercury. Tailings-affected sediment As and Sb concentrations were 20 30 times higher than in muddy sediments not contaminated with tailings, and 50 60 times higher than pre-mining average. Highest mercury concentrations were observed in sediments affected by small-scale mining using mercury amalgamation (5 29 ppm). Concentrations of most other trace elements were comparable in sediments affected by both types of mining and were slightly higher than regional averages for sediments collected before the onset of industrial mining. Elevated concentrations of both As and Sb in approximately equal proportions suggest tailings dispersal of at least 3.5 km. Mercury released from artisanal gold mining dispersed up to 4 km from river mouths. Slight increases in concentrations of non-mercury trace elements in areas affected by artisanal mining over pre-industrial mining concentrations were probably caused by increased rates of erosion.

  1. Mn oxides as efficient traps for metal pollutants in a polyphase low-temperature Pliocene environment: A case study in the Tamra iron mine, Nefza mining district, Tunisia

    NASA Astrophysics Data System (ADS)

    Decrée, Sophie; Ruffet, Gilles; De Putter, Thierry; Baele, Jean-Marc; Recourt, Philippe; Jamoussi, Fakher; Yans, Johan

    2010-05-01

    The Tamra mine, located in the Nefza mining district (NW Tunisia), exploits a 50 m-thick layer of Mio-Pliocene sediments that are heavily mineralized with Fe and other metals (Mn, Pb, Zn), especially in its eastern part, which is highly mineralized in Mn and known as the "manganiferous zone". The textural and geochemical studies of manganiferous minerals in the Tamra mine have allowed the determination of four main paragenetic stages. Stages 1 and 2 relate to the main pedogenetic event that gave rise to the currently exploited Fe ore deposit. The last two stages relate to mineralizing events closely connected with hydrothermal circulation and leaching of underlying mineralization of the Sidi Driss Pb-Zn sedex deposit, with subsequent crystallisation in the supergene environment. Stage 3 is characterized by the formation of massive romanechite, hollandite and Sr-cryptomelane, while stage 4 results in the formation of coronadite and chalcophanite. 39Ar- 40Ar analyses performed on hollandite (stage 3) and coronadite (stage 4) samples yielded ages of 4.7 ± 0.1 Ma and 3.35 ± 0.07 Ma, respectively. Tentative 39Ar- 40Ar analyses on chalcophanite provided aberrant results, due to the poor argon retention in this layer-structure mineral. The youngest age corresponds to the late phase of the late Alpine extension event in northern Tunisia, evidenced through an increased regional thermal gradient as well as by a N-S set of normal faults and fractures. The Tamra mine is obviously a polyphase mineral deposit, recording several distinct metal inputs, part of them originating from the underlying Sidi Driss Pb-Zn deposit, while another part is provided by hydrothermal circulations forced by the high thermal gradient. Three springs flowing from the Tamra ore series are regular sources for drinking water used by the local population. Although the Alpine thermal gradient could have facilitated extensive mixing between subsurface oxidizing meteoric fluids and deep reducing

  2. AGE AND ORIGIN OF BASE- AND PRECIOUS-METAL VEINS OF THE COEUR D'ALENE MINING DISTRICT, IDAHO

    SciTech Connect

    Fleck, R J; Criss, R E; Eaton, G F; Cleland, R W; Wavra, C S; Bond, W D

    2000-11-07

    Ore-bearing quartz-carbonate veins of the Coeur d'Alene mining district yield {sup 87}Sr/{sup 86}Sr ratios of 0.74 to >1.60 for low-Rb/Sr, carbonate gangue minerals, similar to current ranges measured in Middle Proterozoic, high-Rb/Sr rocks of the Belt Supergroup. Stable-isotope and fluid-inclusion studies establish a genetic relationship between vein formation and metamorphic-hydrothermal systems of the region. These extraordinary {sup 87}Sr/{sup 86}Sr ratios require accumulation of radiogenic {sup 87}Sr in a high Rb/Sr system over an extended period prior to incorporation of Sr into the veins by hydrothermal processes. Evaluation of the age and composition of potential sources of highly radiogenic Sr indicates that the ore-bearing veins of the Coeur d'Alene district formed within the last 200 Ma from components scavenged from sedimentary and metasedimentary rocks of the Belt Supergroup, the primary host-rocks of the district. These results are consistent with a Cretaceous or Early Tertiary age for these veins. Pb-Zn deposits that yield Pb isotope, K-Ar, and Ar-Ar results indicative of a Proterozoic age probably formed during deposition or diagenesis of the Belt Supergroup at 1350-1500 Ma, possibly as Sullivan-type syngenetic deposits. K-Ar and Rb-Sr apparent ages and {delta}{sup 18}O values of Belt Supergroup rocks decrease southward from the Coeur d'Alene district toward the Idaho batholith, normal to the trends of metamorphic isograds, fold axes, foliation, and the major reverse faults of the district. Isoclinal folding, thrust faulting, high-temperature metamorphism, granitic plutonism, and regional-scale metamorphic-hydrothermal activity is documented in the region between 140 Ma and 45 Ma, but no similar combination of events is recognized for Late Proterozoic time. Combined with Sr results from the veins, the evidence strongly favors formation of the ore-bearing carbonate veins of the district by fluids related to a complex metamorphic-hydrothermal system

  3. Preliminary investigation of the elemental variation and diagenesis of a tabular uranium deposit, La Sal Mine, San Juan County, Utah

    USGS Publications Warehouse

    Brooks, Robert A.; Campbell, John A.

    1976-01-01

    Ore in the La Sal mine, San Juan County, Utah, occurs as a typical tabular-type uranium deposit of the-Colorado Plateau. Uranium-vanadium occurs in the Salt Wash Member of the Jurassic Morrison Formation. Chemical and petrographic analyses were used to determine elemental variation and diagenetic aspects across the orebody. Vanadium is concentrated in the dark clay matrix, which constitutes visible ore. Uranium content is greater above the vanadium zone. Calcium, carbonate carbon, and lead show greater than fifty-fold increase across the ore zone, whereas copper and organic carbon show only a several-fold increase. Large molybdenum concentrations are present in and above the tabular layer, and large selenium concentrations occur below the uranium zone within the richest vanadium zone. Iron is enriched in the vanadium horizon. Chromium is depleted from above the ore and strongly enriched below. Elements that vary directly with the vanadium content include magnesium, iron, selenium, zirconium, strontium, titanium, lead, boron, yttrium, and scandium. The diagenetic sequence is as follows: (1) formation of secondary quartz overgrowths as cement; (2) infilling and lining of remaining pores with amber opaline material; (3) formation of vanadium-rich clay matrix, which has replaced overgrowths as well as quartz grains; (4) replacement of overgrowths and detrital grains by calcite; (5) infilling of pores with barite and the introduction of pyrite and marcasite.

  4. Exploring Land use and Land cover change in the mining areas of Wa East District, Ghana using Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Basommi, Prosper Laari; Guan, Qingfeng; Cheng, Dandan

    2015-11-01

    Satellite imagery has been widely used to monitor the extent of environmental change in both mine and post mine areas. This study uses Remote sensing and Geographical Information System techniques for the assessment of land use/land cover dynamics of mine related areas in Wa East District of Ghana. Landsat satellite imageries of three different time periods, i.e., 1991, 2000 and 2014 were used to quantify the land use/cover changes in the area. Supervised Classification using Maximum Likelihood Technique in ERDAS was utilized. The images were categorized into five different classes: Open Savannah, Closed Savannah, Bare Areas, Settlement and Water. Image differencing method of change detection was used to investigate the changes. Normalized Differential Vegetative Index valueswere used to correlate the state of healthy vegetation. The image differencing showed a positive correlation to the changes in the Land use and Land cover classes. NDVI values reduced from 0.48 to 0.11. The land use change matrix also showed conversion of savannah areas into bare ground and settlement. Open and close savannah reduced from 50.80% to 36.5% and 27.80% to 22.67% respectively whiles bare land and settlement increased. Overall accuracy of classified 2014 image and kappa statistics was 83.20% and 0.761 respectively. The study revealed the declining nature of the vegetation and the significance of using satellite imagery. A higher resolution satellite Imagery is however needed to satisfactorily delineate mine areas from other bare areas in such Savannah zones.

  5. Oral Health Status of Underground Coal Mine Workers of Ramakrishnapur, Adilabad District, Telangana, India - A Cross-Sectional Study

    PubMed Central

    Abbas, Irram; Mohammad, Shakeel Anjum; Peddireddy, Parthasarathi Reddy; Mocherla, Monica; Koppula, Yadav Rao

    2016-01-01

    Introduction Standard of living and quality of life of people has been improved by the expanding industrial activity, but at the other end it has created many occupational hazards. Coal mining is one of the major age old industries throughout the world and in India. Till date very less literature is available worldwide and in India concerning the oral health status of laborers in this field. Aim To assess the oral health status of underground coal mine workers, oral hygiene practices, alcohol and tobacco habits. Materials and Methods A cross-sectional descriptive study was conducted among the underground coal mine workers of a coal mine located in Adilabad district, Telangana, according to the criteria described in the World Health Organization (WHO) Oral Health Assessment form (2013). Statistical analysis Descriptive statistics were done. Results A total of 356 workers participated in the study. Ninety percent of the subjects were with tobacco and/or alcohol habits. Dental caries was prevalent in more than half (55.6%) of the study subjects with a mean DMFT of 2.32±2.99. About 48.3% study subjects were with untreated dental caries and 20.3% subjects were with missing teeth. DMFT ≤=6 was seen in 45.5% of subjects and 10.1% have DMFT scores ≥=7. Periodontal disease was the most prevalent condition seen in the population with 94.4% subjects having unhealthy periodontium in terms of gingival bleeding and/or periodontal pockets. About 186 (52.25%) and 145 (40.73%) of subjects were with 0-3mm and 4-5mm loss of attachment respectively. Fourteen percent of population showed dental traumatic injuries. Conclusion The findings highlighted the high caries prevalence, higher periodontal disease, traumatic injuries which requires immediate intervention. PMID:26894171

  6. Toxic metal dispersion in mining areas: from point source to diffusion pollution. The case of the Mt. Amiata Hg mining district (Southern Tuscany - Italy): new results.

    NASA Astrophysics Data System (ADS)

    Colica, Antonella; Chiarantini, Laura; Rimondi, Valentina; Benvenuti, Marco; Costagliola, Pilario; Lattanzi, Pierfranco; Paolieri, Mario; Rinaldi, Massimo

    2016-04-01

    Rivers draining mining areas may contribute to the diffusion of contaminants through their dispersion and accumulation into different morphological river units. The Paglia River's catchment (southern Tuscany) hosts the SE portion of the Mt. Amiata mercury district, the third most important worldwide (exploited from 1880 to 1980 with a total production of 100,000 tonnes Hg) before becoming a tributary of the Tiber River, which directly flows into Mediterranean Sea. The goals of this study are: 1) to recognize and distinguish different morphological units along the Paglia River watercourse, 2) to determine spatial/temporal distribution and concentration of Hg (and other toxic elements, particularly As) in different units. The analysis of morphological units was made by mapping their evolution from the beginning of mining activity (1883) to present day along 43 km of the Paglia watercourse defining eleven morphological sections across this river, and one across one of its tributaries, the Siele Creek, which drains various Hg mines located upstream. Four fundamental morphological/sedimentary unit types have been distinguished: stream sediments, bar, floodplain, and terraces. The latter occur in various orders and age: Pleistocenic, pre-mining (i.e., dating before 1880), and coeval to the mining activity. A total of 100 samples were taken from the various units in the selected transects, georeferenced and then analyzed for their Hg and As contents by ICP-OES. Arsenic contents generally never exceed 10 mg/kg. The observed ranges are: stream sediments 4.1÷8.2 mg/kg; bars 4.1÷6.6 mg/kg; floodplains 3.8÷6.6 mg/kg; terrace coeval with mining activity 3.2÷10.1 mg/kg. Hg contents in present-day stream sediments and bars are extremely variable (0.2÷27.5 and 1.4÷22.4 mg/kg respectively), and show a sharp increase at the confluence with Siele Creek. Floodplain sediments may reach up to 98 mg/kg. Terraces coeval with mining activity also show variable Hg contents (0.1÷66

  7. Geochemical investigations and interim recommendations for priority abandoned mine sites on U.S.D.A. Forest Service lands, Mineral Creek watershed, San Juan County, Colorado

    USGS Publications Warehouse

    Nash, J.T.

    1999-01-01

    Field observations, sampling of mine dumps and mine drainage waters, and laboratory studies of dump materials have been made at mining areas deemed to be on public lands administered by the USDA Forest Service in the Mineral Creek watershed. Results of chemical analyses of dump materials, leachates of those materials, and of surface waters draining mines or dumps provide indications of where acid is generated or consumed, and what metals are mobilized below mines or dumps. Information on 25 sites is reviewed and reclamation priorities are ranked into four classes (high, medium, low priority, or no work required). The western side of the upper Animas watershed (the Mineral Creek watershed) has a history of mining and prospecting for about 130 years. The intensity of miningrelated disturbance is higher than in most parts of the San Juan Mountains region, but actually is much less than the eastern half of the watershed (US BLM lands) and none of the mines moved millions of tons of rock and ore as in some of the eastern mines. The majority of the roughly one thousand mining sites on the USFS lands are very small (less than 100 tons or 70 cubic yards of dump material), are more than 2 miles from a major stream, or are so inaccessible as to prohibit reclamation. Twenty five sites have been considered by others to have significant size and potential for significant environmental degradation. These most significant mining areas were evaluated by multiple criteria, including tendency to generate acid or liberate toxic metals, observed acidic pH or dead vegetation (?kill zones?) below dumps or adits, potential mobility of metals, and likelihood of transport into streams of the watershed. In the author?s opinion, no single measurable parameter, such as metal concentration, is reliable for ranking significance or feasibility of reclamation. Rather, subjective estimates are required to evaluate combinations of, or interactions among, several parameters. The most subjective

  8. Terlinguacreekite, Hg32+O2 Cl2, a new mineral species from the Perry pit, Mariposa mine, Terlingua mining district, Brewster County, Texas, U.S.A

    USGS Publications Warehouse

    Roberts, Andrew C.; Gault, Robert A.; Paar, W.H.; Cooper, M.A.; Hawthorne, F.C.; Burns, P.C.; Cisneros, S.; Foord, E.E.

    2005-01-01

    Terlinguacreekite, ideally Hg32+O2 Cl2, has a very pronounced subcell that is orthorhombic, space-group choices Imam, Imcm, Ima2 and 12cm, with unit-cell parameters refined from powder data: a 6.737(3), b 25.528(10), c 5.533(2) A??, V951.6(6) A??3, a:b:c 0.2639:1:0.2167, Z=8. The true symmetry, supercell unit-cell parameters, and details regarding the crystal structure are unknown. The strongest nine lines of the X-ray powder-diffraction pattern [d in A?? (I)(subcell hkl)] are: 5.413(30)(011), 4.063(80)(121), 3.201(50)(080), 3.023(50)(161), 2.983(60)(240), 2.858(30)(211), 2.765(50)(002), 2.518(100b)(091, 251) and 2.026(30)(242). The mineral is found in an isolated area measuring approximately 1 ?? 0.5 m in the lower level of the Perry pit, Mariposa mine, Terlingua mining district, Brewster County, Texas (type locality), as mm-sized anhedral dark orange to reddish orange crusts of variable thickness on calcite, and rarely as 0.5 mm-sized aggregates of crystals of the same color. It has also been identified at the McDermitt mine, Humboldt County, Nevada, U.S.A., where it occurs with kleinite and calomel in silicified volcanic rocks and sediments. Terlinguacreekite is a secondary phase, most probably formed from the alteration of primary cinnabar or native mercury. At Terlingua, most crusts are thin, almost cryptocrystalline, with no discernable forms, and are resinous and translucent to opaque. Crystals are up to 0.2 mm in length, subhedral, acicular to prismatic, elongation [001], with a maximum length-to-width ratio of 4:1. They are vitreous, transparent, and some crystals have brightly reflecting faces, which may be {010} and {110}. The streak is yellow, and the mineral is brittle with an uneven fracture, no observable cleavage, and is soft, nonfluorescent under both long- and short-wave ultraviolet light. D (calc.) is 9.899 g/cm3 (empirical formula). Material from the McDermitt mine is reversibly photosensitive, and turns from vivid orange to black in strong

  9. Isotopically constrained lead sources in fugitive dust from unsurfaced roads in the southeast Missouri mining district

    USGS Publications Warehouse

    Witt, Emitt C.; Pribil, Michael; Hogan, John P; Wronkiewicz, David

    2016-01-01

    The isotopic composition of lead (Pb) in fugitive dust suspended by a vehicle from 13 unsurfaced roads in Missouri was measured to identify the source of Pb within an established long-term mining area. A three end-member model using 207Pb/206Pb and concentration as tracers resulted in fugitive dust samples plotting in the mixing field of well characterized heterogeneous end members. End members selected for this investigation include the 207Pb/206Pb for 1) a Pb-mixture representing mine tailings, 2) aerosol Pb-impacted soils within close proximity to the Buick secondary recycling smelter, and 3) an average of soils, rock cores and drill cuttings representing the background conditions. Aqua regia total concentrations and 207Pb/206Pb of mining area dust suggest that 35.4–84.3% of the source Pb in dust is associated with the mine tailings mixture, 9.1–52.7% is associated with the smelter mixture, and 0–21.6% is associated with background materials. Isotope ratios varied minimally within the operational phases of sequential extraction suggesting that mixing of all three Pb mixtures occurs throughout. Labile forms of Pb were attributed to all three end members. The extractable carbonate phase had as much as 96.6% of the total concentration associated with mine tailings, 51.8% associated with smelter deposition, and 34.2% with background. The next most labile geochemical phase (Fe + Mn Oxides) showed similar results with as much as 85.3% associated with mine tailings, 56.8% associated with smelter deposition, and 4.2% associated with the background soil.

  10. Sources and fate of mercury pollution in Almadén mining district (Spain): Evidences from mercury isotopic compositions in sediments and lichens.

    PubMed

    Jiménez-Moreno, María; Barre, Julien P G; Perrot, Vincent; Bérail, Sylvain; Rodríguez Martín-Doimeadios, Rosa C; Amouroux, David

    2016-03-01

    Variations in mercury (Hg) isotopic compositions have been scarcely investigated until now in the Almadén mining district (Spain), which is one of the most impacted Hg areas worldwide. In this work, we explore and compare Hg isotopic signatures in sediments and lichens from Almadén mining district and its surroundings in order to identify and trace Hg aquatic and atmospheric contamination sources. No statistically significant mass independent fractionation was observed in sediments, while negative Δ(201)Hg values from -0.12 to -0.21‰ (2SD = 0.06‰) were found in lichens. A large range of δ(202)Hg values were reported in sediments, from -1.86 ± 0.21‰ in La Serena Reservoir sites far away from the pollution sources to δ(202)Hg values close to zero in sediments directly influenced by Almadén mining district, whereas lichens presented δ(202)Hg values from -1.95 to -0.40‰ (2SD = 0.15‰). A dilution or mixing trend in Hg isotope signatures versus the distance to the mine was found in sediments along the Valdeazogues River-La Serena Reservoir system and in lichens. This suggests that Hg isotope fingerprints in these samples are providing a direct assessment of Hg inputs and exposure from the mining district, and potential information on diffuse atmospheric contamination and/or geochemical alteration processes in less contaminated sites over the entire hydrosystem. This study confirms the applicability of Hg isotope signatures in lichens and sediments as an effective and complementary tool for tracing aquatic and atmospheric Hg contamination sources and a better constraint of the spatial and temporal fate of Hg released by recent or ancient mining activities.

  11. Metal-residence sites in mine tailings in the Magdalena District, New Mexico, USA

    SciTech Connect

    Larocque, A.C.L.; Chapin, C.E.; Laughlin, A.W.; Hickmott, D.

    1996-05-01

    Mineralization in the Kelly Mining Camp is hosted by the Mississippian Kelly Limestone and comprises Zn-Pb skarn, replacement, and vein deposits related to Tertiary intrusive activity. The ore consists of primary (hypogene) sulfide mineralization which has been oxidized near surface to form secondary (supergene) mineralization. A zone of secondary sulfide-enrichment separates the sulfide and oxide ores. Mine tailings in the camp contain primary sulfide, oxide and gangue minerals, secondary (supergene) minerals formed during weathering of the primary ore, and tertiary minerals formed by alteration of hypogene and supergene assemblages after deposition in the tailings impoundment.

  12. Age and origin of base and precious metal veins of the Coeur d'Alene mining district, Idaho

    USGS Publications Warehouse

    Fleck, R.J.; Criss, R.E.; Eaton, G.F.; Cleland, R.W.; Wavra, C.S.; Bond, W.D.

    2002-01-01

    Ore-bearing quartz-carbonate veins of the Coeur d'Alene mining district yield 87Sr/86Sr ratios of 0.74 to >1.60 for low Rb/Sr, carbonate gangue minerals, similar to current ranges measured in Middle Proterozoic, high Rb/Sr rocks of the Belt Supergroup. Stable isotope and fluid inclusion studies establish a genetic relationship between vein formation and metamorphic-hydrothermal systems of the region. These extraordinary 87Sr/86Sr ratios require accumulation of radiogenic 87Sr in a high Rb/Sr system over an extended period prior to incorporation of Sr into the hydrothermal veins. Evaluation of the age and composition of potential sources of highly radiogenic Sr indicates that the ore-bearing veins of the Coeur d'Alene district formed during the Cretaceous from components scavenged from rocks of the Belt Supergroup, the primary host rocks of the district. Proterozoic Pb isotope ratios observed in galena from many Coeur d'Alene veins were established when Pb separated from uranium during deposition or diagenesis of the Belt Supergroup at 1400 to 1500 Ma, possibly as disseminated syngenetic deposits. K-Ar and Rb-Sr apparent ages and ??18O values of Belt Supergroup rocks decrease from the Coeur d'Alene district toward the Idaho and Kaniksu batholiths, approximately normal to the trends of metamorphic isograds, fold axes, foliation, and the major reverse faults of the district. Isoclinal folding, thrust faulting, high-temperature metamorphism, granitic plutonism, and regional-scale metamorphic-hydrothermal activity is documented in the region between 140 and 45 Ma, representing the only such combination of events in the Coeur d'Alene region subsequent to about 1300 Ma. The Sr and oxygen results and geologic evidence favor formation of the ore-bearing carbonate veins by fluids related to a complex metamorphic-hydrothermal system during the Cretaceous. Pb with Proterozoic isotopic compositions was probably mobilized and incorporated like other metals into the hydrothermal

  13. Soil quality assessment using GIS-based chemometric approach and pollution indices: Nakhlak mining district, Central Iran.

    PubMed

    Moore, Farid; Sheykhi, Vahideh; Salari, Mohammad; Bagheri, Adel

    2016-04-01

    This paper is a comprehensive assessment of the quality of soil in the Nakhlak mining district in Central Iran with special reference to potentially toxic metals. In this regard, an integrated approach involving geostatistical, correlation matrix, pollution indices, and chemical fractionation measurement is used to evaluate selected potentially toxic metals in soil samples. The fractionation of metals indicated a relatively high variability. Some metals (Mo, Ag, and Pb) showed important enrichment in the bioavailable fractions (i.e., exchangeable and carbonate), whereas the residual fraction mostly comprised Sb and Cr. The Cd, Zn, Co, Ni, Mo, Cu, and As were retained in Fe-Mn oxide and oxidizable fractions, suggesting that they may be released to the environment by changes in physicochemical conditions. The spatial variability patterns of 11 soil heavy metals (Ag, As, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, and Zn) were identified and mapped. The results demonstrated that Ag, As, Cd, Mo, Cu, Pb, Sb, and Zn pollution are associated with mineralized veins and mining operations in this area. Further environmental monitoring and remedial actions are required for management of soil heavy metals in the study area. The present study not only enhanced our knowledge regarding soil pollution in the study area but also introduced a better technique to analyze pollution indices by multivariate geostatistical methods.

  14. An ecosystem approach to evaluate restoration measures in the lignite mining district of Lusatia/Germany

    NASA Astrophysics Data System (ADS)

    Schaaf, Wolfgang

    2015-04-01

    Lignite mining in Lusatia has a history of over 100 years. Open-cast mining directly affected an area of 1000 km2. Since 20 years we established an ecosystem oriented approach to evaluate the development and site characteristics of post-mining areas mainly restored for agricultural and silvicultural land use. Water and element budgets of afforested sites were studied under different geochemical settings in a chronosequence approach (Schaaf 2001), as well as the effect of soil amendments like sewage sludge or compost in restoration (Schaaf & Hüttl 2006). Since 10 years we also study the development of natural site regeneration in the constructed catchment Chicken Creek at the watershed scale (Schaaf et al. 2011, 2013). One of the striking characteristics of post-mining sites is a very large small-scale soil heterogeneity that has to be taken into account with respect to soil forming processes and element cycling. Results from these studies in combination with smaller-scale process studies enable to evaluate the long-term effect of restoration measures and adapted land use options. In addition, it is crucial to compare these results with data from undisturbed, i.e. non-mined sites. Schaaf, W., 2001: What can element budgets of false-time series tell us about ecosystem development on post-lignite mining sites? Ecological Engineering 17, 241-252. Schaaf, W. and Hüttl, R. F., 2006: Direct and indirect effects of soil pollution by lignite mining. Water, Air and Soil Pollution - Focus 6, 253-264. Schaaf, W., Bens, O., Fischer, A., Gerke, H.H., Gerwin, W., Grünewald, U., Holländer, H.M., Kögel-Knabner, I., Mutz, M., Schloter, M., Schulin, R., Veste, M., Winter, S. & Hüttl, R.F., 2011: Patterns and processes of initial terrestrial-ecosystem development. Journal of Plant Nutrition and Soil Science, 174, 229-239. Schaaf, W., Elmer, M., Fischer, A., Gerwin, W., Nenov, R., Pretsch, H. and Zaplate, M.K., 2013: Feedbacks between vegetation, surface structures and hydrology

  15. Assessing spatial occurrence of ground level ozone around coal mining areas of Chandrapur District, Maharashtra, India.

    PubMed

    Salve, Pradeep R; Satapathy, Deepty Ranjan; Katpatal, Yashwant B; Wate, Satish R

    2007-10-01

    Stratospheric input and photochemical ozone formation in the troposphere are the two main sources determining the ozone levels in the surface layer of the atmosphere. Because of the importance of ozone in controlling the atmospheric chemistry and its decisive role in the heat balance of atmosphere, leading to climate change, the examination of its formation and destruction are of great interest. This study characterized the distribution of Ground level Ozone (GLO) in Chandrapur district is lying between 19 degrees 25'N to 20 degrees 45'N and 78 degrees 50'E to 80 degrees 10'E. Continuous ozone analyzer was used to quantify GLO at thirteen locations fixed by Global Positioning System (GPS) during the winter of 2005-2006. The daily GLO at all the locations ranged between 6.4 and 24.8 ppbv with an average and standard deviation of 14.9 +/- 6.5 ppbv. The maximum and minimum concentration occurs during 1300-1600 h and 0300-0500 h may be due to high solar radiation facilitating photochemical production of O(3) and downward mixing from the overlying air mass and in situ destruction of ozone by deposition and/or the reaction between O(3) and NO. GIS based spatial distribution of GLO in Chandrapur district is indicates that the central core of the district and southern sites experienced elevated levels of GLO relative to the northern and western areas. The sites near by Chandrapur city are particularly affected by elevated GLO. The average variation of GLO with temperature shows a significant correlation of r = 0.55 indicating a direct relationship between GLO and temperature. Similarly an attempt has been made to compare the GLO monitored data in Chandrapur district with the reported values for other locations in Indian cities. This generated database helps regulatory agencies to identify locations where the natural resources and human health could be at risk.

  16. A Review of the Proposed North County Center in Paso Robles--An Educational Center of the San Luis Obispo County Community College District. Commission Report 97-5.

    ERIC Educational Resources Information Center

    California State Postsecondary Education Commission, Sacramento.

    This three-part report presents the recommendations of the California Postsecondary Education Commission on a proposal by the San Luis Obispo County Community College District (SLOCCCD) to create an educational center in the City of Paso Robles. Part 1 provides the Commission's conclusions and recommendations, indicating that, based on a needs…

  17. Geochemical Results of Lysimeter Sampling at the Manning Canyon Repository in the Mercur Mining District, Utah

    USGS Publications Warehouse

    Earle, John; Choate, LaDonna

    2010-01-01

    This report presents chemical characteristics of transient unsaturated-zone water collected by lysimeter from the Manning Canyon repository site in Utah. Data collected by U.S. Geological Survey and U.S. Department of the Interior, Bureau of Land Management scientists under an intragovernmental order comprise the existing body of hydrochemical information on unsaturated-zone conditions at the site and represent the first effort to characterize the chemistry of the soil pore water surrounding the repository. Analyzed samples showed elevated levels of arsenic, barium, chromium, and strontium, which are typical of acidic mine drainage. The range of major-ion concentrations generally showed expected soil values. Although subsequent sampling is necessary to determine long-term effects of the repository, current results provide initial data concerning reactive processes of precipitation on the mine tailings and waste rock stored at the site and provide information on the effectiveness of reclamation operations at the Manning Canyon repository.

  18. Environmental impact of uranium mining and ore processing in the Lagoa Real District, Bahia, Brazil.

    PubMed

    Carvalho, Ilson G; Cidu, Rosa; Fanfani, Luca; Pitsch, Helmut; Beaucaire, Catherine; Zuddas, Pierpaolo

    2005-11-15

    Uranium mining and processing at Lagoa Real (Bahia, Brazil) started in 2000. Hydrogeochemical monitoring carried out from 1999 to 2001 revealed generally good quality of the water resources outside and inside the mineralized area. No chemical contamination in waters for domestic uses was observed. Hydrochemical characteristics did not vary significantly after 1 year of U exploitation, as compared to premining conditions. Due to the short time of mining, the results cannot exclude future variations in water quality. Leaching experiments helped to describe processes of ore and waste degradation. Sulfate was identified as an indicator for different types of contamination. Potential hazards related to local climate (hot rainy season) were identified. They indicate that tailings derived from the ore processing, destabilized by sulfuric acid attack, may induce acidification and salinization in the surrounding environment. Another potential source of environmental impact could be linked to local radium-rich mineralization, originating radon emission.

  19. Phytoremediation potential of some agricultural plants on heavy metal contaminated mine waste soils, salem district, tamilnadu.

    PubMed

    Padmapriya, S; Murugan, N; Ragavendran, C; Thangabalu, R; Natarajan, D

    2016-01-01

    The Pot culture experiment performed for phytoextraction potential of selected agricultural plants [millet (Eleusine coracana), mustard (Brassica juncea), jowar (Sorghum bicolor), black gram (Vigna mungo), pumpkin (Telfairia occidentalis)] grown in metal contaminated soils around the Salem region, Tamilnadu, India. Physiochemical characterization of soils, reported as low to medium level of N, P, K was found in test soils. The Cr content higher in mine soils than control and the values are 0.176 mg/L in Dalmia soil and 0.049 mg/L in Burn & Co soil. The germination rate low in mine soil than control soils (25 to 85%). The content of chlorophyll, carotenoid, carbohydrate and protein decreased in mine soils than control. The morphological parameters and biomass values decreased in experimental plants due to metal accumulation. Proline content increased in test plants and ranged from 0.113 mg g(-1) to 0.858 mg g(-1) which indicate the stress condition due to toxicity of metals. Sorghum and black gram plants reported as metal tolerant capacity. Among the plants, Sorghum produced good results (both biomass and biochemical parameters) which equal to control plant and suggests Sorghum plant is an ideal for remediation of metal contaminated soils.

  20. Mercury distribution in the soil-plant-air system at the Wanshan mercury mining district in Guizhou, Southwest China.

    PubMed

    Wang, Jianxu; Feng, Xinbin; Anderson, Christopher W N; Zhu, Wei; Yin, Runsheng; Wang, Heng

    2011-12-01

    The level of mercury bioaccumulation in wild plants; the distribution of bioavailable Hg, elemental Hg, and total Hg in soil; and the concentration of total gaseous Hg (TGM) in ambient air was studied at three different mining sites (SiKeng [SK], WuKeng [WK], and GouXi [GX]) in the Wanshan mercury mining district of China. Results of the present study showed that the distribution of soil total Hg, elemental Hg, bioavailable Hg, and TGM varies across the three mining sites. Higher soil total Hg (29.4-1,972.3 mg/kg) and elemental Hg (19.03-443.8 mg/kg) concentrations were recorded for plots SK and WK than for plot GX. Bioavailable Hg was lower at plot SK and GX (SK, 3-12 ng/g; GX, 9-14 ng/g) than at plot WK (11-1,063 ng/g), although the TGM concentration in the ambient air was significantly higher for plot GX (52,723 ng/m(3) ) relative to WK (106 ng/m(3) ) and SK (43 ng/m(3)). Mercury in sampled herbage was elevated and ranged from 0.8 to 4.75 mg/kg (SK), from 2.17 to 34.38 mg/kg (WK), and from 47.45 to 136.5 mg/kg (GX). Many of the sampled plants are used as fodder or for medicinal purposes. High shoot Hg concentrations may therefore pose an unacceptable human health risk. Statistical analysis of the recorded data showed that the Hg concentration in plant shoots was positively correlated with TGM and that the Hg concentration in roots was positively correlated with the bioavailable Hg concentration in the soil. The bioaccumulation factor (BAF) in the present study was defined with reference to the concentration of bioavailable Hg in the soil (Hg([root]) /Hg([bioavail])). Three plant species, Macleaya cordata L., Achillea millefolium L., and Pteris vittata L., showed enhanced accumulation of Hg and therefore may have potential for use in the phytoremediation of soils of the Wanshan mining area.

  1. The geology and mineral deposits of part of the western half of the Hailey 1 degree x 2 degrees quadrangle, Idaho; with sections on the Neal mining district and the Dixie mining district

    USGS Publications Warehouse

    Bennett, Earl H.

    2001-01-01

    hundred mines and prospects in 18 mining districts. The deposits range in age from Cretaceous to Eocene, and many were developed for precious metals. Most of the deposits are in quartz veins in shear zones in granitic rocks of the batholith. Several districts were actively being explored for low-grade, bulk-minable, precious-metal deposits in the late 1980s and early 1990s.

  2. Mineralogy and trace element relative solubility patterns of shallow marine sediments affected by submarine tailings disposal and artisanal gold mining, Buyat-Ratototok district, North Sulawesi, Indonesia

    NASA Astrophysics Data System (ADS)

    Blackwood, George M.; Edinger, Evan N.

    2007-04-01

    Shallow marine sediments of the Buyat-Ratototok district of North Sulawesi, Indonesia, are affected by submarine disposal of industrial gold mine tailings and small-scale gold mining using mercury amalgamation. Industrial mine tailings contained 590 660 ppm arsenic, 490 580 ppm antimony, and 0.8 5.8 ppm mercury. Electron microprobe survey found both colloidal iron arsenic-phases without sulphur and arsenian pyrite in tailings and sites to which tailings had dispersed, but only arsenopyrite in sediments affected by artisanal mining. Antimony in tailings was present as antimony oxides, colloidal iron antimony phases, colloidal iron antimony phases, and stibnite in sediments affected by both types of mining. A sequential extraction found that 2% of arsenic held in tailings and tailings-contaminated sediments was exchangeable, 20 30% was labile, including weakly adsorbed, carbonate- and arsenate bound, 20 30% was metastable, probably incorporated into iron or manganese oxyhydroxides, or strongly adsorbed to silicate minerals, and 40 48% was relatively insoluble, probably incorporated into sulphides or silicates. Arsenic in sediments affected by artisanal gold mining was 75 95% relatively insoluble. Antimony in all sediments was >90% relatively insoluble. Relative solubility patterns of most other metals did not differ between industrial tailings-affected, artisanal-mining affected areas, and fluvial sediments. Results suggest that submarine tailings disposal is not suitable for refractory Carlin-like gold deposits because ore processing converts arsenic to forms unstable in anoxic marine sediments.

  3. Trace element content of gossans at four mines in the West Shasta massive sulfide district.

    USGS Publications Warehouse

    Sanzolone, R.F.; Domenico, J.A.

    1985-01-01

    Paired analyses of the spongy whole-rock gossan and its botryoidal crust ("chipped rock rind') show little differences, whereas duplicate samples of each at individual sites show such extreme differences as to preclude the use of the data in areal mapping. Gossans from disseminated sulphides have lower and less variable trace-element contents than gossans from massive sulphides, due in part to dilution by rock silicates. Computer reduction of the data by a regionalizing algorithm enables determination of pattern differences among the four mines.-G.J.N.

  4. Letters to the state of Utah, the Ten Tribes Partnership, the Southern Ute Indian Tribe and the Ute Mountain Tribe about potentially adding the Bonita Peak Mining District to the Superfund National Priorities List (NPL)

    EPA Pesticide Factsheets

    Feb. 23, 2016: added letters to the state of Utah, the Ten Tribes Partnership, the Southern Ute Indian Tribe and the Ute Mountain Tribe about adding the Bonita Peak Mining District to the Superfund National Priorities List (NPL).

  5. Low-Enthalpy Geothermal Potential of the Czech Republic with Particular Focus on Waters of Metalliferous Mining Districts in Crystalline Structures of the Bohemian Massif

    NASA Astrophysics Data System (ADS)

    Stibitz, M.; Jirakova, H.; Frydrych, V.

    2012-04-01

    Nowadays, numerous underground mines in the Czech Republic are mostly left to spontaneous natural flooding with water. These huges volumes and favourable water temperature represent promissing source of thermal energy. The primary temperature of the mine waters is given by the rock massif temeprature, i.e. by the heat flux which is in the moldanubikum region around 50 - 60 mWm-2 (Michálek et al., 2007). Higher heat flux has been observed in several mountainous regions throughout the country. The real water temperature results form the depth of mines, geothermal gradient and the water circulation in the mine. Temperature measurements suggest a distinct temperature depth stratification. Several metalliferous mining districts in Crystalline Structures with the water outflow exceeding 1 Ls-1 have been subject of investigation. The temperature was not the only determining factoras it is relatively stable in mines all year round. The data on yield, temperatures, etc. prepared for further mathematical modeling were primarily measured in uranium and oremines in Příbram mining district, Jáchymov, Zlaté Hory and Rožná. Water of about 18°C and radioactivity make favourable condition for the Jáchymov spa purposes. The average yield reaches 20 Ls-1. The entire outflow for the Jáchymov mines before its decommissioning reached 136 Ls-1.The entire heat capacity of mine waters is supposed to be around 1.150 kW. Severa l galleries in Zlaté Hory region could be used for thermal purposes. The yield around 60 Ls-1 and temeperature around 7°C was observed in the main drainage gallery. Measurements were accompanied by chemical analysis of water having both a huge pH range from 3 to 9 and huge mineralization range from 135 to 6 500 mgL-1. The Rožná and Příbram conditions are quite similar with the outflow from 20 - 45 Ls-1 and temperatures from 11 - 18°C. Possible temperature decrease originates from the fact that colder shallow groundwater will inflow into mine spaces

  6. Impact of mining activities on soils in a semi-arid environment: Sierra Almagrera district, SE Spain.

    PubMed

    Navarro, Andres; Collado, Diego; Carbonell, Montserrat; Sanchez, Juan A

    2004-12-01

    Field and laboratory-column studies were undertaken in order to investigate soil contamination derived from past mining activity in the Sierra Almagrera (SA) district in southeast Spain. The tailings, soil and sediment samples that were collected showed high concentrations of Ag, As, Ba, Cu, Pb, Sb and Zn when analyzed. The mean concentrations of these elements in the tailings were 29.8, 285.4, 54000, 57.7, 2687.5, 179.0 and 2269.0 ppm, respectively. In the soil samples these decreased to 14.3, 96.9, 24700, 37.5, 1859.1, 168.5 and 815.7 ppm, respectively. Geochemical analyses demonstrated high levels of As, Pb and Zn which were above the intervention values set forth in the Andalusian Regulations for Contaminated Soils for As (>50 ppm), Pb (>500 ppm) and Zn (>2000 ppm). Column experiments and mineralogical studies suggest that the dissolution of sulfates and other secondary phases, accumulated in soils and waste-sites during the dry season, acts to control the mobility of metals. The elution curves obtained from column experiments showed a mobilization of Ba, Cu, Pb and Zn, while a low mobility was seen for Ag, As and Sb.

  7. Gold-silver mining districts, alteration zones, and paleolandforms in the Miocene Bodie Hills Volcanic Field, California and Nevada

    USGS Publications Warehouse

    Vikre, Peter G.; John, David A.; du Bray, Edward A.; Fleck, Robert J.

    2015-09-25

      Based on volcanic stratigraphy, geochronology, remnant paleosurfaces, and paleopotentiometric surfaces in mining districts and alteration zones, present landforms in the Bodie Hills volcanic field reflect incremental construction of stratovolcanoes and large- to small-volume flow-domes, magmatic inflation, and fault displacements. Landform evolution began with construction of the 15–13 Ma Masonic and 13–12 Ma Aurora volcanic centers in the northwestern and northeastern parts of the field, respectively. Smaller volcanoes erupted at ~11–10 Ma in, between, and south of these centers as erosional detritus accumulated north of the field in Fletcher Valley. Distally sourced, 9.7–9.3 Ma Eureka Valley Tuff filled drainages and depressions among older volcanoes and was partly covered by nearly synchronous eruptives during construction of four large 10–8 Ma volcanoes, in the southern part of the field. The lack of significant internal fault displacement, distribution of Eureka Valley Tuff, and elevation estimates derived from floras, suggest that the Bodie Hills volcanic field attained present elevations mostly through volcano construction and magmatic inflation, and that maximum paleoelevations (>8,500 ft) at the end of large volume eruptions at ~8 Ma are similar to present elevations.

  8. Assessment of groundwater quality for irrigation: a case study from Bandalamottu lead mining area, Guntur District, Andhra Pradesh, South India

    NASA Astrophysics Data System (ADS)

    Nagaraju, A.; Sunil Kumar, K.; Thejaswi, A.

    2014-12-01

    Quality of water resources in the Bandalamottu area of Guntur District of Andhra Pradesh in South India is facing a serious challenge due to Pb mining. Therefore, 40 groundwater samples were collected from this area to assess their hydrogeochemistry and suitability for irrigation purposes. The groundwater samples were analyzed for distribution of chemical elements Ca2+, Mg2+, Na+, K+, HCO3 -, CO3 2-, F-, Cl-, and SO4 2-. It also includes pH, electrical conductivity, total hardness, non-carbonate hardness and total alkalinity. The parameters, such as sodium absorption ratio (SAR), adjusted SAR, sodium percentage, potential salinity, residual sodium carbonate, non-carbonate hardness, Kelly's ratio, magnesium ratio, permeability index, indices of base exchange (IBE) and Gibbs ratio were also calculated. The major hydrochemical facieses were Ca-HCO3, Ca-Na-HCO3 and Ca-Mg-Cl types. The result of saturation index calculated by Visual MINTEQ software combined with Gibbs diagram and IBE findings indicate that, dolomite and calcite dissolution and reverse ion exchange can be a major process controlling the water chemistry in the study area. The results also showed that the salinity (85 %, C3 class) and alkalinity due to high concentration of HCO3 - and CO3 - and low Ca:Mg molar ratio (97.5 %, <1), are the major problems with water for irrigation usage. As a result, the quality of the groundwater is not suitable for sustainable crop production and soil health without appropriate remediation.

  9. Lead, cadmium, and zinc concentrations in plaster and mortar from structures in Jasper and Newton Counties, Missouri (Tri-State Mining District).

    PubMed

    Perry, Phyllis M; Pavlik, Jeffrey W; Sheets, Ralph W; Biagioni, Richard N

    2005-01-05

    The primary goal of this study was to evaluate anecdotal evidence that within Jasper and Newton Counties, Missouri, two counties within the Tri-State Mining District, granular mine tailings were commonly used in place of river sands in wall plasters and mortar. Interior wall plaster and mortar samples from structures in this mining district were analyzed for lead, cadmium, and zinc, and compared to samples from Springfield, MO (comparison site). The Jasper and Newton County samples showed elevated concentrations of the three elements, consistent with the inclusion of mine tailings, with a number of samples containing lead and cadmium at concentrations greater than EPA remediation targets for yard soil. X-ray diffraction studies showed the presence of the zinc ore minerals, sphalerite and hemimorphite, in high level samples. Thin section optical studies identified the major component of the aggregate as chert, a mineral abundant within the tailing piles. Because dust from crumbling plaster and mortar could represent an avenue for significant heavy metal exposure to building occupants, we suggest that there may be associated health consequences that should be further evaluated.

  10. Structurally controlled volcanism and contrasting types of mineralization, Tuscarora mining district and vicinity, Nevada

    SciTech Connect

    Wright, B.A. ); Boden, D.R.; Struhsacker, E.M.

    1993-04-01

    The Tuscarora district lies within an Eocene volcanic field that covers [approximately]800 km[sup 2] in the northern Tuscarora Mountains in northwest Elko County. Geologic mapping of [approximately]100 km[sup 2] at Tuscarora and vicinity and new K-Ar age determinations reveal a complex, rapidly evolving volcanic history. Volcanism began with construction of a poorly preserved andesitic stratovolcano(s) at 42+ Ma. Subsequently, the 7- by 10-km Mt. Blitzen graben developed between 41--42 Ma. The graben filled with the tuff of Mt. Blitzen. Graben subsidence occurred along NE to ENE and NNW to NW faults, and a variety of dikes and plugs, including the 39.8-Ma Mt. Neva granodiorite, locally intruded the bounding faults. Rocks of the graben strike NE, dip moderately to steeply, and are cut by penecontemporaneous NE-striking dikes, indicating that the graben formed in response to NW-SE-directed extension. Collapse of the rhyolitic Big Cottonwood Canyon caldera truncated the northern part of the Mt. Blitzen graben between 40.6 and 41.0 Ma. Rocks of the Mt. Blitzen graben range from silicic andesite to rhyodacite, whereas rocks of the Big Cottonwood Canyon caldera are rhyolite and high-silica rhyolite. Mineralization at Tuscarora occurs near the southeast margin of the Mt. Blitzen graben and mainly as quartz-adularia veins filling ENE, N, and NW faults. New K-Ar analyses on adularia from the Dexter and Grand Prize veins yield ages of 38.9 and 39.9 Ma, respectively. Although closely developed in space and time, the Ag-rich, base-metal-bearing mineralization, characterized by the Grand Prize vein, and the Au-rich, base-metal-poor Dexter vein zone likely represent separate, unrelated hydrothermal events. In general, alteration in the district, as observed in outcrops and drill-hole cuttings, changes from fault or fracture controlled in the north to more pervasive in the Dexter pit area and eastward under pediment.

  11. Multifunctional greenway approach for landscape planning and reclamation of a post-mining district: Cartagena-La Unión, SE Spain

    NASA Astrophysics Data System (ADS)

    Acosta, Jose A.; Faz, Ángel; Zornoza, Raúl; Martínez-Martínez, Silvia; Kabas, Sebla; Bech, Jaume

    2015-04-01

    Fragmented structures create metaphorical wounds in the landscape altering the ecological and cultural processes associated with it, as it can be seen in many mine areas. Therefore it is advisable to organize the reclamation plan in the beginning of mine operating to provide spatial and functional integration of the landscape based on scientific arguments and with all possible legal and administrative means, which is generally the case of the Strategic Environmental Assessment. However, there are many abandon mine areas where no reclamation plan has been carried out, such as the case of Mining District of Sierra Minera Cartagena-La Unión, SE Spain. In these cases it is vital to respond in a sustainable manner for healing the landscape wounds of post-mining activities. Reclamation activities of a post-mining district includes not only the mine soils also all land uses around them, for this reason on necessary create practical solutions for returning the functions of ecologic and cultural processes of the area. Greenway approach shows the main veins which are crucial for keeping alive and sustaining the mentioned processes of the area. Therefore the main objectives of this study are to 1) develop an integrated local greenway network to be able to preserve significant resources and values of the district, and to 2) develop this greenway network as a part of reclamation process for degraded areas. Landscape assessments revealed the most valuable and potential connectivity resources of the area. These clustering and linear patterns of resource concentrations include mountain range and valleys, natural drainage network, legally protected areas and cultural-historical resources. Conservation areas, cultural-educational resources of post-mining activities and the riverbeds have been the main building stones for the greenway corridor. The multifunctional greenway approach serves as landscape reclamation and planning tool in a degraded area by showing the priority zones for

  12. Development of risk maps to minimize uranium exposures in the Navajo Churchrock mining district

    PubMed Central

    2009-01-01

    Background Decades of improper disposal of uranium-mining wastes on the Navajo Nation has resulted in adverse human and ecological health impacts as well as socio-cultural problems. As the Navajo people become increasingly aware of the contamination problems, there is a need to develop a risk-communication strategy to properly inform tribal members of the extent and severity of the health risks. To be most effective, this strategy needs to blend accepted risk-communication techniques with Navajo perspectives such that the strategy can be used at the community level to inform culturally- and toxicologically-relevant decisions about land and water use as well as mine-waste remediation. Objective The objective of this study was to develop GIS-based thematic maps as communication tools to clearly identify high risk exposure areas and offer alternatives to minimize public and ecological health impacts. Methods Thematic maps were produced that incorporated data derived from environmental sampling and public health surveys. The maps show the location and quality of unregulated water resources and identify regulated water sources that could be used as alternatives. In addition, the maps show the location of contaminated soil and sediment areas in which disturbance of surface deposits should be avoided. Preliminary feedback was collected from an informal Navajo working group to assess the clarity and efficacy of this proposed communication method. Results The working group found the maps to be both clear and effective, and made suggestions for improvements, such as the addition of more map features. The working group predicted that once the maps are presented to the public, water hauling and soil use behaviors will change, and dialogue with chapter officials will be initiated to accelerate further risk reduction efforts. Implications Because risk communication is complicated by language barriers, lack of infrastructure, and historical mistrust of non-Navajo researchers

  13. 77 FR 66548 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is approving revisions to the San Joaquin Valley Unified Air Pollution Control District... State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District's Rule 4352,...

  14. 77 FR 32493 - Approval of Air Quality Implementation Plans; California; San Joaquin Valley Unified Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... AGENCY 40 CFR Part 52 Approval of Air Quality Implementation Plans; California; San Joaquin Valley Unified Air Pollution Control District; Prevention of Significant Deterioration AGENCY: Environmental... submitted for the San Joaquin Valley Unified Air Pollution Control District (District) portion of...

  15. Assessment and comparison of 1976-77 and 2002 water quality in mineshafts in the Picher Mining District, northeastern Oklahoma and southeastern Kansas

    USGS Publications Warehouse

    DeHay, Kelli L.

    2003-01-01

    The Picher mining district was the site of lead and zinc mining from about 1900 to the mid-1970's. The primary sources of lead and zinc were the sulfide minerals, galena and sphalerite, disseminated in the cherty limestone of the Boone Formation. Water was pumped from the mines while still in operation; however, when mining ceased the mines began to fill with water. Elevated concentrations of metals with depth indicate there may be a substantial quantity of dissolved metals in the ground water. There is concern that the mine water may continue to seep to adjoining portions of the Boone aquifer and to creeks and streams in the area. Water was sampled from abandoned mineshafts in 2002 in the Picher mining area to assess water quality in the mines and to determine how water quality has changed since the late 1970s when similar sampling was conducted. Specific conductance in 2002 increased with depth in the mineshafts. The increases in specific conductance were very slight until the bottom 20 to 40 feet of the shaft where substantial increases occurred. The pH values in 2002 were generally uniform at the top of the water column and were generally neutral. The lowest pH values were measured at the base of most mineshafts. Concentrations of metals and major ions from samples in 2002 varied with depth and between shafts. Specific conductance in 2002 samples was less than in 1976-77 samples. The 1976-77 and 2002 data sets for pH had similar median values; however, the pH values from the 1976- 77 had a much greater range. Concentrations of metals, except copper, from water samples collected from the mineshafts in 2002 were significantly less than concentrations of metals from samples in 1976-77.

  16. Environmental assessment of mercury contamination from the Rwamagasa artisanal gold mining centre, Geita District, Tanzania.

    PubMed

    Taylor, H; Appleton, J D; Lister, R; Smith, B; Chitamweba, D; Mkumbo, O; Machiwa, J F; Tesha, A L; Beinhoff, C

    2005-05-01

    This study presents the results of an environmental assessment of mercury (Hg) contamination in the Rwamagasa artisanal gold mining area, northwest Tanzania, and the potential downstream dispersion along the River Malagarasi to Lake Tanganyika. At the time of sampling, generally low concentrations of Hg (<0.05 mg/kg) occurred in most cultivated soils although higher Hg (0.05-9.2 mg/kg) was recorded in urban soils and vegetable plot soils where these are impacted by Hg-contaminated water and sediment derived from mineral processing activities. Hg in vegetable and grain samples is mostly below the detection limit of 0.004 mg/kg Hg, apart from 0.007 and 0.092 mg/kg Hg in two yam samples and 0.011 to 0.013 mg/kg Hg in three rice samples. The standardized (i.e., standardized to 10 cm length) Hg concentrations in Clarias spp. increase from about 0.01 mg Hg/kg for the River Malagarasi delta to 0.07, 0.2, and 1.6 mg/kg, respectively, for the Rwamagasa 'background', moderately and most contaminated sites. For piscivorous (Lates, Brycinus, and Hydrocynus spp.), insectivorous (Barbus spp.), and planktivorous (Haplochromis spp.) fish species, the 10-cm standardized Hg concentrations increase from about 0.006 mg/kg for the River Malagarasi-Lake Tanganyika area to 0.5 and 3.5 mg/kg, respectively, for the Rwamagasa moderately and most contaminated sites. The low concentrations of Hg in fish from the Malagarasi River delta and Lake Tanganyika indicate that Hg contamination from the Rwamagasa area does not have a readily discernible impact on the biota of Lake Tanganyika. Many of the fish samples from Rwamagasa exceed guidelines for human consumption (0.5 mg/kg) as well as the WHO recommended limit for vulnerable groups (0.2 mg/kg). Tissue total Hg (THg) of all fish collected from the River Malagarasi-Lake Tanganyika subarea is well below these guidelines. Potential human exposure through consumption of 300 g/day of rice grown on Hg-contaminated soils is 5.5 microg

  17. Ecological and water quality impairment resulting from the New Idria Mercury Mine and natural sources in the San Carlos and Silver Creek watersheds, central California

    NASA Astrophysics Data System (ADS)

    Rytuba, J. J.; Hothem, R.; Goldstein, D.; Brussee, B.

    2011-12-01

    The New Idria Mercury Mine in central California is the second largest mercury (Hg) deposit in North America and has been proposed as a US EPA Superfund Site based on ecological impairment to the San Carlos and Silver Creek watersheds. Water, sediment, and biota were sampled in San Carlos Creek in the mine area and downstream for 25 km into the watershed termed Silver Creek. Release of acid rock drainage (ARD) and erosion of mine tailings have impacted the watershed during 120 years of mining and since the mine was closed in 1972. The watershed can be divided into three segments based on water and sediment composition, Hg sources and concentrations, and biodiversity of aquatic invertebrates. Creek waters in segment no. 1 above the mine area consist of Mg-Ca-CO3 meteoric water with pH 8.73. Hg concentrations are elevated in both sediment (100μg/g), and in waters (60 ng/L) because of erosion of Hg mine tailings in the upper part of the watershed. Invertebrate biodiversity is the highest of the sites sampled in the watershed, with seven families (six orders) of aquatic invertebrates collected and six other families observed. In the mine area isotopically heavy ARD (pH 2.7) with high levels of Fe(II), SO4, and total Hg (HgT: 76.7 ng/L) enters and mixes with meteoric creek water, constituting from 10-15% of the water in the 10-km long second creek segment downstream from the mine. Oxidation of Fe(II) from ARD results in precipitation of FeOOH which is transported and deposited as an Fe precipitate that has high Hg and MMeHg concentration (Hg: 15.7-79 μg/g, MMeHg: 0.31 - 1.06 ng/g). Concentrations of HgT are uniformly high (1530-2890 ng/L) with particulate Hg predominant. MMeHg ranges from 0.21-0.99 ng/L. In the area just downstream from the ARD source, biodiversity of invertebrates was low, with only one taxa (water striders) available in sufficient numbers and mass (> 1 g)_to be sampled. Biodiversity further downstream was also low, with only up to 2 families present

  18. Boromuscovite, a new member of the mica group, from the Little Three mine pegmatite, Ramona district, San Diego County, California

    USGS Publications Warehouse

    Foord, E.E.; Martin, R.F.; Fitzpatrick, J.J.; Taggart, J.E.; Crock, J.G.

    1991-01-01

    Boromuscovite, ideally KAl2(Si3B)O10(OH,F)2, in which [4]Al is replaced by B relative to muscovite, occurs as a late-stage, postpocket rupture mineral within the New Spaulding Pocket, main Little Three pegmatite dike. The mineral is white to cream colored and occurs as a porcelaneous veneer and coating on primary minerals. The average grain size is less than 3-4 ??m, but the coatings may be as much as 1 cm or more thick. Fragments of topaz, albite, elbaite, and other pocket minerals are included in the coating. The boromuscovite precipitated from a late-stage hydothermal fluid; it occurs only as a snowlike coating. Chemical composition, unit-cell parameters, Mohs hardness, cleavage, fracture, and optical properties are reported. -from Authors

  19. Control of Precambrian basement deformation zones on emplacement of the Laramide Boulder batholith and Butte mining district, Montana, United States

    USGS Publications Warehouse

    Berger, Byron R.; Hildenbrand, Thomas G.; O'Neill, J. Michael

    2011-01-01

    What are the roles of deep Precambrian basement deformation zones in the localization of subsequent shallow-crustal deformation zones and magmas? The Paleoproterozoic Great Falls tectonic zone and its included Boulder batholith (Montana, United States) provide an opportunity to examine the importance of inherited deformation fabrics in batholith emplacement and the localization of magmatic-hydrothermal mineral deposits. Northeast-trending deformation fabrics predominate in the Great Falls tectonic zone, which formed during the suturing of Paleoproterozoic and Archean cratonic masses approximately 1,800 mega-annum (Ma). Subsequent Mesoproterozoic to Neoproterozoic deformation fabrics trend northwest. Following Paleozoic through Early Cretaceous sedimentation, a Late Cretaceous fold-and-thrust belt with associated strike-slip faulting developed across the region, wherein some Proterozoic faults localized thrust faulting, while others were reactivated as strike-slip faults. The 81- to 76-Ma Boulder batholith was emplaced along the reactivated central Paleoproterozoic suture in the Great Falls tectonic zone. Early-stage Boulder batholith plutons were emplaced concurrent with east-directed thrust faulting and localized primarily by northwest-trending strike-slip and related faults. The late-stage Butte Quartz Monzonite pluton was localized in a northeast-trending pull-apart structure that formed behind the active thrust front and is axially symmetric across the underlying northeast-striking Paleoproterozoic fault zone, interpreted as a crustal suture. The modeling of potential-field geophysical data indicates that pull-apart?stage magmas fed into the structure through two funnel-shaped zones beneath the batholith. Renewed magmatic activity in the southern feeder from 66 to 64 Ma led to the formation of two small porphyry-style copper-molybdenum deposits and ensuing world-class polymetallic copper- and silver-bearing veins in the Butte mining district. Vein orientations

  20. Evolution of the Creede Caldera and its relation to mineralization in the Creede mining district, Colorado

    USGS Publications Warehouse

    Barton, Paul B.; Rye, Robert O.; Bethke, Philip M.

    2000-01-01

    At 25 Ma a major epithermal silver and base metal deposit formed in rhyolitic welded tuff near Creede, Colorado. Nearly 24000 metric tons of silver, appreciable lead, and small amounts of zinc, copper, and gold, have been produced from large, crustified veins under Bachelor and Bulldog Mountains north and northwest of Creede. Prior geologic, hydrologic, and stable-isotope studies showed that ore deposition was associated with the mixing and boiling of waters from diverse sources and suggester that a critical part of the ore-forming fluid may have originated within the ancient lake and sediments of the lacustrine Creede Formation that filled the Creede caldera. Two drill holes that sampled the heretofore hidden lower half of the Creede Formation are the focus of this book. The Creede caldera formed at 26.9 Ma within a high constructional plateau of silicic ashflows that covered and were sporadically interlayed with, intermediate lavas and lahars from large stratovolcanoes. The Creede caldera lake had an inflow evaporation balance that did not permit rapid filling to create a brim-full deep lake. Thus salts were evaporatively concentrated; but, with the exception of possible gypsum, no evaporite minerals preserved. Cool springs deposited travertine as mounds and contributed to limestone interlaminations within the sediment. The lake bottom was anoxic, and bacterial reduction of sulfate led to extreme sulfur isotopic fractionation in diagenetic pyrite. The caldera gradually resurged, converting the initial equant lake into an arcuate moat. Resurgent doming, alluvial fans, lacustrine sediments, ashfalls, and lava domes displaced water, lifted the lake so that it overlapped what later became the southern edge of the mineralized are, and eventually filled the basin. At 25.1 Ma an unseen pluton intruded beneath the northen part of the Creede district and created a convecting olume that drew in brine from the Creede caldera fill, meteotic water from highlands to the north

  1. Chinese liver flukes in latrine sediments from Wong Nim's property, San Bernardino, California: archaeoparasitology of the Caltrans District Headquarters.

    PubMed

    Reinhard, Karl J; Araújo, Adauto; Sianto, Luciana; Costello, Julia G; Swope, Karen

    2008-02-01

    Parasitological analysis of 5 sediment samples from San Bernardino, California latrine deposits spanning the time period from about 1880 to the 1930s are presented. Two sediment samples are from a latrine used by European-Americans. Three sediment samples are from latrines used by Chinese-Americans on the property of Wong Nim, an important member of the Chinese community. Two of the Chinese latrines were positive for human parasites. The human parasites encountered include the human whipworm (Trichuris trichiura), the giant intestinal roundworm (Ascaris lubricoides, c.f.), and the Chinese liver fluke (Clonorchis sinensis). Evidence of the liver fluke is especially important. This parasite cannot complete its life cycle outside of its endemic range in Asia because suitable intermediate hosts are not present in the American continents. Its presence signals that at least some of the Chinese-Americans who used the latrines were immigrants who were infected in Asia and then sustained infections while in the Americas.

  2. Hydrothermal systems in two areas of the Jemez volcanic field: Sulphur Springs and the Cochiti mining district

    SciTech Connect

    WoldeGabriel, G.

    1989-03-01

    K/Ar dates and oxygen isotope data were obtained on 13 clay separates (<2 ..mu..m) of thermally altered mafic and silicic rocks from the Cochiti mining district (SE Jemez Mountains) and Continental Scientific Drilling Project (CSDP) core hole VC-2A (Sulphur Springs, Valles caldera). Illite with K/sub 2/O contents of 6.68%--10.04% is the dominant clay in the silicic rocks, whereas interstratified illite/smectites containing 1.4%--5.74% K/sub 2/O constitute the altered andesites. Two hydrothermal alteration events are recognized at the Cochiti area (8.07 m.y., n = 1, and 6.5--5.6 m.y., n = 6). The older event correlates with the waning stages of Paliza Canyon Formation andesite volcanism (greater than or equal to13 to less than or equal to8.5 m.y.), whereas the younger event correlates with intrusions and gold- and silver-bearing quartz veins associated with the Bearhead Rhyolite (7.54--5.8 m.y.). The majority of K/Ar dates in the hydrothermally altered, caldera-fill rocks of core hole VC-2A (0.83--0.66 m.y., n = 4) indicate that hydrothermal alteration developed contemporaneously with resurgence and ring fracture Valles Rhyolite domes (0.89--0.54 m.y.). One date of 0 +- 0.10 m.y. in acid-altered landslide debris of postcaldera tuffs from the upper 13 m of the core hole probably correlates with Holocene hydrothermal activity possibly associated with the final phases of the Valles Rhyolite (0.13 m.y.).

  3. Geochemical investigations and interim recommendations for priority abandoned mine sites, BLM lands, upper Animas River watershed, San Juan County, Colorado

    USGS Publications Warehouse

    Nash, J. Thomas

    1999-01-01

    Field observations, sampling of mine dumps and mine drainage waters, and laboratory studies of dump materials have been made at mining areas deemed to be on public lands administered by the U. S. Bureau of Land Management (BLM) in the Upper Animas River watershed. Results of chemical analyses of dump materials, leachates of those materials, and surface waters draining mines or dumps provide indications of where acid is generated or consumed, and metal concentrations below mines or dumps. Information on sites previously identified as needing reclamation is reviewed and available geochemical information is used to rank 26 sites into four classes of priority for reclamation. Although there are more than a thousand mining sites (productive mines and prospects) on BLM lands in the Upper Animas River watershed study area, the majority are very small (less than about 70 cubic yards of dump material), are more than 2 miles from a major stream, or so inaccessible as to prohibit reclamation. In the summers of 1997 and 1998 approximately 200 sites were observed and more than 100 of these that appeared to have the potential to geochemically impact the watershed were examined more carefully and sampled. Building upon the prior work of the BLM and associated agencies, this work attempted to identify the most significant sources of mine-related contamination and to rank those sites as to priority for reclamation. These most significant mining areas have been examined within a geologic framework and were evaluated by multiple criteria, including tendency to generate acid and release toxic metals, observed damage to vegetation, potential to release metals based on leach tests, and likelihood of transport into streams of the watershed. No single measurable parameter, such as metal concentration, can be used to rank the sites. Rather, subjective estimates are required to evaluate combinations or interactions among several parameters. The most subjective estimate, while ranking

  4. The Marianas-San Marcos vein system: characteristics of a shallow low sulfidation epithermal Au-Ag deposit in the Cerro Negro district, Deseado Massif, Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Vidal, Conrado Permuy; Guido, Diego M.; Jovic, Sebastián M.; Bodnar, Robert J.; Moncada, Daniel; Melgarejo, Joan Carles; Hames, Willis

    2016-08-01

    The Cerro Negro district, within the Argentinian Deseado Massif province, has become one of the most significant recent epithermal discoveries, with estimated reserves plus resources of ˜6.7 Moz Au equivalent. The Marianas-San Marcos vein system contains about 70 % of the Au-Ag resources in the district. Mineralization consists of Upper Jurassic (155 Ma) epithermal Au- and Ag-rich veins of low to intermediate sulfidation style, hosted in and genetically related to Jurassic intermediate composition volcanic rocks (159-156 Ma). Veins have a complex infill history, represented by ten stages with clear crosscutting relationships that can be summarized in four main episodes: a low volume, metal-rich initial episode (E1), an extended banded quartz episode with minor mineralization (E2), a barren waning stage episode (E3), and a silver-rich late tectonic-hydrothermal episode (E4). The first three episodes are interpreted to have formed at the same time and probably from fluids of similar composition: a 290-230 °C fluid dominated by meteoric and volcanic waters (-3‰ to -0‰ δ18Owater), with <3 % NaCl equivalent salinity and with a magmatic source of sulfur (-1 to -2 ‰ δ34Swater). Metal was mainly precipitated at the beginning of vein formation (episode 1) due to a combination of boiling at ˜600 to 800 m below the paleowater table, and associated mixing/cooling processes, as evidenced by sulfide-rich bands showing crustiform-colloform quartz, adularia, and chlorite-smectite banding. During episodes 2 and 3, metal contents progressively decrease during continuing boiling conditions, and veins were filled by quartz and calcite during waning stages of the hydrothermal system, and the influx of bicarbonate waters (-6 to -8.5 ‰ δ18Owater). Hydrothermal alteration is characterized by proximal illite, adularia, and silica zone with chlorite and minor epidote, intermediate interlayered illite-smectite and a distal chlorite halo. This assemblage is in agreement with

  5. Integrated investigations of environmental effects of historical mining in the Animas River Watershed, San Juan County, Colorado

    USGS Publications Warehouse

    Church, Stanley E.; Von Guerard, Paul; Finger, Susan E.

    2007-01-01

    This publication comprises a Volume Contents of chapters (listed below) and a CD-ROM of data (contents shown in column at right). The Animas River watershed in southwest Colorado is one of many watersheds in the western United States where historical mining has left a legacy of acid mine drainage and elevated concentrations of potentially toxic trace elements in surface streams. U.S. Geological Survey scientists have completed a major assessment of the environmental effects of historical mining in the Animas River watershed focusing on the area upstream of Silverton, Colo.?the Mineral Creek, Cement Creek, and upper Animas River basins. The study demonstrated how the watershed approach can be used to assess and rank mining-affected sites for possible cleanup. The study was conducted in collaboration with State and Federal land-management agencies and regional stakeholders groups. This book is available for purchase at Information Services, U.S. Geological Survey (1-888-ASK-USGS).

  6. Update and revisions for Open-File Report 98-624, synthetic precipitation leaching procedure (SPLP) leachate chemistry data for solid mine-waste composite samples from the Silverton and Leadville districts in Colorado

    USGS Publications Warehouse

    Hageman, Philip L.; Desborough, George A.; Lamothe, Paul J.; Theodorakos, Peter M.

    2000-01-01

    This report supersedes, revises, and updates information and data previously released in Open-File Report 98-624 (Montour and others, 1998). Data for this report were derived from leaching of mine-waste composite samples using a modification of E.P. A. Method 1312, Synthetic Precipitation Leaching Procedure (SPLP). In 1997, members of the U.S. Geological Survey Mine Waste Characterization Project collected four mine-waste composite samples from mining districts near Silverton, Colorado (MAY and YUK), and near Leadville, Colorado (VEN and SUN). This report presents analytical results from these sites.

  7. Estimation of volume and mass and of changes in volume and mass of selected chat piles in the Picher mining district, Ottawa County, Oklahoma, 2005-10

    USGS Publications Warehouse

    Smith, S. Jerrod

    2013-01-01

    From the 1890s through the 1970s the Picher mining district in northeastern Ottawa County, Oklahoma, was the site of mining and processing of lead and zinc ore. When mining ceased in about 1979, as much as 165–300 million tons of mine tailings, locally referred to as “chat,” remained in the Picher mining district. Since 1979, some chat piles have been mined for aggregate materials and have decreased in volume and mass. Currently (2013), the land surface in the Picher mining district is covered by thousands of acres of chat, much of which remains on Indian trust land owned by allottees. The Bureau of Indian Affairs manages these allotted lands and oversees the sale and removal of chat from these properties. To help the Bureau of Indian Affairs better manage the sale and removal of chat, the U.S. Geological Survey, in cooperation with the Bureau of Indian Affairs, estimated the 2005 and 2010 volumes and masses of selected chat piles remaining on allotted lands in the Picher mining district. The U.S. Geological Survey also estimated the changes in volume and mass of these chat piles for the period 2005 through 2010. The 2005 and 2010 chat-pile volume and mass estimates were computed for 34 selected chat piles on 16 properties in the study area. All computations of volume and mass were performed on individual chat piles and on groups of chat piles in the same property. The Sooner property had the greatest estimated volume (4.644 million cubic yards) and mass (5.253 ± 0.473 million tons) of chat in 2010. Five of the selected properties (Sooner, Western, Lawyers, Skelton, and St. Joe) contained estimated chat volumes exceeding 1 million cubic yards and estimated chat masses exceeding 1 million tons in 2010. Four of the selected properties (Lucky Bill Humbah, Ta Mee Heh, Bird Dog, and St. Louis No. 6) contained estimated chat volumes of less than 0.1 million cubic yards and estimated chat masses of less than 0.1 million tons in 2010. The total volume of all

  8. 77 FR 43350 - Draft Environmental Assessment and Proposed Habitat Conservation Plan for the San Diego Unified...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ... San Diego Unified School District's Jonas Salk Elementary School Project in the City of San Diego, San... Elementary School Project in response to an application from the San Diego Unified School District (District... Elementary School'' in the subject line of the message. Fax: Attn: Jim Bartel, Field Supervisor, (760)...

  9. Stable isotope and fluid inclusion studies of carbonate deposits from the Tolfa Mountains mining district (Latium, central Italy)

    USGS Publications Warehouse

    Masi, U.; Ferrini, V.; O'Neil, J.R.; Batchelder, J.N.

    1980-01-01

    Carbon and oxygen isotope analyses were made of representative samples of calcite and quartz from the carbonate deposits in the Tolfa Mountains mining district. Measurements were also made of hydrogen isotope compositions, filling temperatures and salinities of fluid inclusions in these minerals. There are three stages of mineralization at Tolfa. In stage I, characterized by calc-silicate hornfels, the carbonates have relatively high ?? 18O values of 14.5 to 21.6 suggesting a rather low water/rock ratio. ??13C values of -0.3 to 2.1 indicate that appreciable decarbonation or introduction of deep-seated carbon did not occur. Stage II is marked by phanerocrystalline carbonates; ?? 18O values of 13.1 to 20.0 and ??13C values of 0.7 to 5.0 identify them as hydrothermal veins rather than marbles. ?? D values of -56 to -50 for inclusion fluids suggest a possible magmatic component to the hydrothermal fluid. Filling temperatures of coarse-grained samples of Calcite II are 309?? to 362?? C with a salinity range of 5.3 to 7.1 weight percent NaCl. Calculated ??18O values of 11-12 for these fluids are again indicative of low water/rock ratios. The sparry calcites of stage III have ??18O and ??13C values of 8.1 to 12.9 and -1.7 to 3.2, respectively. ?? D values of inclusion fluids are -40 to -33, clearly heavier than in earlier stages and similar to values of modern local ground waters. A salinity measurement of <0.1 weight percent NaCl in a sample of Calcite III is compatible with a relatively unaltered ground water origin for this fluid. Precipitation of the sparry calcite took place at much lower temperatures, around 160?? C. For quartz, ??18O values of 9.3 to 12.4 and ?? D values for inclusions of -53 to -28 are consistent with its late occurrence and paragenetic link with associated carbonates. ?? 1980 Springer-Verlag.

  10. Gaseous Mercury Monitoring at a Complex Source: The Las Cuevas Decommissioned Mining Complex and Current Hg Storage Facility (Almadén District, Spain)

    NASA Astrophysics Data System (ADS)

    Higueras, P. L.; Esbri, J. M.; Llanos, W. R.; Oyarzun, R.; Martinez-Coronado, A.; Grupo de Estudios En Minería Y Medioambiente-Gemm

    2010-12-01

    The Las Cuevas decommissioned mining complex was the third in importance in the world’s largest mercury mining district: Almadén (south-central Spain). Mining took place during two well differentiated periods: 1. Roman time; and 2. From 1982 to 2000. In 2004 the mine was transformed into a mercury storage and handling facility, away from urban areas. Furthermore, the area served as a test site for the design and implementation of a mercury safe storage vessel, a study funded by European LIFE-Env programme (Project MERSADE, LIFE06 ENV/ES/PREP/03) (Llanos et al., 2010). On this basis, Las Cuevas site can be regarded as a complex source of atmospheric mercury for the local environmental compartments, including emissions from the plant activity, partly reclamated old mineral dumps, contaminated soils, and other minor sources, such as cavities produced by mine collapse. We studied the emissions with two LUMEX RA-915+ Hg analyzers, one LUMEX RA-915Light device and a complete TEKRAN equipment, including Mercury Speciation Unit (model 1130) and Particulate Mercury Unit (Model 1135). Data has been treated with ISC-AERMOD program, in order to obtain models for contamination plumes derived from Las Cuevas whole area. The results confirm the mercury storage facility as the main local source for mercury, releasing some 3,15 kg Hg y-1, whereas contaminated soils and reclamated dumps represent local minor sources. Over 99,9% of local atmospheric mercury is Gaseous Elemental Mercury, with Reactive Gaseous Mercury representing 0,25 per mil, and particulate bound mercury, 1,8 per mil. Citation: Llanos, W.; Higueras, P.; Oyarzun, R.; Esbrí, J.M.; López-Berdonces, M.A.; García-Noguero, E.M.; Martínez-Coronado, A. (2010) A preliminary environmental assessment at the site of the European prototype installation of a safe deposit for surplus mercury from industry: The Las Cuevas mining complex, Almadén District, Spain. Science of the Total Environment, 408: 4901-4905.

  11. Evaluation of mercury stress in plants from the Almadén mining district by analysis of phytochelatins and their Hg complexes.

    PubMed

    Dago, Àngela; González, Inmaculada; Ariño, Cristina; Martínez-Coronado, Alba; Higueras, Pablo; Díaz-Cruz, José Manuel; Esteban, Miquel

    2014-06-03

    To evaluate plant response to Hg stress, glutathione, phytochelatins, and their Hg complexes were analyzed using HPLC with amperometric detection in samples of Asparagus acutifolius grown in the Almadén mining district (Ciudad Real, Spain), one of the most Hg-contaminated sites in the world. Soils of the Almadén mining district, and specifically from the Almadenejos zone, are highly contaminated, with some zones having values above 4,000 μg Hg g(-1) soil. Although soils have an extremely high concentration of mercury, generally less than 2% is available for plants, as is shown by various soil extractions simulating bioavailability. In plants, Hg concentration increases depending on the content of Hg in soils. In addition, Hg levels in roots are higher than in aerial parts, which is a strategy of plants for protecting their more sensitive aerial parts from the deleterious effects of metal stress. The total content of phytochelatins (PCs) and their complexes are directly related with the amount of mercury in soils. These findings highlight the important role of thiol compounds and their metal complexes in capturing and fixing Hg from soils, giving plants the capacity to deal with the heavy metal toxicity of polluted soils.

  12. Mercury residues in free-grazing cattle and domestic fowl form the artisanal gold mining area of Geita district, Tanzania.

    PubMed

    Chibunda, R T; Janssen, C R

    2009-11-01

    Environmental contamination with mercury from artisanal gold mines in Tanzania has been widely reported. People living around mining villages keep domestic animals which are allowed to feed freely in mercury-contaminated areas. This study investigated Hg accumulation in the liver and muscle tissue of cattle and domestic fowl reared in mining villages. Total mercury levels up to 436 and 820 microg/kg wet weight were found in liver samples taken from cattle and domestic fowl, respectively. Significantly higher mercury concentrations were found in liver samples collected at mining villages (p<0.05) than those taken from the reference area. While mercury concentrations in liver samples exceeded the acceptable maximum concentrations for humans set in the Netherlands and Poland, the Hg concentrations in muscle were below the limits of most countries. It is recommended that the keeping of freely grazing cattle and domestic fowl in or around artisanal gold mines should be avoided.

  13. Mercury accumulation in soils and plants in the Almadén mining district, Spain: one of the most contaminated sites on Earth.

    PubMed

    Molina, José Antonio; Oyarzun, Roberto; Esbrí, José María; Higueras, Pablo

    2006-10-01

    Although mercury (Hg) mining in the Almadén district ceased in May 2002, the consequences of 2000 years of mining in the district has resulted in the dissemination of Hg into the surrounding environment where it poses an evident risk to biota and human health. This risk needs to be properly evaluated. The uptake of Hg has been found to be plant-specific. To establish the different manners in which plants absorb Hg, we carried out a survey of Hg levels in the soils and plants in the most representative habitats of this Mediterranean area and found that the Hg concentrations varied greatly and were dependent on the sample being tested (0.13-2,695 microg g(-1) Hg). For example, the root samples had concentrations ranging from 0.06 (Oenanthe crocata, Rumex induratus) to 1095 (Polypogon monspeliensis) microg g(-1) Hg, while in the leaf samples, the range was from 0.16 (Cyperus longus) to 1278 (Polypogon monspeliensis) microg g(-1) Hg. There are four well-differentiated patterns of Hg uptake: (1) the rate of uptake is constant, independent of Hg concentration in the soil (e.g., Pistacia lentiscus, Quercus rotundifolia); (2) after an initial linear relationship between uptake and soil concentration, no further increase in Hg(plant) is observed (e.g., Asparagus acutifolius, Cistus ladanifer); (3) no increase in uptake is recorded until a threshold is surpassed, and thereafter a linear relationship between Hg(plant) and Hg(soil) is established (e.g., Rumex bucephalophorus, Cistus crispus); (4) there is no relationship between Hg(plant) and Hg(soil )(e.g., Oenanthe crocata and Cistus monspeliensis). Overall, the Hg concentrations found in plants from the Almadén district clearly reflect the importance of contamination processes throughout the study region.

  14. Review of samples of water, sediment, tailings, and biota at the Little Bonanza mercury mine, San Luis Obispo County, California

    USGS Publications Warehouse

    Rytuba, James J.; Hothem, Roger L.; Goldstein, Daniel N.; Brussee, Brianne E.; May, Jason T.

    2011-01-01

    Sample Sites and Methods Samples were collected to assess the concentrations of Hg and biogeochemically relevant constituents in tailings and wasterock piles at the Little Bonanza Hg mine. Tailings are present adjacent to a three-pipe retort used to process the Hg ore. The tailings occur in the upper 15 cm of the soil adjacent to the retort and slag from the retort is present on the surface. An area of disturbed soil and rock uphill from the retort was likely formed during construction of a dam that provided water for mining activities. Wasterock in these piles was sampled. The largest amount of tailings is exposed to the west of the retort in the bank of WF Las Tablas Creek. Water, sediment, and biota were sampled from WF Las Tablas Creek, which flows through the mine area. Sample-site locations are shown in figures 10 and 11 and listed in table 1. Samples were collected when streamflow was low and no precipitation had occurred.

  15. Triggering Effect of the Static Stress Transfer in Mining-Induced Seismicity from Rudna Mine in the Legnica-Gogow Copper District, in Poland

    NASA Astrophysics Data System (ADS)

    Orlecka-Sikora, B.; Papadimitriou, E.; Kwiatek, G.

    2008-12-01

    The static stress transfer is often considered as a possible source of earthquake interaction. Some examples from natural seismicity show that even small stress perturbations resulting from the coseismic slip can enhance or prevent future occurrences. In case of the mining-induced seismicity the coseismic stress changes expressed in terms of the Coulomb failure function (CFF) are at least one order smaller than those for earthquakes. Furthermore, they are only a small component of the stress field variations in mines. In order to recognize whether the static stress transfer can influence also the generation process of the mining induced seismicity we analyze seismic data from Rudna Mine in Poland. We consider events of ML>=2.0 occurred in Rudna Mine from 1993-2006. We examine the possible triggering checking correlation between event locations and the stress-increased zones, expressed by the proportion of events consistent with increased CFF areas. We find that more than 50 per-cent of the analyzed events occurred in areas where stress was enhanced due to the occurrence of previous events. In order to recognize the significance of the effect we test the null hypothesis stating that there is no influence of CFF changes due to previous events on the subsequent event. To attain the significance of this null hypothesis we estimate the distribution of the proportion of events located inside positive CFF areas from 2000 results for random permutations of the original series of events. For CFF changes >= 0.02 bar the null hypothesis was rejected at the 95% confidence level. This result indicates that the static CFF triggering in Rudna Mine exists and this effect is statistically significant. This work was prepared within the framework of the research project No. PBS- Grecja/10/2007, financed by the Ministry of Education and Science of Poland during the period 2007 to 2009.

  16. Statistical treatment and preliminary interpretation of chemical data from a uranium deposit in the northeast part of the Church Rock area, Gallup mining district, New Mexico

    USGS Publications Warehouse

    Spirakis, C.S.; Pierson, C.T.; Santos, E.S.; Fishman, N.S.

    1983-01-01

    Statistical treatment of analytical data from 106 samples of uranium-mineralized and unmineralized or weakly mineralized rocks of the Morrison Formation from the northeastern part of the Church Rock area of the Grants uranium region indicates that along with uranium, the deposits in the northeast Church Rock area are enriched in barium, sulfur, sodium, vanadium and equivalent uranium. Selenium and molybdenum are sporadically enriched in the deposits and calcium, manganese, strontium, and yttrium are depleted. Unlike the primary deposits of the San Juan Basin, the deposits in the northeast part of the Church Rock area contain little organic carbon and several elements that are characteristically enriched in the primary deposits are not enriched or are enriched to a much lesser degree in the Church Rock deposits. The suite of elements associated with the deposits in the northeast part of the Church Rock area is also different from the suite of elements associated with the redistributed deposits in the Ambrosia Lake district. This suggests that the genesis of the Church Rock deposits is different, at least in part, from the genesis of the primary deposits of the San Juan Basin or the redistributed deposits at Ambrosia Lake.

  17. Occurrence, distribution, and volume of metals-contaminated sediment of selected streams draining the Tri-State Mining District, Missouri, Oklahoma, and Kansas, 2011–12

    USGS Publications Warehouse

    Smith, D. Charlie

    2016-12-14

    Lead and zinc were mined in the Tri-State Mining District (TSMD) of southwest Missouri, northeast Oklahoma, and southeast Kansas for more than 100 years. The effects of mining on the landscape are still evident, nearly 50 years after the last mine ceased operation. The legacies of mining are the mine waste and discharge of groundwater from underground mines. The mine-waste piles and underground mines are continuous sources of trace metals (primarily lead, zinc, and cadmium) to the streams that drain the TSMD. Many previous studies characterized the horizontal extent of mine-waste contamination in streams but little information exists on the depth of mine-waste contamination in these streams. Characterizing the vertical extent of contamination is difficult because of the large amount of coarse-grained material, ranging from coarse gravel to boulders, within channel sediment. The U.S. Geological Survey, in cooperation with U.S. Fish and Wildlife service, collected channel-sediment samples at depth for subsequent analyses that would allow attainment of the following goals: (1) determination of the relation between concentration and depth for lead, zinc and cadmium in channel sediments and flood-plain sediments, and (2) determination of the volume of gravel-bar sediment from the surface to the maximum depth with concentrations of these metals that exceeded sediment-quality guidelines. For the purpose of this report, volume of gravel-bar sediment is considered to be distributed in two forms, gravel bars and the wetted channel, and this study focused on gravel bars. Concentrations of lead, zinc, and cadmium in samples were compared to the consensus probable effects concentration (CPEC) and Tri-State Mining District specific probable effects concentration (TPEC) sediment-quality guidelines.During the study, more than 700 sediment samples were collected from borings at multiple sites, including gravel bars and flood plains, along Center Creek, Turkey Creek, Shoal Creek

  18. Sequential Extraction of Mercury from Sediments in San Francisco Bay Estuary

    NASA Astrophysics Data System (ADS)

    Kerin, E.; Conaway, C. H.; Flegal, A.

    2002-12-01

    Mercury is found as both a natural component of weathering and as an industrial contaminant in sediments in central California. Although the mercury in most of California's coastal rivers is primarily derived from natural weathering processes, the bulk mercury in San Francisco Bay is derived from historic mining. In the northern reach of the estuary, this contamination is largely from elemental mercury used in gold mining in the Sierra Nevada and California Coast Ranges; whereas in the southern reach of the estuary the contamination is from weathering of mercury sulfide deposits and mining wastes in the nearby New Almaden mercury mining district. This disparity in sources is consistent with the results of our investigation of phase distributions of mercury in sediments using a sequential extraction method proposed by Bloom and Katon (2000). The extractions show that in the northern reach about 90% of the mercury was strongly complexed or elemental mercury, but only about 60% was strongly complexed in the southern reach. Moreover, almost all (greater than 90%) of the mercury at the New Almaden mine site was in the refractory sulfide fraction (cinnabar), but only 15% of the mercury was in that fraction downstream in the southern reach, showing the effects of chemical weathering and physical processes on mercury speciation in this system. Bloom, N. and Katon, J., 2000. Application of Selective Extraction to the Determination of Mercury Speciation in Mine Tailings and Adjacent Soils, Assessing and Managing Mercury from Historic and Current Mining Activities, San Francisco, CA.

  19. Evaluation of a monitoring program for assessing the effects of management practices on the quantity and quality of drainwater from the Panoche Water District, western San Joaquin Valley, California

    USGS Publications Warehouse

    Leighton, David A.; Fio, John L.

    1995-01-01

    An evaluation was made of an existing monitoring program in the Panoche Water District for 1986-93. The Panoche Water District is an agricultural area located in the western San Joaquin Valley of California. Because irrigation drainage from this area has high concentrations of dissolved solids and selenium, management strategies have been developed to improve the quality of drainwater discharge. The purpose of the Panoche Water District's monitoring program is to assess the effects of water- and land-use practices on local ground water and drain flow from the district. Drainflow from the district consists of the discharge from 50 separate on-farm underground tile-drainage systems. The Panoche Water District maintains information on water deliveries, planned and actual crop types, and planned and actual acreages planted each year. In addition, the water district monitors ground-water and drainage-system discharges using a variety of data-collection methods. A total of 62 observation well sites are used to monitor ground-water level and quality. A total of 42 sites were monitored for drainflow quantity, and drain flow quality samples were collected from the outlets of each of the 50 drainage systems. However, these data were collected inconsistently and (or) intermittently during the period studied. All data obtained from the water district were compiled and stored in a geographic information system database. Water delivered for irrigation by the Panoche Water District is a mix of imported water and local ground water pumped directly into delivery canals. Although delivered water is a mix, information on the proportion of water from the two sources is not reported. Also, individual growers pump directly to their crops unknown quantities of ground water, the total of which could be greater than 60 percent of total applications during years when water district deliveries are greatly reduced (for example, the years during and following a drought). To evaluate the

  20. 7 CFR 917.14 - District.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... County, and San Benito County. (i) Lake District includes and consists of Lake County. (j) Mendocino... County, Fresno County, and Mono County. (o) Tulare District includes and consists of Tulare County...

  1. 7 CFR 917.14 - District.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... County, and San Benito County. (i) Lake District includes and consists of Lake County. (j) Mendocino... County, Fresno County, and Mono County. (o) Tulare District includes and consists of Tulare County...

  2. 7 CFR 917.14 - District.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... County, and San Benito County. (i) Lake District includes and consists of Lake County. (j) Mendocino... County, Fresno County, and Mono County. (o) Tulare District includes and consists of Tulare County...

  3. 7 CFR 917.14 - District.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... County, and San Benito County. (i) Lake District includes and consists of Lake County. (j) Mendocino... County, Fresno County, and Mono County. (o) Tulare District includes and consists of Tulare County...

  4. 7 CFR 917.14 - District.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... County, and San Benito County. (i) Lake District includes and consists of Lake County. (j) Mendocino... County, Fresno County, and Mono County. (o) Tulare District includes and consists of Tulare County...

  5. Influence of Acid Mine Drainage (AMD) on recent phyto- and zooplankton in "the Anthropogenic Lake District" in south-west Poland

    NASA Astrophysics Data System (ADS)

    Sienkiewicz, Elwira; Gasiorowski, Michal

    2015-04-01

    In south-west Poland (central Europe) many the post-mining lakes formed so-called "the Anthropogenic Lake District". Areas, where water comes in contact with lignite beds characterized by high concentration of sulfide minerals are called Acid Mine Drainage (AMD). Pyrite oxidation and other sulfide compounds caused release sulfuric acids and heavy metal ions. These processes caused decline of water pH, sometimes to extremely low pH < 2.8. Presently, pit lakes located in south-west Poland have water pH ranged between 2.7 and 8.9. Differences of water reaction in the mine lakes depend on many factors, such as bedrock buffer capacity, geological structure of carboniferous area, exploitation technique of lignite, methods of filling and water supply of reservoirs and their age. During the evolution of lakes' ecosystems, sulfate-iron-calcium type of waters occurring in acid lakes will transform in alkaline hydrogen-carbonate-calcium type of waters. Due to the different time of the completion of lignite exploitation, lakes' age varied between forty and over one hundred years. Studies showed that younger lakes are more acidic in compare to older. To estimate impact of AMD we analyzed recent diversity of diatoms and Cladocera remains and water chemistry from extremely acidic, relatively young lakes and from alkaline, older water bodies. As we expected, flora and fauna from acidic lakes have shown very low diversity and species richness. Among diatoms, Eunotia exigua (Bréb. ex Kütz.) Rabenhorst and/or E. paludosa Grunow were dominated taxa, while fauna Cladocera did not occurred in lakes with water pH < 3. On this area, exploitation of lignite continued up to 1973. Older lakes were formed in the region where the mine started work in 1880 and lignite mining stopped in 1926. Measurements of pH value in situ point to neutral or alkaline water, but because of the possibility of hysteresis phenomenon, the studies of phyto- and zooplankton have shown if there has already been a

  6. Heavy metals in waters and suspended sediments affected by a mine tailing spill in the upper San Lorenzo River, Northwestern México.

    PubMed

    Páez-Osuna, F; Bojórquez-Leyva, H; Bergés-Tiznado, M; Rubio-Hernández, O A; Fierro-Sañudo, J F; Ramírez-Rochín, J; León-Cañedo, J A

    2015-05-01

    Concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), silver (Ag) and zinc (Zn) were evaluated in water and suspended sediments of the upper waters of San Lorenzo River in NW Mexico following a mine tailing spill. Except As (6.64-35.9 µg L(-1)), dissolved metal concentrations were low (Ag <0.06-0.22; Cd 0.01-0.34; Cu 4.71-10.2; Hg 0.02-0.24; Pb <0.15-0.65; Zn 86-1,080 µg L(-1)) and were less than the upper limits established by UNEP (Water quality for ecosystem and human health, 2nd edn. United Nations Environment Programme Global Environment Monitoring System/Water Programme, Burlington, 2008), EPA (2014) and the Mexican regulation (NOM 1994). In contrast, the suspended metal concentrations were high (As 91.4-130; Ag 22.1-531; Cd 3.14-6.30; Cu 65-123; Hg 0.47-1.09; Pb 260-818; Zn 742-1,810 mg kg(-1)) and most of samples exceeded the probable effect level of the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life.

  7. Disaster risk management in prospect mining area Blitar district, East Java, using microtremor analysis and ANP (analytical network processing) approach

    SciTech Connect

    Parwatiningtyas, Diyan E-mail: erlinunindra@gmail.com; Ambarsari, Erlin Windia E-mail: erlinunindra@gmail.com; Marlina, Dwi E-mail: erlinunindra@gmail.com; Wiratomo, Yogi E-mail: erlinunindra@gmail.com

    2014-03-24

    Indonesia has a wealth of natural assets is so large to be managed and utilized, either from its own local government and local communities, especially in the mining sector. However, mining activities can change the state of the surface layer of the earth that have a high impact disaster risk. This could threaten the safety and disrupt human life, environmental damage, loss of property, and the psychological impact, sulking to the rule of law no 24 of 2007. That's why we strive to manage and minimize the risk of mine disasters in the region, how to use the method of calculation of Amplification Factor (AF) from the analysis based microtremor sulking Kanai and Nakamura, and decision systems were tested by analysis of ANP. Based on the amplification factor and Analytical Network Processing (ANP) obtained, some points showed instability in the surface layer of a mining area include the site of the TP-7, TP-8, TP-9, TP-10, (Birowo2). If in terms of structure, location indicated unstable due to have a sloping surface layer, resulting in the occurrence of landslides and earthquake risk is high. In the meantime, other areas of the mine site can be said to be a stable area.

  8. Disaster risk management in prospect mining area Blitar district, East Java, using microtremor analysis and ANP (analytical network processing) approach

    NASA Astrophysics Data System (ADS)

    Parwatiningtyas, Diyan; Ambarsari, Erlin Windia; Marlina, Dwi; Wiratomo, Yogi

    2014-03-01

    Indonesia has a wealth of natural assets is so large to be managed and utilized, either from its own local government and local communities, especially in the mining sector. However, mining activities can change the state of the surface layer of the earth that have a high impact disaster risk. This could threaten the safety and disrupt human life, environmental damage, loss of property, and the psychological impact, sulking to the rule of law no 24 of 2007. That's why we strive to manage and minimize the risk of mine disasters in the region, how to use the method of calculation of Amplification Factor (AF) from the analysis based microtremor sulking Kanai and Nakamura, and decision systems were tested by analysis of ANP. Based on the amplification factor and Analytical Network Processing (ANP) obtained, some points showed instability in the surface layer of a mining area include the site of the TP-7, TP-8, TP-9, TP-10, (Birowo2). If in terms of structure, location indicated unstable due to have a sloping surface layer, resulting in the occurrence of landslides and earthquake risk is high. In the meantime, other areas of the mine site can be said to be a stable area.

  9. Reconnaissance investigations of ancient gold mines in the southern part of the Wadi Bidah District, Jabal Ibrahim and Al Aqiq quadrangles, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Worl, R.G.; Smith, C.W.

    1982-01-01

    Ancient gold mines in the southern part of the Wadi Bidah district, Kingdom of Saudi Arabia, are located either within lenses of ferruginous chert or in large felsic intrusions of Precambrian age. All are associated with quartz veins, stringers, and stockworks. Samples from both types of deposits have low silver and base-metal contents; samples from deposits within ferruginous chert have anomalous arsenic contents. None of the deposits are large enough to be considered as prime exploration targets at this time. Analytical results from the Bani Sar deposit, which is located within felsic plutonic rocks, are encouraging, but additional surface investigations are needed to define the size and extent of the mineralized zone. Deposits associated with ferruginous chert are also of exploration interest. Anomalous gold contents and other evidence of mineralization were found along a considerable exposure of the metasedimentary unit that contains the chert lenses.

  10. Bio-availability of tungsten in the vicinity of an abandoned mine in the English Lake District and some potential health implications.

    PubMed

    Wilson, Bob; Pyatt, F Brian

    2006-11-01

    This research addresses the occurrence, detection and possible fate of tungsten in the vicinity of an abandoned mine in the English Lake District. Aqua regia extraction and subsequent analysis of spoil and vegetation confirmed the presence of tungsten and other heavy metals. Spoil samples examined were last worked almost 100 years ago and the concentrations of copper, zinc, tungsten and arsenic detected demonstrate the environmental persistence of these metals in an area of relatively high rainfall. The bioaccumulation of tungsten by two species of plants is indicated and partitioning within different tissues of Calluna vulgaris is demonstrated. Mechanisms relating to mobility and speciation of the metals present were explored using sequential and single stage extraction systems. Tungsten appears to be relatively immobile when subjected to sequential extraction but increased bioavailability is indicated when single stage extraction using EDTA is employed.

  11. Incidence of the Almadén historical mining district on the hydrochemical characteristics of Valdeazogues Basin (Spain)

    NASA Astrophysics Data System (ADS)

    García-Ordiales, Efren; Loredo, Jorge; Higueras, Pablo L.; Esbrí, Jose M.; Cienfuegos, Pablo; Roqueñí, Nieves

    2016-10-01

    The distribution of dissolved potentially harmful elements (PHEs), major ions and physico-chemical parameters in the Valdeazogues river basin was studied during 9 surveys, carried out between 2010 and 2013. The observed physico-chemical parameters depend on the season, the major ions depend of the nature of the lithological materials and the PHEs depend of the characteristics of the mine inputs. The Principal Component Analysis performed on the analysed dataset, distinguished the sources of contaminants introduced into waters and that nowadays mine runoffs play a role higher than the played by the natural inputs.

  12. Time relationships between volcanism-plutonism-alteration-mineralization in Cu-stratabound ore deposits from the Michilla mining district, northern Chile: a 40Ar/39Ar geochronological approach

    NASA Astrophysics Data System (ADS)

    Oliveros, Verónica; Tristá-Aguilera, Dania; Féraud, Gilbert; Morata, Diego; Aguirre, Luis; Kojima, Shoji; Ferraris, Fernando

    2008-01-01

    The Michilla mining district comprises one of the most important stratabound and breccia-style copper deposits of the Coastal Cordillera of northern Chile, hosted by the Middle Jurassic volcanic rocks of the La Negra Formation. 40Ar/39Ar analyses carried out on igneous and alteration minerals from volcanic and plutonic rocks in the district allow a chronological sequence of several magmatic and alteration events of the district to be established. The first event was the extrusion of a thick lava series of the La Negra Formation, dated at 159.9 ± 1.0 Ma (2 σ) from the upper part of the series. A contemporaneous intrusion is dated at 159.6 ± 1.1 Ma, and later intrusive events are dated at 145.5 ± 2.8 and 137.4 ± 1.1 Ma, respectively. Analyzed alteration minerals such as adularia, sericite, and actinolite apparently give valid 40Ar/39Ar plateau and miniplateau ages. They indicate the occurrence of several alteration events at ca. 160-163, 154-157, 143-148, and 135-137 Ma. The first alteration event, being partly contemporaneous with volcanic and plutonic rocks, was probably produced in a high thermal gradient environment. The later events may be related either to a regional low-grade hydrothermal alteration/metamorphism process or to plutonic intrusions. The Cu mineralization of the Michilla district is robustly bracketed between 163.6 ± 1.9 and 137.4 ± 1.1 Ma, corresponding to dating of actinolite coexisting with early-stage chalcocite and a postmineralization barren dyke, respectively. More precisely, the association of small intrusives (a dated stock from the Michilla district) with Cu mineralization in the region strongly suggests that the main Michilla ore deposit is related to a magmatic/hydrothermal event that occurred between 157.4 ± 3.6 and 163.5 ± 1.9 Ma, contemporaneous or shortly after the extrusion of the volcanic sequence. This age is in agreement with the Re-Os age of 159 ± 16 Ma obtained from the mineralization itself (Tristá-Aguilera et al

  13. Use of imaging in the 0.46-2.36 [micrometers] spectral region for alteration mapping in the Cuprite mining district, Nevada

    USGS Publications Warehouse

    Abrams, Michael J.; Ashley, R.P.; Rowan, L.C.; Goetz, A.F.H.; Kahle, A.B.

    1977-01-01

    Color composites of Landsat MSS ratio images that display variations in the intensity of ferric-iron absorption bands are highly effective for mapping limonitic altered rocks, but ineffective for mapping nonlimonitic altered rocks. Analysis of 0.45-2.5 ?m field and laboratory spectra shows that iron-deficient opalites in the Cuprite mining district, Nevada, have an intense OH-absorption band near 2.2 ?m owing to their clay mineral and alunite contents and that this spectral feature is absent or weak in adjacent unaltered tuff and basalt. To evaluate the usefulness of this spectral feature for discriminating between altered and unaltered rocks, we generated color-ratio composite images from multispectral (0.46-2.36 ?m) aircraft data. The altered rocks in the district can be discriminated from unaltered rocks with few ambiguities; in addition, some effects of mineralogical zoning can be discriminated within the altered area. Only variations in amounts of limonite can be discerned in shorter wavelength aircraft data, Landsat MSS bands, and color aerial photographs.

  14. Effects of soil composition and mineralogy on the bioaccessibility of arsenic from tailings and soil in gold mine districts of Nova Scotia.

    PubMed

    Meunier, Louise; Walker, Stephen R; Wragg, Joanna; Parsons, Michael B; Koch, Iris; Jamieson, Heather E; Reimer, Kenneth J

    2010-04-01

    Bioaccessibility tests and mineralogical analyses were performed on arsenic-contaminated tailings and soils from gold mine districts of Nova Scotia, Canada, to examine the links between soil composition, mineralogy, and arsenic bioaccessibility. Arsenic bioaccessibility ranges from 0.1% to 49%. A weak correlation was observed between total and bioaccessible arsenic concentrations, and the arsenic bioaccessibility was not correlated with other elements. Bulk X-ray absorption near-edge structure analysis shows arsenic in these near-surface samples is mainly in the pentavalent form, indicating that most of the arsenopyrite (As(1-)) originally present in the tailings and soils has been oxidized during weathering reactions. Detailed mineralogical analyses of individual samples have identified up to seven arsenic species, the relative proportions of which appear to affect arsenic bioaccessibility. The highest arsenic bioaccessibility (up to 49%) is associated with the presence of calcium-iron arsenate. Samples containing arsenic predominantly as arsenopyrite or scorodite have the lowest bioaccessibility (<1%). Other arsenic species identified (predominantly amorphous iron arsenates and arsenic-bearing iron(oxy)hydroxides) are associated with intermediate bioaccessibility (1 to 10%). The presence of a more soluble arsenic phase, even at low concentrations, results in increased arsenic bioaccessibility from the mixed arsenic phases associated with tailings and mine-impacted soils.

  15. Effects of Soil Composition and Mineralogy on the Bioaccessibility of Arsenic from Tailings and Soil in Gold Mine Districts of Nova Scotia

    SciTech Connect

    Meunier, Louise; Walker, Stephen R.; Wragg, Joanna; Parsons, Michael B.; Koch, Iris; Jamieson, Heather E.; Reimer, Kenneth J.

    2010-10-20

    Bioaccessibility tests and mineralogical analyses were performed on arsenic-contaminated tailings and soils from gold mine districts of Nova Scotia, Canada, to examine the links between soil composition, mineralogy, and arsenic bioaccessibility. Arsenic bioaccessibility ranges from 0.1% to 49%. A weak correlation was observed between total and bioaccessible arsenic concentrations, and the arsenic bioaccessibility was not correlated with other elements. Bulk X-ray absorption near-edge structure analysis shows arsenic in these near-surface samples is mainly in the pentavalent form, indicating that most of the arsenopyrite (As{sup 1-}) originally present in the tailings and soils has been oxidized during weathering reactions. Detailed mineralogical analyses of individual samples have identified up to seven arsenic species, the relative proportions of which appear to affect arsenic bioaccessibility. The highest arsenic bioaccessibility (up to 49%) is associated with the presence of calcium-iron arsenate. Samples containing arsenic predominantly as arsenopyrite or scorodite have the lowest bioaccessibility (<1%). Other arsenic species identified (predominantly amorphous iron arsenates and arsenic-bearing iron(oxy)hydroxides) are associated with intermediate bioaccessibility (1 to 10%). The presence of a more soluble arsenic phase, even at low concentrations, results in increased arsenic bioaccessibility from the mixed arsenic phases associated with tailings and mine-impacted soils.

  16. Biochemical effects of lead, zinc, and cadmium from mining on fish in the Tri-States district of northeastern Oklahoma, USA

    USGS Publications Warehouse

    Schmitt, Christopher J.; Whyte, Jeffrey J.; Brumbaugh, William G.; Tillitt, Donald E.

    2005-01-01

    We assessed the exposure of fish from the Spring and Neosho Rivers in northeast Oklahoma, USA, to lead, zinc, and cadmium from historical mining in the Tri-States Mining District (TSMD). Fish (n = 74) representing six species were collected in October 2001 from six sites on the Spring and Neosho Rivers influenced to differing degrees by mining. Additional samples were obtained from the Big River, a heavily contaminated stream in eastern Missouri, USA, and from reference sites. Blood from each fish was analyzed for Pb, Zn, Cd, Fe, and hemoglobin (Hb). Blood also was analyzed for ??-aminolevulinic acid dehydratase (ALA-D) activity. The activity of ALA-D, an enzyme involved in heme synthesis, is inhibited by Pb. Concentrations of Fe and Hb were highly correlated (r = 0.89, p < 0.01) across all species and locations and typically were greater in common carp (Cyprinus carpio) than in other taxa. Concentrations of Pb, Zn, and Cd typically were greatest in fish from sites most heavily affected by mining and lowest in reference samples. The activity of ALA-D, but not concentrations of Hb or Fe, also differed significantly (p < 0.01) among sites and species. Enzyme activity was lowest in fish from mining-contaminated sites and greatest in reference fish, and was correlated negatively with Pb in most species. Statistically significant (p < 0.01) linear regression models that included negative terms for blood Pb explained as much as 68% of the total variation in ALA-D activity, but differences among taxa were highly evident. Positive correlations with Zn were documented in the combined data for channel catfish (Ictalurus punctatus) and flathead catfish (Pylodictis olivaris), as has been reported for other taxa, but not in bass (Micropterus spp.) or carp. In channel catfish, ALA-D activity appeared to be more sensitive to blood Pb than in the other species investigated (i.e., threshold concentrations for inhibition were lower). Such among-species differences are consistent

  17. The nature of fracturing and stress distribution in quartzite around the 1128-M (3700-FT) level of the crescent mine, Coeur d'Alene mining district, Idaho

    USGS Publications Warehouse

    Miller, C.H.; Skinner, E.H.

    1980-01-01

    Silver and copper are the principal ores mined from the quartzite at the Crescent mine. Both the main ore-bearing veins and foliation in the quartzite are parallel to the nearly vertical formational contacts. Anisotropy of the quartzite is indicated by both dynamic and static tests. Disking and breakage of core from holes perpendicular to the foliation are about twice what they are in core from holes parallel to foliation. Natural cleavage as well as slabbing and blasting fractures around the tunnels are also controlled by the foliation. Extensive overcore deformation measurements indicate that most of the influence of the tunnels on the "free" stress field is between the rib and a depth of 2.7 m (1 tunnel diameter). The maximum principal stress axis in the free field is nearly horizontal; its magnitude is not much greater than the vertical component and calculations indicate a nearly hydrostatic free stress field. Stress considerably greater than the free field was measured between about 0.3-2.7 m behind the rib and is caused by a transfer of load from above the tunnel opening. Peak stress is in the vertical direction and about 1.7 m behind the rib. An air-injection survey shows that high permeabilities are confined to the highly fractured annulus around a tunnel to a depth of at least 0.6 m. Air-injection measurements could be taken in the interval of about 0.6-1.8 m, but more fractures with high permeabilities may also be present in the annulus from about 0.6-1.2 m. Permeabilities measured deeper than about 1.8 m by the air-injection technique are either very low or nonexistent. The absence of open and noncontinuous fractures beyond about 1.8 m is also indicated by very low porosities and permeabilities of core, very high stresses (which presumably would close fractures), the lack of stains or secondary fillings in disking fractures, a conspicuous lack of ground water in the tunnels, and the fact that fractures encountered in an experimental 0.9-m tunnel did not

  18. Primary surface rupture associated with the Mw 7.1 16 October 1999 Hector Mine earthquake, San Bernardino County, California

    USGS Publications Warehouse

    Treiman, J.A.; Kendrick, K.J.; Bryant, W.A.; Rockwell, T.K.; McGill, S.F.

    2002-01-01

    The Mw 7.1 Hector Mine earthquake occurred within the Mojave Desert portion of the eastern California shear zone and was accompanied by 48 km of dextral surface rupture. Complex northward rupture began on two branches of the Lavic Lake fault in the northern Bullion Mountains and also propagated southward onto the Bullion fault. Lesser amounts of rupture occurred across two right steps to the south. Surface rupture was mapped using postearthquake, 1:10,000-scale aerial photography. Field mapping provided additional detail and more than 400 fault-rupture observations; of these, approximately 300 measurements were used to characterize the slip distribution. En echelon surface rupture predominated in areas of thick alluvium, whereas in the bedrock areas, rupture was more continuous and focused within a narrower zone. Measured dextral offsets were relatively symmetrical about the epicentral region, with a maximum displacement of 5.25 ?? 0.85 m. Vertical slip was a secondary component and was variable, with minor west-side-down displacements predominat.ing in the Bullion Mountains. Field and aerial photographic evidence indicates that most of the faults that ruptured in 1999 had had prior late-Quaternary displacement, although only limited sections of the rupture show evidence for prior Holocene displacement.

  19. Hydrochemical characteristics and quality assessment of deep groundwater from the coal-bearing aquifer of the Linhuan coal-mining district, Northern Anhui Province, China.

    PubMed

    Lin, Man-Li; Peng, Wei-Hua; Gui, He-Rong

    2016-04-01

    There is little information available about the hydrochemical characteristics of deep groundwater in the Linhuan coal-mining district, Northern Anhui Province, China. In this study, we report information about the physicochemical parameters, major ions, and heavy metals of 17 groundwater samples that were collected from the coal-bearing aquifer. The results show that the concentrations of total dissolved solids, electrical conductivity, and potassium and sodium (K(+) + Na(+)) in most of the groundwater samples exceeded the guidelines of the World Health Organization (WHO) and the Chinese National Standards for Drinking Water Quality (GB 5749-2006). The groundwater from the coal-bearing aquifer was dominated by the HCO3·Cl-K + Na and HCO3·SO4-K + Na types. Analysis with a Gibbs plot suggested that the major ion chemistry of the groundwater was primarily controlled by weathering of rocks and that the coal-bearing aquifer in the Linhuan coal-mining district was a relatively closed system. K(+) and Na(+) originated from halite and silicate weathering reactions, while Ca(2+) and Mg(2+) originated from the dissolution of calcite, dolomite, and gypsum or anhydrite. Ion exchange reactions also had an influence on the formation of major ions in groundwater. The concentrations of selected heavy metals decreased in the order Mn > Zn > Cr > Cu > Ni > Pb. In general, the heavy metal concentrations were low; however, the Cr, Mn, and Ni concentrations in some of the groundwater samples exceeded the standards outlined by the WHO, the GB 5749-2006, and the Chinese National Standards for Groundwater (GB/T 14848-93). Analysis by various indices (% Na, SAR, and EC), a USSL diagram, and a Wilcox diagram showed that both the salinity and alkalinity of the groundwater were high, such that the groundwater could not be used for irrigating agricultural land without treatment. These results will be significant for water resource exploiting and utilization in

  20. District cooling gets hot

    SciTech Connect

    Seeley, R.S.

    1996-07-01

    Utilities across the country are adopting cool storage methods, such as ice-storage and chilled-water tanks, as an economical and environmentally safe way to provide cooling for cities and towns. The use of district cooling, in which cold water or steam is pumped to absorption chillers and then to buildings via a central community chiller plant, is growing strongly in the US. In Chicago, San Diego, Pittsburgh, Baltimore, and elsewhere, independent district-energy companies and utilities are refurbishing neglected district-heating systems and adding district cooling, a technology first developed approximately 35 years ago.

  1. A Sequential Chemical Extraction and Spectroscopic Assessment of the Potential Bioavailability of Mercury Released From the Inoperative New Idria Mercury Mine, San Benito Co., CA

    NASA Astrophysics Data System (ADS)

    Jew, A. D.; Luong, P. N.; Rytuba, J. J.; Brown, G. E.

    2012-12-01

    The inoperative New Idria mercury mine in San Benito Co., CA, is a potential point source of Hg to the Central Valley of California. To determine the phases and the potential bioavailability of Hg present in stream bed deposits downstream of the mine, sequential chemical extractions (SCEs) targeting Hg-bearing phases and synchrotron-based spectroscopic and imaging techniques were used on sediment samples taken from the acid mine drainage (AMD) system, Hg sorbed in the laboratory to ferrihydrite (synthetic 2-line and natural), and Hg associated with diatom-rich samples. In all field samples examined, both the wet and dry seasons, removal of > 97% of the Hg required 1M KOH or harsher chemical treatments. X-ray absorption spectroscopy (XAS) showed that HgS was the dominant inorganic Hg phase present, with no detectable Hg associated with the ferrihydrite. Uptake and subsequent SCE analysis of Hg to both synthetic and natural ferrihydrite showed that 1M MgCl2 removed ≥ 90% of the total Hg, suggesting that Hg does not sorb strongly to ferrihydrite. This finding is surprising, because in most settings ferrihydrite is considered to be a strong adsorbent of heavy metals. Due to the lack of Hg sorption to ferrihydrite in field samples, another pool for the non-HgS/HgSe fraction in sediments is needed. SEM analysis of the downstream samples showed that regardless of pH, freshwater diatoms were present. To determine if diatoms were the sink for dissolved Hg in this system, SCE analysis on commercially available and diatom-rich field samples from the New Idria site and Harley Gulch (Lake County, CA) were completed. The vast majority of Hg in diatom-rich samples was removed by 1M KOH, which corresponds to the non-HgS/HgSe fraction of the New Idria field samples. Analysis for carbon and nitrogen in the diatom-rich samples showed no detectable nitrogen, indicating little to no organic material was left in the samples. We therefore infer that Hg in the diatoms is contained in

  2. A preliminary combined geochemical and rock-magnetic study of tailings of non-magnetic ores from Tlalpujahua-El Oro mining districts, Michoacán and Estado de México States

    NASA Astrophysics Data System (ADS)

    Morales, J.; Hernández-Bernal, M.; Corona-Chávez, P.

    2013-05-01

    Mining activities in Mexico have been continuously developed since 1550. Since then several thousands of million tons of waste produced as a result of the mining activity have been accumulated and scattered throughout the territory. These wastes can contain minerals with potentially toxic elements (PTEs) such as Cr, As, Cd, Cu, Pb, Zn, which show a distribution and mobility in the environment according to the chemical species in which are hosted. The Tlalpujahua - El Oro mining district (TOMD) concentrates an impressive number of mines and historical tailings. Due to their in-slope hydrographic position, the mining activities increase the risk of generating anthropogenic effluent that could contribute with a certain amount of mine-water with high contents of PTEs. Although magnetic methods have been widely applied to pollution studies of regions with high anthropogenic impact, its application to tailings is scarce in spite of the several studies that document the environmental effects as a result of the mining waste. We present the results obtained by combined geochemical and rock-magnetic studies in these tailings. Similarly to the traditional EPTs vs SiO2 diagrams, EPTs vs Fe show good linear (inverse) correlation with most of these health-risk elements. Fe concentrations determined magnetically from room-temperature susceptibility measurements agrees with those obtained by traditionally geochemical methods.

  3. Concentrations, spatial distribution, and risk assessment of soil heavy metals in a Zn-Pb mine district in southern China.

    PubMed

    Qi, Jianying; Zhang, Hailong; Li, Xiangping; Lu, Jian; Zhang, Gaosheng

    2016-07-01

    China is one of the largest producers and consumers of lead and zinc in the world. Lead and zinc mining and smelting can release hazardous heavy metals such as Cd, Pb, Zn, and As into soils, exerting health risks to human by chronic exposure. The concentrations of Cd, Zn, Pb, and As in soil samples collected from a Pb-Zn mining area with exploitation history of 60 years were investigated. Health risks of the heavy metals in soil were evaluated using US Environmental Protection Agency (US EPA) recommended method. A geo-statistical technique (Kriging) was used for the interpolation of heavy metals pollution and Hazard Index (HI). The results indicated that the long-term Pb/Zn mining activities caused the serious pollution in the local soil. The concentrations of Cd, As, Pb, and Zn in topsoil were 40.3 ± 6.3, 103.7 ± 37.3, 3518.4 ± 896.1, and 10,413 ± 2973.2 mg/kg dry weight, respectively. The spatial distribution of the four metals possessed similar patterns, with higher concentrations around Aayiken (AYK), Maseka (MSK), and Kuangshan (KS) area and more rapidly dropped concentrations at upwind direction than those at downwind direction. The main pollutions of Cd and Zn were found in the upper 60 cm, the Pb was found in the upper 40 cm, and the As was in the upper 20 cm. The mobility of metals in soil profile of study area was classed as Cd > Zn ≫ Pb > As. Results indicated that there was a higher health risk (child higher than adult) in the study area. Pb contributed to the highest Hazard Quotient (57.0 ~ 73.9 %) for the Hazard Index.

  4. 77 FR 65305 - Approval of Air Quality Implementation Plans; California; San Joaquin Valley Unified Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... Unified Air Pollution Control District; Prevention of Significant Deterioration AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: The Environmental Protection Agency (EPA) is taking... (SIP) revision for the San Joaquin Valley Unified Air Pollution Control District (District) portion...

  5. The geology and 40Ar/ 39Ar geochronology of magmatic activity and related mineralization in the Nevados del Famatina mining district, La Rioja province, Argentina

    NASA Astrophysics Data System (ADS)

    Losada-Calderón, A. J.; McBride, S. L.; Bloom, M. S.

    1994-01-01

    The Nevados del Famatina mining district (NFMD) is located in La Rioja province, Argentina. This district contains porphyry-style mineralization (Nevados del Famatina) and high sulfidation veins (La Mejicana). The stratigraphic column in the NFMD begins with Cambrian siltstones which were metamorphosed during the Late Ordovician - Early Silurian and intruded by Late Ordovician-Silurian granitic rocks. These units were covered by Upper Paleozoic and Tertiary continental sedimentary rocks which are intercalated with and overlain by dacitic-rhyodacitic porphyritic rocks (Mogote Formation) emplaced during the Pliocene. All these units are covered by Pleistocene sediments and Quaternary alluvial and colluvial deposits. Magmatic activity and related mineralization in the NFMD have been dated by the 40Ar/ 39Ar technique. Step heating studies of orthoclase and biotite phenocrysts from the Mogote Formation in the NFMD suggest that the igneous rocks were emplaced around 5.0±0.3 Ma ago. However, plateau ages of biotite from the outer carapace of the subjacent granodioritic magma chamber and of muscovite from quartz-sericite alteration at both Nevados del Famatina and La Mejicana are around 3.8±0.2 Ma. Emplacement of the shallow stocks is separated from cooling of the outer carapace of the subjacent granodioritic magma chamber to temperatures below 350° C by a time span of approximately 1 Ma. During this interval, a convective hydrothermal system was established proximal to the granodioritic magma chamber, which resulted in porphyry molybdenumcoppergold mineralization adjacent to the igneous rocks and more distal high sulfidation veins located in fault zones.

  6. Biostratigraphy and structure of paleozoic host rocks and their relationship to Carlin-type gold deposits in the Jerritt Canyon mining district, Nevada

    USGS Publications Warehouse

    Peters, S.G.; Armstrong, A.K.; Harris, A.G.; Oscarson, R.L.; Noble, P.J.

    2003-01-01

    The Jerritt Canyon mining district in the northern Independence Range, northern Nevada, contains multiple, nearly horizontal, thrust masses of platform carbonate rocks that are exposed in a series of north- to northeast-elongated, tectonic windows through rocks of the Roberts Mountains allochthon. The Roberts Mountains allochthon was emplaced during the Late Devonian to Early Mississippian Antler orogeny. These thrust masses contain structurally and stratigraphically controlled Carlin-type gold deposits. The gold deposits are hosted in tectonically truncated units of the Silurian to Devonian Hanson Creek and Roberts Mountains Formations that lie within structural slices of an Eastern assemblage of Cambrian to Devonian carbonate rocks. In addition, these multiply thrust-faulted and folded host rocks are structurally interleaved with Mississippian siliciclastic rocks and are overlain structurally by Cambrian to Devonian siliciclastic units of the Roberts Mountains allochthon. All sedimentary rocks were involved in thrusting, high-angle faulting, and folding, and some of these events indicate substantial late Paleozoic and/or Mesozoic regional shortening. Early Pennsylvanian and late Eocene dikes also intrude the sedimentary rocks. These rocks all were uplifted into a northeast-trending range by subsequent late Cenozoic Basin and Range faulting. Eocene sedimentary and volcanic rocks flank part of the range. Pathways of hydrothermal fluid flow and locations of Carlin-type gold orebodies in the Jerritt Canyon mining district were controlled by structural and host-rock geometries within specific lithologies of the stacked thrust masses of Eastern assemblage rocks. The gold deposits are most common proximal to intersections of northeast-striking faults, northwest-striking dikes, and thrust planes that lie adjacent to permeable stratigraphic horizons. The host stratigraphic units include carbonate sequences that contained primary intercrystalline permeability, which

  7. Geology of the area adjacent to the Free Enterprise uranium-silver Mine, Boulder District, Jefferson County, Montana

    USGS Publications Warehouse

    Roberts, W.A.; Gude, A.J.

    1952-01-01

    Uranium minerals.occur in pods associated with cryptocrystalline silica, silver minerals, and scattered sulfide mineral grains in a hydrothermal vein that cuts quartz monzonite and alaskite at the Free Enterprise mine, 2 miles west of Boulder, Mont. The Free Enterprise vein is one of many silicified reef-like structures in this area, most of which trend about N. 60° E. The cryptocrystalline silica zones of the area are lenticular and are bordered by an altered zone where quartz monzonite is the wall rock. No alteration was noticed where alaskite is adjacent to silica zones. No uranium minerals were observed at the surface, but radioactivity anomalies were noted at 57 outcrops. Underground mining has shown that leaching by downward percolating waters has removed most of the uranium from the near-surface part of the Free Enterprise vein and probably has enriched slightly, parts of the vein and the adjacent wall rock from the bottom of the leached zone to the ground-water level. It is possible that other veins that show low to moderate radioactivity at the surface may contain significant concentrations of uranium minerals at relatively shallow depth. The quartz monzonite appears to be a more favorable host rock for the cryptocrystalline silica and associated uranium minerals than the alaskite. The alaskite occurs as vertical_dikes plug-like masses, and as irregularly shaped, gently dipping masses that are believed to have been intruded into open fractures formed during the cooling of the quartz monzonite.

  8. Mercury uptake and distribution in Lavandula stoechas plants grown in soil from Almadén mining district (Spain).

    PubMed

    Sierra, M J; Millán, R; Esteban, E

    2009-11-01

    This work studies mercury root uptake by Lavandula stoechas var. Kew Red (lavender) and the distribution of this metal through the plant under greenhouse conditions along three consecutive seasons. Mercury concentration in plant tissues and in the different products obtained from lavender plants (essential oil, toilet water and in lavender tea) was assessed in order to evaluate the possible cultivation of lavender as a profitable alternative land use to mercury mining in the Almadén area once the mine had been closed down. Mercury concentration in useful parts of the plant was low (0.03-0.55 mg kg(-1)). Likewise, the essential oil, toilet water and tea obtained from these plants presented very low mercury levels, below the detection limit of the used equipment (<0.5 microg kg(-1)). In the case of the obtained tea, according to the recommendations given by the World Health Organization, the maximum daily intake of it without intoxication risk would be 85.2l. So, although other sources of mercury intake should also be considered in order to elaborate a complete toxicological risk assessment. Lavender data, obtained under this greenhouse working conditions, shows that lavender cultivation could be an alternative crop in the Almadén area.

  9. The importance of ingested soils in supplying fluorine and lead to sheep grazing contaminated pastures in the Peak District mining area of Derbyshire, UK.

    PubMed

    Abrahams, Peter W; Blackwell, Nia L

    2013-12-01

    For sheep grazing pastures in areas of mineralisation and former metalliferous mining activity, an excessive intake of potentially harmful elements (PHEs) such as fluorine (F) and lead (Pb) can result in clinical and subclinical toxicity. The prime aim of our work was to calculate the intakes of both of these PHEs by sheep grazing pastures in the mineralised/mined Peak District area of Derbyshire. The bi-monthly sampling of topsoils (0-15 cm depth) and the faeces of sheep from fields at seven farms was undertaken for a 1-year period. These samples were analysed for titanium that allowed the rates of soil ingestion (and hence also herbage ingestion since we assume that the sheep have an overall diet of 1 kg dry matter (DM)/day) to be determined. Our findings were then combined with previously published soil and soil-free pasture herbage F and Pb concentrations determined from the seven farms to calculate the intakes of both PHEs. The results show seasonal variations of soil ingestion at the seven farms ranging from <0.1 to 20.1 % of the DM intake (median=3 %), with the highest rates of ingestion being associated with the winter-spring (i.e. December-April) period. Our calculations show that at some farms, sheep can be exposed to dietary concentrations in excess of recommended guidelines potentially throughout the whole year, though livestock movement to less-contaminated pastures would lessen any toxic impact. Because the soil concentrations are greater than those associated with soil-free pasture herbage, ingested soils are the main dietary source of Pb and (especially) F to sheep. However, subjecting freshly sampled topsoils to sequential extraction procedures undertaken in the laboratory indicates that the majority of Pb and (especially) F may not be readily soluble in the ovine digestion system, so reducing the quantities of both PHEs available for absorption.

  10. Economic geology of the Bingham mining district, Utah, with a section on areal geology, and an introduction on general geology

    USGS Publications Warehouse

    Boutwell, J.M.; Keith, Arthur; Emmons, S.F.

    1905-01-01

    The field work of which this report represents the final results was first undertaken in the summer of the year 1900. This district had long been selected by the writer as worthy of special economic investigation, as well on account of the importance of its products as because of its geological structure and the peculiar relations of its ore deposits. It was not, however, until the summer mentioned above that the means at the disposal of the Survey, both pecuniary and scientific, justified its undertaking. As originally planned, the areal or surface geology was to have been worked out by Mr. Keith, who had already spent many years in unraveling the complicated geological structure of the Appalachian province, while Mr. Boutwell, who had more recently become attached to the Survey, was to have charge of the underground geology, or a study of the ore deposits, under the immediate supervision of the writer. When the time came for actually taking the field, it was found that the pressure of other work would not permit Mr. Keith to carry out fully the part allotted to him, and in consequence a part of his field work has fallen to Mr. Boutwell. Field work was commenced by the writer and Mr. Boutwell early in July, 1900. Mr. Keith joined the party on August 10, but was obliged to leave for other duties early in September. Mr. Boutwell carried on his field work continuously from July until December, taking up underground work after the snowfall had rendered work on the surface geology impracticable. The geological structure had proved to be unexpectedly intricate and complicated, so that, on the opening of the field season of 1901, it was found necessary to make further study in the light of results already worked out, and Mr. Boutwell spent some weeks in the district in the early summer of 1901. His field work that year, partly in California and partly in Arizona, as assistant to Mr. Waldemar Lindgren, lasted through the summer and winter and well into the spring of 1902

  11. New potassium-argon data on the age of mineralization and metamorphism in the Willow Creek mining district, southern Talkeetna Mountains, Alaska: A section in The United States Geological Survey in Alaska: Accomplishments during 1977

    USGS Publications Warehouse

    Silberman, Miles L.; Csejtey, Bela; Smith, James G.; Lanphere, Marvin A.; Wilson, Frederic H.

    1978-01-01

    The now largely abandoned Willow Creek mining district, southern Talkeetna Mountains, Alaska, produced nearly $18,000,000 in gold and minor silver between 1909 and the early 1950's. Mineralized quartz veins, which contain gold and silver along with minor quantities of base metals (in pyrite, galena, chalcopyrite, sphalerite, molybdenite, and arsenopyrite), cut Late Cretaceous and early Tertiary tonalite and quartzmica schist of probable Jurassic age (Ray, 1954; Silberman and others, 1976; Bela Csejtey, Jr., unpub. data, 1978).

  12. Potential Field, Geoelectrical and Reflection Seismic Investigations for Massive Sulphide Exploration in the Skellefte Mining District, Northern Sweden

    NASA Astrophysics Data System (ADS)

    Tavakoli, Saman; Dehghannejad, Mahdieh; García Juanatey, María de los Ángeles; Bauer, Tobias E.; Weihed, Pär; Elming, Sten-Åke

    2016-12-01

    Multi-scale geophysical studies were conducted in the central Skellefte district (CSD) in order to delineate the geometry of the upper crust (down to maximum 4.5 km depth) for prospecting volcanic massive sulphide (VMS) mineralization. These geophysical investigations include potential field, resistivity/induced polarization (IP), reflection seismic and magnetotelluric (MT) data which were collected between 2009 and 2010. The interpretations were divided in two scales: (i) shallow ( 1.5 km) and (ii) deep ( 4.5 km). Physical properties of the rocks, including density, magnetic susceptibility, resistivity and chargeability, were also used to improve interpretations. The study result delineates the geometry of the upper crust in the CSD and new models were suggested based on new and joint geophysical interpretation which can benefit VMS prospecting in the area. The result also indicates that a strongly conductive zone detected by resistivity/IP data may have been missed using other geophysical data.

  13. The Laramide Mesa formation and the Ojo de Agua caldera, southeast of the Cananea copper mining district, Sonora, Mexico

    USGS Publications Warehouse

    Cox, Dennis P.; Miller, Robert J.; Woodbourne, Keith L.

    2006-01-01

    The Mesa Formation extends from Cananea, Mexico, southeast to the Sonora River and is the main host rock of Laramide porphyry copper deposits in the Cananea District and at the Alacran porphyry prospect to the east. The Mesa consists of two members-a lower andesite and an upper dacite. The lowest part of the dacite member is a crystal tuff about 100 m thick. This tuff is the outfall of a caldera centered near the village of Ojo de Agua, dated by 40Ar/39Ar at 65.8 Ma ?0.4. The Ojo de Agua Caldera is about 9 km in diameter and is filled by a light gray biotite dacite tuff with abundant flattened pumice fragments. The volume of the caldera is estimated to be 24 km3.

  14. Impact of Zn-Pb mining in the Olkusz ore district on the Permian aquifer (SW Poland).

    PubMed

    Motyka, Jacek; Postawa, Adam

    2013-11-01

    Long-term extensive mining of Zn-Pb ores in the Olkusz area resulted in significant changes of water table levels and chemical composition of water in all aquifers in this area. Within the Permian aquifer, hydrochemical type of water evolved in two general stages. Short-term effect was freshening in the zones of contact with overlying the Triassic limestones and dolomites. Long-term effect was a change in flow pattern and, as a consequence, an inflow of naturally altered and antropogenically contaminated water from the Triassic aquifer into the Permian complex. This was especially intensive in densely fissured and fault zones. As a result of all these processes, hydrochemical type of water shifted from multi-ion types with various combinations of ions towards higher shares of sulphates, calcium and magnesium.

  15. Raman and micro-thermometric investigation of the fluid inclusions in quartz in a gold-rich formation from Lepaguare mining district (Honduras, Central America)

    NASA Astrophysics Data System (ADS)

    Bersani, D.; Salvioli-Mariani, E.; Mattioli, M.; Menichetti, M.; Lottici, P. P.

    2009-08-01

    Fluid inclusions in the quartz crystals present in gold-rich veins from central Honduras have been studied by means of micro-thermometry and micro-Raman spectroscopy in order to provide information on the physico-chemical conditions and chemical composition of the mineralizing fluids. The use of a confocal micro-Raman apparatus allowed to obtain information on the fluid composition, in particular on the gas phase, minimizing the contributions of the host matrix to the Raman signal. The samples studied were collected from an area (Lepaguare mining district, Northern-Central Honduras) rich in ore deposits due to the Cenozoic magmatic activity, where the gold and sulphide mineralization is connected with a system of quartz veins (few decimetres thick) occurring in low-grade metamorphic rocks and produced by hydrothermal fluids. The quartz crystals present in the gold-rich veins often contain fluid inclusions. Four types of fluid inclusions have been observed, but their assemblage in the same clusters and fracture systems, as well as their comparable salinity and homogenization data, suggest that they have the same origin. Micro-thermometry and Raman spectroscopy provide a composition of the mineralizing fluids attributable to the system H 2O-NaCl-KCl-CO 2-CH 4, with temperature and pressure intervals of 210-413 °C and 1050-3850 bar, respectively. These data agree with an epigenetic origin of the gold deposit (depth < 6 km) related to granitoid or granodiorite intrusions associated to orogenic environments.

  16. Comparison of Landsat Thematic Mapper and Geophysical and Environmental Research Imaging Spectrometer data for the Cuprite mining district, Esmeralda, and Nye counties, Nevada

    NASA Technical Reports Server (NTRS)

    Kierein-Young, Kathryn S.; Kruse, Fred A.

    1989-01-01

    Landsat TM images and Geophysical and Environmental Research Imaging Spectrometer (GERIS) data were analyzed for the Cuprite mining district and compared to available geologic and alteration maps of the area. The TM data, with 30 m resolution and 6 broadbands, allowed discrimination of general mineral groups. Clay minerals, playa deposits, and unaltered rocks were mapped as discrete spectral units using the TM data, but specific minerals were not determined, and definition of the individual alteration zones was not possible. The GERIS, with 15 m spatial resolution and 63 spectral bands, permitted construction of complete spectra and identification of specific minerals. Detailed spectra extracted from the images provided the ability to identify the minerals alunite, kaolinite, hematite, and buddingtonite by their spectral characteristics. The GERIS data show a roughly concentrically zoned hydrothermal system. The mineralogy mapped with the aircraft system conforms to previous field and multispectral image mapping. However, identification of individual minerals and spatial display of the dominant mineralogy add information that can be used to help determine the morphology and genetic origin of the hydrothermal system.

  17. Raman and micro-thermometric investigation of the fluid inclusions in quartz in a gold-rich formation from Lepaguare mining district (Honduras, Central America).

    PubMed

    Bersani, D; Salvioli-Mariani, E; Mattioli, M; Menichetti, M; Lottici, P P

    2009-08-01

    Fluid inclusions in the quartz crystals present in gold-rich veins from central Honduras have been studied by means of micro-thermometry and micro-Raman spectroscopy in order to provide information on the physico-chemical conditions and chemical composition of the mineralizing fluids. The use of a confocal micro-Raman apparatus allowed to obtain information on the fluid composition, in particular on the gas phase, minimizing the contributions of the host matrix to the Raman signal. The samples studied were collected from an area (Lepaguare mining district, Northern-Central Honduras) rich in ore deposits due to the Cenozoic magmatic activity, where the gold and sulphide mineralization is connected with a system of quartz veins (few decimetres thick) occurring in low-grade metamorphic rocks and produced by hydrothermal fluids. The quartz crystals present in the gold-rich veins often contain fluid inclusions. Four types of fluid inclusions have been observed, but their assemblage in the same clusters and fracture systems, as well as their comparable salinity and homogenization data, suggest that they have the same origin. Micro-thermometry and Raman spectroscopy provide a composition of the mineralizing fluids attributable to the system H(2)O-NaCl-KCl-CO(2)-CH(4), with temperature and pressure intervals of 210-413 degrees C and 1050-3850 bar, respectively. These data agree with an epigenetic origin of the gold deposit (depth < 6 km) related to granitoid or granodiorite intrusions associated to orogenic environments.

  18. Mercury species accumulation and trophic transfer in biological systems using the Almadén mining district (Ciudad Real, Spain) as a case of study.

    PubMed

    Patiño Ropero, M J; Rodríguez Fariñas, N; Mateo, R; Berzas Nevado, J J; Rodríguez Martín-Doimeadios, R C

    2016-04-01

    The impact of mercury (Hg) pollution in the terrestrial environments and the terrestrial food chains including the impact on human food consumption is still greatly under-investigated. In particular, studies including Hg speciation and detoxification strategies in terrestrial animals are almost non-existing, but these are key information with important implications for human beings. Therefore, in this work, we report on Hg species (inorganic mercury, iHg, and monomethylmercury, MeHg) distribution among terrestrial animal tissues obtained from a real-world Hg exposure scenario (Almadén mining district, Spain). Thus, we studied Hg species (iHg and MeHg) and total selenium (Se) content in liver and kidney of red deer (Cervus elaphus; n = 41) and wild boar (Sus scrofa; n = 16). Similar mercury species distribution was found for both red deer and wild boar. Major differences were found between tissues; thus, in kidney, iHg was clearly the predominant species (more than 81%), while in liver, the species distribution was less homogeneous with a percentage of MeHg up to 46% in some cases. Therefore, Hg accumulation and MeHg transfer were evident in terrestrial ecosystems. The interaction between total Se and Hg species has been evaluated by tissue and by animal species. Similar relationships were found in kidney for both Hg species in red deer and wild boar. However, in liver, there were differences between animals. The possible underlying mechanisms are discussed.

  19. Comparison of Landsat Thematic Mapper and Geophysical and Environmental Research Imaging Spectrometer data for the Cuprite mining district, Esmeralda, and Nye counties, Nevada

    NASA Astrophysics Data System (ADS)

    Kierein-Young, Kathryn S.; Kruse, Fred A.

    Landsat TM images and Geophysical and Environmental Research Imaging Spectrometer (GERIS) data were analyzed for the Cuprite mining district and compared to available geologic and alteration maps of the area. The TM data, with 30 m resolution and 6 broadbands, allowed discrimination of general mineral groups. Clay minerals, playa deposits, and unaltered rocks were mapped as discrete spectral units using the TM data, but specific minerals were not determined, and definition of the individual alteration zones was not possible. The GERIS, with 15 m spatial resolution and 63 spectral bands, permitted construction of complete spectra and identification of specific minerals. Detailed spectra extracted from the images provided the ability to identify the minerals alunite, kaolinite, hematite, and buddingtonite by their spectral characteristics. The GERIS data show a roughly concentrically zoned hydrothermal system. The mineralogy mapped with the aircraft system conforms to previous field and multispectral image mapping. However, identification of individual minerals and spatial display of the dominant mineralogy add information that can be used to help determine the morphology and genetic origin of the hydrothermal system.

  20. Mesozoic Magmatism and Base-Metal Mineralization in the Fortymile Mining District, Eastern Alaska - Initial Results of Petrographic, Geochemical, and Isotopic Studies in the Mount Veta Area

    USGS Publications Warehouse

    Dusel-Bacon, Cynthia; Slack, John F.; Aleinikoff, John N.; Mortensen, James K.

    2009-01-01

    We present here the initial results of a petrographic, geochemical, and isotopic study of Mesozoic intrusive rocks and spatially associated Zn-Pb-Ag-Cu-Au prospects in the Fortymile mining district in the southern Eagle quadrangle, Alaska. Analyzed samples include mineralized and unmineralized drill core from 2006 and 2007 exploration by Full Metal Minerals, USA, Inc., at the Little Whiteman (LWM) and Fish prospects, and other mineralized and plutonic samples collected within the mining district is part of the USGS study. Three new ion microprobe U-Pb zircon ages are: 210 +- 3 Ma for quartz diorite from LWM, 187 +- 3 Ma for quartz monzonite from Fish, and 70.5 +- 1.1 Ma for altered rhyolite porphyry from Fish. We also present 11 published and unpublished Mesozoic thermal ionization mass spectrometric U-Pb zircon and titanite ages and whole-rock geochemical data for the Mesozoic plutonic rocks. Late Triassic and Early Jurassic plutons generally have intermediate compositions and are slightly foliated, consistent with synkinematic intrusion. Several Early Jurassic plutons contain magmatic epidote, indicating emplacement of the host plutons at mesozonal crustal depths of greater than 15 km. Trace-element geochemical data indicate an arc origin for the granitoids, with an increase in the crustal component with time. Preliminary study of drill core from the LWM Zn-Pb-Cu-Ag prospect supports a carbonate-replacement model of mineralization. LWM massive sulfides consist of sphalerite, galena, and minor pyrite and chalcopyrite, in a gangue of calcite and lesser quartz; silver resides in Sb-As-Ag sulfosalts and pyrargyrite, and probably in submicroscopic inclusions within galena. Whole-rock analyses of LWM drill cores also show elevated In, an important metal in high-technology products. Hypogene mineralized rocks at Fish, below the secondary Zn-rich zone, are associated with a carbonate host and also may be of replacement origin, or alternatively, may be a magnetite

  1. 78 FR 58049 - Proposed Establishment of the Adelaida District, Creston District, El Pomar District, Paso Robles...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ... tributaries, has created a variety of landforms within the viticultural area, including alluvial fans... precipitation of 11.5 inches; Winkler Region II climate. El Pomar District High terraces, alluvial fans, and... rainfall of 10.4 inches; transitional Winkler Region III to IV climate. San Miguel District Alluvial...

  2. Three-dimensional oxygen isotope imaging of convective fluid flow around the Big Bonanza, Comstock lode mining district, Nevada

    USGS Publications Warehouse

    Criss, R.E.; Singleton, M.J.; Champion, D.E.

    2000-01-01

    Oxygen isotope analyses of propylitized andesites from the Con Virginia and California mines allow construction of a detailed, three-dimensional image of the isotopic surfaces produced by the convective fluid flows that deposited the famous Big Bonanza orebody. On a set of intersecting maps and sections, the δ18O isopleths clearly show the intricate and conformable relationship of the orebody to a deep, ~500 m gyre of meteoric-hydrothermal fluid that circulated along and above the Comstock fault, near the contact of the Davidson Granodiorite. The core of this gyre (δ18O = 0 to 3.8‰) encompasses the bonanza and is almost totally surrounded by rocks having much lower δ18O values (–1.0 to –4.4‰). This deep gyre may represent a convective longitudinal roll superimposed on a large unicellular meteoric-hydrothermal system, producing a complex flow field with both radial and longitudinal components that is consistent with experimentally observed patterns of fluid convection in permeable media.

  3. Stable mercury isotope variation in rice plants (Oryza sativa L.) from the Wanshan mercury mining district, SW China.

    PubMed

    Yin, Runsheng; Feng, Xinbin; Meng, Bo

    2013-03-05

    To study the sources and transformations of Hg in the rice plant ( Oryza sativa L.), stable Hg isotope variations in different tissues (foliage, root, stem, and seed) of rice which were collected from the Wanshan mercury mine (WSMM, Guizhou province, SW China) were investigated by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS). In comparison, Hg isotope compositions of paddy soil, lichen, and direct ambient air samples in WSMM were also analyzed. We observed that mass dependent fractionation (MDF) of Hg differed by up to ∼ 3.0‰ in δ(202)Hg values and that mass independent fractionation (MIF) of Hg isotopes affected the odd Hg isotopes to produce a ∼ 0.40‰ range in Δ(199)Hg (and Δ(201)Hg) values in tissues of rice plant. The 1:1 Δ(199)Hg/Δ(201)Hg ratio in tissues of rice supported the hypothesis that a fraction of Hg in tissues of rice plants has undergone a photoreduction process prior to being accumulated by rice plants. We suggest that the variation of MIF represents a mixing between soil Hg and atmospheric Hg in rice plants. The estimated fraction of atmospheric Hg (f) in tissues of rice followed the trend of f leaf > f stem > f seed > f root. Finally, we demonstrated a significant MDF of >1.0‰ in δ(202)Hg during the processes of absorption of atmospheric Hg by leaf tissues and of absorption of soil Hg by roots. Our study demonstrated that Hg isotopes may represent an important contribution both to the study of Hg transportation in plants and to the understanding of sources of Hg contamination to critical food crops.

  4. Geology and Mineral Resources of the North Absaroka Wilderness and Vicinity, Park County, Wyoming, with Sections on Mineralization of the Sunlight Mining Region and Geology and Mineralization of the Cooke City Mining District, and a Section on Aeromagnetic Survey

    USGS Publications Warehouse

    Nelson, Willis H.; Prostka, Harold J.; Williams, Frank E.; Elliott, James E.; Peterson, Donald L.

    1980-01-01

    ; but such deposits, if present in the wilderness, would be too deeply buried, too small, or too sporadically distributed to be profitably located and exploited. Copper and gold mines and prospects are present on the fringes of the wilderness, but otherwise the area seems to be devoid of economically valuable concentrations of metallic minerals. No surface evidence of geothermal-energy potential was found. Known mineral deposits in the vicinity of the North Absaroka Wilderness are associated with intrusive rocks. From the Cooke City mining district, just north of the wilderness, replacement deposits in Upper Cambrian carbonate rocks may extend a short distance into the north edge of the wilderness, In the Sunlight mining region, an enclave nearly surrounded by the wilderness, mineralization occurs in veins and is disseminated in volcanic and plutonic rocks. Richer concentrations of metallic minerals may occur in carbonate rocks adjacent to intrusive bodies at depth beneath the volcanic rocks in the Sunlight region. A few small intrusive bodies occur in the wilderness, but no significant associated mineralization was detected. Aeromagnetic data indicate that other intrusives not exposed by erosion may occur in the wilderness; however, no significant metamorphism or alteration is evident at the surface to indicate their presence. Although most of the rocks of the wilderness are of igneous origin, they are all so old (Eocene) that it is unlikely that they retain any original heat. The Pleistocene rhyolitic ash-flow tuffs in the southwestern part of the wilderness were erupted from sources in Yellowstone National Park just to the west; however, in the wilderness these tuffs are too thin to contain any residual heat.

  5. Geochemistry, mineralization, structure, and permeability of a normal-fault zone, Casino mine, Alligator Ridge district, north central Nevada

    NASA Astrophysics Data System (ADS)

    Hammond, K. Jill; Evans, James P.

    2003-05-01

    We examine the geochemical signature and structure of the Keno fault zone to test its impact on the flow of ore-mineralizing fluids, and use the mined exposures to evaluate structures and processes associated with normal fault development. The fault is a moderately dipping normal-fault zone in siltstone and silty limestone with 55-100 m of dip-slip displacement in north-central Nevada. Across-strike exposures up to 180 m long, 65 m of down-dip exposure and 350 m of along-strike exposure allow us to determine how faults, fractures, and fluids interact within mixed-lithology carbonate-dominated sedimentary rocks. The fault changes character along strike from a single clay-rich slip plane 10-20 mm thick at the northern exposure to numerous hydrocarbon-bearing, calcite-filled, nearly vertical slip planes in a zone 15 m wide at the southern exposure. The hanging wall and footwall are intensely fractured but fracture densities do not vary markedly with distance from the fault. Fault slip varies from pure dip-slip to nearly pure strike-slip, which suggests that either slip orientations may vary on faults in single slip events, or stress variations over the history of the fault caused slip vector variations. Whole-rock major, minor, and trace element analyses indicate that Au, Sb, and As are in general associated with the fault zone, suggesting that Au- and silica-bearing fluids migrated along the fault to replace carbonate in the footwall and adjacent hanging wall rocks. Subsequent fault slip was associated with barite and calcite and hydrocarbon-bearing fluids deposited at the southern end of the fault. No correlation exists at the meter or tens of meter scale between mineralization patterns and fracture density. We suggest that the fault was a combined conduit-barrier system in which the fault provides a critical connection between the fluid sources and fractures that formed before and during faulting. During the waning stages of deposit formation, the fault behaved as

  6. Finding Gold in Data Mining

    ERIC Educational Resources Information Center

    Flaherty, Bill

    2013-01-01

    Data-mining systems provide a variety of opportunities for school district personnel to streamline operations and focus on student achievement. This article describes the value of data mining for school personnel, finance departments, teacher evaluations, and in the classroom. It suggests that much could be learned about district practices if one…

  7. Geology and geochemistry of the Mammoth breccia pipe, Copper Creek mining district, southeastern Arizona: Evidence for a magmatic-hydrothermal origin

    USGS Publications Warehouse

    Anderson, E.D.; Atkinson, W.W.; Marsh, T.; Iriondo, A.

    2009-01-01

    The Copper Creek mining district, southeastern Arizona, contains more than 500 mineralized breccia pipes, buried porphyry-style, copper-bearing stockworks, and distal lead-silver veins. The breccia pipes are hosted by the Copper Creek Granodiorite and the Glory Hole volcanic rocks. The unexposed Mammoth breccia pipe, solely recognized by drilling, has a vertical extent of 800 m and a maximum width of 180 m. The pipe consists of angular clasts of granodiorite cemented by quartz, chalcopyrite, bornite, anhydrite, and calcite. Biotite 40Ar/ 39Ar dates suggest a minimum age of 61.5??0.7 Ma for the host Copper Creek Granodiorite and 40Ar/39Ar dates on hydrothermal sericite indicate an age of 61.0??0.5 Ma for copper mineralization. Fluid inclusion studies suggest that a supercritical fluid with a salinity of approximately 10 wt.% NaCl equiv. condensed to a dilute aqueous vapor (1-2.8 wt.% NaCl equiv.) and a hypersaline brine (33.4-35.1 wt.% NaCl equiv.). Minimum trapping temperatures are 375??C and trapping depths are estimated at 2 km. Sulfur isotope fractionation of cogenetic anhydrite and chalcopyrite yields a temperature of mineralization of 469??25??C. Calculated oxygen and hydrogen isotope values for fluids in equilibrium with quartz and sericite range from 10.2??? to 13.4??? and -60??? to -39???, respectively, suggesting that the mineralizing fluid was dominantly magmatic. Evidence from the stable isotope and fluid inclusion analyses suggests that the fluids responsible for Cu mineralization within the Mammoth breccia pipe exsolved from a gray porphyry phase found at the base of the breccia pipe. ?? Springer-Verlag 2008.

  8. On the origin of zebra textures in Mississippi Valley-Type Pb-Zn Deposits with a special emphasis on the San Vicente Mine, Peru

    NASA Astrophysics Data System (ADS)

    Kelka, Ulrich; Koehn, Daniel

    2014-05-01

    grain boundaries move according to a rate law based on dissolution-precipitation processes as a function of differences in surface energy. Layered distributions of particle densities are initially set as a background. With this simple simulation of grain growth influenced by particle distributions we show, that this process is able to develop structural patterns that are very similar to those present in the natural samples from the San Vicente Mine in Peru. References BONS P D, KOEHN D, and JESSELL W (2008) Microdynamic Simulation. Springer-Verlag Berlin Heidelberg FONTBONTé L (1993) Self-organization fabrics in carbonate-hosted ore deposits: the example of diagenetic crystallization rhythmites (DCRs), In: Current research in geology applied to ore deposits. Proceedings of the Second Biennial SGA Meeting, Granada, Spain, p. 11 -14 MERINO E, CANALS A, and FLECHTER R C (2006) Genesis of self-organized zebra textures in burial dolomites: Displacive veins, induced stress, and dolomitization. Geologica Acta, Vol. 4 No. 3, p. 383-393

  9. 75 FR 3996 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... Planning, San Joaquin Valley Air Pollution Control District; letter dated and received August 17, 2009... Sadredin, Executive Director/Air Pollution Control Officer of San Joaquin Valley Air Pollution Control...: EPA's Analysis of San Joaquin Valley Unified Air Pollution Control District's Rule 4684,...

  10. Bayesian integration of radioisotope dating (210Pb, 137Cs, 241Am, 14C) and an 18-20th century mining history of Brotherswater, English Lake District

    NASA Astrophysics Data System (ADS)

    Schillereff, Daniel; Chiverrell, Richard; Macdonald, Neil; Hooke, Janet; Welsh, Katharine; Piliposyan, Gayane; Appleby, Peter

    2014-05-01

    Lake sediment records are often a useful tool for investigating landscape evolution as geomorphic changes in the catchment are reflected by altered sediment properties in the material transported through the watershed and deposited at the lake bed. Recent research at Brotherswater, an upland waterbody in the Lake District, northwest England, has focused on reconstructing historical floods from their sedimentary signatures and calculating long-term sediment and carbon budgets from fourteen sediment cores extracted from across the basin. Developing accurate chronological control is essential for these tasks. One sediment core (BW11-2; 3.5 m length) from the central basin has been dated using artificial radionuclide measurements (210Pb, 137Cs, 241Am) for the uppermost sediments and radiocarbon (14C) for lower sediments. The core appears to span the past 1500 years, however a number of problems have arisen. We present our explanations for these errors, the independent chronological techniques used to generate an accurate age-depth model for this core and methods for its transferral to the other 13 cores extracted from the basin. Two distinct 137Cs markers, corresponding to the 1986 Chernobyl disaster and 1960s weapons testing, confirm the 210Pb profile for sediment deposition since ~1950, but calculations prior to this appear erroneous, possibly due to a hiatus in the sediment record. We used high-resolution geochemical profiles (measured by XRF) to cross-correlate with a second 210Pb-dated chronology from a more distal location, which returned more sensible results. Unfortunately, the longer 14C sequence exhibits two age-reversals (radiocarbon dates that are too old). We believe the uppermost two dates are erroneous, due to a shift in inflow location as a flood prevention method ~1900 A.D., dated using information from historical maps. The lower age-reversal coincides with greater supply of terrigenous material to the lake (increased Zr, K, Ti concentrations

  11. Development of biological soil crusts and their influence on soil hydrology in the recultivation area of lignite open-cast mining district in Lower Lusatia (Germany)

    NASA Astrophysics Data System (ADS)

    Spröte, R.; Veste, M.; Fischer, T.; Raab, T.; Bens, O.; Hüttl, R. F.

    2012-04-01

    Cyanobacteria, green algae, mosses and lichens are often the first colonizers of substrate and initial soil surfaces. They are an important factor of initial soil formation as they stabilize the substrate and decrease erosion processes. Biological soil crusts accumulate the initial soil organic matter and provide nitrogen fixation. Once settled, the crusts influence the soil water regime by delaying or limiting infiltration through enhanced water repellency. Aim of this study was to compare the influence of biological soil crusts on soil hydrology under conditions on various substrates and of different ages in recultivated areas of the open-cast mining district of Lower Lusatia (Brandenburg, NE Germany) with various recultivation aims. In Brandenburg (NE Germany), where the climate is transitional between oceanic and continental and the summers are characterized by generally low of precipitation (mean annual rainfall 559 mm, mean annual temperature 9.3° C) open landscapes provide ideal conditions for biological soil crusts, e. g. on mobile sand dunes in former military training areas and in recultivation areas related to open-cast mining with initial soil development. Here biological soil crusts are commonly found (Spröte et al., 2010). At five study sites in recultivation areas with different reclamation approaches (natural development, pine reforestation, birch reforestation) we defined four types of biological soil crusts: i) cyanobacterial and green algae crusts on the soil surface with no vegetation where dominating sand grains were physically stabilized in their contact zones by this crust type (type 1), ii) cyanobacteria and green algae partially filled in the matrix pores and enmeshed sand grains between sparse vegetation cover (type 2), iii) biological soil crusts with mosses which covered most of the surface between the vegetation (type 3) and (iv) with soil lichens (type 4). We investigated the development of the amount of chlorophyll a which is an

  12. Tables of basic data to accompany report on geologic and hydrologic features of the San Bernardino area, California, with special reference to underflow across the San Jacinto fault

    USGS Publications Warehouse

    Garrett, A.A.; Dutcher, L.C.

    1954-01-01

    This appendix presents a part of the basic data collected by the United States Geological Survey in cooperation with the San Bernardino County Flood Control District in the ground-water investigation of the San Bernardino area, California.

  13. Prediction of ground motion due to mining seismic activity: a general prediction scheme applied to assess impacts on tailings pond in Legnica-Glogow Copper District in Poland in the years 2011-2050

    NASA Astrophysics Data System (ADS)

    Lasocki, S.; Orlecka-Sikora, B.

    2012-04-01

    Copper-ore excavation in the Legnica-Głogow Copper District (LGCD) in south-west Poland is accompanied by intense induced seismic activity. In-mine seismic systems record altogether thousands events annually, whose local magnitude ranges from 0.4 to 4.5. Within a range of mining tremors impact is the Zelazny Most tailings pond, one of the largest waste dumps in the world. To ensure its safety a probabilistic seismic hazard analysis (PSHA) is performed every few years and its results are used to adjust mining plans. In this work we present the newest predictions of limits of ground motion at the Żelazny Most pond embankments for the period 2011-2050. A seismic process in mines is controlled predominantly by time-varying mining works, therefore the results of PSHA for mining induced seismicity are predictions related to a prescribed time period in the future. Here, ground motion has been parameterized by peak horizontal and peak vertical acceleration and the exceedance probability of the limit is 5 per-cent. The work is done in a general prediction scheme. The expected seismic excitation is linked to the continuation of mining in LGCD. Based on mining plans 84 seismic zones, expected to become active in the years 2011-2050, have been identified and their periods of activity have been established. Seismic activity associated with past and current mining works is used to choose alternative models of event rate and event size distribution for the seismicity in the zones of future activity. Analyzing mining seismic catalogs, 188 zones active in the past and/or at present have been singled out and their probabilistic characteristics have been determined. It is assumed that the a priori probability of a model to be followed in a future zone is inversely proportional to the distance between the past zone, which originated the model, and the future active zone. As an epicenter distribution in future zones, the 2D uniform distribution is assumed, supposing that tremors may

  14. 33 CFR 165.T11-534 - Safety zone; Bay Bridge construction, San Francisco Bay, San Francisco, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Safety zone; Bay Bridge construction, San Francisco Bay, San Francisco, CA. 165.T11-534 Section 165.T11-534 Navigation and Navigable... Eleventh Coast Guard District § 165.T11-534 Safety zone; Bay Bridge construction, San Francisco Bay,...

  15. 33 CFR 165.1102 - Security Zone; Naval Base Point Loma; San Diego Bay, San Diego, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Naval Base Point... Guard District § 165.1102 Security Zone; Naval Base Point Loma; San Diego Bay, San Diego, CA. (a) Location. The following area is a security zone: The water adjacent to the Naval Base Point Loma, San...

  16. 33 CFR 165.T11-630 - Safety zone; Giants Enterprises Fireworks Display, San Francisco Bay, San Francisco, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Fireworks Display, San Francisco Bay, San Francisco, CA. 165.T11-630 Section 165.T11-630 Navigation and... Areas Eleventh Coast Guard District § 165.T11-630 Safety zone; Giants Enterprises Fireworks Display, San... safety zone applies to the nearest point of the fireworks barge within a radius of 100 feet during...

  17. 6. Photocopy of photograph, c. 1892. DISTANT VIEW OF SAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photocopy of photograph, c. 1892. DISTANT VIEW OF SAN JUAN SMELTING AND MINING COMPANY WORKS WITH EXTANT SMELTER STACK AT LEFT. (Original print in possession of Strater Hotel, Durango, Colorado. Photographer unknown.) - San Juan & New York Mining & Smelting Company, Smelter Stack, State Route 160, Durango, La Plata County, CO

  18. 76 FR 76046 - Interim Final Determination To Defer Sanctions, San Joaquin Valley Unified Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-06

    ... approval of revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD or... Valley Unified Air Pollution Control District (``SJVUAPCD'' or ``District'') Rules 2020 (Exemptions) and... AGENCY 40 CFR Part 52 Interim Final Determination To Defer Sanctions, San Joaquin Valley Unified...

  19. Seeking Justice in San Francisco

    ERIC Educational Resources Information Center

    Pascopella, Angela

    2010-01-01

    This article discusses the life of Carlos A. Garcia, superintendent at the San Francisco Unified School District. Garcia was born in Chicago, but his parents shortly thereafter moved back to their homeland of Mexico for a few years. When Garcia was almost 5, his family moved to Los Angeles, where his parents worked in factories and Garcia was…

  20. Environment of ore deposition in the creede mining district, San Juan Mountains, Colorado: Part V. Epithermal mineralization from fluid mixing in the OH vein

    USGS Publications Warehouse

    Hayba, D.O.

    1997-01-01

    Detailed fluid inclusion studies on coarse-grained sphalerite from the OH vein, Creede, Colorado, have shown that the abrupt color changes between growth zones correspond to abrupt changes in the nature of the ore fluids. Within each growth zone, however, the composition of the fluids remained constant. The base of a distinctive orange-brown growth zone marks a sharp increase in both temperature and salinity relative to the preceding yellow-white zone. The orange-brown growth zone can be correlated along much of the vein and is believed to represent a time-stratigraphic interval. Along the vein, temperatures and salinities of fluid inclusions within this interval show a systematic decrease from about 285??C and 11.5 wt percent NaCl equiv near the base of the vein to about 250??C and 8 wt percent NaCl equiv, respectively, near the top of the vein. The iron concentration of this sphalerite growth zone shows a similar pattern, decreasing from about 2.8 to 1.2 mole percent FeS. When plotted on an enthalpy-salinity diagram, the fluid inclusion data define a spatial trend indicating the progressive mixing of deeply circulating hydrothermal brines with overlying, dilute ground waters. The hydrothermal brines entered the OH vein from below at a temperature, salinity, and density of approximately 285??C, 11.5 wt percent NaCl equiv, and 860 kg/m3, respectively, whereas the overlying ground waters appear to have been preheated to roughly 150??C and had an assumed salinity of 0 wt percent and a density of 920 kg/m3. The greater density of the heated ground water promoted mixing with the hydrothermal brine within the open fractures, causing sphalerite deposition. Although there were also episodes of boiling during vein mineralization, boiling appears unimportant for this sphalerite. Isotopic evidence and geochemical modeling studies also indicate that mixing was the depositional mechanism for sphalerite. An important aspect of the mixing hydrology of the Creede system involves an aquitard overlying the OH vein. This low permeability zone restricted the flow of ground water into the vein from above and forced the upwelling hydrothermal fluids to flow laterally along the vein. The mixing environment thus occurred along the interface between a deeply circulating hydrothermal convection cell and a topographically driven shallow ground-water system.

  1. Environment of ore deposition in the Creede mining district, San Juan Mountains, Colorado: Part VI. Maximum duration for mineralization of the OH vein

    USGS Publications Warehouse

    Campbell, W.R.; Barton, P.B.

    2005-01-01

    The rate at which ore deposits form is one of the least well established parameters in all of economic geology. However, increased detail in sampling, improved technology of dating, and sophistication in modeling are reducing the uncertainties and establishing that ore formation, at least for the porphyry copper-skarn-epithermal base and precious metals deposit package, may take place in surprisingly brief intervals. This contribution applies another approach to examine the duration of mineralization. The degree to which compositional gradients within single crystals has flattened through solid-state diffusion offers a measure of the thermal dose (that is temperature combined with time) that the crystals have been subjected to since deposition. Here we examine the steepness of gradients in iron content within individual single sphalerite crystals from the epithermal silver-lead-zinc deposit in the OH vein at Creede, Colorado. Two initial textures are considered: growth-banded crystals and compositionally contrasting overgrowths that succeed crosscutting dissolution or fractured surfaces. The model used estimates the maximum possible time by assuming a perfectly sharp original compositional step, and it asks how long it would take at a known temperature for the gradient measured today to have formed. Applying the experimentally determined diffusion rates of Mizuta (1988a) to compositional gradients (ranging from 0.4-2.2 mol % FeS/??m) measured by the electron microprobe in 2-??m steps on banded sphalerite formed early in the paragenetic history yields a maximum duration of less than ???10,000 yr. Sphalerite from a solution unconformity in a position midway through the paragenetic sequence is indistinguishable from instantaneous deposition, supporting the conclusion of rapid ore formation. While this formation interval seems very brief, it is consistent with less well constrained estimates using entirely different criteria. ?? 2005 Society of Economic Geologists, Inc.

  2. Environment of ore deposition in the Creede mining district, San Juan Mountains, Colorado; Part IV, source of fluids, from oxygen, hydrogen, and carbon isotope studies

    USGS Publications Warehouse

    Bethke, P.M.; Rye, R.O.

    1979-01-01

    The hydrogen isotopic composition of fluids responsible for formation of the near-surface silver-base metal vein deposits at Creede was measured by direct analysis of inclusion fluids in sphalerite, quartz, and rhodochrosite and was estimated from analyses of illite and chlorite. The oxygen isotopic composition was determined directly on inclusion fluids in sphalerite and was estimated from analyses of quartz, illite, rhodochrosite, siderite, and adularia. The carbon isotopic composition was estimated from analyses of rhodochrosite and siderite. The ranges in isotopic composition for water and CO2 in the fluids associated with the formation of each of the minerals is given below (number of determinations given in parentheses):Mineral delta D (sub H2) O ppm delta 18 O (sub H2) O ppm delta 13 C (sub CO2) ppmSphalerite -81 to -54 (4) -10.1 to -4.5 (4)Quartz -97 to -86 (4) -5.9 to 1.8 (18)Illite -62 to -50 (8) -1.6 to 1.2(7)Chlorite -64 to -55 (10) -2.2 to 0.8 (10)Adularia 4.2 (1)Rhodochrosite -82 to -78 (2) 4.2 to 9.4 (9) -5.7 to -4.2 (9)Siderite 4.9 to 9.9 (6) -6.9 to -2.7 (6)The delta D (sub H2) O and delta 18 O (sub H2) O values of fluids associated with the formation of sphalerite, quartz, illite/chlorite, and carbonate minerals differ substantially from one another, and these differences appear to have been maintained throughout the depositional history, regardless of the positions of the minerals in the paragenetic sequence.The data suggest that waters from three coexisting reservoirs fed the vein system alternately and episodically during vein formation, and apparently there was little mixing of the fluids from the different reservoirs. The hydrogen, oxygen, and carbon isotope data suggest that the carbonate waters were deep seated, probably dominantly magmatic, in origin. The sphalerite and illite/chlorite waters must have been dominantly meteoric in origin and substantially oxygen shifted by exchange with the volcanic country rocks. The quartz waters were also oxygen shifted meteoric waters but were some 40 per mil lower in deuterium content than the sphalerite and illite/chlorite waters.We propose that the quartz fluids entered the vein system from reservoirs beneath the mountainous areas to the north in the vicinity of the present Continental Divide, but that the sphalerite and illite/chlorite fluids entered the vein system from a topographically low area to the south along the structural moat of the Creede caldera. The difference in delta D between the two meteoric waters may reflect differences in altitude of the recharge areas for the two reservoirs or may be clue to isotopic evolution of the closed-basin lake and interstitial waters in the moat surrounding the Creede caldera.

  3. Sources of mercury to San Francisco Bay surface sediment as revealed by mercury stable isotopes

    NASA Astrophysics Data System (ADS)

    Gehrke, Gretchen E.; Blum, Joel D.; Marvin-DiPasquale, Mark

    2011-02-01

    Mercury (Hg) concentrations and isotopic compositions were examined in shallow-water surface sediment (0-2 cm) from San Francisco (SF) Bay to determine the extent to which historic Hg mining contributes to current Hg contamination in SF Bay, and to assess the use of Hg isotopes to trace sources of contamination in estuaries. Inter-tidal and wetland sediment had total Hg (Hg T) concentrations ranging from 161 to 1529 ng/g with no simple gradients of spatial variation. In contrast, inter-tidal and wetland sediment displayed a geographic gradient of δ 202Hg values, ranging from -0.30‰ in the southern-most part of SF Bay (draining the New Almaden Hg District) to -0.99‰ in the northern-most part of SF Bay near the Sacramento-San Joaquin River Delta. Similar to SF Bay inter-tidal sediment, surface sediment from the Alviso Slough channel draining into South SF Bay had a δ 202Hg value of -0.29‰, while surface sediment from the Cosumnes River and Sacramento-San Joaquin River Delta draining into north SF Bay had lower average δ 202Hg values of -0.90‰ and -0.75‰, respectively. This isotopic trend suggests that Hg-contaminated sediment from the New Almaden Hg District mixes with Hg-contaminated sediment from a low δ 202Hg source north of SF Bay. Tailings and thermally decomposed ore (calcine) from the New Idria Hg mine in the California Coast Range had average δ 202Hg values of -0.37 and +0.03‰, respectively, showing that Hg calcination fractionates Hg isotopes resulting in Hg contamination from Hg(II) mine waste products with higher δ 202Hg values than metallic Hg(0) produced from Hg mines. Thus, there is evidence for at least two distinct isotopic signals for Hg contamination in SF Bay: Hg associated with calcine waste materials at Hg mines in the Coast Range, such as New Almaden and New Idria; and Hg(0) produced from these mines and used in placer gold mines and/or in other industrial processes in the Sierra Nevada region and SF Bay area.

  4. Sources of mercury to San Francisco Bay surface sediment as revealed by mercury stable isotopes

    USGS Publications Warehouse

    Gehrke, Gretchen E.; Blum, Joel D.; Marvin-DePasquale, Mark

    2011-01-01

    Mercury (Hg) concentrations and isotopic compositions were examined in shallow-water surface sediment (0–2 cm) from San Francisco (SF) Bay to determine the extent to which historic Hg mining contributes to current Hg contamination in SF Bay, and to assess the use of Hg isotopes to trace sources of contamination in estuaries. Inter-tidal and wetland sediment had total Hg (HgT) concentrations ranging from 161 to 1529 ng/g with no simple gradients of spatial variation. In contrast, inter-tidal and wetland sediment displayed a geographic gradient of δ202Hg values, ranging from -0.30% in the southern-most part of SF Bay (draining the New Almaden Hg District) to -0.99% in the northern-most part of SF Bay near the Sacramento–San Joaquin River Delta. Similar to SF Bay inter-tidal sediment, surface sediment from the Alviso Slough channel draining into South SF Bay had a δ202Hg value of -0.29%, while surface sediment from the Cosumnes River and Sacramento–San Joaquin River Delta draining into north SF Bay had lower average δ202Hg values of -0.90% and -0.75%, respectively. This isotopic trend suggests that Hg-contaminated sediment from the New Almaden Hg District mixes with Hg-contaminated sediment from a low δ202Hg source north of SF Bay. Tailings and thermally decomposed ore (calcine) from the New Idria Hg mine in the California Coast Range had average δ202Hg values of -0.37 and +0.03%, respectively, showing that Hg calcination fractionates Hg isotopes resulting in Hg contamination from Hg(II) mine waste products with higher δ202Hg values than metallic Hg(0) produced from Hg mines. Thus, there is evidence for at least two distinct isotopic signals for Hg contamination in SF Bay: Hg associated with calcine waste materials at Hg mines in the Coast Range, such as New Almaden and New Idria; and Hg(0) produced from these mines and used in placer gold mines and/or in other industrial processes in the Sierra Nevada region and SF Bay area.

  5. Origin of intraformational folds in the Jurassic Todilto Limestone, Ambrosia Lake uranium mining district, McKinley and Valencia counties, New Mexico

    USGS Publications Warehouse

    Green, M.W.

    1982-01-01

    The Todilto Limestone of Middle Jurassic age in the Ambrosia Lake uranium mining district of McKinley and Valencia Counties, New Mexico, is the host formation for numerous small- to medium-sized uranium deposits in joints, shear zones, and fractures within small- to large-scale intraformational folds. The folds probably were formed as a result of differential sediment loading when eolian sand dunes of the overlying Summerville Formation of Middle Jurassic age migrated over soft, chemically precipitated, lime muds of the Todilto shortly after their deposition in a regressive, mixed fresh and saline lacustrine or marine environment of deposition. Encroachment of Summerville eolian dunes over soft Todilto lime muds was apparently a local phenomenon and was restricted to postulated beltlike zones which trended radially across the Todilto coastline toward the receding body of water. Intraformational folding is believed to be confined to the pathways of individual eolian dunes or clusters of dunes within the dune belts. During the process of sediment loading by migrating sand dunes, layers of Todilto lime mud were differentially compacted, contorted, and dewatered, producing both small- and large-scale plastic deformation structures, including convolute laminations, mounds, rolls, folds, and small anticlines and synclines. With continued compaction and dewatering, the mud, in localized areas, reached a point of desaturation at which sediment plasticity was lost. Prolonged loading by overlying dune sands thus caused faulting, shearing, fracturing, and jointing of contorted limestone beds. These areas or zones of deformation within the limestone became the preferred sites of epigenetic uranium mineralization because of the induced transmissivity created by sediment rupture. Along most of the prograding Todilto coastline, adjacent to the eolian dune belts, both interdune and coastal sabkha environments dominated during Todilto-Summerville time. Sediments in coastal areas

  6. East Bay Municipal Utility District Settlement

    EPA Pesticide Factsheets

    The East Bay Municipal Utility District and its seven member communities own and operate a separate sanitary sewer system, which serves approximately 650,000 customers on the eastern side of San Francisco Bay in California.

  7. 7 CFR 920.12 - District.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Del Norte, Humboldt, Trinity, Mendocino, Lake, Sonoma, Marin, Napa, Solano, Yolo, Colusa, and Glenn..., Santa Cruz, San Benito and Monterey. (f) District 6 shall include the counties of Mono, Mariposa,...

  8. Mt. San Antonio Community College Information Notebook; Volume Two, 1985.

    ERIC Educational Resources Information Center

    Mount San Antonio Community Coll. District, Walnut, CA.

    This databook contains some of the basic information to be used in decision making and planning in the Mt. San Antonio College (MSAC) District. Part I focuses on the demographic characteristics of the district population, feeder school districts, and data from other educational providers. Part II presents statewide data on potential enrollment by…

  9. 75 FR 56889 - Revisions to the California State Implementation Plan, San Diego County Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-17

    ...: EPA is taking direct final action to approve revisions to the San Diego County Air Pollution Control... Environmental protection, Air pollution control, Incorporation by reference, Intergovernmental relations.... * * * * * (c) * * * (379) * * * (i) * * * (B) San Diego County Air Pollution Control District. (1) Rule...

  10. Crustal extension and magmatism during the mid-Cenozoic ignimbrite flare-up in the Guazapares Mining District and Cerocahui basin regions, northern Sierra Madre Occidental, western Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Murray, Bryan Patrick

    Silicic large igneous provinces are significant in the geologic record, due to their unusually extensive areal coverage (>100,000 km2) and large volumes (>250,000 km3), and may be characteristic of continental regions undergoing broad lithospheric extension. The Sierra Madre Occidental of northwestern Mexico is the biggest and best-preserved silicic large igneous province of the Cenozoic and is considered part of the extensive mid-Cenozoic ignimbrite flare-up that affected much of the southwestern North American Cordillera. Despite its size and preservation, very little is known about the geology of the Sierra Madre Occidental, and the timing and spatial extent of ignimbrite flare-up volcanism in relation to crustal extension is relatively unknown. This study presents new geologic mapping, stratigraphy, zircon U-Pb laser ablation ICP-MS dating, modal analysis, and geochemical data from the Guazapares Mining District and Cerocahui basin regions, two adjacent areas of the northern Sierra Madre Occidental in western Chihuahua. The rock exposure and topographic relief in this previously unmapped ~450 km2 area make it ideal for studying the relationships between silicic large igneous province volcanism and crustal extension. Three informal formations are identified in the study area: (1) the ca. 27.5 Ma Parajes formation, a ~1-km-thick succession of primarily welded silicic outflow ignimbrite sheets erupted from sources within ~50--100 km of the study area that were active during the Early Oligocene pulse of the mid-Cenozoic ignimbrite flare-up; (2) the ca. 27--24.5 Ma Temoris formation, composed primarily of locally erupted mafic-intermediate lavas and associated intrusions with interbedded alluvial deposits, likely related to rocks of the Southern Cordillera basaltic andesite province that were intermittently erupted across all of the northern Sierra Madre Occidental following the Early Oligocene ignimbrite pulse; and (3) the ca. 24.5--23 Ma Sierra Guazapares

  11. 30 CFR 49.50 - Certification of coal mine rescue teams.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Certification of coal mine rescue teams. 49.50... TRAINING MINE RESCUE TEAMS Mine Rescue Teams for Underground Coal Mines § 49.50 Certification of coal mine... coal mine, the mine operator shall send the District Manager an annual statement certifying that...

  12. 30 CFR 49.50 - Certification of coal mine rescue teams.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Certification of coal mine rescue teams. 49.50... TRAINING MINE RESCUE TEAMS Mine Rescue Teams for Underground Coal Mines § 49.50 Certification of coal mine... coal mine, the mine operator shall send the District Manager an annual statement certifying that...

  13. 30 CFR 49.50 - Certification of coal mine rescue teams.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Certification of coal mine rescue teams. 49.50... TRAINING MINE RESCUE TEAMS Mine Rescue Teams for Underground Coal Mines § 49.50 Certification of coal mine... coal mine, the mine operator shall send the District Manager an annual statement certifying that...

  14. 30 CFR 49.50 - Certification of coal mine rescue teams.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Certification of coal mine rescue teams. 49.50... TRAINING MINE RESCUE TEAMS Mine Rescue Teams for Underground Coal Mines § 49.50 Certification of coal mine... coal mine, the mine operator shall send the District Manager an annual statement certifying that...

  15. 30 CFR 49.50 - Certification of coal mine rescue teams.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Certification of coal mine rescue teams. 49.50... TRAINING MINE RESCUE TEAMS Mine Rescue Teams for Underground Coal Mines § 49.50 Certification of coal mine... coal mine, the mine operator shall send the District Manager an annual statement certifying that...

  16. AERIAL VIEW, LOOKING NORTH, OF SILVER LAKE. NOTE IOWA MINE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    AERIAL VIEW, LOOKING NORTH, OF SILVER LAKE. NOTE IOWA MINE RUINS AT LEFT CENTER AND SILVER LAKE MINE RUINS BEYOND NORTHWEST SHORE. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  17. Potential environmental impact at São Domingos mining district (Iberian Pyrite Belt, SW Iberian Peninsula): evidence from a chemical and mineralogical characterization

    NASA Astrophysics Data System (ADS)

    Álvarez-Valero, A. M.; Pérez-López, R.; Matos, J.; Capitán, M. A.; Nieto, J. M.; Sáez, R.; Delgado, J.; Caraballo, M.

    2008-10-01

    São Domingos like other long-term activity mines of the Iberian Pyrite Belt (IPB) dating back to pre-Roman times, is supposed to produce considerable amounts of mining wastes which cause significant downstream negative environment impact related to the acid mine drainage (AMD) production and high content of potentially toxic metals and metalloids in Chanza and Guadiana Rivers. The AMD production of a given mining waste depends on the ratio of its acid production to neutralizing phases. In this work, a chemical and mineralogical characterization of the sulphide-rich wastes from São Domingos has been developed to discriminate which residues are the main sources of AMD generation. A total of 47 representative samples of the different residue types were collected to estimate their possible contamination hazards through detailed studies of (1) for a mineralogical characterization: reflected-light optical microscope, scanning electron microscope (SEM) and XRD analysis; and (2) for a chemical characterization: bulk-rock analysis. AMD prediction by the standard acid-base accounting method (ABA) was used in order to determine the acidification potential of each residue type. This study also offers an estimation of the contribution of toxic elements to the environment, being thus, a base for future remediation actions at São Domingos and other abandoned massive sulphide mines within the IPB.

  18. 33 CFR 3.55-20 - Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Francisco Bay Marine Inspection Zone and Captain of the Port Zone. 3.55-20 Section 3.55-20 Navigation and..., MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-20 Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone. The Sector San...

  19. 33 CFR 3.55-20 - Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Francisco Bay Marine Inspection Zone and Captain of the Port Zone. 3.55-20 Section 3.55-20 Navigation and..., MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-20 Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone. The Sector San...

  20. 33 CFR 3.55-20 - Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Francisco Bay Marine Inspection Zone and Captain of the Port Zone. 3.55-20 Section 3.55-20 Navigation and..., MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-20 Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone. The Sector San...

  1. 33 CFR 3.55-20 - Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Francisco Bay Marine Inspection Zone and Captain of the Port Zone. 3.55-20 Section 3.55-20 Navigation and..., MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-20 Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone. The Sector San...

  2. 33 CFR 3.55-20 - Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Francisco Bay Marine Inspection Zone and Captain of the Port Zone. 3.55-20 Section 3.55-20 Navigation and..., MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-20 Sector San Francisco: San Francisco Bay Marine Inspection Zone and Captain of the Port Zone. The Sector San...

  3. Edoylerite, Hg32+Cr6+O4S2 a new mineral from the Clear Creek claim, San Benito County, California

    USGS Publications Warehouse

    Erd, Richard C.; Roberts, Andrew C.; Bonardi, M.; Criddle, A.J.; Le, Page Y.; Gabe, E.J.

    1993-01-01

    Edoylerite is a rare constituent of a small prospect near the long-abandoned Clear Creek mercury mine, New Idria district, San Benito County, California. It is most closely associated with cinnabar, from which it is a primary alteration product, in a host rock composed predominantly of quartz, chalcedony and ferroan magnesite. Edoylerite typically occurs as acicular to stellate crystal groups on and around corroded masses of cinnabar. The mineral is canary yellow to orangish yellow, and possesses a yellow streak and an adamantine luster. The crystallographic, physical and optical properties of edoylerite are described. -after Authors

  4. Underground at Black Diamond Mines

    SciTech Connect

    Higgins, C.T.

    1989-10-01

    Although California is noted for its mining history and annually leads the nation in total monetary value of minerals produced, there a few opportunities for the public to tour underground mines. One reason is that nearly all mining in the state today is done above ground in open pits. Another reason is that active underground mines are not commonly favorable to public tours. There is one place, Black Diamond Mines Regional Preserve, where the public can safely tour a formerly active underground mine. Black Diamond Mines Regional Preserve is a 3,600-acre parkland about 5 miles southwest of Antioch in Contra Costa County. The Preserve was established in the early 1970s and is administered by the East Bay Regional Park District. Black Diamond Mines Preserve is noteworthy for its mining history as well as its natural history, both of which are briefly described here.

  5. Case-case study of factors associated to hMLH1, hMSH2, and hMSH6 protein expression among endometrial cancer patients of the University District Hospital of San Juan, Puerto Rico

    PubMed Central

    González, Lorena; Ortiz, Ana P.; Suárez, Erick; Umpierre, Sharee; Marcos, Maria J.; Billoch, Jorge; Joy, Leilani; Charneco, Eileen; Lacourt, Mercedes Y.; Bernabe-Dones, Raúl D.; Cruz-Correa, Marcia

    2012-01-01

    Lynch syndrome (LS) is an autosomal dominant disorder caused by DNA mismatch repair (MMR) system deficiencies. Women affected by LS present a 40 to 60% lifetime risk of endometrial cancer (EC). Objective This case-case study aims to determine the frequency of the hMLH1, hMSH2, and hMSH6 MMR proteins and the factors (age, family history of cancer [FHC] related to LS, and body mass index [BMI]) associated to their absence in EC patients attending the University District Hospital of San Juan, Puerto Rico. Method/Materials Twenty cases were preliminary evaluated for the MMR protein expression by immunohistochemistry testing and classified as positive-cases (presence of protein) or negative-cases (absence of protein). The statistical analysis was based on the logistic regression model using the Maximum Likelihood estimation (MLE). The Bayesian approach was used to determine the posterior probability {posterior Pr[OR>1]}. Results Results showed absence for at least one MMR protein in 25% of the cases; 15% for hMLH1 and 10% for hMSH2. None of the cases showed an absence for hMSH6. The MLE demonstrated that women diagnosed with EC before the age of 50 (OR: 12.4; 95%CI = 0.5–322.7), having FHC related to LS (OR: 17.7; 95%CI = 0.6–534.6), and having lower BMI (OR: 2.38; 95%CI = 0.39–14.28) present higher odds than their counterparts of lacking an MMR protein, once adjusting for potential predictors (p > .05). The posterior probability that an excess risk of lacking an MMR protein occurs was ≥ 95% for each predictor. Conclusion Our study in this Hispanic population supports previous studies in that younger age, FHC, and lower BMI are associated with increased odds of having an absence of MMR protein expression. Further studies with larger sample sizes should be performed. PMID:22635031

  6. The Little District that Could: Literacy Reform Leads to Higher Achievement in California District

    ERIC Educational Resources Information Center

    Kelly, Patricia R.; Budicin-Senters, Antoinette; King, L. McLean

    2005-01-01

    This article describes educational reform developed over a 10-year period in California's Lemon Grove School District, which resulted in a steady and remarkable upward shift in achievement for the students of this multicultural district just outside San Diego. Six elements of literacy reform emerged as the most significant factors affecting…

  7. 76 FR 45212 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: In this action, we are proposing to approve San Joaquin Valley Unified Air Pollution Control... the environment. San Joaquin Valley Unified Air Pollution Control District SJVUAPCD is an...

  8. 75 FR 56942 - Revisions to the California State Implementation Plan, San Diego County Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-17

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Diego County Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Diego Air Pollution Control District...

  9. 75 FR 28509 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Association of Home Builders v. San Joaquin Valley Unified Air Pollution Control District, No. 08-17309...

  10. A geologic and anthropogenic journey from the Precambrian to the new energy economy through the San Juan volcanic field

    USGS Publications Warehouse

    Yager, Douglas B.; Burchell,; Johnson, Raymond H.

    2010-01-01

    The San Juan volcanic field comprises 25,000 km2 of intermediate composition mid-Tertiary volcanic rocks and dacitic to rhyolitic calderas including the San Juan–Uncompahgre and La Garita caldera-forming super-volcanoes. The region is famous for the geological, ecological, hydrological, archeological, and climatological diversity. These characteristics supported ancestral Puebloan populations. The area is also important for its mineral wealth that once fueled local economic vitality. Today, mitigating and/or investigating the impacts of mining and establishing the region as a climate base station are the focuses of ongoing research. Studies include advanced water treatment, the acid neutralizing capacity (ANC) of propylitic bedrock for use in mine-lands cleanup, and the use of soil amendments including biochar from beetle-kill pines. Biochar aids soil productivity and revegetation by incorporation into soils to improve moisture retention, reduce erosion, and support the natural terrestrial carbon sequestration (NTS) potential of volcanic soils to help offset atmospheric CO2 emissions. This field trip will examine the volcano-tectonic and cultural history of the San Juan volcanic field as well as its geologic structures, economic mineral deposits and impacts, recent mitigation measures, and associated climate research. Field trip stops will include a visit to (1) the Summitville Superfund site to explore quartz alunite-Au mineralization, and associated alteration and new water-quality mitigation strategies; (2) the historic Creede epithermal-polymetallic–vein district with remarkably preserved resurgent calderas, keystone-graben, and moat sediments; (3) the historic mining town of Silverton located in the nested San Juan–Silverton caldera complex that exhibits base-metal Au-Ag mineralization; and (4) the site of ANC and NTS studies. En route back to Denver, we will traverse Grand Mesa, a high NTS area with Neogene basalt-derived soils and will enjoy a soak

  11. Determination of acid forming potential of massive sulfide minerals and the tailings situated in lead/zinc mining district of Balya (NW Turkey)

    NASA Astrophysics Data System (ADS)

    Çelebi, E. Ender; Öncel, M. Salim

    2016-12-01

    Weathering of sulfide minerals is a major source of acid production in nature and especially in mining territories. Pyrite is not the only principal mineral that generates acid drainage: other sulfide minerals (sphalerite, galena, chalcopyrite, etc.) may also be responsible for acid production. In addition to massive sulfide minerals, sulfide-bearing mine tailings may also produce acid drainage due to oxidation and hydrolysis reactions in waste dumps. The lead/zinc (Pb/Zn) mining region in Balya and Balıkesir, in Turkey, has operated mines intensively since the 1860s; so that characterization of the sulfide minerals and tailings situated and formed around the mining site is of great importance to secure a sustainable environment. For this purpose, acid production and neutralization potentials of massive sulfide ores of the region, and in the Pb/Zn process facility mine tailings from ten different points of tailings dam, have been determined by applied conventional Acid-Base Accounting (ABA) and Net Acid Generation (NAG) static tests after chemical and mineralogical analysis. The NAG pH and net acid production potential (NAPP) values were compared on a chart in order to classify the samples as either acid generating or non-acid generating. According to the comparisons, the sulfide minerals were classified as potentially acid forming (PAF). Massive pyrite had the highest NAPP and NAG pH value of 1966.6 kg H2SO4/ton and 1.91, respectively and the galena had the lowest NAPP value of 558.9 kg H2SO4/ton. However, the sphalerite NAG leachate pH value of 4.30 was the highest in sulfide minerals so that the sphalerite plotted near the uncertainty reference border in the PAF zone. In the mine tailings, NAPP values of 105.9 kg H2SO4/ton on average and the NAG pH values of over 7.5 were determined. In addition to these tests, water leaching (agitation test) was carried out on tailings in order to generate more information. The tailings did not generate acidic leachates as

  12. From Blueprint to Reality: San Diego's Education Reforms

    ERIC Educational Resources Information Center

    Betts, Julian R.; Zau, Andrew C.; King, Kevin

    2005-01-01

    In 2000, the Public Policy of Institute of California entered into an agreement with the San Diego Unified School District to provide the research and financial support to collect, format, and analyze student, teacher, and classroom data needed to create an accurate portrait of what affects student achievement in San Diego. This report is the…

  13. Industrial and natural sources of gaseous elemental mercury in the Almadén district (Spain): an updated report on this issue after the ceasing of mining and metallurgical activities in 2003 and major land reclamation works.

    PubMed

    Higueras, Pablo; Esbrí, José María; Oyarzun, Roberto; Llanos, Willans; Martínez-Coronado, Alba; Lillo, Javier; López-Berdonces, Miguel Angel; García-Noguero, Eva Maria

    2013-08-01

    Two events during the last decade had major environmental repercussions in Almadén town (Spain). First it was the ceasing of activities in the mercury mine and metallurgical facilities in 2003, and then the finalization of the restoration works on the main waste dump in 2008. The combination of both events brought about a dramatic drop in the emissions of gaseous elemental mercury (GEM) to the atmosphere. Although no one would now call the Almadén area as 'mercury-free', the GEM levels have fallen beneath international reference safety levels for the first time in centuries. This has been a major breakthrough because in less than one decade the site went from GEM levels in the order of "tens of thousands" to mere "tens" nanogram per cubic meter. Although these figures are per se a remarkable achievement, they do not mark the end of the environmental concerns in the Almadén district. Two other sites remain as potential environmental hazards. (1) The Las Cuevas mercury storage complex, a partially restored ex-mining site where liquid mercury is being stored. The MERSADE Project (LIFE-European Union) has tested the Las Cuevas complex as a potential site for the installation of a future European prototype safe deposit of surplus mercury from industrial activities. Despite restoration works carried out in 2004, the Las Cuevas complex can still be regarded as hotspot of mercury contamination, with high concentrations above 800μgg(-1) Hgsoil and 300ngm(-3) Hggas. However, as predicted by air contamination modeling using the ISC-AERMOD software, GEM concentrations fade away in a short distance following the formation of a NW-SE oriented narrow plume extending for a few hundred meters from the complex perimeter. (2) Far more dangerous from the human health perspective is the Almadenejos area, hosting the small Almadenejos village, the so-called Cerco de Almadenejos (CDA; an old metallurgical precinct), and the mines of La Nueva Concepción, La Vieja Concepción and El

  14. 33 CFR 165.776 - Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zone; Coast Guard Base... Guard District § 165.776 Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico (a.... Coast Guard or U.S. naval vessels. (c) Regulations. (1) No person or vessel may enter into the...

  15. 33 CFR 165.776 - Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zone; Coast Guard Base... Guard District § 165.776 Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico. (a.... Coast Guard or U.S. naval vessels. (c) Regulations. (1) No person or vessel may enter into the...

  16. 33 CFR 165.776 - Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Coast Guard Base... Guard District § 165.776 Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico (a.... Coast Guard or U.S. naval vessels. (c) Regulations. (1) No person or vessel may enter into the...

  17. 33 CFR 165.776 - Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zone; Coast Guard Base... Guard District § 165.776 Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico (a.... Coast Guard or U.S. naval vessels. (c) Regulations. (1) No person or vessel may enter into the...

  18. Quality of water and sediment in streams affected by historical mining, and quality of Mine Tailings, in the Rio Grande/Rio Bravo Basin, Big Bend Area of the United States and Mexico, August 2002

    USGS Publications Warehouse

    Lambert, Rebecca B.; Kolbe, Christine M.; Belzer, Wayne

    2008-01-01

    The U.S. Geological Survey, in cooperation with the International Boundary and Water Commission - U.S. and Mexican Sections, the National Park Service, the Texas Commission on Environmental Quality, the Secretaria de Medio Ambiente y Recursos Naturales in Mexico, the Area de Proteccion de Flora y Fauna Canon de Santa Elena in Mexico, and the Area de Proteccion de Flora y Fauna Maderas del Carmen in Mexico, collected samples of stream water, streambed sediment, and mine tailings during August 2002 for a study to determine whether trace elements from abandoned mines in the area in and around Big Bend National Park have affected the water and sediment quality in the Rio Grande/Rio Bravo Basin of the United States and Mexico. Samples were collected from eight sites on the main stem of the Rio Grande/Rio Bravo, four Rio Grande/Rio Bravo tributary sites downstream from abandoned mines or mine-tailing sites, and 11 mine-tailing sites. Mines in the area were operated to produce fluorite, germanium, iron, lead, mercury, silver, and zinc during the late 1800s through at least the late 1970s. Moderate (relatively neutral) pHs in stream-water samples collected at the 12 Rio Grande/Rio Bravo main-stem and tributary sites indicate that water is well mixed, diluted, and buffered with respect to the solubility of trace elements. The highest sulfate concentrations were in water samples from tributaries draining the Terlingua mining district. Only the sample from the Rough Run Draw site exceeded the Texas Surface Water Quality Standards general-use protection criterion for sulfate. All chloride and dissolved solids concentrations in water samples were less than the general-use protection criteria. Aluminum, copper, mercury, nickel, selenium, and zinc were detected in all water samples for which each element was analyzed. Cadmium, chromium, and lead were detected in samples less frequently, and silver was not detected in any of the samples. None of the sample concentrations of

  19. Geohydrology of the aquifers that may be affected by the surface mining of coal in the Fruitland Formation in the San Juan Basin, northwestern New Mexico

    USGS Publications Warehouse

    Myers, R.G.; Villanueva, E.D.

    1986-01-01

    A monitoring network of 50 wells was installed from 1975 to 1979 in the surface-mineable coal area. The purpose of the network was to collect hydrologic data and to establish a data base. The hydrologic data consist of water level measurements, water chemistry, and selected aquifer characteristics. The four aquifers considered in this study are: (1) The Pictured Cliffs Sandstone; (2) coal seams and interbedded lithologic units of the Fruitland Formation; (3) overburden of the Kirtland Shale and Fruitland Formation; and (4) the alluvium along the Chaco River and its eastern and northeastern tributaries. Five sites were selected for study. Four of these sites, Western Coal Company 's lease near Fruitland, Bisti West, Kimbeto, and Ojo Encino, have surface-mineable coal. The Chaco River alluvium was selected because it is downstream from anticipated mining activity. The specific conductances of the representative water samples from selected wells in the 4 aquifers in the 5 study areas ranged from 800 to 23,000 microsiemens/cm at 25 C. The dominant cation in all samples was sodium. The water is brackish in the Pictured Cliffs Sandstone and in the coal seams and interbedded lithologic units of the Fruitland Formation. It is fresh to saline in the overburden of the Fruitland Shale and Fruitland Formation, and fresh to brackish in the Chaco River alluvium. (Author 's abstract)

  20. Developing Alternative Placement Criteria for English Courses at City College of San Francisco. Issue Brief

    ERIC Educational Resources Information Center

    Castrechini, Sebastian

    2013-01-01

    Recognizing the need to improve postsecondary access and success for underrepresented populations, the San Francisco Unified School District (SFUSD), City College of San Francisco (CCSF), the City and County of San Francisco, and key community organizations formed the Bridge to Success initiative in 2009. The John W. Gardner Center for Youth and…

  1. 75 FR 2079 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ... facilities. Also, please see our response to CPF comment 3. B. San Joaquin Valley Air Pollution Control...) San Joaquin Valley Unified Air Pollution Control District. (1) Rule 4570, ``Confined Animal Facilities... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Joaquin Valley...

  2. Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, San Rafael Swell, Utah

    USGS Publications Warehouse

    Freeman, Michael L.; Naftz, David L.; Snyder, Terry; Johnson, Greg

    2008-01-01

    During July and August of 2006, 117 solid-phase samples were collected from abandoned uranium waste dumps, geologic background sites, and adjacent streambeds in the San Rafael Swell, in southeastern Utah. The objective of this sampling program was to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps on Bureau of Land Management property. Uranium waste dump samples were collected using solid-phase sampling protocols. After collection, solid-phase samples were homogenized and extracted in the laboratory using a field leaching procedure. Filtered (0.45 micron) water samples were obtained from the field leaching procedure and were analyzed for Ag, As, Ba, Be, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, U, V, and Zn at the Inductively Coupled Plasma-Mass Spectrometry Metals Analysis Laboratory at the University of Utah, Salt Lake City, Utah and for Hg at the U.S. Geological Survey National Water Quality Laboratory, Denver, Colorado. For the initial ranking of chemical loading potential of suspect uranium waste dumps, leachate analyses were compared with existing aquatic life and drinking-water-quality standards and the ratio of samples that exceeded standards to the total number of samples was determined for each element having a water-quality standard for aquatic life and drinking-water. Approximately 56 percent (48/85) of the leachate samples extracted from uranium waste dumps had one or more chemical constituents that exceeded aquatic life and drinking-water-quality standards. Most of the uranium waste dump sites with elevated trace-element concentrations in leachates were along Reds Canyon Road between Tomsich Butte and Family Butte. Twelve of the uranium waste dump sites with elevated trace-element concentrations in leachates contained three or more constituents that exceeded drinking-water-quality standards. Eighteen of the uranium waste dump sites had three or more constituents that exceeded trace

  3. Remediation System Evaluation, Summitville Mine Superfund Site

    EPA Pesticide Factsheets

    The Summitville Mine Superfund Site is located in the southeastern portion of the San Juan Mountains,in Rio Grande County, approximately 60 miles west of Alamosa, Colorado and 10 to 15 miles south ofDel Norte, Colorado.

  4. Local Control and Self-Determination: The San Juan Case.

    ERIC Educational Resources Information Center

    Garman, Keats; Jack, Donald

    Rapidly increasing Navajo enrollment in San Juan County, Utah, public schools in the 1960's forced the rural school district to improve educational services to a sizable Navajo population while attempting to preserve local control in the face of changing Indian self-determination policy. The district implemented a Curriculum Development Center, a…

  5. San Diego Schools Set a New Agenda after Backlash

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2010-01-01

    Ten years after the San Diego school district gained national attention for its short-lived "Blueprint for Student Success," a crowd of district officials last week rolled out a new improvement plan that is almost the opposite of its controversial predecessor. The city's blueprint reforms--largely dismantled after a charismatic and…

  6. Hamilton County: A Rural School District Profile.

    ERIC Educational Resources Information Center

    Harned, Catherine

    Using state education agency, census, industry employment and occupational information data, this paper provides a detailed picture of a rural school district in Southern Illinois. Mining and agriculture are the major industries in Hamilton County. The major mining employer closed in February 1988, and the drought of 1988 is likely to adversely…

  7. 78 FR 48591 - Refuge Alternatives for Underground Coal Mines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-08

    ... Refuge Alternatives for Underground Coal Mines; Proposed Rules #0;#0;Federal Register / Vol. 78 , No. 153... 30 CFR Part 75 RIN 1219-AB84 Refuge Alternatives for Underground Coal Mines AGENCY: Mine Safety and... alternatives in underground coal mines. The U.S. Court of Appeals for the District of Columbia Circuit...

  8. 4. Photocopy of plat (from U.S. Land Commission, U.S. District ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Photocopy of plat (from U.S. Land Commission, U.S. District Court, Northern District of California, G. Black, Surveyor, 1854) SITE PLAN OF MISSION SAN FRANCISCO SOLANO DE SONOMA - Mission San Francisco Solano de Sonoma, First & Spain Streets, Sonoma, Sonoma County, CA

  9. Navigation Improvement Design Memorandum Number 1, General Design for San Diego Harbor, San Diego County, California.

    DTIC Science & Technology

    1975-02-28

    half of Arizona, New Mexico (less the eight northernmost counties), West Texas and the Mexican states of Chihuahua, Sonora and Baja California Norte...DESIGN MEMORANDUM NO. 1 GENERAL DESIGN FOR SAN DIEGO HARBOR ~3AN -DIEGO COUNTY, CALIFORNIA -- 4 U.S. ARMY ENGINEER DISTRICT, LOS ANGELES CORPS OF... CALIFORNIA S. PERFORMING ORG. REPORT NUMBER 1 £,’ru~*,~ ta. CONTRACT OR GRANT NUME=") - ’ US ARMY CORPS OF ENGINEERS LOS ANGELES DISTRICT P.O. BOX 2711

  10. Study of dung, urine, and milk of selected grazing animals as bioindicators in environmental geoscience--a case study from Mangampeta barite mining area, Kadapa District, Andhra Pradesh, India.

    PubMed

    Raghu, V

    2015-01-01

    The ancient scientific Sanskrit texts of Ayurveda (science of longevity) deal with waters, plants, and animals in relation to human health. Based on the studies mentioned in Ayurveda and modern literature, biological responses of grazing animals in Mangampeta barite mining area in Kadapa District, Andhra Pradesh, were studied. A non-mineralized Tirupati area in Chittoor District, Andhra Pradesh, was selected for the purpose of comparison. In these areas, certain animal products of selected grazing animals were studied if they could be used as tools in mineral exploration. Samples of dung, urine, and milk from cow, bullock, she-buffalo, he-buffalo, sheep, and goat were collected from these two areas during winter and summer seasons. Goat dung was found to have lowest moisture content and highest organic matter while goat urine contained highest amounts of organic matter and ash content. All these animal products were analyzed for 11 trace elements. The concentration of trace elements released through dung, urine, and milk widely varied in different animal species with seasonal variations. The elemental concentration was higher in dung and lower in urine, when compared to that of milk. The concentration of all elements in dung, urine, and milk of all animals, in both the areas, was higher in winter than that in summer. Dung represents the metabolic process of the whole animal and reflects the dietary conditions whether fed on natural or inorganic supplement. It can be inferred that dung, urine, and milk of any animal can be used as tools in mineral exploration during winter, while during summer, only dung can be useful. The dung of goat when compared to that of the other cattle serves as a better tool in environmental studies as goat depends almost entirely on natural vegetation without human interference.

  11. Geology and mining industry of the Tintic district, Utah: Section in Nineteenth Annual Report of the United States Geological Survey to the Secretary of the Interior 1897 - 1898: Part III - Economic Geology

    USGS Publications Warehouse

    Tower, George Warren; Smith, George Otis

    1899-01-01

    The field work upon which this report is based was begun in July, 1897, and continued without interruption until December of the same year. The area studied is approximately 15 miles square and contains 234 square miles. The topographic maps, which are two in number, were prepared under the direction of Mr. R. U. Goode, Mr. S. S. Gannett doing the triangulation and Messrs. Marshall and Griswold the topography in the fall of 1896 and summer of 1897. The mapping is done on two scales; the larger area, approximately 15 miles square, is mapped on a scale of 1: 62,500. This map is designed to form a part of the Geologic Atlas of the United States. The other map represents the portion of the larger area in which the majority of the mines are located. It is on a scale of 1: 9,600, and covers an area of 12 square miles. The work has been greatly facilitated through the assistance rendered by the mining men of the district, among whom special thanks are due to Messrs. G. H. Robinson, W. J. Craig, W. M. Nesbit, and C. H. Blanchard. The chemical work on the ores and country rocks from the district has been done in the laboratory of the Survey by Messrs. H. N. Stokes and George Steiger, and the determination of the fossils collected is to be credited to Mr. G. H. Girty, also of the Geological Survey. In the field work the authors have cooperated constantly on every phase of the varied problems. The same is true for the office work, except that the stratigraphic and economic problems have been the especial studies of Mr. Tower, while the petrologic and remaining problems have been the special studies of Mr. Smith. In pursuance of this system of work the introduction has been written conjointly, Chapter II of Part I and all of Part II have been written by Mr. Tower, and Chapters I and III to VII of Part I by Mr. Smith.

  12. Space Radar Image of San Francisco, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This image of San Francisco, California shows how the radar distinguishes between densely populated urban areas and nearby areas that are relatively unsettled. Downtown San Francisco is at the center and the city of Oakland is at the right across the San Francisco Bay. Some city areas, such as the South of Market, called the SOMA district in San Francisco, appear bright red due to the alignment of streets and buildings to the incoming radar beam. Various bridges in the area are also visible including the Golden Gate Bridge (left center) at the opening of San Francisco Bay, the Bay Bridge (right center) connecting San Francisco and Oakland, and the San Mateo Bridge (bottom center). All the dark areas on the image are relatively smooth water: the Pacific Ocean to the left, San Francisco Bay in the center, and various reservoirs. Two major faults bounding the San Francisco-Oakland urban areas are visible on this image. The San Andreas fault, on the San Francisco peninsula, is seen in the lower left of the image. The fault trace is the straight feature filled with linear reservoirs which appear dark. The Hayward fault is the straight feature on the right side of the image between the urban areas and the hillier terrain to the east. The image is about 42 kilometers by 58 kilometers (26 miles by 36 miles) with north toward the upper right. This area is centered at 37.83 degrees north latitude, 122.38 degrees east longitude. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on October 3, 1994. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth.

  13. USGS Abandoned Mine Lands Research Presented at the NAAMLP Meeting in Billings, Mont., Sept. 25, 2006

    USGS Publications Warehouse

    Johnson, Kate; Church, Stan

    2006-01-01

    The following talk was an invited presentation given at the National Association of Abandoned Mine Lands Programs meeting in Billings, Montana on Sept. 25, 2006. The objective of the talk was to outline the scope of the U.S. Geological Survey research, past, present and future, in the area of abandoned mine research. Two large Professional Papers have come out of our AML studies: Nimick, D.A., Church, S.E., and Finger, S.E., eds., 2004, Integrated investigations of environmental effects of historical mining in the Basin and Boulder mining districts, Boulder River watershed, Jefferson County, Montana: U.S. Geological Survey Professional Paper 1652, 524 p., 2 plates, 1 DVD, URL: http://pubs.er.usgs.gov/usgspubs/pp/pp1652 Church, S.E., von Guerard, Paul, and Finger, S.E., eds., 2006, Integrated Investigations of Environmental Effects of Historical Mining in the Animas River Watershed, San Juan County, Colorado: U.S. Geological Survey Professional Paper 1651, 1,096 p., 6 plates, 1 DVD (in press). Additional publications and links can be found on the USGS AML website at URL: http://amli.usgs.gov/ or are accessible from the USGS Mineral Resource Program website at URL: http://minerals.usgs.gov/.

  14. 76 FR 26609 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-09

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... Valley Unified Air Pollution Control District (No. 08-17309)] to overturn a District Court ruling...

  15. Oakland and San Francisco Create Course Pathways through Common Core Mathematics. White Paper

    ERIC Educational Resources Information Center

    Daro, Phil

    2014-01-01

    The Common Core State Standards for Mathematics (CCSS-M) set rigorous standards for each of grades 6, 7 and 8. Strategic Education Research Partnership (SERP) has been working with two school districts, Oakland Unified School District and San Francisco Unified School District, to evaluate extant policies and practices and formulate new policies…

  16. A comparison of the efficacy and ecosystem impact of residual-based and topsoil-based amendments for restoring historic mine tailings in the Tri-State mining district.

    PubMed

    Brown, Sally; Mahoney, Michele; Sprenger, Mark

    2014-07-01

    A long-term research and demonstration site was established on Pb and Zn mine wastes in southwestern Missouri in 1999. Municipal biosolids and lime and composts were mixed into the wastes at different loading rates. The site was monitored intensively after establishment and again in 2012. A site restored with topsoil was also included in the 2012 sampling. Initial results including plant, earthworm and small mammal assays indicate that the bioaccessibility of metals had been significantly reduced as a result of amendment addition. The recent sampling showed that at higher loading rates, the residual mixtures have maintained a vegetative cover and are similar to the topsoil treatment based on nutrient availability and cycling and soil physical properties including bulk density and water holding capacity. The ecosystem implications of restoration with residuals versus mined topsoil were evaluated. Harvesting topsoil from nearby farms would require 1875 years to replace based on natural rates of soil formation. In contrast, diverting biosolids from combustion facilities (60% of biosolids generated in Missouri are incinerated) would result in greenhouse gas savings of close to 400 Mg CO2 per ha.

  17. Biotic and abiotic factors influencing the long-term stability of covers on waste rock piles in the uranium mining district of Saxony and Thuringia (Germany)

    SciTech Connect

    Heinze, M.; Koehler, M.; Saenger, H.

    1999-07-01

    This report presents the results of basic investigations of root penetration on various partially covered excavation discard material mounds of the Saxonian-Thuringian uranium mining region (Germany) in comparison to root penetration in autochthonous (native) soils. Bioturbation is an essential, unavoidable impact to consider in addition to root penetration. With increasing age, the functionality of each layer of a cover system becomes diminished through the workings of the local flora and fauna. Pedological cover layers can only temporarily maintain their initial positions and technical functionality. Considering actual prevailing biotic and abiotic influences (e.g., site-specific transpiration rates), the planning and installation of cover systems should take into account (within acceptable balances) factors which are able to at least partially compensate for eventual diminishing of technical functionality.

  18. Environmental assessment of the arsenic-rich, Rodalquilar gold-(copper-lead-zinc) mining district, SE Spain: data from soils and vegetation

    NASA Astrophysics Data System (ADS)

    Oyarzun, Roberto; Cubas, Paloma; Higueras, Pablo; Lillo, Javier; Llanos, Willians

    2009-08-01

    The Rodalquilar mineral deposits (SE Spain) were formed in Miocene time in relation to caldera volcanic episodes and dome emplacement phenomena. Two types of ore deposits are recognized: (1) the El Cinto epithermal, Au-As high sulphidation vein and breccia type; and (2) peripheral low sulphidation epithermal Pb-Zn-Cu-(Au) veins. The first metallurgical plants for gold extraction were set up in the 1920s and used amalgamation. Cyanide leaching began in the 1930s and the operations lasted until the mid 1960s. The latter left a huge pile of ~900,000-1,250,000 m3 of abandoned As-rich tailings adjacent to the town of Rodalquilar. A frustrated initiative to reactivate the El Cinto mines took place in the late 1980s and left a heap leaching pile of ~120,000 m3. Adverse mineralogical and structural conditions favoured metal and metalloid dispersion from the ore bodies into soils and sediments, whereas mining and metallurgical operations considerably aggravated contamination. We present geochemical data for soils, tailings and wild plant species. Compared to world and local baselines, both the tailings and soils of Rodalquilar are highly enriched in As (mean concentrations of 950 and 180 μg g-1, respectively). Regarding plants, only the concentrations of As, Bi and Sb in Asparagus horridus, Launaea arborescens, Salsola genistoides, and Stipa tenacissima are above the local baselines. Bioaccumulation factors in these species are generally lower in the tailings, which may be related to an exclusion strategy for metal tolerance. The statistical analysis of geochemical data from soils and plants allows recognition of two well-differentiated clusters of elements (As-Bi-Sb-Se-Sn-Te and Cd-Cu-Hg-Pb-Zn), which ultimately reflect the strong chemical influence of both El Cinto and peripheral deposits mineral assemblages.

  19. Carbon and oxygen isotope composition of Pb-, Cu- and Bi-carbonates of the Schwarzwald mining district: Carbon sources, first data on bismutite and the discovery of an oxidation zone formed by ascending thermal water

    NASA Astrophysics Data System (ADS)

    Haßler, Kathrin; Taubald, Heinrich; Markl, Gregor

    2014-05-01

    The carbon and oxygen isotope composition of cerussite, bismutite, malachite and azurite samples from the Schwarzwald mining district, SW Germany, was analyzed in order to evaluate carbon sources and conditions of formation. We deliberately chose samples showing various textures and coming from deposits at various altitudes and geological settings. δ13C values vary from +1.0‰ to -21.0‰ VPDB, cerussite, bismutite, malachite and azurite δ18O values show a variation from +11.2‰ to +17.9‰, +16.8‰ to +21.0‰, +23.0‰ to +28.1‰ and +26.3‰ to +30.2‰ VSMOW2, respectively. In accordance with earlier studies, the δ13C values indicate carbon partially derived from biogenic (vegetation-respired or from heterotrophic degradation of organic matter) soil CO2 combined with carbon from an isotopically heavier reservoir (e.g. atmospheric CO2, carbonate rocks, hydrothermal calcite from the ore vein) in varying proportions.

  20. 33 CFR 3.35-25 - Sector San Juan Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Sector San Juan Marine Inspection..., DEPARTMENT OF HOMELAND SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Seventh Coast Guard District § 3.35-25 Sector San Juan Marine Inspection...

  1. 33 CFR 3.55-15 - Sector San Diego Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Sector San Diego Marine... GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-15 Sector San Diego...

  2. Industrial and natural sources of gaseous elemental mercury in the Almadén district (Spain): An updated report on this issue after the ceasing of mining and metallurgical activities in 2003 and major land reclamation works

    SciTech Connect

    Higueras, Pablo; María Esbrí, José; Oyarzun, Roberto; Llanos, Willans; Martínez-Coronado, Alba; and others

    2013-08-15

    Two events during the last decade had major environmental repercussions in Almadén town (Spain). First it was the ceasing of activities in the mercury mine and metallurgical facilities in 2003, and then the finalization of the restoration works on the main waste dump in 2008. The combination of both events brought about a dramatic drop in the emissions of gaseous elemental mercury (GEM) to the atmosphere. Although no one would now call the Almadén area as ‘mercury-free’, the GEM levels have fallen beneath international reference safety levels for the first time in centuries. This has been a major breakthrough because in less than one decade the site went from GEM levels in the order of “tens of thousands” to mere “tens” nanogram per cubic meter. Although these figures are per se a remarkable achievement, they do not mark the end of the environmental concerns in the Almadén district. Two other sites remain as potential environmental hazards. (1) The Las Cuevas mercury storage complex, a partially restored ex-mining site where liquid mercury is being stored. The MERSADE Project (LIFE—European Union) has tested the Las Cuevas complex as a potential site for the installation of a future European prototype safe deposit of surplus mercury from industrial activities. Despite restoration works carried out in 2004, the Las Cuevas complex can still be regarded as hotspot of mercury contamination, with high concentrations above 800 μg g{sup −1} Hg{sub soil} and 300 ng m{sup −3} Hg{sub gas}. However, as predicted by air contamination modeling using the ISC-AERMOD software, GEM concentrations fade away in a short distance following the formation of a NW–SE oriented narrow plume extending for a few hundred meters from the complex perimeter. (2) Far more dangerous from the human health perspective is the Almadenejos area, hosting the small Almadenejos village, the so-called Cerco de Almadenejos (CDA; an old metallurgical precinct), and the mines of La

  3. San Francisco floating STOLport study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The operational, economic, environmental, social and engineering feasibility of utilizing deactivated maritime vessels as a waterfront quiet short takeoff and landing facility to be located near the central business district of San Francisco was investigated. Criteria were developed to evaluate each site, and minimum standards were established for each criterion. Predicted conditions at the two sites were compared to the requirements for each of the 11 criteria as a means of evaluating site performance. Criteria include land use, community structure, economic impact, access, visual character, noise, air pollution, natural environment, weather, air traffic, and terminal design.

  4. 33 CFR 3.55-15 - Sector San Diego Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Inspection Zone and Captain of the Port Zone. 3.55-15 Section 3.55-15 Navigation and Navigable Waters COAST... ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-15 Sector San Diego Marine Inspection Zone and Captain of the Port Zone. Sector San Diego's office is located in San Diego, CA....

  5. 33 CFR 3.55-15 - Sector San Diego Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Inspection Zone and Captain of the Port Zone. 3.55-15 Section 3.55-15 Navigation and Navigable Waters COAST... ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-15 Sector San Diego Marine Inspection Zone and Captain of the Port Zone. Sector San Diego's office is located in San Diego, CA....

  6. 33 CFR 3.55-15 - Sector San Diego Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Inspection Zone and Captain of the Port Zone. 3.55-15 Section 3.55-15 Navigation and Navigable Waters COAST... ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-15 Sector San Diego Marine Inspection Zone and Captain of the Port Zone. Sector San Diego's office is located in San Diego, CA....

  7. 33 CFR 3.35-25 - Sector San Juan Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Zone and Captain of the Port Zone. 3.35-25 Section 3.35-25 Navigation and Navigable Waters COAST GUARD... CAPTAIN OF THE PORT ZONES Seventh Coast Guard District § 3.35-25 Sector San Juan Marine Inspection Zone and Captain of the Port Zone. Sector San Juan's office is located in San Juan, PR. The boundaries...

  8. 33 CFR 3.35-25 - Sector San Juan Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Zone and Captain of the Port Zone. 3.35-25 Section 3.35-25 Navigation and Navigable Waters COAST GUARD... CAPTAIN OF THE PORT ZONES Seventh Coast Guard District § 3.35-25 Sector San Juan Marine Inspection Zone and Captain of the Port Zone. Sector San Juan's office is located in San Juan, PR. The boundaries...

  9. 33 CFR 3.35-25 - Sector San Juan Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Zone and Captain of the Port Zone. 3.35-25 Section 3.35-25 Navigation and Navigable Waters COAST GUARD... CAPTAIN OF THE PORT ZONES Seventh Coast Guard District § 3.35-25 Sector San Juan Marine Inspection Zone and Captain of the Port Zone. Sector San Juan's office is located in San Juan, PR. The boundaries...

  10. 33 CFR 3.35-25 - Sector San Juan Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Zone and Captain of the Port Zone. 3.35-25 Section 3.35-25 Navigation and Navigable Waters COAST GUARD... CAPTAIN OF THE PORT ZONES Seventh Coast Guard District § 3.35-25 Sector San Juan Marine Inspection Zone and Captain of the Port Zone. Sector San Juan's office is located in San Juan, PR. The boundaries...

  11. 33 CFR 3.55-15 - Sector San Diego Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Inspection Zone and Captain of the Port Zone. 3.55-15 Section 3.55-15 Navigation and Navigable Waters COAST... ZONES, AND CAPTAIN OF THE PORT ZONES Eleventh Coast Guard District § 3.55-15 Sector San Diego Marine Inspection Zone and Captain of the Port Zone. Sector San Diego's office is located in San Diego, CA....

  12. 33 CFR 165.1187 - Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay, California. 165.1187 Section 165.1187... Limited Access Areas Eleventh Coast Guard District § 165.1187 Security Zones; Golden Gate Bridge and...

  13. 33 CFR 165.1187 - Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay, California. 165.1187 Section 165.1187... Limited Access Areas Eleventh Coast Guard District § 165.1187 Security Zones; Golden Gate Bridge and...

  14. 33 CFR 165.1187 - Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay, California. 165.1187 Section 165.1187... Limited Access Areas Eleventh Coast Guard District § 165.1187 Security Zones; Golden Gate Bridge and...

  15. Jensenite, Cu3 Te (super 6+) O6 .2H2O, a new mineral species from the Centennial Eureka Mine, Tintic District, Juab County, Utah

    USGS Publications Warehouse

    Roberts, Andrew C.; Grice, Joel D.; Groat, Lee A.; Criddle, Alan J.; Gault, Robert A.; Erd, Richard C.; Moffatt, Elizabeth A.

    1996-01-01

    Jensenite, ideally Cu 3 Te (super 6+) O 6 .2H 2 O, is monoclinic, P2 1 /n (14), with unit-cell parameters refined from powder data: a 9.204(2), b 9.170(2), c 7.584(1) Aa, beta 102.32(3) degrees , V 625.3(3) Aa 3 , a:b:c 1.0037:1:0.8270, Z = 4. The strongest six reflections of the X-ray powder-diffraction pattern [d in Aa(I)(hkl)] are: 6.428(100)(101,110), 3.217(70)(202), 2.601(40)(202), 2.530(50)(230), 2.144(35)(331) and 1.750(35)(432). The mineral is found on the dumps of the Centennial Eureka mine, Juab County, Utah, where it occurs as isolated crystals or as groups of crystals on drusy white quartz. Associated minerals are mcalpineite, xocomecatlite and unnamed Cu(Mg,Cu,Fe,Zn) 2 Te (super 6+) O 6 .6H 2 O. Individual crystals of jensenite are subhedral to euhedral, and form simple rhombs that are nearly equant. Some crystals are slightly elongate [101], with a length-to-width ratio up to 2:1. The largest crystal is approximately 0.4 mm in size; the average size is between 0.1 and 0.2 mm. Cleavage {101} fair. Forms are: {101} major; {110} medium; {100} minor; {301}, {201}, {203}, {102}, {010} very small. The mineral is transparent, emerald green, with a less intense streak of the same color and an uneven fracture. Jensenite is adamantine, brittle and nonfluorescent; H (Mohs) 3-4; D (calc.) 4.78 for the idealized formula, 4.76 g/cm 3 for the empirical formula. In a polished section, jensenite is very weakly bireflectant and nonpleochroic. In reflected plane-polarized light in air, it is a nondescript grey, and in oil, it is a much darker grey in color with a brownish tint, with ubiquitous bright green internal reflections. Anisotropy is not detectable. Measured values of reflectance, in air and in oil, are tabulated. Electron-microprobe analyses yielded CuO 50.91, ZnO 0.31, TeO 3 38.91, H 2 O (calc.) [8.00], total [98.13] wt.%. The empirical formula, derived from crystal-structure analysis and electron-microprobe analyses, is (Cu (sub 2.92) Zn (sub 0.02) ) (sub

  16. 30 CFR 77.1200 - Mine map.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... boundary lines of the active areas of the mine; (c) Contour lines passing through whole number elevations..., except that a broader spacing of contour lines may be approved by the District Manager for steeply pitching coalbeds. Contour lines may be placed on overlays or tracings attached to mine maps. (d)...

  17. Use of short-term (5-Minute) and long-term (18-Hour) leaching tests to characterize, fingerprint, and rank mine-waste material from historical mines in the Deer Creek, Snake River, and Clear Creek Watersheds in and around the Montezuma Mining District, Colorado

    USGS Publications Warehouse

    Hageman, Philip L.

    2004-01-01

    Precipitation-induced runoff from historical mine-waste located adjacent to the headwaters of the Snake River, Deer Creek, Saints John Creek, Grizzly Gulch, Stevens Gulch, and Leavenworth Creek contributes to the degradation of water quality in these streams. Because historical mine-waste piles have had long-term exposure to the atmosphere, it is surmised that runoff from these piles, induced by meteorological events such as cloudbursts and snowmelt, may cause mobility of acid and metals into a watershed due to dissolution of soluble minerals. For this study, 13 mine-waste composite samples from various mine-wastes in these drainage basins were leached using both a short-term and a long-term leach test. Analytical results from this combination of leach tests are tools that allow the investigator to quantify (fingerprint) which geochemical components could be expected in runoff from these piles if they were leached by a cloudburst (5-minute leach test), as well as what the ?worst-case? geochemical profile would look like if the material were subject to extended leaching and breakdown of the mine-waste material (18-hour leach test). Also, this combination of leach tests allows the geoscientist the ability to see geochemical changes in the mine-waste leachate over time. That is, does the leachate become more or less acidic over time; does the specific conductance increase or decrease; and are there changes in the concentrations of major or trace elements? Further, use of a ranking scheme described herein will aid in prediction of which historical mine-waste piles have the greatest potential for impact on a watershed should runoff occur. Because of long-term weathering of these historical mine-waste piles, geochemical profiles, leachate time-trends, and relative ranking of the mine-wastes produced from analysis of the leachates are Hageman_SIR_2508.doc 1 7/21/2004 2:50 PM indicative of how the mine-waste piles can be expected to act in the environment and may help to

  18. 76 FR 68106 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Unified Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  19. 76 FR 53640 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-29

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  20. 76 FR 70886 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  1. 76 FR 37044 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control..., Air pollution control, Intergovernmental relations, Nitrogen dioxide, Ozone, Particulate...

  2. 77 FR 24883 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control,...

  3. 77 FR 25384 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Environmental protection, Air pollution control, Intergovernmental relations, Ozone, Reporting and...

  4. 77 FR 2228 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  5. 77 FR 35329 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control,...

  6. 76 FR 52623 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Intergovernmental...

  7. 76 FR 33181 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve a revision to the San Joaquin Valley Unified Air Pollution Control..., Air pollution control, Intergovernmental relations, Ozone, Reporting and recordkeeping...

  8. 76 FR 56134 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... protection, Air pollution control, Intergovernmental relations, Ozone, Reporting and...

  9. 76 FR 56706 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Environmental protection, Air pollution control, Intergovernmental relations, Ozone, Reporting and...

  10. 77 FR 35327 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control,...

  11. 76 FR 47076 - Revision to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of a revision to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  12. 78 FR 6740 - Revisions to the California State Implementation Plan, San Joaquin Valley United Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley United Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  13. 76 FR 69135 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  14. 77 FR 58352 - Revisions to the California State Implementation Plan, San Diego County, Antelope Valley and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Diego County, Antelope... Antelope Valley Air Quality Management District (AVAQMD) portions of the California State...

  15. Breakthrough for Bilingual Education: Lau v. Nichols and the San Francisco School System

    ERIC Educational Resources Information Center

    Waugh, Dexter; Koon, Bruce

    1974-01-01

    An examination of the issues and implications of the Lau case in which the San Francisco school district was instructed to provide meaningful bilingual-bicultural educational programs for non-English speaking students. (EH)

  16. SAN JOAQUIN ROADLESS AREA, CALIFORNIA.

    USGS Publications Warehouse

    McKee, Edwin H.; Capstick, Donald O.

    1984-01-01

    The San Joaquin Roadless Area is composed of three noncontiguous areas on the eastern side of the Sierra Nevada in Madera County, California. The results of geologic, geochemical, and mining-activity and production surveys in the central part of the area indicate little promise for the occurrence of metallic-mineral or energy resources in the area. Sand, gravel, and pumice exist in the area but occurrences are small and isolated and farther from major markets than similar deposits outside the roadless area. Rocks in the area are exhibited in exposures of unaltered and nonmineralized granitic and metavolcanic rock along the steep western wall of the glacially carved valley of the Middle Fork of the San Joaquin River. Drainage in the area consists of seeps along fractures in the cliff or small cascading streams, a hydraulic setting not favorable for the development of placer deposits. No mines or prospect workings were found in the roadless area. Alteration zones within the granitic and metamorphic rock that crop out within the area are small, isolated, and consist only of limonitic staining and bleached quartzose rock.

  17. 33 CFR 165.T11-568 - Safety Zone; San Diego Symphony Summer POPS Fireworks 2013 Season, San Diego, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Summer POPS Fireworks 2013 Season, San Diego, CA. 165.T11-568 Section 165.T11-568 Navigation and... Areas Eleventh Coast Guard District § 165.T11-568 Safety Zone; San Diego Symphony Summer POPS Fireworks... fireworks barge in approximate position 32°42′16″ N, 117°09′59″ W. (b) Enforcement period. This rule will...

  18. 76 FR 12720 - City of Escondido, CA, and Vista Irrigation District; Notice of Application Accepted for Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... District (Vista). e. Name of Project: Escondido Hydroelectric Project. f. Location: On the San Luis Rey... also occupies 66 acres of Indian reservation lands owned by the La Jolla, San Pasqual, and Rincon... storage reservoirs (Lake Henshaw on San Luis Rey River and Lake Wohlford on Escondido Creek) with...

  19. Comparative Fluid Inclusion Chemistry of Miarolitic Pegmatites from San Diego County, California, USA

    NASA Astrophysics Data System (ADS)

    Nymberg, D.; Sirbescu, M. L. C.

    2014-12-01

    Miarolitic Li-Cs-Ta pegmatites are an important source of gemstones such as tourmaline var. elbaite and spodumene var. kunzite, but the distribution of gem-bearing pegmatites within a pegmatite field is not understood. This microthermometry, LA-ICP-MS, Raman spectroscopy, and crush-leach study of fluid inclusions in pegmatite quartz aims to discern the chemical variations of late-stage pegmatite fluids in relation to gem mineralization. We studied five mines from three San Diego Co. districts: Chihuahua Valley (C), Jacumba (J), and Pala (P). The ~100 Ma old, 1-10 m thick, subparallel magma sheets intruded plutons of the Peninsular Ranges Batholith or prebatholitic metasediments at an estimated pressure of 200-300 MPa. The pegmatites formed sequentially, from outer zones with comb, layered, and graphic quartz-feldspar textures at the magmatic stage to massive cores and miarolitic pockets at a late, fluid-saturated stage. Pocket quartz was analyzed from pegmatites of variable host rock, magmatic mineral assemblages, and known gem production. The inclusions contained two-phase aqueous fluids and no CO2 or other gases. Fluid salinity ranged from 0.5 to 8.6 wt.% NaCl eq. and correlated positively with inclusion homogenization temperature. Isochoric T at 250 MPa calculated for primary and pseudosecondary inclusions in pocket quartz ranged from 280 to 500 °C in district P, 310-420°C in J, and 230-290°C in C. We attribute the higher T of pocket formation in districts P and J to higher surrounding T at emplacement caused by proximity to other dikes. This preliminary study suggests that gem elbaite and/or kunzite occurrence correlates to Li and B contents in the pocket fluid, which, in turn, are a function of consumption by early, magmatic minerals. The P district has a simple leucogranite mineralogy at the magmatic stage; has as much as 5760 ppm B and 4950 ppm Li in the pocket fluid; and produced both elbaite and kunzite. The J district has abundant magmatic tourmaline

  20. SHENANDOAHDIVES (MAYFLOWER) MINE PORTAL SITE, LOOKING WEST. NOTE FOUNDATION AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SHENANDOAH-DIVES (MAYFLOWER) MINE PORTAL SITE, LOOKING WEST. NOTE FOUNDATION AT RIGHT AND RADIATOR AT LOWER LEFT, BOTH REMNANTS OF THE DORMITORY. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  1. Performance potential of the coal strip mining in the east of Russia

    SciTech Connect

    Cheskidov, V.I.

    2007-07-15

    The potentialities of the leading mining districts in Russia to improve coal production by strip mining are analyzed. The operational issues of the Erunakovskiy (Kuzbass), Kansko-Achinskiy and South Yakutia territorial production complexes are considered.

  2. 2010 Five-Year Plan: Assessment of Health and Environmental Impacts of Uranium Mining and Milling

    EPA Pesticide Factsheets

    The five-year plan is intended to compile all activities contributing to the identification and cleanup of legacy uranium milling and mining activities in the Grants Mining District in the State of New Mexico.

  3. 33 CFR 165.1101 - Security Zone: San Diego Bay, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zone: San Diego Bay, CA. 165.1101 Section 165.1101 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Navigation Areas and Limited Access Areas Eleventh Coast Guard District § 165.1101 Security Zone: San...

  4. 76 FR 68103 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Unified Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... Rulemaking For the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

  5. 76 FR 45199 - Interim Final Determination To Defer Sanctions, San Joaquin Valley Unified Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... of revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Incorporation by reference... AGENCY 40 CFR Part 52 Interim Final Determination To Defer Sanctions, San Joaquin Valley Unified...

  6. The Unimpressible Race. A Century of Educational Struggle by the Chinese in San Francisco.

    ERIC Educational Resources Information Center

    Low, Victor

    This book traces the history of the Chinese experience in America, particularly in the San Francisco area, from the California Gold Rush era of the 1850s to the construction of a new all-Chinese school in San Francisco's Chinatown district in the 1950s. The first five chapters of the book detail the withholding of school privileges from both…

  7. La Biblioteca Latino Americana: User Survey (San Jose Public Library). Studies in Librarianship No. 2.

    ERIC Educational Resources Information Center

    Johnstone, James C.; And Others

    To assist a neighborhood committee in applying for federal funding of a bilingual/bicultural library with a distinct Latin American emphasis, a student research group from San Jose State University designed and administered a bilingual questionnaire to a stratified sample of 400 households in the Gardner District of San Jose, California. The…

  8. 76 FR 55842 - Partial Approval and Partial Disapproval of Air Quality Implementation Plans; California; San...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-09

    ... AGENCY 40 CFR Part 52 Partial Approval and Partial Disapproval of Air Quality Implementation Plans; California; San Joaquin Valley; Reasonably Available Control Technology for Ozone AGENCY: Environmental... disapprove a revision to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD or...

  9. Assessing Instructional Reform in San Diego: A Theory-Based Approach

    ERIC Educational Resources Information Center

    O'Day, Jennifer; Quick, Heather E.

    2009-01-01

    This article provides an overview of the approach, methodology, and key findings from a theory-based evaluation of the district-led instructional reform effort in San Diego City Schools, under the leadership of Alan Bersin and Anthony Alvarado, that began in 1998. Beginning with an analysis of the achievement trends in San Diego relative to other…

  10. Legacy Mercury in Alviso Slough, South San Francisco Bay, California: Concentration, Speciation and Mobility

    USGS Publications Warehouse

    Marvin-DiPasquale, Mark; Cox, Marisa H.

    2007-01-01

    Mercury (Hg) is a significant contaminant in the waters, sediment and biota of San Francisco Bay, largely resulting from extensive historic regional mining activities. Alviso Slough represents one of the most mercury contaminated waterways entering south San Francisco Bay, as it is associated with the drainage of the New Almaden mercury mining district. Wetland habitat restoration of former salt manufacturing ponds adjacent to Alviso Slough is currently being planned. One management scenario being considered is a levee breach between Alviso Slough and Pond A8, which will allow reconnection of the salt pond with the tidal slough. This action is projected to increase the tidal prism within Alviso Slough and result in some degree of sediment remobilization as the main channel deepens and widens. The focus of the current study is to assess: a) the current mercury species composition and concentration in sediments within the Alviso Slough main channel and its associated fringing marsh plain, b) how much of each mercury species will be mobilized as a result of projected channel deepening and widening, and c) potential changes in inorganic reactive mercury bioavailability (for conversion to toxic methylmercury) associated with the mobilized sediment fraction. The current report details the field sampling approach and all laboratory analyses conducted, as well as provides the complete dataset associated with this project including a) a quantitative assessment of mercury speciation (total mercury, reactive mercury and methylmercury), b) estimates of the quantity of sediment and mercury mobilized based on 20-foot and 40-foot levee wall notch scenarios, and c) results from a sediment scour experiment examining the changes in the reactive mercury pool under four treatment conditions (high / low salinity and oxic / anoxic water). Ancillary sediment data also collected and reported herein include bulk density, organic content, magnetic susceptibility, percent dry weight, grain

  11. Mineralogy from Cores in Prospect Gulch, San Juan County, Colorado

    USGS Publications Warehouse

    Bove, Dana J.; Johnson, Raymond H.; Yager, Douglas B.

    2007-01-01

    In the late nineteenth century, San Juan County, Colorado, was the center of a metal mining boom in the San Juan Mountains. Although most mining activity ceased by the 1990s, the effects of historical mining continue to contribute metals to ground water and surface water. Previous research by the U.S. Geological Survey identified ground-water discharge as a significant pathway for the loading of metals to surface water from both acid-mine drainage and acid-rock drainage. In an effort to understand the ground-water flow system in the upper Animas River watershed, Prospect Gulch was selected for further study because of the amount of previous data provided in and around that particular watershed. In support of this ground-water research effort, data was collected from drill core, which included: (1) detailed descriptions of the subsurface geology and hydrothermal alteration patterns, (2) depth of sulfide oxidation, and (3) quantitative mineralogy.

  12. Impacts of historical mining in the Coeur d'Alene River Basin

    USGS Publications Warehouse

    Balistrieri, Laurie S.; Box, Stephen E.; Bookstrom, Arthur A.; Hooper, Robert L.; Mahoney, J. Brian

    2010-01-01

    Mining began in the late 1880s in the Coeur d'Alene mining district in northern Idaho (fig. 1). Although only two mines, the Galena and Lucky Friday, currently are operating, more than 90 historical mines exist in this region (Bennett and others, 1989).

  13. COMPARISON OF APATITE II™ TREATMENT SYSTEM AT TWO MINES FOR METALS REMOVAL

    EPA Science Inventory

    Two abandoned lead-zinc mine sites, the Nevada Stewart Mine (NSM) and Success Mine, are located within the Coeur d'Alene Mining District, in northern Idaho. An Apatite II™ Treatment System (ATS) was implemented at each site to treat metal-laden water, mainly zinc. In the ATS, f...

  14. Longwall mining

    SciTech Connect

    1995-03-14

    As part of EIA`s program to provide information on coal, this report, Longwall-Mining, describes longwall mining and compares it with other underground mining methods. Using data from EIA and private sector surveys, the report describes major changes in the geologic, technological, and operating characteristics of longwall mining over the past decade. Most important, the report shows how these changes led to dramatic improvements in longwall mining productivity. For readers interested in the history of longwall mining and greater detail on recent developments affecting longwall mining, the report includes a bibliography.

  15. Mercury Benthic Flux: A Comparison Between 3 Mining-Impacted Water Bodies in the Western United States

    NASA Astrophysics Data System (ADS)

    Topping, B. R.; Kuwabara, J. S.; Marvin-Dipasquale, M. C.; Agee, J. L.; Kieu, L. H.; Flanders, J. R.; Parchaso, F.

    2004-12-01

    The legacy of mining in the Western United States has left an indelible environmental imprint on terrestrial and aquatic systems. On both sides of the Sierra Nevada mountain range (Sierras), mercury was used copiously in the amalgamation of gold and silver. Mercury deposits in close proximity to San Francisco Bay (e.g., the New Almaden mining district) provided much of the mercury for these processes. To evaluate mercury benthic flux, three geographically distinct water bodies were studied: Lahontan Reservoir (NV) on the eastern side of the Sierras, affected by historic gold and silver mining; Camp Far West Reservoir (CA) on the western side of the Sierras, down stream of historic hydraulic gold mining and processing; and South San Francisco Bay (CA), the estuarine component down stream of the New Almaden Mercury Mines. Average benthic flux of total-dissolved mercury was highest in Lahontan Reservoir ( ˜1400 pmol/m2/hr), followed by Camp Far West Reservoir ( ˜180 pmol/m2/hr), and lowest in South San Francisco Bay ( ˜50 pmol/m2/hr). In spite of this wide range of values, and the unique character of each watershed (e.g., forested vs. urbanized), all three systems exhibited quantitatively significant mercury benthic fluxes relative to riverine inputs. That is, areally averaged benthic fluxes (thus, expressed as annual loads) were of similar or greater magnitude relative to riverine loads. System-averaged values of dissolved methylmercury fluxes were similar for South San Francisco Bay (undetectable) and Camp Far West Reservoir (average of ˜0 pmol/m2/hr; some fluxes undetectable), and only slightly higher in Lahontan Reservoir ( ˜2 pmol/m2/hr). Similarly, system averaged potential rates of methylmercury production (by sulfate-reducing bacteria; as assessed by 203Hg(II) radiotracer studies) in the surficial sediment were not significantly different among the three locations. However, within-system variability was approximately an order of magnitude in each case

  16. Geothermal district heating systems

    NASA Astrophysics Data System (ADS)

    Budney, G. S.; Childs, F.

    1982-06-01

    Ten district heating demonstration projects and their present status are described. The projects are Klamath County YMCA, Susanville District Heating, Klamath Falls District Heating, Reno Salem Plaza Condominium, El Centro Community Center Heating/Cooling, Haakon School and Business District Heating, St. Mary's Hospital, Diamond Ring Ranch, Pagosa Springs District Heating, and Boise District Heating.

  17. 77 FR 214 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-04

    ... Air Pollution Control District (SJVUAPCD) AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control... and air districts for evaluating air pollution control economics. 3. Farms can change owners...

  18. 75 FR 2796 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ... is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control District portion... topcoats; and that Ventura County Air Pollution Control District's (VCAPCD) rule has more stringent VOC...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  19. 75 FR 10690 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control District (SJVAPCD...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control... Joaquin Valley Unified Air Pollution Control District. (1) Rule 4104, ``Reduction of Animal Matter,''...

  20. 76 FR 39777 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollutions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Air Pollutions Control District (SJVUAPCD) AGENCY: Environmental Protection Agency (EPA). ACTION... San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State... Rule 344 D.2.b.2 require that fixed covers be equipped with a 95% efficient Air Pollution Control...

  1. 77 FR 64427 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... County Air Pollution Control District (VCAPCD) there is no VOC concentration limit for reinjection...

  2. 77 FR 58313 - Revisions to the California State Implementation Plan, San Diego County, Antelope Valley and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Diego County, Antelope... District (MBUAPCD) and Antelope Valley Air Quality Management District (AVAQMD) portions of the California..., ``Graphic Arts Operations,'' adopted on November 9, 2011 and effective on May 9, 2012. (D) Antelope...

  3. The San Andreas Fault 'Supersite' (Invited)

    NASA Astrophysics Data System (ADS)

    Hudnut, K. W.

    2013-12-01

    struck in 1992 (Landers), 1994 (Northridge) and 1999 (Hector Mine) as well as the 2010 El Mayor - Cucapah (EM-C) earthquake (just south of the US-Mexico border). Of these four notable events, all produced extensive surface faulting except for the 1994 Northridge event, which was close to the Los Angeles urban area on a buried thrust fault. Northridge caused by far the most destruction, topping $20B (US) and resulting in 57 fatalities due to its location under an urban area. The Landers, Hector Mine and EM-C events occurred in desert areas away from major urban centers, and each proved to be a new and unique test-bed for making rapid progress in earthquake science and creative use of geodetic imagery. InSAR studies were linked to GPS deformation and mapping of surface ruptures and seismicity in a series of important papers about these earthquakes. The hazard in California remains extremely high, with tens of millions of people living in close proximity to the San Andreas Fault system as it runs past both San Francisco and Los Angeles. Dense in-situ networks of seismic and geodetic instruments are continually used for research and earthquake monitoring, as well as development of an earthquake early warning capability. Principles of peer review from funding agencies and open data availability will be observed for all data. For all of these reasons, the San Andreas Fault system is highly appropriate for consideration as a world-class permanent Supersite in the GEO framework.

  4. East Valley Water District: Public Assistance Worksheets for Damage from 2010 Floods

    EPA Pesticide Factsheets

    East Valley Water District (EVWD) in San Bernardino, California had significant damage due to flooding in December 2010. There was a presidentially-declared disaster. EVWD applied to FEMA under the Public Assistance Grant Program.

  5. SPUR: Moving San Diego, California Schools toward Integrated Pest Management.

    ERIC Educational Resources Information Center

    Taylor, Sharon

    1991-01-01

    The preparation of a report, slide show, and brochure to promote awareness of the hazards of toxic pest control for school pest management personnel in the San Diego Unified School District is discussed. The future plans of the coalition are proposed. (CW)

  6. 30 CFR 71.301 - Respirable dust control plan; approval by District Manager and posting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Respirable dust control plan; approval by... WORK AREAS OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.301 Respirable dust control... control plans on a mine-by-mine basis. When approving respirable dust control plans, the District...

  7. 30 CFR 71.301 - Respirable dust control plan; approval by District Manager and posting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Respirable dust control plan; approval by... WORK AREAS OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.301 Respirable dust control... control plans on a mine-by-mine basis. When approving respirable dust control plans, the District...

  8. 30 CFR 71.301 - Respirable dust control plan; approval by District Manager and posting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust control plan; approval by... WORK AREAS OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.301 Respirable dust control... control plans on a mine-by-mine basis. When approving respirable dust control plans, the District...

  9. Web Mining

    NASA Astrophysics Data System (ADS)

    Fürnkranz, Johannes

    The World-Wide Web provides every internet citizen with access to an abundance of information, but it becomes increasingly difficult to identify the relevant pieces of information. Research in web mining tries to address this problem by applying techniques from data mining and machine learning to Web data and documents. This chapter provides a brief overview of web mining techniques and research areas, most notably hypertext classification, wrapper induction, recommender systems and web usage mining.

  10. Data Mining.

    ERIC Educational Resources Information Center

    Benoit, Gerald

    2002-01-01

    Discusses data mining (DM) and knowledge discovery in databases (KDD), taking the view that KDD is the larger view of the entire process, with DM emphasizing the cleaning, warehousing, mining, and visualization of knowledge discovery in databases. Highlights include algorithms; users; the Internet; text mining; and information extraction.…

  11. 40. Historic American Buildings Survey San Francisco Chronicle Collection San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Historic American Buildings Survey San Francisco Chronicle Collection San Francisco, California March 24, 1924 VIEW OF HIGH ALTAR - Mission San Carlos Borromeo, Rio Road & Lausen Drive, Carmel-by-the-Sea, Monterey County, CA

  12. The National Evaluation of Project SEED in Five School Districts 1997-1998.

    ERIC Educational Resources Information Center

    Webster, William J.

    This study reports the results of the implementation of Project SEED, a mathematics program for urban elementary school students, in five urban districts: Camden (New Jersey); Dallas (Texas); Detroit (Michigan); Indianapolis (Indiana); and the West Contra Costa Unified School District in Richmond and San Pablo (California). Students exposed to at…

  13. Coordinated School Health and the Contribution of a District Wellness Coordinator

    ERIC Educational Resources Information Center

    Westrich, Lisa; Sanchez, Monika; Strobel, Karen

    2015-01-01

    Background: A San Francisco Bay Area school health initiative was established in fall 2010 to improve wellness programs in 4 local school districts using the Coordinated School Health (CSH) model. This study examines the role of district-wide wellness coordinators and the ways in which they contribute to intentional coordination of health and…

  14. 76 FR 60474 - Intent To Prepare a Draft Environmental Impact Statement (DEIS) for the Haile Gold Mine in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... notice is available on Charleston District's public Web site at: http://www.sac.usace.army.mil/?action... open pit mining, and to construct associated facilities. The Haile Gold Mine Site encompasses approximately 4,231 acres. Mining will occur in phases involving eight open mining pits over a...

  15. 33 CFR 165.1184 - Safety Zone; Coast Guard Use of Force Training Exercises, San Pablo Bay, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Force Training Exercises, San Pablo Bay, CA. 165.1184 Section 165.1184 Navigation and Navigable Waters... Coast Guard District § 165.1184 Safety Zone; Coast Guard Use of Force Training Exercises, San Pablo Bay.... If the exercises conclude prior to the scheduled termination time, the Coast Guard will...

  16. 78 FR 45268 - Notice of Availability of the San Diego Gas & Electric Ocotillo Sol Solar Project Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ... Project Final Environmental Impact Statement and Proposed California Desert Conservation Area Plan... Desert Conservation Area (CDCA) Plan Amendment and Final Environmental Impact Statement (EIS) for the San... governments. Copies are also available in the BLM California Desert District Office at 22835 Calle San Juan...

  17. San Antonio Experience Based Career Education Demonstration Project. Final Narrative Performance Report, September 15, 1976-August 31, 1979.

    ERIC Educational Resources Information Center

    Lafferty, Bill R.

    The San Antonio Experience-Based Career Education (EBCE) project was evaluated by a third party for its three years of operation. The project was designed to assist youth in making a successful transition to adulthood through community-based and learning center experiences, and was implemented by the Harlandale and San Antonio school districts.…

  18. Partners in Innovation: How a High School and College Are Improving Outcomes for Youth in San Diego

    ERIC Educational Resources Information Center

    Coates, Joy; Webb, Michael

    2013-01-01

    The early college high school program at San Diego City College is a partnership of the college, San Diego Unified School District, and several state and national organizations. The partnership has successfully implemented a variety of college-readiness and college-connected strategies, including an early college school, to better prepare students…

  19. The San Andreas Fault

    USGS Publications Warehouse

    Schulz, Sandra S.; Wallace, Robert E.

    1993-01-01

    The presence of the San Andreas fault was brought dramatically to world attention on April 18, 1906, when sudden displacement along the fault produced the great San Francisco earthquake and fire. This earthquake, however, was but one of many that have resulted from episodic displacement along the fault throughout its life of about 15-20 million years.

  20. California: San Joaquin Valley

    Atmospheric Science Data Center

    2014-05-15

    article title:  Fog and Haze in California's San Joaquin Valley   ... is noted for its hazy overcasts and a low, thick ground fog known as the Tule. Owing to the effects of the atmosphere on reflected ... as the angle of view changes. An area of thick, white fog in the San Joaquin Valley is visible in all three of the images. However, ...

  1. School District Mergers: What One District Learned

    ERIC Educational Resources Information Center

    Kingston, Kathleen

    2009-01-01

    Throughout the planning process for a school district merger in a northwestern Pennsylvania school district, effective communication proved to be a challenge. Formed in 1932, this school district of approximately 1400 students was part of a utopian community; one established by a transportation system's corporation that was a major industrial…

  2. 33 CFR 165.T11-560 - Safety Zone; Sea World San Diego Fireworks 2013 Season, Mission Bay; San Diego, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Fireworks 2013 Season, Mission Bay; San Diego, CA. 165.T11-560 Section 165.T11-560 Navigation and Navigable... Eleventh Coast Guard District § 165.T11-560 Safety Zone; Sea World San Diego Fireworks 2013 Season, Mission... fireworks barge in approximate position 32°46′03″ N, 117°13′11″ W. (b) Enforcement period. This rule will...

  3. Central San Juan caldera cluster: regional volcanic framework

    USGS Publications Warehouse

    Lipman, Peter W.

    2000-01-01

    Eruption of at least 8800 km3 of dacitic-rhyolitic magma as 9 major ash-slow sheets (individually 150-5000 km3) was accompanied by recurrent caldera subsidence between 28.3 and about 26.5 Ma in the central San Juan Mountains, Colorado. Voluminous andesitic-decitic lavas and breccias were erupted from central volcanoes prior to the ash-flow eruptions, and similar lava eruptions continued within and adjacent to the calderas during the period of explosive volcanism, making the central San Juan caldera cluster an exceptional site for study of caldera-related volcanic processes. Exposed calderas vary in size from 10 to 75 km in maximum diameter, the largest calderas being associated with the most voluminous eruptions. After collapse of the giant La Garita caldera during eruption if the Fish Canyon Tuff at 17.6 Ma, seven additional explosive eruptions and calderas formed inside the La Garita depression within about 1 m.y. Because of the nested geometry, maximum loci of recurrently overlapping collapse events are inferred to have subsided as much as 10-17 km, far deeper than the roof of the composite subvolcanic batholith defined by gravity data, which represents solidified caldera-related magma bodies. Erosional dissection to depths of as much as 1.5 km, although insufficient to reach the subvolcanic batholith, has exposed diverse features of intracaldera ash-flow tuff and interleaved caldera-collapse landslide deposits that accumulated to multikilometer thickness within concurrently subsiding caldera structures. The calderas display a variety of postcollapse resurgent uplift structures, and caldera-forming events produced complex fault geometries that localized late mineralization, including the epithermal base- and precious-metal veins of the well-known Creede mining district. Most of the central San Juan calderas have been deeply eroded, and their identification is dependent on detailed geologic mapping. In contrast, the primary volcanic morphology of the

  4. EPA awards $50,000 to Los Angeles Unified School District to educate and empower students to conserve water

    EPA Pesticide Factsheets

    SAN FRANCISCO - The U.S. Environmental Protection Agency has awarded an environmental education grant of $50,000 to the Los Angeles Unified School District (LAUSD) to develop and implement curriculum focused on water sustainability in a changing cli

  5. Lead isotope compositions as guides to early gold mineralization: The North Amethyst vein system, Creede district, Colorado

    USGS Publications Warehouse

    Foley, Nora K.; Ayuso, Robert A.

    1994-01-01

    Pb isotope compositions from the late stage of the North Amethyst vein system and from the Bondholder and central and southern Creede mining districts are more radiogenic than the host volcanic rocks of the central cluster of the San Juan volcanic field. Our Pb isotope results indicate that early Au mineralization of the North Amethyst area may represent the product of an older and relatively local hydrothermal system distinct from that of the younger base metal and Ag mineralization found throughout the region. Fluids that deposited Au minerals may have derived their Pb isotope composition by a greater degree of interaction with shallow, relatively less radiogenic volcanic wall rocks. The younger, base metal and Ag-rich mineralization that overprints the Au mineralization in the North Amethyst area clearly has a more radiogenic isotopic signature, which implies that the later mineralization derived a greater component of its Pb from Proterozoic source rocks, or sediments derived from them.Paragenetically early sulfide-rich vein assemblages have the least radiogenic galenas and generally also have the highest Au contents. Thus, identification of paragenetically early vein assemblages with relatively unradiogenic Pb isotope compositions similar to those of the North Amethyst area provides an additional exploration tool for Au in the central San Juan Mountains area.

  6. The Development of a Teacher Salary Parcel Tax: The Quality Teacher and Education Act in San Francisco

    ERIC Educational Resources Information Center

    Hough, Heather J.; Loeb, Susanna

    2009-01-01

    This case study will serve primarily as an historical account detailing the development of Quality Teacher and Education Act (QTEA). QTEA and the most salient details that led to its eventual passage, serving as an information source for San Francisco Unified School District (SFUSD) and other districts when they take on potentially controversial…

  7. Geology and quicksilver deposits of the Terlingua district, Texas

    USGS Publications Warehouse

    Yates, R.G.; Thompson, G.A.

    1959-01-01

    The Terlingua quicksilver district, which has produced more than 150,000 flasks of quicksilver, is in the southern part of the Big Bend region of southwestern Texas. It is a narrow, eastwest area about 20 miles long and lies mainly in southwestern Brewster County. The district is connected by graded road with the nearest railroad, 84 miles north of its center. Quicksilver minerals were first discovered in the district in the latter part of the 19th century, but there was no substantial production until 1900. Although there are about 20 mines and many prospects, more than 90 percent of the quicksilver came from the Chisos-Rainbow, Mariposa, and Study Butte mines. The most productive years were during World War I; since 1946 the district has been idle. Future production depends upon the discovery of new ore bodies-which will be costly-and the working of deposits now considered of too low grade to be profitable.

  8. African mining

    SciTech Connect

    Not Available

    1987-01-01

    This book contains papers presented at a conference addressing the development of the minerals industry in Africa. Topics covered include: A review - past, present and future - of Zimbabwe's mining industry; Geomorphological processes and related mineralization in Tanzania; and Rock mechanics investigations at Mufulira mine, Zambia.

  9. Geochemistry of soils from the San Rafael Valley, Santa Cruz County, Arizona

    USGS Publications Warehouse

    Folger, Helen W.; Gray, Floyd

    2013-01-01

    This study was conducted to determine whether surficial geochemical methods can be used to identify subsurface mineraldeposits covered by alluvium derived from surrounding areas. The geochemical investigation focused on an anomalous geo-physical magnetic high located in the San Rafael Valley in Santa Cruz County, Arizona. The magnetic high, inferred to be asso-ciated with a buried granite intrusion, occurs beneath Quaternary alluvial and terrace deposits. Soil samples were collected at a depth of 10 to 30 centimeters below land surface along transects that traverse the inferred granite. The samples were analyzed by inductively coupled plasma-mass spectrometry and by the partial-leach Mobile Metal Ion™ method. Principal component and factor analyses showed a strong correlation between the soils and source rocks hosting base-metal replacement deposits in the Harshaw and Patagonia Mining Districts. Factor analysis also indicated areas of high metal concentrations associated with the Meadow Valley Flat. Although no definitive geochemical signature was identified for the inferred granite, concentrations otungsten and iron in the surrounding area were slightly elevated.

  10. SAN JACINTO WILDERNESS, CALIFORNIA.

    USGS Publications Warehouse

    Cox, Brett F.; Conyac, Martin D.

    1984-01-01

    The San Jacinto Wilderness, located in the San Jacinto Mountains approximately 4 to 11 mi west of Palm Springs, California, was investigated by field and laboratory studies. The wilderness contains no known mineral deposits and no evidence of past mineral production. Geologic, geochemical, and geophysical studies indicate that the San Jacinto Wilderness has little promise for the occurrence of mineral or energy resources. However, if future studies of plutonism and related processes of mineralization are conducted in the San Jacinto Mountains and vicinity, the metasedimentary rocks and bordering intrusive contacts in the south parcel of the wilderness might merit further examination. In particular, such future studies might further evaluate the origin and significance of minor stream-sediment geochemical anomalies for tungsten, cerium, and lanthanum detected in our panned-concentrate samples collected near the heads of Murray and Andreas Canyons.

  11. Long Period Ground Motions in the San Bernardino Region for Hypothetical San Andreas and San Jacinto Earthquakes

    NASA Astrophysics Data System (ADS)

    Graves, R. W.

    2001-12-01

    The San Bernardino region of southern California is situated on a wedge shaped sedimentary basin bounded to the north by the San Andreas fault and to the south by the San Jacinto fault. Not only is this region fairly heavily populated, but both of these active faults are capable of generating Mw 7+ earthquakes, stressing the need for timely assessment of the ground shaking hazard for future scenario earthquakes. Ground motion estimation in this region is further complicated by the highly variable nature of the subsurface geology. Sediment accumulations are relatively thin in the northern portion of the basin, and then steadily increase in thickness toward the south. The maximum sediment thickness is about 1.5 km just north of the San Jacinto fault, with an abrupt step-up and shallowing of the basement surface along (and to the south of) the San Jacinto fault. Existing observations of long period (T > 1 sec) ground motions for both large (1999 Mw 7.2 Hector Mine) and small (2001 Mw 4.7 Big Bear Lake) earthquakes show significant amplification and extended durations of shaking at recording sites within the basin. Recent studies using 3D numerical simulation methods have modeled these recorded ground motions in order to develop and constrain the 3D velocity structure of the basin region. The current 3D velocity models do reasonably well at matching the recorded waveforms at periods of about 2 seconds and longer. To estimate the expected levels of ground shaking for future events in this region, I have performed 3D finite difference ground motion simulations for hypothetical Mw 7 earthquakes on the San Andreas and San Jacinto faults. The simulations use the existing 3D structural models of the region and incorporate a suite of variable slip finite-fault rupture models. To address uncertainty in the source characterizion, I consider several hypocenter locations and slip distributions on each of the faults. Preliminary results indicate that the largest long period

  12. U.S. EPA Proposes to Add California Mine Site to Superfunds National Priorities List

    EPA Pesticide Factsheets

    SAN FRANCISCO - The U.S. Environmental Protection Agency is proposing to add eight hazardous waste sites to the Superfund program's National Priorities List (NPL), including California's Argonaut Mine. Superfund is the federal program that investiga

  13. EPA Update on Gold King Mine Response: Additional Data Results and Public Records

    EPA Pesticide Factsheets

    WASHINGTON - Today the U.S. Environmental Protection Agency (EPA) released an update on water quality and sediment data for the Animas and San Juan Rivers, as well as additional public records on the Gold King Mine response.

  14. Lessons from Country Borders: Preparing Leaders for Social Justice and Diversity through a District and University Partnership

    ERIC Educational Resources Information Center

    Murakami Ramalho, Elizabeth; Garza, Encarnacion, Jr.; Merchant, Betty

    2009-01-01

    The purpose of this study was to explore the preparation of educators as school leaders in a master's degree program focused on diversity and social justice. This program is a partnership between the University of Texas at San Antonio and the San Antonio Independent School District. The program's proximity to the Mexican border provides an…

  15. A History of the Los Angeles District, U.S. Army Corps of Engineers, 1898-1965

    DTIC Science & Technology

    1975-01-01

    Arroyo drainage area, and along Julian Wash. About 40 miles southeast of Phoenix, the District completed in November 1960 the Whitlow Ranch Reservoir...Luis, California. By Porter-Urquhart- McCreary -O’Brien, Consulting Engineers, 1958. 370 Review Report for Navigation, Port San Luis (San Luis Obispo

  16. Economic geology of the Central City district, Gilpin County, Colorado

    USGS Publications Warehouse

    Sims, P.K.; Drake, A.A.; Tooker, E.W.

    1963-01-01

    The Central City district, in Gilpin County, Colo., is on the east flank of the Front Range, about 30 miles west of Denver. The district is the most important mining camp in the Front Range mineral belt, and has yielded more than $100 million worth of gold, silver, uranium, and base-metal ores since 1859. Gold accounts for about 85 percent of the dollar value of the ore. In recent years mining activity has been slack but from 1950 to 1955 the search for uranium ores stimulated prospecting and development.

  17. Overview of mine drainage geochemistry at historical mines, Humboldt River basin and adjacent mining areas, Nevada. Chapter E.

    USGS Publications Warehouse

    Nash, J. Thomas; Stillings, Lisa L.

    2004-01-01

    Reconnaissance hydrogeochemical studies of the Humboldt River basin and adjacent areas of northern Nevada have identified local sources of acidic waters generated by historical mine workings and mine waste. The mine-related acidic waters are rare and generally flow less than a kilometer before being neutralized by natural processes. Where waters have a pH of less than about 3, particularly in the presence of sulfide minerals, the waters take on high to extremely high concentrations of many potentially toxic metals. The processes that create these acidic, metal-rich waters in Nevada are the same as for other parts of the world, but the scale of transport and the fate of metals are much more localized because of the ubiquitous presence of caliche soils. Acid mine drainage is rare in historical mining districts of northern Nevada, and the volume of drainage rarely exceeds about 20 gpm. My findings are in close agreement with those of Price and others (1995) who estimated that less than 0.05 percent of inactive and abandoned mines in Nevada are likely to be a concern for acid mine drainage. Most historical mining districts have no draining mines. Only in two districts (Hilltop and National) does water affected by mining flow into streams of significant size and length (more than 8 km). Water quality in even the worst cases is naturally attenuated to meet water-quality standards within about 1 km of the source. Only a few historical mines release acidic water with elevated metal concentrations to small streams that reach the Humboldt River, and these contaminants and are not detectable in the Humboldt. These reconnaissance studies offer encouraging evidence that abandoned mines in Nevada create only minimal and local water-quality problems. Natural attenuation processes are sufficient to compensate for these relatively small sources of contamination. These results may provide useful analogs for future mining in the Humboldt River basin, but attention must be given to

  18. Radar image San Francisco Bay Area, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The San Francisco Bay Area in California and its surroundings are shown in this radar image from the Shuttle Radar Topography Mission (SRTM). On this image, smooth areas, such as the bay, lakes, roads and airport runways appear dark, while areas with buildings and trees appear bright. Downtown San Francisco is at the center and the city of Oakland is at the right across the San Francisco Bay. Some city areas, such as the South of Market district in San Francisco, appear bright due to the alignment of streets and buildings with respect to the incoming radar beam. Three of the bridges spanning the Bay are seen in this image. The Bay Bridge is in the center and extends from the city of San Francisco to Yerba Buena and Treasure Islands, and from there to Oakland. The Golden Gate Bridge is to the left and extends from San Francisco to Sausalito. The Richmond-San Rafael Bridge is in the upper right and extends from San Rafael to Richmond. Angel Island is the large island east of the Golden Gate Bridge, and lies north of the much smaller Alcatraz Island. The Alameda Naval Air Station is seen just below the Bay Bridge at the center of the image. Two major faults bounding the San Francisco-Oakland urban areas are visible on this image. The San Andreas fault, on the San Francisco peninsula, is seen on the left side of the image. The fault trace is the straight feature filled with linear reservoirs, which appear dark. The Hayward fault is the straight feature on the right side of the image between the urban areas and the hillier terrain to the east.

    This radar image was acquired by just one of SRTM's two antennas and, consequently, does not show topographic data, but only the strength of the radar signal reflected from the ground. This signal, known as radar backscatter, provides insight into the nature of the surface, including its roughness, vegetation cover and urbanization. The overall faint striping pattern in the images is a data processing artifact due to the

  19. U.S. EPA Releases Monitoring Plan to Evaluate Conditions in the Animas and San Juan Rivers

    EPA Pesticide Factsheets

    WASHINGTON - The U.S. Environmental Protection Agency today released its final monitoring plan for the Animas and San Juan rivers following the Aug. 5, 2015, Gold King Mine incident. The agency also posted on its Gold King Mine website the results o

  20. Liquefaction sand boils in San Francisco during 1989 Loma Prieta Earthquake

    SciTech Connect

    Bardet, J.P.; Kapuskar, M. )

    1993-03-01

    This paper presents and analyzes the observations of the sand boils that emerged in the Marina District of San Francisco after the Loma Prieta Earthquake of October 17, 1989. The sand boils were located within the boundary of an old lagoon, the periphery of which was severely damaged in the 1906 San Francisco earthquake. During the 1989 Loma Prieta Earthquake, the soils underlying the Marina District amplified the ground motion as in 1906 and caused the liquefaction of the superficial sandy materials that were used to fill the old lagoon in 1915. Damage in the Marina District was concentrated along the edges of the old lagoon. The sand boils left behind by liquefaction were useful to delineate the liquefied area and to understand the ground displacement in the Marina District. The sand boils covered uniformly the liquefied area that experienced lateral spreading and settlement. The present work also indicates the high damage potential of transition zones between liquefiable and nonliquefiable soils.

  1. North American Bats and Mines Project: A cooperative approach for integrating bat conservation and mine-land reclamation

    SciTech Connect

    Ducummon, S.L.

    1997-12-31

    Inactive underground mines now provide essential habitat for more than half of North America`s 44 bat species, including some of the largest remaining populations. Thousands of abandoned mines have already been closed or are slated for safety closures, and many are destroyed during renewed mining in historic districts. The available evidence suggests that millions of bats have already been lost due to these closures. Bats are primary predators of night-flying insects that cost American farmers and foresters billions of dollars annually, therefore, threats to bat survival are cause for serious concern. Fortunately, mine closure methods exist that protect both bats and humans. Bat Conservation International (BCI) and the USDI-Bureau of Land Management founded the North American Bats and Mines Project to provide national leadership and coordination to minimize the loss of mine-roosting bats. This partnership has involved federal and state mine-land and wildlife managers and the mining industry. BCI has trained hundreds of mine-land and wildlife managers nationwide in mine assessment techniques for bats and bat-compatible closure methods, published technical information on bats and mine-land management, presented papers on bats and mines at national mining and wildlife conferences, and collaborated with numerous federal, state, and private partners to protect some of the most important mine-roosting bat populations. Our new mining industry initiative, Mining for Habitat, is designed to develop bat habitat conservation and enhancement plans for active mining operations. It includes the creation of cost-effective artificial underground bat roosts using surplus mining materials such as old mine-truck tires and culverts buried beneath waste rock.

  2. Can a District-Level Teacher Salary Incentive Policy Improve Teacher Recruitment and Retention? Policy Brief 13-4

    ERIC Educational Resources Information Center

    Hough, Heather J.; Loeb, Susanna

    2013-01-01

    In this policy brief, Heather Hough and Susanna Loeb examine the effect of the Quality Teacher and Education Act of 2008 (QTEA) on teacher recruitment, retention, and overall teacher quality in the San Francisco Unified School District (SFUSD). They provide evidence that a salary increase can improve a school district's attractiveness within their…

  3. Cajon Valley Union School District: Changing the Culture of Learning to Empower Students. From the Field. Digital Learning Series

    ERIC Educational Resources Information Center

    Schwartzbeck, Terri Duggan

    2013-01-01

    The K-8 Cajon Valley Union School District (Cajon Valley USD) is one of forty-two school districts in the greater San Diego, California metropolitan area. Serving approximately 16,000 students, the Cajon Valley USD is extremely diverse; 36 percent of students are Hispanic, 46 percent are white, 7 percent are African American, and many students are…

  4. Development of District-Based Mineral-Hazards Maps for Highways in California

    NASA Astrophysics Data System (ADS)

    Higgins, C. T.; Churchill, R. K.; Fonseca, M. C.

    2011-12-01

    The California Geological Survey (CGS) currently is developing a series of unpublished maps for the California Department of Transportation (Caltrans) that shows potential for mineral hazards within each of the twelve highway districts administered by that agency. Where present along or near highway corridors, such hazards may pose problems for human health and safety or the environment. Prepared at a scale of 1:250,000, the maps are designed as initial screening tools for Caltrans staff to use to improve planning of activities that involve new construction projects, routine maintenance of highways, and emergency removal of debris deposited on roads by natural processes. Although the basic presentation of each type of thematic map in the series is the same, some customization and focus are allowed for each district because each has unique issues concerning potential for mineral hazards. The maps display many natural and man-made features that may be potential sources of mineral hazards within each district. Features compiled and evaluated under our definition of "mineral hazards" are: 1) naturally-occurring asbestos (NOA); 2) natural occurrences of various regulated metals (Ag, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Tl, V, Zn) and metalloids (As, Sb, Se) as well as other pertinent metals, such as Mn and U; 3) faults, which can be sites of increased potential for certain types of mineralization, such as NOA; 4) mines and prospects, which can be sources of anomalous concentrations of metals as well as ore-processing chemicals; 5) natural petroleum features, such as oil and natural-gas seeps; 6) natural geothermal features, such as thermal springs and fumaroles; and 7) oil, natural-gas, and geothermal wells. Because of their greater potential as sources of mineral hazards, localities designated on the maps as "areas of potential mineralogical concern" are of particular interest to Caltrans. Examples include significant mining districts, such as New Almaden (Hg) near

  5. History of San Marco

    NASA Technical Reports Server (NTRS)

    Caporale, A. J.

    1968-01-01

    A brief history is reported of the first San Marco project, a joint program of the United States and Italy. The Project was a three phase effort to investigate upper air density and associated ionosphere phenomena. The initial phase included the design and development of the spacecraft, the experiments, the launch complex, and a series of suborbital flights, from Wallops Island. The second phase, consisting of designing, fabricating, and testing a spacecraft for the first orbital mission, culminated in an orbital launch also from Wallops Island. The third phase consisted of further refining the experiments and spacecraft instrumentation and of establishing a full-bore scout complex in Kenya. The launch of San Marco B, in April 1967, from this complex into an equatorial orbit, concluded the initial San Marco effort.

  6. California's Districts of Choice

    ERIC Educational Resources Information Center

    Kronholz, June

    2014-01-01

    This article describes the results of a California state law established in 2010 that created "Districts of Choice." The District of Choice law was meant to encourage districts to compete for students by offering innovative programs and this-school-fits-my-child options that parents wanted. This designation meant that children from any…

  7. Combustion testing of San Miguel lignite

    SciTech Connect

    Jones, M.L.; Goblirsch, G.M.

    1982-01-01

    Results from pilot plant testing of the San Miguel lignite are: (1) The ash fouling furnace is an empirical tool which provides good information on relative fouling potential of various fuels. In the case of San Miguel lignite tests suggest a severe fouling problem is conventional boiler designs are employed. (2) No effect in either deposition rate or deposit strength was seen when MgO and CaCO/sub 3/ were used at additives. For these tests a single addition rate was utilizing two different injection points in the system. (3) No bed agglomeration was noted under the varied run conditions used in testing of this lignite fuel. (4) The atmospheric fluidized-bed combustor (AFBC) NO/sub x/ level emitted in the flue gas were always less than the NSPS limit of 0.6 lbs NO/sub 2//10/sup 6/ Btu. (5) Utilization of inherent alkali was less than that observed for North Dakota lignites. It was possible to meet NSPS standards of 90 percent sulfur capture using limestone addition. (6) Pulverized-coal combustion of San Miguel lignite resulted in a larger portion of <1 ..mu..m size particulates than has been noted in similar tests with the Arapahoe subbituminous coal and the Ledbetter Texas lignite. (7) The composition of particulates from P-C combustion of San Miguel lignite has a more varied composition than has been seen in testing with other types of coal. Use of lower grade fuels such as the lignite from the San Miguel mine is inevitable if we are to meet the expanding needs for energy in the United States today. To make use of these different fuels extensive testing on laboratory and pilot scales will be beneficial in avoiding major problems due to the different characteristics these materials possess. The present successful operation of a full scale boiler using the San Miguel lignite is a good example of the value pilot scale studies can have on the road to successful operation.

  8. Simulating the Fate and Transport of an Acid Mine Drainage Release

    EPA Science Inventory

    On August 5, 2015, approximately 3 million gallons of acid mine drainage were released from the Gold King Mine into Cement Creek in the San Juan River watershed (CO, NM, UT). The release further mobilized additional metals, which resulted in a large mass of solids and dissolved m...

  9. Mesozoic magmatism and timing of epigenetic Pb-Zn-Ag mineralization in the western Fortymile mining district, east-central Alaska: Zircon U-Pb geochronology, whole-rock geochemistry, and Pb isotopes

    USGS Publications Warehouse

    Dusel-Bacon, Cynthia; Aleinkoff, J.N.; Day, W.C.; Mortensen, J.K.

    2015-01-01

    Epigenetic Pb-Zn-Ag ± Cu prospects in the western Fortymile district are spatially associated with splays of the northeast-trending Kechumstuk sinistral-normal fault zone and with ca. 68-66 Ma felsic intrusions and dikes. The similarity between Pb isotope compositions of feldspars from the Late Cretaceous igneous bodies and sulfides from the epithermal prospects suggests a Late Cretaceous age for most of the mineralization. Fluid flow along the faults undoubtedly played a major role in mineralization. We interpret displacement on the northeast-trending faults to be a far-field effect of dextral translation along Late Cretaceous plate-scale boundaries and faults that were roughly parallel to the subsequently developed Denali and Tintina fault systems, which currently bound the region.

  10. The isotopic composition of ore lead of the Creede mining district and vicinity, San Juan Mountains, Colorado: Text of a talk presented at the San Juan Mountains symposium to honor Thomas A. Steven; Rocky Mountain Section meeting of the Geological Society of America, May 2, 1987, Boulder, Colorado

    USGS Publications Warehouse

    Foley, N.K.; Barton, P.B.; Bethke, P.M.; Doe, B.R.

    1988-01-01

    Recent work allows us to extend the results of Doe et al. and to consider alternative processes to explain the widespread homogeneity and radiogenic nature of the ore lead: 1) David Matty (pers. commun., 1986) has shown that some minor volcanic units in the area have unusually radiogneic lead values; magmas comparable in composition to the units are a possible, though improbable, source of the ore lead. 2) The uniformity of the isotopic values of galenas may have resulted from homogenization during an extensive potassium-metasomatic event that predated the ores; this possibility is being tested in an on-going study of feldspars from metasomatized and unmetasomatized rocks. 3) Recent regional studies suggest the possibility of a prevolcanic, NNW-trending graben system filled by clastic sediments derived from the Precambrian basement, a process that would have an homogenizing effect on the lead isotopes. This interpretation implies importation, deep within the Creede hydrologic system, of fluids from remote sources. These alternatives show that the Pbisotope systematics may have a profound impact on the interpretation of the Creede hydrothermal system, and that further study is warranted.

  11. SAN PEDRO GEODATA BROWSER

    EPA Science Inventory

    The San Pedro Data Browser was developed by the Landscape Ecology Branch of the U.S. Environmental Protection Agency (Las Vegas, NV). The goal of the Landscape Sciences Program is to improve decision-making relative to natural and human resource management through the development...

  12. SAN PEDRO WATERSHED DATABASE

    EPA Science Inventory

    The San Pedro River Geo-Data Browser was jointly developed by the Landscape Ecology Branch of the U.S. Environmental Protection Agency and the U.S. Department of Agriculture, Agricultural Research Service (Tucson, AZ). Since 1995, U.S. Environmental Protection Agency (EP A) and U...

  13. 4D seismic data acquisition method during coal mining

    NASA Astrophysics Data System (ADS)

    Du, Wen-Feng; Peng, Su-Ping

    2014-06-01

    In order to observe overburden media changes caused by mining processing, we take the fully-mechanized working face of the BLT coal mine in Shendong mine district as an example to develop a 4D seismic data acquisition methodology during coal mining. The 4D seismic data acquisition is implemented to collect 3D seismic data four times in different periods, such as before mining, during the mining process and after mining to observe the changes of the overburden layer during coal mining. The seismic data in the research area demonstrates that seismic waves are stronger in energy, higher in frequency and have better continuous reflectors before coal mining. However, all this is reversed after coal mining because the overburden layer has been mined, the seismic energy and frequency decrease, and reflections have more discontinuities. Comparing the records collected in the survey with those from newly mined areas and other records acquired in the same survey with the same geometry and with a long time for settling after mining, it clearly shows that the seismic reflections have stronger amplitudes and are more continuous because the media have recovered by overburden layer compaction after a long time of settling after mining. By 4D seismic acquisition, the original background investigation of the coal layers can be derived from the first records, then the layer structure changes can be monitored through the records of mining action and compaction action after mining. This method has laid the foundation for further research into the variation principles of the overburden layer under modern coal-mining conditions.

  14. Asteroid mining

    NASA Technical Reports Server (NTRS)

    Gertsch, Richard E.

    1992-01-01

    The earliest studies of asteroid mining proposed retrieving a main belt asteroid. Because of the very long travel times to the main asteroid belt, attention has shifted to the asteroids whose orbits bring them fairly close to the Earth. In these schemes, the asteroids would be bagged and then processed during the return trip, with the asteroid itself providing the reaction mass to propel the mission homeward. A mission to one of these near-Earth asteroids would be shorter, involve less weight, and require a somewhat lower change in velocity. Since these asteroids apparently contain a wide range of potentially useful materials, our study group considered only them. The topics covered include asteroid materials and properties, asteroid mission selection, manned versus automated missions, mining in zero gravity, and a conceptual mining method.

  15. 78 FR 58878 - Safety Zone; San Diego Shark Fest Swim; San Diego Bay, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Shark Fest Swim; San Diego Bay... Diego Shark Fest Swim. This safety zone is necessary to provide for the safety of the participants, crew... this rule because the logistical details of the San Diego Shark Fest Swim were not finalized...

  16. San Jose, Costa Rica

    NASA Technical Reports Server (NTRS)

    2007-01-01

    San Jose, capital city of Costa Rica, fills the valley between two steep mountain ranges. In this image made from data collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite, visible, shortwave, and near-infrared wavelengths of light that the sensor observed have been combined to produce a false-color version of the scene in which vegetation is red, urban areas are silvery gray, water is dark blue, and clouds are white. The image was captured on February 8, 2007. San Jose is in the center of the image. The Rio Torres winds through downtown San Jose. Cartago, the much smaller colonial capital, sits in the lower right corner, while the city of Alajuela appears across the river, northwest of San Jose. The cities' manmade surfaces contrast sharply with the lushly vegetated landscape surrounding the city. Greenhouses are common in the region, and their glass roofs may be the brilliant white spots around the outer edges the cities. The long, straight runway of the Tobias Bolanos International Airport is visible as a dark line southeast of Alajuela. The landscape around the two cities shown here is rugged. Steep mountain peaks cast dark shadows across their leeward slopes. Patches of dark red vegetation on the mountains north of San Jose may be rainforest. Coffee plantations also cover the slopes of the mountains around the city. February is the dry season in Costa Rica. During the rainy season, from about April to November, clouds usually block the satellite's view of this tropical location. NASA image created by Jesse Allen, using data provided courtesy of Asaf Ullah and Tim Gubbels, SERVIR project.

  17. Map showing potential metal-mine drainage hazards in Colorado, based on mineral-deposit geology

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Streufert, Randall K.; Smith, Kathleen S.; Smith, Steven M.; Wallace, Alan R.; Toth, Margo I.; Nash, J. Thomas; Robinson, Rob A.; Ficklin, Walter H.; Lee, Gregory K.

    1995-01-01

    This map, compiled by the U.S. Geological Survey (USGS) in cooperation with the Colorado Geological Survey (CGS) and the U. S. Bureau of Land Management (BLM), shows potential mine-drainage hazards that may exist in Colorado metal-mining districts, as indicated by the geologic characteristics of the mineral deposits that occur in the respective districts. It was designed to demonstrate how geologic and geochemical information can be used on a regional scale to help assess the potential for mining-related and natural drainage problems in mining districts, unmined mineralized areas, and surrounding watersheds. The map also provides information on the distribution of different mineral deposit types across Colorado. A GIS (Geographic Information System) format was used to integrate geologic, geochemical, water-quality, climate, landuse, and ecological data from diverse sources. Likely mine-drainage signatures were defined for each mining district based on: (1) a review of the geologic characteristics of the mining district, including mineralogy, trace-element content, host-rock lithology, and wallrock alteration, and; (2) results of site specific studies on the geologic controls on mine-drainage composition.

  18. Preliminary analysis of cores from north San Francisco Bay, California

    USGS Publications Warehouse

    Allison, Dan; Hampton, Margaret; Jaffe, Bruce

    2003-01-01

    In March 2000, the U.S. Geological Survey collected sediment cores in the study area to determine the location of mercury-contaminated hydraulic mining debris. The study area (Figure 1) comprises 400 km2 and consists of San Pablo Bay and Suisun Bay, both of which are part of the San Francisco Bay estuary. Grizzly Bay, a subembayment of Suisun Bay, is also part of the study area. For the purpose of this report the term Suisun Bay will be used collectively for both areas. The present channel system in Suisun Bay is composed of three channels that flow through the bay. The primary channel runs in the southern section of Suisun Bay. A smaller channel flows between Roe Island and Ryer Island. The deepest channel flows through Suisun Cutoff, north of Ryer Island, and past Grizzly Bay. All three channels join at Carquinez Strait where they continue through the southern section of San Pablo Bay, and into San Francisco Bay. The average depths in San Pablo and Suisun Bays at mean sea level are 3.7 m and 5.8 m, respectively (Smith et al., 2002).

  19. Geology and gold deposits of the Cripple Creek district, Colorado

    USGS Publications Warehouse

    Lindgren, Waldemar; Ransome, F.L.

    1906-01-01

    The Cripple Creek gold deposits, discovered in 1891, were investigated by Messrs. Cross and Penrose, of the United States Geological Survey, in 1894. The present reexamination was requested by citizens of Colorado, and . has been carried out under the financial cooperation of the State with the Federal Survey. It has involved complete revision of the topographic map of the district used as a base by Cross and Penrose, the running of a line of accurate levels from Colorado Springs to Cripple Creek, remapping of the geology, and a thorough study of the extensive mine workings opened during the past ten years. Due acknowledgment is made, of the cordial assistance rendered by mining men, and a list is given of the important publications concerning the geology or mines of the district.

  20. 75 FR 4759 - Withdrawal of Proposed Rule Revising the California State Implementation Plan, San Joaquin Valley...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-29

    ... Joaquin Valley Unified Air Pollution Control District AGENCY: Environmental Protection Agency (EPA... proposing to correct EPA's May 2004 final approval of revisions to the San Joaquin Valley Unified Air... submitted in December 2006, would conform the SIP to a State law generally known as Senate Bill 700...

  1. 76 FR 5276 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  2. 76 FR 298 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation......... 12/17/92 08/24/07 On September 17, 2007, the submittal for San Joaquin Valley Unified Air Pollution... require that fixed covers be equipped with a 95% efficient Air Pollution Control (APC) device. c....

  3. 77 FR 66429 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-05

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Incorporation...

  4. 75 FR 24408 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-05

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  5. 75 FR 57862 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Incorporation...

  6. 77 FR 50021 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-20

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: In this action, EPA is finalizing approval of San Joaquin Valley Unified Air Pollution Control... plans that are specifically tailored to the nature of the air pollution sources in each state. The...

  7. 76 FR 56132 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... preempt Tribal law. List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  8. 77 FR 5709 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-06

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  9. 77 FR 745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) Correction In rule document 2011-33660 appearing on...

  10. 76 FR 40660 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    .... SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Air Pollution Control District....0 for the following terms: Air Pollution Control Officer, Board, Environmental Protection Agency.... New Section 6.3 requires the SJVUAPCD Air Pollution Control Officer (APCO) to prepare and present...

  11. 75 FR 1715 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-13

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  12. 76 FR 16696 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-25

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  13. 33 CFR 80.805 - Rock Island, FL to Cape San Blas, FL.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... extremity of the St. George Island Channel Jetties. (g) A line drawn from the northwesternmost extremity of... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Rock Island, FL to Cape San Blas... SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Eighth District § 80.805 Rock Island,...

  14. 33 CFR 80.805 - Rock Island, FL to Cape San Blas, FL.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Rock Island, FL to Cape San Blas, FL. 80.805 Section 80.805 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Eighth District § 80.805 Rock Island,...

  15. San Diego City Schools: Comprehensive Reform Strategies at Work. Teaching Quality Policy Briefs. Number 5

    ERIC Educational Resources Information Center

    Center for the Study of Teaching and Policy, 2002

    2002-01-01

    The optimum situation for a school system is one in which bureaucratic influences and practices support classroom learning. The study reported in this policy brief examines a transformation toward this state of affairs in the country's eighth largest school district, the 140,000-student San Diego City Schools. An unusual leadership arrangement…

  16. The Quality Teacher and Education Act in San Francisco: Lessons Learned. Policy Brief 09-2

    ERIC Educational Resources Information Center

    Hough, Heather J.

    2009-01-01

    This policy brief reviews the recent experience of the San Francisco Unified School District (SFUSD) with the development and approval of Proposition A. Proposition A (also known as the Quality Teacher and Education Act, or QTEA) included a parcel tax mainly dedicated to increasing teachers' salaries, along with a variety of measures introducing…

  17. A Study of the Job Satisfaction of Special Education Local Plan Area (SELPA) Directors and Local School District Special Education Directors in Four Counties of Southern California

    ERIC Educational Resources Information Center

    Alexander, Gregory Haynes, III

    2009-01-01

    Purpose. The purpose of this study was to compare the perceived level of job satisfaction of SELPA directors with that of local school district special education directors in the counties of Riverside, San Bernardino, San Diego, and Orange of Southern California and to identify factors that contribute to their job satisfaction. Additionally, this…

  18. ASSESSING AND MANAGING MERCURY FROM HISTORIC AND CURRENT MINING ACTIVITIES

    EPA Science Inventory

    In order for ORD to address uncertainties resulting from past or historical mining practices a technology transfer workshop was conducted in November, 2000 in San Francisco, CA. Two primary objectives for this workshop were: 1) identify state-of-the-science practices and techniqu...

  19. Isotopic variability of mercury in ore, mine-waste calcine, and leachates of mine-waste calcine from areas mined for mercury

    USGS Publications Warehouse

    Stetson, S.J.; Gray, J.E.; Wanty, R.B.; Macalady, D.L.

    2009-01-01

    The isotopic composition of mercury (Hg) was determined in cinnabar ore, mine-waste calcine (retorted ore), and leachates obtained from water leaching experiments of calcine from two large Hg mining districts in the U.S. This study is the first to report significant mass-dependent Hg isotopic fractionation between cinnabar ore and resultant calcine. Data indicate that ??202Hg values relative to NIST 3133 of calcine (up to 1.52???) in the Terlingua district, Texas, are as much as 3.24??? heavier than cinnabar (-1.72???) prior to retorting. In addition, ??202Hg values obtained from leachates of Terlingua district calcines are isotopically similar to, or as much as 1.17??? heavier than associated calcines, most likely due to leaching of soluble, byproduct Hg compounds formed during ore retorting that are a minor component in the calcines. As a result of the large fractionation found between cinnabar and calcine, and because calcine is the dominant source of Hg contamination from the mines studied, ??202Hg values of calcine may be more environmentally important in these mined areas than the primary cinnabar ore. Measurement of the Hg isotopic composition of calcine is necessary when using Hg isotopes for tracing Hg sources from areas mined for Hg, especially mine water runoff. ?? 2009 American Chemical Society.

  20. Isotopic variability of mercury in ore, mine-waste calcine, and leachates of mine-waste calcine from areas mined for mercury.

    PubMed

    Stetson, Sarah J; Gray, John E; Wanty, Richard B; Macalady, Donald L

    2009-10-01

    The isotopic composition of mercury (Hg) was determined in cinnabar ore, mine-waste calcine (retorted ore), and leachates obtained from water leaching experiments of calcine from two large Hg mining districts in the U.S. This study is the first to report significant mass-dependent Hg isotopic fractionation between cinnabar ore and resultant calcine. Data indicate that delta202Hg values relative to NIST 3133 of calcine (up to 1.52 per thousand) in the Terlingua district, Texas, are as much as 3.24 per thousand heavier than cinnabar (-1.72 per thousand) prior to retorting. In addition, delta202Hg values obtained from leachates of Terlingua district calcines are isotopically similar to, or as much as 1.17 per thousand heavier than associated calcines, most likely due to leaching of soluble, byproduct Hg compounds formed during ore retorting that are a minor component in the calcines. As a result of the large fractionation found between cinnabar and calcine, and because calcine is the dominant source of Hg contamination from the mines studied, delta202Hg values of calcine may be more environmentally important in these mined areas than the primary cinnabar ore. Measurement of the Hg isotopic composition of calcine is necessary when using Hg isotopes for tracing Hg sources from areas mined for Hg, especially mine water runoff.