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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. PMID:25354433

  2. Hydrothermal geochemistry of silver-gold vein formation in the Tayoltita mine and San Dimas mining district, Durango and Sinaloa, Mexico

    SciTech Connect

    Clarke, M.

    1986-01-01

    The San Dimas mining district, including the Tayoltita mine, is a Tertiary silver-gold epithermal vein system deposited in a calcalkaline volcanic pile. Hydrothermal alteration and vein formation is temporally related to a granite batholith intruded into the volcanics. Alteration mineralogy in andesites is compatible with a hydrothermal flow model in which heated water rises through the batholith, cools to 260 C, and flows out into the volcanics. Lateral elongation of Ag:Au ratio zoning plotted on vertical projections of veins is interpreted to reflect hydrothermal fluid flow principally in a horizontal direction during ore deposition. Quartz vein-filling, accompanied by chlorite, calcite, rhodonite, and adularia, is widest in a vertical interval approximately 500 to 1000 meters below the original surface. Pyrite is widely distributed, but silver minerals, electrum, and base-metal sulfides are restricted to the upper portion of the vertical interval of veining in a zone termed the ore horizon. Fluid inclusion studies of quartz from the Cinco Senores vein indicate that ore deposited at an average temperature of 260 C from boiling fluids of apparent salinities ranging from 0.15 to 0.3 m/sub NaCl/ equivalent. The greater apparent salinities probably reflect dissolved gases as well as chloride salts. Correlation of Ag:Au ratios in deposited vein with ice-melting temperatures in fluid inclusions suggests that evolution of ore fluids in space was accompanied by both increase in deposited Ag:Au ratios and decline in fluid solute concentration. Correlation of ice-melting temperatures with paragenetic age of associated quartz suggests that vein-depositing hydrothermal fluids evolved in both space and time from relatively concentrated to dilute conditions.

  3. 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.

  4. 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

    ... in 33 CFR 165.33 apply to the security zone described in paragraph (a) of this section. (2) Entry... 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;...

  5. 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.

  6. 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

  7. Mining induced seismicity in the Ruhr coal mining district, Germany

    NASA Astrophysics Data System (ADS)

    Fischer, Kasper D.; Wehling-Benatelli, Sebastian; Erstling, Stefanie; Brüstle, Andrea; Wlecklik, Dennis

    2013-04-01

    In 2012 four hard coal mines (at about 1000 m depth) were operating in Germany, three of them are in the Ruhr coal mining district. The mining method used (longwall mining in combination with caving) causes induced earthquakes due to the stress redistribution in the surrounding rock. Seismic events of magnitude 1.2 and larger are generally perceived by the population and thus trigger a wide interest. The Ruhr-University of Bochum routinely monitors the seismicity and its temporal evolution and energy release since the 1980s. The current seismological network consists of 14 stations (broad-band and short-period seismometers) in the Ruhr area. Six stations are located at the Ruhr-University Bochum at distances of approximately 20-40 km to the active coal fields. The remaining 8 stations are located in the vicinity of the mines (app. 1 to 5 km from the active mining). The magnitude of completeness is 0.9 throughout the entire Ruhr coal mining district with a local magnitude of completeness of 0.7 depending on the network configuration. In general, the identified earthquakes have a horizontal location uncertainty of 3 km. The routine detection and location of the seismicity is done by classical methods, e. g. based on first arrivals, and advanced methods like array techniques or cross-correlation of waveforms of master events with recorded seismograms from selected stations. Additionally selected event clusters are studied in more detail by reprocessing sub-datasets with methods like cluster analysis or consistent phase-picking. Reassessing this unique dataset of 30 years continuous recordings with newly developed methods and modern data processing techniques can provide new insights of the nature of mining induced seismicity. This methods may also be usable in the field of geothermal energy, unconventional hydrocarbon reservoirs or underground storage of carbon dioxide which also deals with the detection and handling of large amounts of small magnitude earthquakes.

  8. 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…

  9. Agreement between the San Bernardino Community College District and the San Bernardino Community College District Chapter, CTA/NEA, 1986-1989.

    ERIC Educational Resources Information Center

    San Bernardino Community Coll. District, CA.

    This collective bargaining agreement between the San Bernardino Community College District and the San Bernardino Community College District Chapter of the California Teachers Association/National Education Association establishes conditions of employment for all certificated regular, contract, and hourly instructors; counselors; librarians;…

  10. They were "Happy to Rock Along in This Trend," The San Felipe Independent School District.

    ERIC Educational Resources Information Center

    Prewitt, Steven W.

    The history of San Felipe School District (Texas), 1894-1971, depicts a situation in which Mexican Americans had control of local schools. Established in the Mexican "barrio" of the racially divided border town of Del Rio, San Felipe resisted annexation to the Anglo school district and became an independent school district in 1929. Mexican…

  11. 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…

  12. 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.

  13. 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…

  14. 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.

  15. 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

    ... Energy Regulatory Commission San Luis Obispo Flood Control and Water Conservation District; Notice of... for a Conduit Hydroelectric Project \\1\\ to the San Luis Obispo Flood Control and Water Conservation...\\ San Luis Obispo Flood Control and Water Conservation District, 17 FERC ] 62,113 (1981). On October...

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

    ERIC Educational Resources Information Center

    Harrison, Helene W.

    The program covers two public school districts, Harlandale and San Marcos, and Southwest Texas State University. This report, however, deals only with the San Marcos Bilingual Education Program, which provides bilingual education for pupils in grades K-5 who have limited English speaking ability. Due to parental requests, 19% monolingual English…

  17. 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... March 27, 1997 (62 FR 14639). The SDAPCD adopted revisions to the SIP- approved version on December...

  18. 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...

  19. Directions for the '80s: Educational Master Plan. San Francisco Community College District.

    ERIC Educational Resources Information Center

    Duncan-Hall, Tyra L., Ed.

    Designed to assist staff in the San Francisco Community College District (SFCCD) in synthesizing the trends, events and issues that are likely to influence educational programs and services, this master plan assesses the district's internal and external environments and describes the SFCCD's two-phase planning process. Chapter 1 discusses the…

  20. 27 CFR 9.130 - San Ysidro District.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... northerly drainage of San Ysidro Creek southeast for approximately 2,000 feet to the seasonal pond adjacent to Canada Road; (7) From the seasonal pond, the boundary follows the southerly drainage of San Ysidro... end of a seasonal pond on the San Felipe, Calif., U.S.G.S. map; (10) The boundary follows...

  1. Monitoring of environmental factors at the San Manuel mine

    SciTech Connect

    Calizaya, F.; Mousset-Jones, P.; Casten, T.

    1995-12-31

    Currently, a 4.3 km long drift is being developed on the 3440 level in the Lower Kalamazoo project at the San Manuel Mine, Magma Copper Company, AZ. The drift, located at 1050 m below surface, is being constructed using a 4.6 m diameter tunnel boring machine (TBM). The drift is ventilated by a forcing type auxiliary ventilation system. At the face, to mitigate the impact on the work environment of the TBM, the system is equipped with dust extraction and refrigeration systems. Recently, to evaluate the ventilation conditions in the drift, a continuous monitoring system has been installed. The system can be used to measure the air velocity, barometric pressure, relative humidity and air and rock temperatures. This study describes the capabilities and limitations of this system, and presents a summary of the results.

  2. 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.

  3. 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

  4. 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.

  5. A Tale of Two Districts: A Comparative Study of Student-Based Funding and School-Based Decision Making in San Francisco and Oakland Unified School Districts

    ERIC Educational Resources Information Center

    Chambers, Jay; Shambaugh, Larisa; Levin, Jesse; Muraki, Mari; Poland, Lindsay

    2008-01-01

    Though the number of districts with student-based funding-type (SBF) policies has grown, the literature on the implementation and possible impacts of these policies is limited. To address this, this report describes the implementation of SBF policies in two California school districts--San Francisco Unified School District and Oakland Unified…

  6. 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.

  7. Evaluation of San Francisco Unified School District Desegregation/Integration, 1971-72.

    ERIC Educational Resources Information Center

    Barnett, Saul; And Others

    From the Fall of 1971 to Spring of 1972, the evaluation staff from Component V cooperated with the district research staff in collecting data for a product report determining how well the desegregation in San Francisco elementary schools was succeeding. The product evaluation strategy for this ESAP report is based on the Western Regional…

  8. 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…

  9. Growing more with less in the Westlands Water District in the San Joaquin Valley, California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disposal of saline drainage water is a problem for irrigated agricultural throughout the world. In California the Westlands Water District in the San Joaquin Valley had its drainage service eliminated because of selenium contamination in the Kesterson Reservoir. A five-year study developed alternati...

  10. 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…

  11. 77 FR 66578 - San Bernardino National Forest, Mountaintop Ranger District, CA, Santa Ana Watershed Hazardous...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ...The Mountaintop Ranger District, San Bernardino National Forest proposes to reduce fire risk and improve forest health within approximately 19,850 acres around the Barton Flats area of the upper Santa Ana Watershed under the authority of the Healthy Forests Restoration Act (HFRA) of 2003. To meet the primary purposes of providing for firefighter safety and community protection, it is proposed......

  12. 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…

  13. Comprehensive Profile of the San Antonio Independent School District, 1984-1985.

    ERIC Educational Resources Information Center

    San Antonio Independent School District, TX.

    This report is a collection of statistical data about the San Antonio (Texas) Independent School District. Perspectives are presented at two different levels. First, information from the 1984-85 school year is displayed. Second, trends from past years are presented using five or ten year groupings, depending on information availability. Most…

  14. 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.

  15. 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.

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... CFR chapter II. ... 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...

  17. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... CFR chapter II. ... 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...

  18. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... CFR chapter II. ... 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...

  19. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... CFR chapter II. ... 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...

  20. 25 CFR 215.23 - Cooperation between superintendent and district mining supervisor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... CFR chapter II. ... 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...

  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. 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…

  3. Changes in the substrate of rivers in historic mining districts

    USGS Publications Warehouse

    Milhous, R.T.

    2004-01-01

    The restoration of rivers in watersheds with historic mining districts has become a topic of interest during the last decade. Rivers restoration in these areas is difficult because the mines and mills can be scattered over a wide area and often small. Many have also been abandoned. This paper presents two substrate related factors that are important in the evaluation of river restoration alternatives in watersheds with significance impacts from mines and mills most of which are old and abandoned. The two factors are 1) changes in the size distribution and specific weights of the substrate, and 2) the changes in quality of the interstecial waters caused by metals associated with the tailings in the substrate. The most important impacts of tailings from mills may be on the physical characteristics of the substrate (porosity) and on the quality of the pore waters. The measurements presented in this paper do show significant variation in the porosity in gravel bed rivers and in the quality of the pore waters. Copyright ASCE 2004.

  4. A Study of Equality of Educational Opportunity for Mexican Americans in Nine School Districts of the San Antonio Area. United States Commission on Civil Rights, Staff Report.

    ERIC Educational Resources Information Center

    Commission on Civil Rights, Washington, DC.

    The report is the result of a study that investigated the extent to which Mexican American students in 9 independent school districts in metropolitan San Antonio, Texas, were afforded equal educational opportunities. The districts were Alamo Heights, East Central, Edgewood, Harlandale, North East, Northside, San Antonio, South San Antonio, and…

  5. 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

  6. Mercury speciation on three European mining districts by XANES techniques

    NASA Astrophysics Data System (ADS)

    Esbri, J. M.; Garcia-Noguero, E. M.; Guerrero, B.; Kocman, D.; Bernaus, A.; Gaona, X.; Higueras, P.; Alvarez, R.; Loredo, J.; Horvat, M.; Ávila, M.

    2009-04-01

    The mobility, bioavailability and toxicity of mercury in the environment depend on the chemical species in which is present in soil, sediments, water or air. In this work we used synchrotron radiation to determine mercury species in geological samples of three mercury mining districts: Almadén (Spain), Idria (Slovenia) and Asturias (Spain). The aim of this study was to find differences on mobility and bioavailability of mercury on three mining districts with different type of mineralization. For this porpoises we selected samples of ore, calcines, soils and stream sediments from the three sites, completely characterized by the Almadén School of Mines, Josef Stefan Institute of Ljubljana and Oviedo School of Mines. Speciation of mercury was carried out on Synchrotron Laboratories of Hamburg (HASYLAB) by XANES techniques. Spectra of pure compounds [HgCl2, HgSO4, HgO, CH3HgCl, Hg2Cl2 (calomel), HgSred (cinnabar), HgSblack (metacinnabar), Hg2NCl0.5(SO4)0.3(MoO4)0.1(CO3)0.1(H2O) (mosesite), Hg3S2Cl2 (corderoite), Hg3(SO4)O2 (schuetteite) y Hg2ClO (terlinguaite)] were obtained on transmittance mode. The number and type of the compounds required to reconstruct experimental spectra for each sample was obtained by PCA analysis and linear fitting of minimum quadratics of the pure compounds spectra. This offers a semiquantitative approach to the mineralogical constitution of each analyzed sample. The results put forward differences on the efficiency of roasting furnaces from the three studied sites, evidenced by the presence of metacinnabar on the less efficient (Almadén and Asturias) and absence on the most efficient (Idria). For the three studied sites, sulfide species (cinnabar and metacinnabar) were largely more abundant than soluble species (chlorides and sulfates). On the other hand, recent results on the mobility of both Hg and As on the target sites will be presented. These results correlate with the related chemical species found by XANES techniques.

  7. 75 FR 71668 - Cibota National Forest, Mount Taylor Ranger District, NM, Roca Honda Mine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-24

    ...Roca Honda Resources, LLC has submitted a Plan of Operations proposing to develop and conduct underground uranium mining operations on their mining claims on and near Jesus Mesa in the Mount Taylor Ranger District of the Cibola National Forest. The proposed mine is located within portions of Sections 9, 10 and 16, Township 13 North, Range 8 West, New Mexico Principal Meridian. These sections......

  8. 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.

  9. 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.

  10. 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.

  11. San Diego City School District's Small School Successes: The Stanley E. Foster Construction Tech Academy and the School of International Business. Case Study

    ERIC Educational Resources Information Center

    Alliance for Excellent Education, 2009

    2009-01-01

    San Diego Unified School District (SDUSD) is the second-largest school district in California and the eighth-largest district in the United States. As is often the case in large cities, too many of the district's students were leaving high school without preparation for success. In early 2000, to improve these unsatisfactory outcomes, SDUSD…

  12. 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

  13. Executive summary of the US Bureau of Mines investigations in the Colville Mining District, Alaska. Open file report (Final)

    SciTech Connect

    Meyer, M.P.

    1995-12-31

    During 1991 through 1993, the U.S. Bureau of Mines (Bureau) - Alaska Field Operations Center (AFOC) in cooperation with the Bureau of Land Management (BLM) - Arctic District Office and the State of Alaska, Division of Geological and Geophysical Surveys (ADGGS), conducted exploration, geological, geochemical, geophysical, mineral resource, and mineral potential investigations in the 6.7 million hectare Colville Mining District (CMD) study area. The document discusses the pertinent recent and historical information about the CMD, summarizes the findings of Bureau work performed in the CMD to date, and can be used as a principal reference to information on mineral resources within the CMD study area.

  14. Assessment of solar power potential at abandoned mine promotion districts in South Korea

    NASA Astrophysics Data System (ADS)

    Song, Jinyoung; Choi, Yosoon

    2015-04-01

    This study assessed the solar power potential at 7 abandoned mine promotion districts in Korea such as Taebaek, Samcheok, Jeongseon, Yeongwol, Mungyeong, Hwasun and Boryeong. The photovoltaic system with a capacity of 99 kW was considered at each abandoned mine promotion district. The estimated electric power productions and economic effects of photovoltaic systems were analyzed using RETScreen software developed by Natural Resources Canada(NRC). The results showed that the Boryeong district is the highest photovoltaic potential where the estimated electric power production is about 83.43 MWh/year, the net present value is 69.2 million KRW, and the payback period is about 13 years.

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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 of local inequality…

  20. SEEDS of Opportunity: Final Report on the San Francisco United School District's Child Development Program. Executive Summary.

    ERIC Educational Resources Information Center

    Child Care Law Center, San Francisco, CA.

    An in-depth assessment of all aspects of the San Francisco School District's Child Development Program (CDP) was conducted. Assessment measures included: (1) on-site observations of preschool, kindergarten, and school-age child care classroom environments and of teacher behaviors and sensitivity; (2) reviews of physical environments and provisions…

  1. Cambrian rocks of the Pioche mining district, Nevada, with a section on Pioche shale faunules

    USGS Publications Warehouse

    Merriam, Charles Warren; Palmer, Allison R.

    1964-01-01

    The Pioche mining district in the Ely Range, southeastern Nevada, is one of several districts in the Great Basin where Cambrian rocks are hosts of important ore deposits. Cambrian strata underlying the Ely Range are intruded by porphyritic granite and other dikes. Tertiary volcanic rocks and Pliocene fresh-water clastic deposits of the Panaca Formation occupy adjacent valleys and extend over the Cambrian strata on the south and east.

  2. Seismic events with implosional focal mechanisms in the Coeur d'Alene mining district, northern Idaho

    NASA Astrophysics Data System (ADS)

    Stickney, Michael C.; Sprenke, Kenneth F.

    1993-04-01

    Rockbursts are a major hazard in the Coeur d'Alene mining district of northern Idaho. To study the source mechanisms of mining-related seismicity, we operated 15 portable seismographs in the Coeur d'Alene mining district for one week in September 1990. We found the velocity model of the district to consist of a halfspace with a P wave velocity of 5.74 km/s and an S wave velocity of 3.47 km/s. In-mine seismic monitoring systems provided excellent control on the velocity model and most hypocenter locations. Twenty-one events, with sufficient focal sphere coverage for fault plane solutions, were recorded. Eleven of the events produced all-dilatational first motions; for all events, 90 percent of first motions observed were dilatational. Ten events produced unsolvable first-motion data in terms of the usual double-couple mechanism, but seven of these unsolvable events were found consistent with an implosional source and two others were consistent with a shear-implosional source. Our results provide firm observational evidence that dilatational first motions are predominant in this deep metal-mining district, probably the result of implosional and shear-implosional source mechanisms.

  3. 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

  4. 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.

  5. 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.

  6. 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. PMID:19824231

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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…

  12. 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.

  13. Human-induced Geomorphic Changes caused by Coal Mining: The Example of Mining Subsidence in the Ruhr District (Germany)

    NASA Astrophysics Data System (ADS)

    Harnischmacher, Stefan

    2013-04-01

    For the first time, an area-wide and large-scale calculation of differences in elevation between 1892 and today was conducted for the Ruhr District (Germany), a metropolitan region influenced by subsidence due to deep-seam coal mining starting in the middle of the 19th century. Elevation data on historical maps from 1892 was digitised with the help of a Geographic Information System and the interpolated historical surface was intersected with a current Digital Elevation Model, in order to calculate the differences in elevation. As a result, the highest values of elevation differences, amounting to more than 25 m, were observed within the coal-fields of the former coal mine "Zollverein" which is distinguished for its long mining history and its World Heritage status. A comparison of single reliable elevation data, derived from surface levelling data of the land registry office, with the interpolated values from 1892 reveals an astonishing correlation with differences of not more than 1 m. Two examples from the cities of Essen and Dortmund analysed in detail reveal that not only depressions but also elevation features are affected by mining subsidence. These kinds of surface transformations are not visible in the field without a comparison of digital topographical models. The change detections allow for a correlation with mining activities, because most of the mining subsidence areas are located next to a former coal mine. Furthermore, tectonic features of the Carboniferous strata are reflected by the location of subsidence areas, since they are located along synclines with a gentle dip of coal seams or confined by the location of predominant faults. The average amount of surface lowering was calculated for all maps digitised and analysed, resulting in a mean net value of 1.6 m or 13.9 mm per year (1892-2007) for the total area un-der investigation (2,827 km2). Even that mean surface lowering rate exceeds nearly all of the highest denudation rates of river catchments

  14. 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. PMID:23477568

  15. 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.

  16. 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

  17. A successful university-school-district partnership to help San Francisco's K-12 students learn about science and medicine.

    PubMed

    Clark, M R

    1996-09-01

    The Science and Health Education Partnership (SEP) is a program at the University of California, San Francisco, established in 1987 to support the San Francisco School District ("the District") in its efforts to improve science education in grades K-12. A large cadre of active biomedical scientists and health professionals and a core program staff provide support to 90-95% of the District's schools. The District's students are from a variety of racial and ethnic groups, including a large percentage from underrepresented minorities (URMs). The SEP program has numerous components, some designed to help teachers (e.g., a clinician or scientist forms an ongoing partnership with a teacher to enrich classroom instruction) and some involving direct work with students (e.g., a contest where teams of students design and present lessons on science or health to their peers; activities related specifically to the encouragement of URM students). The SEP's perspective has evolved from an emphasis on assisting individual teachers and students to one of supporting systemic change throughout the District (e.g., supporting full implementation of hands-on, inquiry-based science instruction throughout the District via professional development). During this evolution, the kinds of issues facing program staff have changed and a great deal has been learned about fostering successful partnership activities. For example, (1) having a coordinator is crucial to make such a program work well; (2) it is easier to find start-up funding than to find continuing funding for ongoing activities that are working; and (3) it is important to work with the volunteering scientists and the teachers to help them understand what each has to offer the partnership and to encourage explicit dialogue about roles and expectations. The author concludes with advice for starting a new partnership: think big but start small, and work toward a long-term association based on communication and trust. PMID:9125981

  18. 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

  19. 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. PMID:27130541

  20. 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. PMID:26457623

  1. Biogeochemical behavior of Ampelozizyphus amazonicus Ducke in the Pitinga mining district, Amazon, Brazil

    NASA Astrophysics Data System (ADS)

    Lima E Cunha, M. C.; Pereira, V. P.; Menegotto, E.; Bastos Neto, A. C.; Oliveira, L. D.; Formoso, M. L. L.

    2008-09-01

    The vegetal species Ampelozizyphus amazonicus Ducke (Rhamnaceae Family) was chosen as a sampling medium for the lateritic surfaces of the Pitinga Mine in the Amazon region, in order to study the biogeochemical behavior of this species and compare it with the chemical composition of a reference plant. The Pitinga mining district is one of the largest producers of tin in the world. This district contains unique deposits of cryolite and rare metals such as Zr, Nb, Ta, Y and REEs related to granitic bodies that intrude into the volcanic and acid pyroclastic rocks. The results showed that the species A. amazonicus predominantly concentrates significant levels of Zr, Nb, Ta, Th, Be, Sc over U, Hf, Ga and In. These elements are characteristic of the mineral paragenesis for the region, suggesting that this plant can provide a representative sampling medium future geochemical exploration programs in the region.

  2. PRE-ORE POTASSIUM METASOMATISM, CREEDE MINING DISTRICT, COLORADO.

    USGS Publications Warehouse

    Bethke, P.M.; Rye, R.O.; Barton, P.B., Jr.

    1985-01-01

    Rhyolitic welded-tuff wallrocks of the epithermal base and precious metal veins of the Creede district were pervasively altered by the addition of more than two billion metric tons of potassium some 1. 5-2 million years before mineralization. Sodium, calcium and magnesium were strongly depleted, yielding a nearly binary quartz plus potassium feldspar assemblage containing as much as 13 weight percent K//2O. This large-scale metasomatism, originally noted by Steven and Rattle (1965), took place progressively by initial alteration of plagioclase phenocrysts to orthoclase or microcline followed by alteration of the groundmass feldspar to orthoclase and gradual change of the sanidine phenocrysts to more Or-rich compositions. Oxygen isotope and chemical studies show that the metasomatism resulted from the interaction of the tuffs with deeply circulating heated ground water and suggest that the potassium metasomatism of rhyolitic rocks is the facies equivalent of propylitization of volcanic rocks of more basic composition.

  3. 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.

  4. 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. PMID:23771631

  5. 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".

  6. 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.

  7. 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.

  8. Impact assessment of coal mines in Erai watershed of Chandrapur district using geoinformatics.

    PubMed

    Patil, S A; Katpatal, Y B

    2008-10-01

    The industrial development and growing population in India is in demand of more energy. Coal based thermal power generation is a major source of energy and is expanding at a very high rate leading to over exploitation of coal reserves, which is causing adverse impacts on the environment. Remote sensing and GIS techniques have been found to be useful in mapping and monitoring of dynamic changes taking place due to mining activity. Satellite based environmental impact assessment involves various aspects, such as land use, water resources, land degradation, etc. These studies help in formulating environmental management plan for the mining sector. Coal mines in Erai watershed of Chandrapur district so far have lost 2139.68 hectares of land constituting a fertile agriculture land, reserve forest, protected forest and natural river course of Erai river, Upsa nala and Motaghat nala severely affecting the watershed eco-system. Therefore, an in-depth impact assessment study of coal mines in Erai watershed of Chandrapur district was carried out using geoinformatics and the results are presented in this paper. PMID:19697761

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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. PMID:23029934

  14. 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).

  15. 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

  16. 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

  17. Effects of metal pollution on genetics of freshwater mussels in a southeastern Missouri mining district

    SciTech Connect

    Young, M.Y.

    1994-12-31

    Lead mining has historically been in operation in Missouri since the 1700`s, and an extensively mineralized region known as the ``Old Lead Belt`` in the southeastern portion of the state contained some of the most substantial deposits in the district. Although mining is currently inactive in this region, intensive past mining resulted in accumulation of large tailings piles placed adjacent to aquatic resources. Erosion and accidental releases of mine tailings rich in lead, zinc, cadmium and copper have resulted in contamination in the Big River drainage, one of two principal tributaries in the Meramec River Basin. Substantial bioaccumulation of metals has previously been documented for freshwater mussels collected from the Big River, as well as for other aquatic biota. This research project investigated the effects of metal pollution on biochemical genetic variability among three populations of the freshwater mussel Lampsilis ventricosa in the Meramec River Basin. Specimens were collected from metal-contaminated reaches of the Big River, and two reference populations in Meramec and Bourbeuse Rivers. Using techniques of starch gel electrophoresis, significant differences were found in allozyme frequencies at the phosphoglucomutase locus between mussels collected from the metal-contaminated Big River versus reference populations, suggesting that certain allozyme genotypes may be more sensitive than others to metal pollutants. The genetic response to geographic variation in environmental contamination between the L. ventricosa populations examined in the Meramec River Basin suggests that differential pollution-induced selection of allozyme genotypes has occurred in the Big River.

  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. 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

  20. 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

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

    USGS Publications Warehouse

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

    2005-01-01

    The Tri-State Mining District (Oklahoma, Kansas, and Missouri) is 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 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.

  2. A Study on the Implementation of the Ecotran Systems, Inc. Computerized Routing and Scheduling Pupil Transportation System. San Diego Unified School District, Superintendent's Organizational Study Team.

    ERIC Educational Resources Information Center

    Carriedo, Ruben; And Others

    The San Diego Unified School District (California) began operating a computerized routing and scheduling system for its pupil transportation services at the beginning of the 1985-86 academic school year. The computerized system, provided by Ecotran Systems, Inc. (ECO) of Cleveland, Ohio experienced an inordinate number of difficulties. A…

  3. The CEO Horizon Scholarship Program: A Case Study of School Vouchers in the Edgewood Independent School District, San Antonio, Texas. Final Report.

    ERIC Educational Resources Information Center

    Greene, Jay P.

    This report describes the results of an institutional analysis that examined the effects of the CEO Horizon Scholarship Program on schools in San Antonio, Texas. The scholarship program offered virtually all families in the school district a scholarship to send their children to the school of their choice, both public and private. The analysis is…

  4. The Cajon Valley Union School District/San Diego State University Model Education Center (MEC).

    ERIC Educational Resources Information Center

    Berg, Marlowe; Nagel, Thomas

    The Cajon Valley/San Diego State University Model Education Center (MEC) focuses on the training of elementary school teachers, teacher inservice, and collaborative leadership. It provides an exemplary training site for preparing elementary school teachers, and uses staff development to create a school environment/climate which will produce…

  5. Santa Clara Valley water district multi-aquifer monitoring-well site, Coyote Creek Outdoor Classroom, San Jose, California

    USGS Publications Warehouse

    Hanson, R.T.; Newhouse, M.W.; Wentworth, C.M.; Williams, C.F.; Noce, T.E.; Bennett, M.J.

    2002-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Santa Clara Valley Water District (SCVWD), has completed the first of several multiple-aquifer monitoring-well sites in the Santa Clara Valley. This site monitors ground-water levels and chemistry in the one of the major historic subsidence regions south of San Jose, California, at the Coyote Creek Outdoor Classroom (CCOC) (fig. 1) and provides additional basic information about the geology, hydrology, geochemistry, and subsidence potential of the upper- and lower-aquifer systems that is a major source of public water supply in the Santa Clara Valley. The site also serves as a science education exhibit at the outdoor classroom operated by SCVWD.

  6. SpecTIR and SEBASS analysis of the National Mining District, Humboldt County, Nevada

    NASA Astrophysics Data System (ADS)

    Morken, Todd O.

    The purpose of this study was to evaluate the minerals and materials that could be uniquely identified and mapped from measurements made with airborne hyperspectral SpecTIR VNIR/SWIR and SEBASS TIR sensors over areas in the National Mining District. SpecTIR Corporation and Aerospace Corporation acquired Hyperspectral measurements on June 26, 2008 using their ProSpecTIR and SEBASS sensors respectively. In addition the effects of vegetation, elevation, the atmosphere on spectral measurements were evaluated to determine their impact upon the data analysis and target identification. The National Mining District is located approximately 75 miles northeast of Winnemucca, Nevada at the northern end of the Santa Rosa Mountains. Precious metal mining has been dormant in this area since the 1940's, however with increased metal prices over the last decade economic interest in the region has increased substantially. Buckskin Mountain has a preserved alteration assemblage that is exposed in topographically steep terrain, ideal for exploring what hydrothermal alteration products can be identified and mapped in these datasets. These Visible Near Infrared (VNIR), Short Wave Infrared (SWIR), and Long Wave Infrared (LWIR) hyperspectral datasets were used to identify and map kaolinite, alunite, quartz, opal, and illite/muscovite, all of which are useful exploration target identifiers and can indicate regions of alteration. These mapping results were then combined with and compared to other geospatial data in a geographic information systems (GIS) database. The TIR hyperspectral data provided significant additional information that can benefit geologic exploration and demonstrated its usefulness as an additional tool for geological exploration.

  7. 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

  8. 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

  9. Review of Lead-Zinc Mining Impact on Landscape in the Tri-State Mining District using Small Unmanned Aerial Vehicles.

    NASA Astrophysics Data System (ADS)

    Bhakta, K. D.; Yeboah-Forson, A.

    2015-12-01

    The Tri-State lead and zinc mining district in SW Missouri, SE Kansas, and NE Oklahoma encompasses nearly 2,500 sq. miles of land and at its peak accounted for half of the US zinc (23,000,000 tons) production that surpassed one billion dollars in economic value. Once these lead and zinc rich ores were extracted, mining and milling sites were abandoned leaving behind a new landscape with numerous environmental challenges. Since 1970, most of the sites have been targeted for remediation and reclamation by federal and state agencies including the EPA. In order to capture the full extent of the impact of lead and zinc mining in the Tri-State area, numerous geoscientific approaches including data from small unmanned aerial vehicle (UAV) were employed to investigate the influence of mining in the study area. The study presented here is focused on observational assessment of the existing landscape using multiple commercial high-definitions data from UAVs to study different sites across areas of concern in the three states. Primary results (images) gathered and analyzed DEM and GIS data from abandoned mines showed the potential to provide a quick snapshot of successful or unsuccessful remediated areas. Although research and remediation of the Tri-State mining district are a continuous process, evidence from this geomorphic study suggest that UAVs can provide a quick overview of the remediated landscape or serve as a primary background tool for a more detail site-specific environmental study.

  10. Yuma District Resource Management Plan, Yuma, La Paz, and Mohave Counties, Arizona and San Bernardino, Riverside and Imperial Counties, California

    SciTech Connect

    Not Available

    1985-08-01

    Implementation of a resource management plan is proposed for 1.2 million acres within the 2.7-million-acre Yuma District, located in Yuma, La Paz, and Mohave counties, Arizona and San Bernardino, Riverside, and Imperial counties, California. Under the preferred alternative, wildlife habitat would be a priority consideration on approximately 247,740 acre, and nine special management areas would be designated. A portion of the Cactus Plain and the Chemehuevi/Needles wilderness study areas would be recommended for wilderness designation. Two areas totaling 31,360 acres would be designated as special management areas, and another six areas totaling 155,705 acres would be managed to protect their natural values. Livestock grazing would be authorized at 3998 animal unit months on four allotments. Approximately 55,490 acres of federal lands would be available for disposal and 31,220 acres would be acquired. Nine utility corridors and nine communication sites would be designated. Existing recreational facilities would be maintained, with additional facilities provided when warranted. Along Parker Strip, only floodproofed day-use facilities would be allowed within the 100-year flood plain. Off-road vehicle (ORV) use designations would be made on 640 acres and ORV use in the remainder of the district would be limited to existing roads and trails. Continuous occupancy of mobile home sites would be restricted to one five-month period in a single year. Permanent residential use would be phased out.

  11. Organizational Practices of High-Achieving Rural School Districts in California's San Joaquin Valley

    ERIC Educational Resources Information Center

    Doerksen, Amanda López; Wise, Donald

    2016-01-01

    For over 25 years, researchers have identified "best practices" used by high-achieving school districts. However, little research exists regarding rural school systems, making it difficult to determine whether the best practices identified are relevant within this context. This study filled a void in research by focusing on the…

  12. 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.

  13. Geology of the Humboldt region and the Iron King mine, Bigbug mining district, Yavapai County, Arizona

    USGS Publications Warehouse

    Creasey, Saville Cyrus

    1951-01-01

    The Humboldt region is in central Yavapai County, Arizona. The intersection of the 112? 15' meridian and the 34? 30' N parallel is in the approximate geographical center of the region, and the Iron King mine is about 2000 feet west-northwest of the intersection. Pre-Cambrian rocks form the bedrock in the Humboldt region. Late Cenozoic unconsolidated river wash and valley fill, including some interbedded basalt, locally mantle the pre-Cambrian rocks, especially in the north-central part of the region (Lonesome Valley). The pre-Cambrian rocks consist of five newly defined metavolcanic formations derived from flows and tuff s, and of six intrusive units ranging in composition from granite to gabbro or perhaps more mafic types. Relic bedding-and pillow structures are locally prominent in the metavolcanics; geopetal structures are uncommon, but where present, generally indicate that the top is toward the west, though the evidence is too meager to be conclusive. Low-grade dynamothermal metamorphism altered the metavolcanics and to a lesser extent the intrusive rocks, forming textures, structures, and mineral assemblages characteristic of low temperature and moderate stress. The Texas Gulch formation, which is the easternmost metavolcanic formation, consists of five lithologic units. Arranged in the general order of their appearance from east to west they are meta-andesite breccia, purple slate, metarhyolite tuff, meta-andesite, and green slate. The boundary between the Texas Gulch formation and the Iron King meta-andesite is apparently gradational. The Iron King meta-andesite consists of three meta-andesite tuff units, two meta-andesite flow units and one metarhyolite tuff and conglomerate unit. The assemblage chlorite-albite-epitode with or without quartz is dominant in the meta-andesites. Mafic intrusive rocks, which may be approximately contemporaneous with metamorphism, may explain the presence of actinolitic hornblende in the central part of the formation. Toward

  14. 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. PMID:19782239

  15. 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

  16. 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

  17. 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.

  18. 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

  19. Prediction of diffuse sulfate emissions from a former mining district and associated groundwater discharges to surface waters

    NASA Astrophysics Data System (ADS)

    Graupner, Bastian J.; Koch, Christian; Prommer, Henning

    2014-05-01

    Rivers draining mining districts are often affected by the diffuse input of polluted groundwaters. The severity and longevity of the impact depends on a wide range of factors such as the source terms, the hydraulic regime, the distance between pollutant sources and discharge points and the dilution by discharge from upstream river reaches. In this study a deterministic multi-mine life-cycle model was developed. It is used to characterize pollutant sources and to quantify the resulting current and future effects on both groundwater and river water quality. Thereby sulfate acts as proxy for mining-related impacts. The model application to the Lausitz mining district (Germany) shows that the most important factors controlling concentrations and discharge of sulfate are mixing/dilution with ambient groundwater and the rates of biological sulfate reduction during subsurface transport. In contrast, future impacts originating from the unsaturated zones of the mining dumps showed to be of little importance due to the high age of the mining dumps and the associated depletion in reactive iron-sulfides. The simulations indicate that currently the groundwater borne diffuse input of sulfate into the rivers Kleine Spree and Spree is ∼2200 t/years. Our predictions suggest a future increase to ∼11,000 t/years within the next 40 years. Depending on river discharge rates this represents an increase in sulfate concentration of 40-300 mg/L. A trend reversal for the surface water discharge is not expected before 2050.

  20. 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.

  1. 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.

  2. 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.

  3. A geochemical study of oil in metalliferous veins, Idarado Mine, San Juan Mountains, Colorado

    USGS Publications Warehouse

    Gerrild, Peter M.

    1976-01-01

    A tarry, benzene-soluble material is present in metal-rich veins in the Idarado mine, Ouray County, Colo., in an area not known to have petroleum resources. The material was compared chemically, spectometrically, and chromatographically with oils from four fields in the nearby Paradox basin. Each of these oil fields contains reservoir rocks equivalent to rock units known to extend beneath volcanic rocks near the mine. Carbon and sulfur isotope data and gas chromatographic data indicate a similarity between the oil from the nearby Sierra field and the oil from the mine. Thus, it seems both geologically and chemically possible that oil in the mine originated in Cretaceous sediments. Variations in the composition of oil from the mine and differences between the mine oil and Sierra oil, notably in the distributions of hydrocarbons, are attributed to bacterial degradation.

  4. 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

  5. Comparison of Body Wave Displacement with Damage Observations of a Rockburst, Coeur d'Alene Mining District, Idaho

    SciTech Connect

    Sprenke, K F.; White, B. G; Rohay, Alan C. ); Whyatt, J K.; Stickney, M C.

    2002-12-31

    Fault plane solutions for seismic events in the deep underground mines of the Coeur d'Alene Mining District in northern Idaho have been difficult to reconcile with actual observations of mine damage. Examination of rockburst damage in stopes as well as measurements of slip movements on bedding planes suggests that rockbursts in the Lucky Friday Mine are closely associated with gradual bedding plane slip. This progressive slip reduces the physical dimensions of slopes and increases compressive stress resulting in sudden implosive failure of the stope margins. Thus, much of the difficulty in evaluating seismological data arises from the implosional nature of these rockbursts, making the first motion of the events difficult to interpret. In the summer of 1998, we acquired several months of high-quality seismic data from five stations in the vicinity of the Lucky Friday Mine. This is the first time that a network of high dynamic-range, three-component instruments has been deployed in this mining district. On August 29, 1988 at 6:09 UTC, a ML2.9 event occurred at the Lucky Friday Mine. This event resulted from bedding plane slip and caused extensive damage in the mine that was carefully documented. Using a least-squares procedure, we were able to find a well-constrained moment tensor solution that matched the P and S displacement amplitudes measured at the five temporary stations. We derived a model of the mechanism to compare with the underground observations of ground displacement related to the observed damage. We conclude that high-quality seismological instrumentation is required if meaningful results are to be obtained for understanding the source mechanisms of shear-implosional rockbursts.

  6. 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.

  7. 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

  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. 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.

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

    SciTech Connect

    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, whereas that from the CO veins contains both Se and Fe in solid solution. The impurity content varies within the same specimen and within individual crystals as well and demonstrates lack of chemical equilibrium. 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 delta/sup 18/O and delta/sup 13/C values. Quartz displays delta/sup 18/O ranging from 18.5 to 21.5 per thousand, distinctly lower than the associated dolomites, suggesting that the two minerals may have formed at two different stages. The range of delta/sup 34/S values for metacinnabar overlaps with that of cinnabar. The delta/sup 34/S for pyrite ranges from 3.1 to 13.0 per thousand; pyrite with framboidal nuclei shows the highest delta/sup 34/S 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.

  11. 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.

  12. Relationships between deformation and mesothermal veins in the Sunshine Mine area, Coeur d'Alene district, Idaho

    NASA Astrophysics Data System (ADS)

    Ferraro, Jaclyn Marie

    The Coeur d'Alene district in northern Idaho is a world class Pb-Ag mesothermal vein system that has produced about 360 million ounces of silver, lead, and zinc since the 1880s. Despite the long history of exploration and production, the district does not have a predictive model for exploration based on a sound understanding of structural controls on the silver ore deposits; this is certainly the case for the Sunshine Mine and surrounding area. Fault kinematic history in the district shows a regional scale fault system reactivated over time with dextral, sinistral, and dip-slip displacement. The fault system is superimposed on regional deformation fabrics that were examined for this study in the Sunshine Mine area. Cleavage sets observed in the Sunshine mine area, distinguished by orientation and superposition relationships, are consistent with the findings of Smith (2004) which defined cleavage sets referred to as S1, S2, and S3. Two additional deformation fabrics that appear spatially tied to fault zones formed between development of cleavages S2 and S3. The multiple cleavages, fault zones, and their intersections are interpreted to act as pathways for hydrothermal fluids associated with vein formation and silver ore deposition. Thin section kinematic analysis of vein and shear zone samples defined a dip-slip sense of shear associated with the Sterling vein. Electron Backscatter Diffraction (EBSD) analysis of vein and shear zone samples failed to define a lattice preferred crystallographic orientation that defined shear sense. Similarly, cathodoluminescence (CL) analysis of thin section textures failed to define a dominant shear sense and fault kinematics. Nevertheless, additional study using these techniques is warranted. Both field observation and thin section analysis demonstrate a direct relationship between shear zones, veins, and mineralization potential, clarifying the need for detailed fault maps for the Sunshine Mine area and Coeur d'Alene district.

  13. A dataset of magnetic susceptibility, metalization, and alteration for samples from the Stinkingwater Mining District, Absaroka Mountains, Wyoming

    USGS Publications Warehouse

    Gettings, Mark E.

    2004-01-01

    Magnetic susceptibility was measured for 700 samples of drill core from thirteen drill holes in the porphyry copper-molybdenum deposit of the Stinkingwater mining district in the Absaroka Mountains, Wyoming. Measurements were performed on splits from 3 m (10 ft) sections of pulverized core. The measurements constitute a useful dataset because the same samples were studied to identify their alteration state and have been subjected to chemical analysis. Tables of the data are included in this report.

  14. Mercury pollution on district of Dimembe river system North Sulawesi, Indonesia, due to traditional gold mining activities

    NASA Astrophysics Data System (ADS)

    Ayhuan, D.; Atteng, O.; Dondokambey, A.; Randuk, M.

    2003-05-01

    Mercury contamination caused by the amalgamation of gold in small scale gold mining is a environmental problem. Small-scale gold mining (SSGM) is common in mineral endowed developing countries. It offers an important means of livehood and has served as a safety net in times of natural calamities or economic distress. In north Sulawesi Province alone, approximately 22,000 small-scale gold miners were active in 1998, and produced an estimated 10 tonnes of gold bullion. Activities of traditional / illegal gold mining (PETI) in Dimembe of district, which is located in Minahasa Regency, North Sulawesi Province. The major environmental concern associated with PETI in mercury pollution from processing of gold-bearing ore. In both the inorganic and organic forms, mercury is one of the most toxic substances to humans. One of the environmental pollution is water pollution on district of Dimembe river system that is probably caused by the use of mercury (Hg) in processing mine ore. This mercury is used in an iron rolling vessel, wllich is called tromol. Mercury concentration at employed in this operation reaches 1 kg out of 30 kg ore. Sampling stage was conducted at Warat river, downstream Taiawaan river, Merut river and Kadumut river on late April 2002 by BAPEDALDA team together with Health Laboratory staff. Material which were sampled was water. Sampling methods carried out were bottle sample immersed about 10 cm below the water surface. The analysis method used was mercury analyzer. The analysis result show that total concentration of mercury range from 1. 69 to 25. 54 ppb. This concentration is closed to Water Quality Standard IV Class that is 0.005 mg/L (Regulation Government No. 82/2001). The result of this research indicate that the district of Dimembe river system in the gold mining area have been contaminated by mercury.

  15. Recharge sources and hydrogeochemical evolution of groundwater in the coal-mining district of Jiaozuo, China

    NASA Astrophysics Data System (ADS)

    Huang, Pinghua; Chen, Jiansheng

    2012-06-01

    Investigations in the Jiaozuo coal-mining district (China) aim to link water-inrush aquifers with the sources of groundwater recharge. Concentrations of TDS, HCO{3/-}, Cl- and Na+ in the groundwater samples gradually decrease with increasing depth; in contrast, the factor 1 value of the Q-mode analysis gradually increases, which indicates that the deep groundwater may upflow, recharging the aquifers near the faulted zone. Some groundwater samples (above the local meteoric water line and `evaporation line 1') may originate from recharge by infiltrating local rainfall. Spring and river samples are symmetrically distributed on the regression line of the Ordovician and Carboniferous limestone aquifer groundwater (δ2H = 3.76 × δ18O - 31.77) and may, therefore, originate from groundwater recharge in the northern Taihang mountains. This mechanism is supported by the observation that groundwater levels change with rainfall. According to radiocarbon residence-time estimates, two groundwater sample sites may have been recharged during the late glacial stage.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. Mineral zoning and gold occurrence in the Fortuna skarn mine, Nambija district, Ecuador

    NASA Astrophysics Data System (ADS)

    Markowski, Agnès; Vallance, Jean; Chiaradia, Massimo; Fontboté, Lluìs

    2006-07-01

    The Fortuna oxidized gold skarn deposit is located in the northern part of the Nambija gold district, southern Ecuador. It has been subdivided into four mineralized sites, covering a distance of 1 km, which are named from north to south: Cuerpo 3, Mine 1, Mine 2, and Southern Sector. Massive skarn bodies occur in K-Na metasomatized volcanic and volcaniclastic rocks of the Triassic Piuntza unit. They appear to result from selective replacement of volcaniclastic rocks. Very minor presence of bioclast relicts suggests the presence of subordinate limestone. Endoskarn type alteration with development of Na-rich plagioclase, K-feldspar, epidote, actinolite, anhedral pyroxene, and titanite affects a quartz-diorite porphyritic intrusion which crops out below the skarn bodies in Mine 2 and the Southern Sector. Endoskarn alteration in the intrusion grades into a K-feldspar ± biotite ± magnetite assemblage (K-alteration), suggesting that skarn formation is directly related to the quartz-diorite porphyritic intrusion, the latter being probably emplaced between 141 and 146 Ma. The massive skarn bodies were subdivided into a dominant brown garnet skarn, a distal green pyroxene-epidote skarn, and two quartz-rich varieties, a blue-green garnet skarn and light green pyroxene-garnet skarn, which occur as patches and small bodies within the former skarn types. The proximal massive brown garnet skarn zone is centered on two 060° trending faults in Mine 2, where the highest gold grades (5-10 g/t) were observed. It grades into a distal green pyroxene-epidote skarn zone to the North (Cuerpo 3). Granditic garnet shows iron enrichment from the proximal to the distal zone. Diopsidic pyroxene exhibits iron and manganese enrichment from proximal to distal zones. The retrograde stage is weakly developed and consists mainly of mineral phases filling centimeter-wide veins, vugs, and interstices between garnet and pyroxene grains. The main filling mineral is quartz, followed by K

  1. 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.

  2. Alteration patterns and structural controls of the El Espino IOCG mining district, Chile

    NASA Astrophysics Data System (ADS)

    Lopez, G. P.; Hitzman, M. W.; Nelson, E. P.

    2014-02-01

    The El Espino IOCG mining district is characterized by several mineralized bodies the largest of which is the El Espino deposit, which has an estimated geologic resource of 123 Mt at 0.66 % Cu and 0.24 g/t Au. Mineralized bodies are distributed in a 7 × 10 km2 area throughout a 1,000-m vertical section. They range from single veins to stockworks and breccias to manto-type deposits. The ore bodies are hosted primarily by volcanic, volcaniclastic, and sedimentary rocks of the Early Cretaceous Arqueros and Quebrada Marquesa formations, with a few mineralized zones within Late Cretaceous dioritic intrusions. The fault and vein architecture shows that El Espino IOCG system was localized within a dilatational jog along a major transtensional dextral fault system. Sodic alteration (albite) is the most extensive style of alteration in the district, and it is bounded by major NS-NNE trending faults. Sodic-calcic (epidote-albite) alteration occurs at deep to medium elevations (1,000-500 m) and grades inward into calcic alteration. Calcic alteration surrounds dioritic intrusions of the Llahuin plutonic suite. Significant iron oxides are associated with later calcic alteration associations (actinolite-epidote-hematite). The upper portions of the alteration system (0-500 m) display hydrolytic alteration associations with abundant hematite. Hydrolytic veins are feeders to zones of manto-type alteration and mineralization within favorable volcano-sedimentary lithologies that formed El Espino deposit. Sulfides are largely confined to calcic and hydrolytic alteration associations. Hydrothermal fluids responsible for hematite and sulfide mineralization had salinities between 32 and 34 wt% NaCleq and temperature of approximately 425 °C at an estimated depth of 3-4 km. Geochronological U-Pb and 40Ar/39Ar data indicate that hydrothermal alteration was coeval with magmatic intrusive activity. One particular dioritic intrusion (88.5 Ma) preceded the calcic stage (88.4 Ma), which was

  3. 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. PMID:26379258

  4. Distribution and speciation of metals in soils of the former mining district of Touiref (Northwest Tunisia)

    NASA Astrophysics Data System (ADS)

    Othmani, M. A.; Soussi, F.; Ferreira da Silva, E.; Moussi, A.; Oueslati, W.; Jebali, R.

    2012-04-01

    The former mining district of Touiref (1901-1958), located North-West of Tunisia, and where the activities have stopped 50 years ago, gave rise to large volumes of mine (extraction, flotation) tailings containing sulphides (galena, sphalerite, jordanite, pyrite, marcasite) associated with a carbonate gangue. Analysis of a hundred samples of soil has been used to develop isoconcentration maps of Pb, Zn, Cd and As across the study area, beyond the local geochemical background (LGB). The drawing of these maps has allowed the delineation of the contaminated areas using Geographic Information Systems (GIS). In addition, the soils of the study area were characterized in terms physico-chemical (pH and Corg), grain size, mineralogical and chemical means. Their neutral to slightly alkaline pH is (7.91 to 8.81), and their clay (32 and 57%)-silt (26 and 42%) texture, are characteristic of soils developed on carbonate bedrocks. The percentages in organic carbon (Corg) are between 0.71 and 5.6%. From a mineralogical point of view, mainly Pb-Fe sulphides associated with their alteration products have been observed within these soils. The levels of Pb, Zn, Cd and As, may go up 0.99%, 1.99%, 140 ppm and 409 ppm, respectively. These high concentrations were recorded around the extraction, processing and storage sites on the one hand and through the flood zones and the prevailing wind direction (NW-SSE) on the other. These soils have also been subjected to sequential extraction tests in order to characterize the metal-bearing phases and assess the mobility and bioavailability of heavy metals. The results have shown that Pb is mainly associated with the acid-soluble fraction (carbonates) and to a lesser extent with the Fe-(oxy)hydroxides, whereas Zn and Cd are mainly associated with Fe-(oxy)hydroxides and to a lesser degree with sulphides. Metals associated with these phases can be easily mobilized in response to physico-chemical changes and become phytoaccessible.

  5. 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

  6. 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.

  7. Assessment of metal contamination in groundwater and soils in the Ahangaran mining district, west of Iran.

    PubMed

    Mehrabi, Behzad; Mehrabani, Shiva; Rafiei, Behrouz; Yaghoubi, Behrouz

    2015-12-01

    In this study, 28 groundwater and 13 soil samples from Ahangaran mining district in Hamedan Province, west of Iran were collected to evaluate the level of contamination. Average concentrations of As, Cu, Pb, Zn, Mn, Sb, and Ni in groundwater samples were 1.39, 3.73, 2.18, 9.37, 2.35, 4.44, and 5.50 μg/L (wet season), and 11.64, 4.92, 4.32, 14.77, 5.43, 4.12, and 0.98 μg/L (dry season), respectively. Results of groundwater samples analysis showed that the average of analyzed metals in the wet and dry seasons were below the permissible limits, except As in the dry season which displays concentrations that exceed US EPA water quality criteria recommended for drinking water. Also, the heavy metal pollution index (HPI) values in each sampling station were less than the critical index limit and were suitable for drinking. Factor analysis revealed that variables influential to groundwater quality in one season may not be as important in another season. Average concentrations of Ag, As, Cd, Cu, Pb, Sb, and Zn in soil samples were 2.61, 31.44, 0.51, 55.90, 1284.9, 21.26, and 156.04 mg kg(-1), respectively. The results of the geoaccumulation index (I geo) showed the following decreasing order: Pb > Zn > Cu > As > Sb > Cd > Ag. Potential ecological risk index (RI) suggests that the contamination in the investigated area is moderate to very high risk and the ranking of the contaminants in decreasing order is Ag > Sb > Pb > Cd > As > Cu > Zn. PMID:26545371

  8. Geology and geochemistry of the Mercur mining district, Tooele County, Utah

    SciTech Connect

    Tafuri, W.J.

    1987-01-01

    The Mercur mining district is located in the southern end of the Oquirrh Mountains approximately 35 miles southwest of Salt Lake City, Utah. The gold deposits occur in the east dipping limb of the Ophir anticline and are confined to favorable beds in the Mercur Member of the Mississippian Great Blue Formation. Host rocks are thin bedded bioelastic limestones and calcareous siltstones. The mineralized zones are cut by extensive small displacement high angle normal faults. Gold mineralization forms stratiform and strata-bound disseminated ore bodies within the favorable beds. The apparent control of the mineralization is the porosity and permeability of the host rocks combined with strong fracturing caused by the faulting. Mineralization occurs in zones of hydrothermal alteration consisting of partial decalcification followed by the introduction of varying amounts of silica and organic carbon and slight amounts of kaolinite and sericite. Gold has been observed, in the sulfide zone, in three forms: as one to two micron sized inclusions in marcasite; as gold bonded with complex organic molecules; and, rarely, in the native state as grains less than 5 microns in size. Commonly occurring minerals associated with the gold mineralizations are; pyrite, marcasite, orpiment, realgar and barite. The introduced organic matter occurs as extractable hydrocarbons and as insoluble activated carbon. Gold is found in the asphaltene phase of the extractable hydrocarbons and in the activated carbon. Both the asphaltene and the activated carbon are thought to be degradation products of a more mobile petroleum precursor that circulated in the hydrothermal system. The degradation to asphaltene and activated carbon could have been due to the increase in temperature, increase in Eh and water washing as the hydrothermal system matured.

  9. An assessment of the radiological scenario around uranium mines in Singhbhum East district, Jharkhand, India.

    PubMed

    Tripathi, R M; Sahoo, S K; Mohapatra, S; Patra, A C; Lenka, P; Dubey, J S; Jha, V N; Puranik, V D

    2012-07-01

    The present work deals with the prevalent radiological scenario around uranium-mining sites in the Singhbhum East district of Jharkhand state, India. The concentration of naturally occurring radioactive materials (NORMs) was estimated from 27 soil samples collected around three regions in the study area, namely Bagjata, Turamdih and Jaduguda. The mean activity concentrations of (238)U in Bagjata, Turamdih and Jaduguda regions were found to be 128.6, 95.7 and 49.2 Bq kg(-1), respectively. Similarly for (232)Th and (40)K the activity concentrations were found to be 57.3, 78.4, 68.9 and 530, 425 and 615 Bq kg(-1) in the Bagjata, Turamdih and Jaduguda regions, respectively, which are comparable with other reported values worldwide, except for some high values. The calculated gamma dose rate, obtained from the concentrations of (238)U, (232)Th and (40)K in the samples, was compared with the observed dose rate in air. A good correlation (0.96) was observed between the calculated and the observed gamma dose rate. The annual outdoor effective dose rate was estimated and the values falls between 0.04-0.3, 0.07-0.3 and 0.07-.14 mSv y(-1) with mean values of 0.14, 0.12 and 0.11 mSv y(-1) for the Bagjata, Turamdih and Jaduguda regions, respectively. The terrestrial dose rates in all the three regions are comparable with other reported values worldwide, except for a few high values in Greece, Rio Grande Do Norte (Brazil) and Kalpakkam (India). PMID:22155799

  10. 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.

  11. Urban sediment contamination in a former Hg mining district, Idrija, Slovenia.

    PubMed

    Bavec, Spela; Biester, Harald; Gosar, Mateja

    2014-06-01

    Road sediments from gully pots of the drainage system and stream sediments from local streams were investigated for the first time in the urban area of Idrija town, the central part of the second largest and strongly contaminated Hg mining district in the world. Hg concentrations in road sediments were lower than in stream sediments. They ranged from 16 to 110 mg/kg (Md = 29 mg/kg) for <0.125 mm particles and from 7 to 125 mg/kg (Md = 35 mg/kg) for <0.04 mm particles, while Hg concentrations in stream sediments ranged from 10 to 610 mg/kg (Md = 95 mg/kg) for <0.125 particles and from 10 to 440 mg/kg (Md = 105 mg/kg) for <0.04 mm particles. High Hg loadings in stream sediments were successfully linked with identified mercury sources (rocks containing mercury ore, areas of former ore roasting sites, ore residue dumps), because they are located in the drainage areas of streams, from which the sediments were collected. Links between Hg loadings in road sediments and identified mercury sources were not recognized. Solid phases of Hg were determined by thermo-desorption technique and are similar for both types of sediments. Results show the occurrence of three different forms: elemental mercury, mercury bound to matrix components and cinnabar. Approximately 50 % of Hg in samples consist of non-cinnabar fractions. This is important, since they are potentially bioavailable. An interesting new discovery according to previous research of environmental media from Idrija area by solid-phase Hg thermo-desorption technique is that elemental mercury was determined in almost all investigated sediments in minor amounts (Md = 3 %). PMID:24114255

  12. 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

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

    USGS Publications Warehouse

    Walton-Day, Katie; 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

  14. Isolation of influenza A viruses from migratory waterfowls in San-in District, Western Japan, in the winter of 1982-1983.

    PubMed

    Otsuki, K; Takemoto, O; Fujimoto, R; Yamazaki, K; Kubota, N; Hosaki, H; Kawaoka, Y; Tsubokura, M

    1987-09-01

    From November 1982 to March 1983, winter migratory waterfowls of some species staying in San-in District, Western Japan, were surveyed for influenza virus at five stations. A total of eight influenza A viruses were isolated from 354 faeces samples of whistling swans; in contrast, no virus was isolated from any sample of 261 black-tailed gulls, of 113 pintails and of 10 mallards. Five of eight isolates belonged to human pandemic subtype H2N2, two isolates belonged to fowl plague subtype H7N7, and the remaining one to subtype H4N6. PMID:2891283

  15. 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. PMID:27266655

  16. 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

  17. 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.

  18. 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)

  19. Geological and geochemical studies in the Robinson Mining District, White Pine County, Nevada, using Skylab S190A imagery

    NASA Technical Reports Server (NTRS)

    Jensen, M. L. (Principal Investigator); Rogers, R. J.; Erickson, M. P.

    1973-01-01

    The author has identified the following significant results. In the Robinson mining district which included the Ruth porphyry copper mines, three large positive aeromagnetic anomalies exist over a Tertiary volcanic area north west of Ruth. Prior studies of this area have suggested that the volcanics may or may not be the cause of the anomalies. Skylab Sl90A imagery, however, indicates possible outcrops in the volcanic area of the Paleozoic sediments. Field studies or ground truth verify the existence of these inliers suggesting that the magnetic anomaly may be the result of a buried intrusive body for which potential mineralization has been covered by the post-ore blanket of volcanics. The area is being mapped in more detail and samples of mercury-bearing soil-gas area being collected within and outside the area.

  20. Distribution of the platinum group elements in peat deposit near a historic lead and silver mining district.

    PubMed

    Strnad, Ladislav; Mihaljevic, Martin; Ettler, Vojtech; Barsová, Linda; Zuna, Milan; Sebek, Ondrej

    2008-08-01

    Concentrations of platinum group elements (PGE) and Ag were studied in a minerotrophic peat deposit near a historic Pb-Ag mining district (Príbram, Czech Republic). The PGE determinations were performed by quadrupole ICP-MS after NiS fire assay procedure. In the individual peat layers (dated by measurement of (210)Pb activity) the PGE concentrations were low and ranged from 0.015 ng g(-1) (Ir) to 11.8 ng g(-1) (Pt). The enrichment of PGE (especially Pt) compared to the Earth crust contents were observed during two periods. The peak in the second half of 19th century was explained by massive increase of ore mining and affinity of PGE to concentrate in molten lead during Pb processing. The recent PGE enrichment in peat layers might be explained by automobile (with catalytic converters) exhaust fumes or processing of computer electronic parts by the smelter. PMID:18373043

  1. 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. PMID:23179723

  2. Electrical resistivity imaging survey to detect uncharted mine galleries in the mining district of Linares, Jaén, Spain

    NASA Astrophysics Data System (ADS)

    Martínez-López, J.; Rey, J.; Dueñas, J.; Hidalgo, C.; Benavente, J.

    2012-02-01

    The scarcity of information about the existence of old mining shafts and galleries in urban areas is an important issue for future urban development. Electrical resistivity tomography is a non-destructive geophysical technique that can detect and characterize such subsurface cavities based on differences in the behaviour of electrical current in the void and in the embedding rock. Here we present a study in which this technique was used to determine the location of old engineered structures around the city of Linares, southern Spain, and to relate these structures to the abandoned deep mines present in the area. Eight electrical resistivity imaging profiles were performed, with a total of 22 808 measurements. Correlations between geoelectrical anomalies allow detection of the depth and the direction of several galleries, as well as the voids that result from mining extraction. Given the depth at which these structures are located (in some cases less than 5 m), they pose an important risk for future construction projects in areas of urban expansion. This technique is shown to be a useful tool for locating areas that pose important urban risks and, by extension, for the decision-making process in territorial planning, especially in areas with a history of deep mining.

  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. 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

  5. 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

  6. Oxygen and hydrogen isotope geochemistry of the Star-Morning mine, Coeur d'Alene mining district, Idaho

    NASA Astrophysics Data System (ADS)

    Constantopoulos, James; Larson, Peter B.

    1991-02-01

    Oxygen isotope values of vein quartz from the Star-Morning mine range from 13.2‰ to16.2‰ relative to standard mean ocean water. Calculated isotopic values of water in equilibrium with the vein quartz at 325 °C range from 7.2‰ to 10.2‰. The δ18Oquartz values decrease with depth in the mine. The δD values of quartz inclusion fluids range from -18‰ to -105‰ and do not significantly correlate with depth. Oxygen isotope values of Belt Supergroup wholerock samples range from 13.8‰ to 16.8‰. The data indicate that the fluids were a mix of metamorphic water released from the Belt rocks during low-grade metamorphism, and 18O-shifted meteoric water.

  7. 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. PMID:25966938

  8. 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. PMID:16820188

  9. Accumulation trends of metal contamination in sediments of the former Pb-Zn mining district of Touiref (NW Tunisia)

    NASA Astrophysics Data System (ADS)

    Othmani, Mohamed Ali; Souissi, Fouad; da Silva, Eduardo Ferreira; Coynel, Alexandra

    2015-11-01

    Wastes of the former Pb-Zn mining district of Touiref (Pb/Zn) can be eroded during strong rainfall. The presence of a downstream lake offers the opportunity to perform geochemical characterisation of lacustrine sediments and analyze the temporal evolution of metal contamination. For this reason, a sedimentary core (C1) has been collected at the outlet of the Oued Sidi Bou Said which runs along the North side of the dike flotation tailings and a second core (C2) was sampled in front of the river flowing outside the mine site and reaching the plain on the East side of the endoreic study area. The scope of the present paper is characterize the temporal variability of major and minor elements in both sedimentary cores. The study of the historical contamination in both Touiref cores shows a clear impact of mining on the total endorheic basin, especially for the period going from 1914 until 1955 as well as the influence of urban development.

  10. 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

  11. 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

  12. Greater Expectations. The San Jose District Did Away with a Two-Track High School System and Instead Demanded that All of Its Students Take a College-Prep Course of Study

    ERIC Educational Resources Information Center

    Maxwell, Lesli A.

    2006-01-01

    Responding to demands by parents and a concern that high school was just too easy, the San Jose Unified School District (California) did away with a two-track high school system, demanded that all of its students take a college-prep course of study, and adopted some of the most rigorous graduation requirements in California. In the two-tiered high…

  13. 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.

  14. 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

  15. 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

  16. Interaction of acid mine drainage with waters and sediments of West Squaw Creek in the West Shasta Mining District, California

    USGS Publications Warehouse

    Filipek, L.H.; Kirk, Nordstrom D.; Ficklin, W.H.

    1987-01-01

    Acid mine drainage has acidified large volumes of water and added high concentrations of dissolved heavy metals to West Squaw Creek, a California stream draining igneous rocks of low acid-neutralizing capacity. During mixing of the acid sulfate stream waters in the South Fork of West Squaw Creek with an almost equal volume of dilute uncontaminated water, Cu, Zn, Mn, and Al remained in solution rather than precipitating or adsorbing on solid phases. Changes in the concentration of these generally conservative metals could be used to determine relative flow volumes of acid tributaries and the main stream. An amorphous orange precipitate (probably ferric hydroxides or a mixture of ferric hydroxides and jarosite) was ubiquitous in the acid stream beds and was intimately associated with algae at the most acid sites. Relative sorption of cations decreased with decreasing water pH. However, arsenic was almost completely scavenged from solution within a short distance from the sulfide sources.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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. PMID:26774309

  2. Application of complex trace analysis for improved target identification in gem-tourmaline-bearing pegmatites in the Himalaya mine, San Diego County, California

    NASA Astrophysics Data System (ADS)

    Patterson, Jeffrey E.; Cook, Frederick A.

    2000-04-01

    Gem bearing miarolitic cavities in rare metal, lithium enriched, granitic pegmatites pose challenging exploration targets, as they are not readily identifiable using normal geophysical methods. Application of ground penetrating radar (GPR) has been successful in delineating gem-bearing zones in the Himalaya pegmatite mine in San Diego County, California. Careful setup and data processing, using complex signal analysis, have so far allowed us to distinguish between gem- bearing pockets, non-gem bearing pockets, and barren/frozen dike. Each of us independently hypothesized, in 1995, that GPR could be an appropriate tool for gemstone exploration in the subsurface exposures in adits, drifts and stopes of many gem mines (Patterson, 1996; Cook, 1997). The culmination of these efforts was reached in June, 1998, with the first documented discovery of gem tourmaline pockets using this technique.

  3. 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. PMID:26956012

  4. 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

  5. 7 CFR 920.12 - District.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... (e) District 5 shall include the counties of San Joaquin, Calaveras, Tuolumne, Merced, Stanislaus, Contra Costa, El Dorado, Amador, Sacramento, Alpine, San Francisco, Alameda, San Mateo, Santa Clara, Santa Cruz, San Benito and Monterey. (f) District 6 shall include the counties of Mono, Mariposa,...

  6. 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.

  7. Techniques used in mine-water problems of the east Tennessee zinc district

    USGS Publications Warehouse

    Kent, Deane Frederick

    1950-01-01

    A study of ground water as related to mining in cavernous limestones and dolomites in eastern Tennessee was made in 1946 by the U. S. Geological Survey. Surface and subsurface mapping indicated the geologic control of underground channels. Several methods of tracing water were tried and new techniques in using these methods evolved from the work. Rainfall data, when correlated with ground-water volumes and velocities, gave much information as to expected pumping volumes for any period. The use of fluorescent dye for tracing the flow of the water is described and other methods are discussed briefly. Four examples, each from a different mine, are discussed in detail and some remedies for the problems are suggested.

  8. Impact of tailings from the Kilembe copper mining district on Lake George, Uganda

    NASA Astrophysics Data System (ADS)

    Owor, Michael; Hartwig, Tina; Muwanga, Andrew; Zachmann, Dieter; Pohl, Walter

    2007-01-01

    The abandoned Kilembe copper mine in western Uganda is a source of contaminants, mobilised from mine tailings into R. Rukoki flowing through a belt of wetlands into Lake George. Water and sediments were investigated on the lakeshore and the lakebed. Metal associations in the sediments reflect the Kilembe sulphide mineralisation. Enrichment of metals was compared between lakebed sediments, both for wet and dry seasons. Total C in a lakebed core shows a general increment, while Cu and Co decrease with depth. The contaminants are predominant (> 65%) in the ≤ 63 μm sediment size range with elevated Cu and Zn (> 28%), while Ni, Pb and Co are low (< 18%) in all the fractions. Sequential extraction of Fe for lakeshore sediment samples reveals low Fe mobility. Relatively higher mobility and biological availability is seen for Co, Cu and S. Heavy metal contents in lake waters are not an immediate risk to the aquatic environment.

  9. 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. PMID:26366709

  10. Trace metals in fugitive dust from unsurfaced roads in the Viburnum Trend resource mining District of Missouri--implementation of a direct-suspension sampling methodology.

    PubMed

    Witt, Emitt C; Wronkiewicz, David J; Pavlowsky, Robert T; Shi, Honglan

    2013-09-01

    Fugitive dust from 18 unsurfaced roadways in Missouri were sampled using a novel cyclonic fugitive dust collector that was designed to obtain suspended bulk samples for analysis. The samples were analyzed for trace metals, Fe and Al, particle sizes, and mineralogy to characterize the similarities and differences between roadways. Thirteen roads were located in the Viburnum Trend (VT) mining district, where there has been a history of contaminant metal loading of local soils; while the remaining five roads were located southwest of the VT district in a similar rural setting, but without any mining or industrial process that might contribute to trace metal enrichment. Comparison of these two groups shows that trace metal concentration is higher for dusts collected in the VT district. Lead is the dominant trace metal found in VT district dusts representing on average 79% of the total trace metal concentration, and was found moderately to strongly enriched relative to unsurfaced roads in the non-VT area. Fugitive road dust concentrations calculated for the VT area substantially exceed the 2008 Federal ambient air standard of 0.15μgm(-3) for Pb. The pattern of trace metal contamination in fugitive dust from VT district roads is similar to trace metal concentrations patterns observed for soils measured more than 40years ago indicating that Pb contamination in the region is persistent as a long-term soil contaminant. PMID:23659966

  11. 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.

  12. 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. PMID:21935979

  13. Geology of the epithermal Ag-Au Huevos Verdes vein system and San José district, Deseado massif, Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Dietrich, Andreas; Gutierrez, Ronald; Nelson, Eric P.; Layer, Paul W.

    2012-03-01

    The San José district is located in the northwest part of the Deseado massif and hosts a number of epithermal Ag-Au quartz veins of intermediate sulfidation style, including the Huevos Verdes vein system. Veins are hosted by andesitic rocks of the Bajo Pobre Formation and locally by rhyodacitic pyroclastic rocks of the Chon Aike Formation. New 40Ar/39Ar constraints on the age of host rocks and mineralization define Late Jurassic ages of 151.3 ± 0.7 Ma to 144.7 ± 0.1 Ma for volcanic rocks of the Bajo Pobre Formation and of 147.6 ± 1.1 Ma for the Chon Aike Formation. Illite ages of the Huevos Verdes vein system of 140.8 ± 0.2 and 140.5 ± 0.3 Ma are 4 m.y. younger than the volcanic host rock unit. These age dates are among the youngest reported for Jurassic volcanism in the Deseado massif and correlate well with the regional context of magmatic and hydrothermal activity. The Huevos Verdes vein system has a strike length of 2,000 m, with several ore shoots along strike. The vein consists of a pre-ore stage and three main ore stages. Early barren quartz and chalcedony are followed by a mottled quartz stage of coarse saccharoidal quartz with irregular streaks and discontinuous bands of sulfide-rich material. The banded quartz-sulfide stage consists of sulfide-rich bands alternating with bands of quartz and bands of chlorite ± illite. Late-stage sulfide-rich veinlets are associated with kaolinite gangue. Ore minerals are argentite and electrum, together with pyrite, sphalerite, galena, chalcopyrite, minor bornite, covellite, and ruby silver. Wall rock alteration is characterized by narrow (< 3 m) halos of illite and illite/smectite next to veins, grading outward into propylitic alteration. Gangue minerals are dominantly massive quartz intergrown with minor to accessory adularia. Epidote, illite, illite/smectite, and, preferentially at deeper levels, Fe-chlorite gangue indicate near-neutral pH hydrothermal fluids at temperatures of >220°C. Kaolinite occurring with

  14. 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

  15. 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

  16. 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., Jr.; 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

  17. Mobilities of heavy metals in surface waters: A field study of Mineral Branch, Tri-State Mining District

    SciTech Connect

    Piechowski, M.F.; Carroll, S.A. . Dept. of Geological Sciences)

    1992-01-01

    A field study of the mobilities of heavy metals was done in the Tri-State Mining District near Joplin, Missouri. The processing of ores left many large tailings piles in this region which are predominantly chert, but contain minor amounts of carbonate and sulfide minerals. The residual sphalerite, galena, marcasite, and pyrite readily dissolve when exposed to surface waters, increasing the acidity and concentrations of Pb, Zn, and Cd in the streams of the region. Mineral Branch is a local stream that originates in and flows through a tailings field. Water and sediment (bed and suspended load) samples were collected and analyzed by ICP and XRD methods in order to determine trace and major element concentrations and mineral compositions, respectively. The solids are primarily chert and carbonates, with small amounts of crystalline and amorphous iron hydroxides and oxyhydroxides. Over the two mile study area, pH increases steadily downstream. As the pH rises, the dissolved heavy metal concentrations fall, some by an order of magnitude or more. It was also found that over 99% of the Pb, Zn,and Cd in the system is presents in the solids. Precipitation of carbonates or hydroxides does not adequately explain the concentration changes seen in the system. The adsorption of the metal species onto the carbonates and iron oxyhydroxides of the stream sediments as a function of pH is an additional controlling factor in the Mineral Branch.

  18. 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.

    2015-01-01

      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.

  19. Biogeochemical removal of Zn and Cd in the Coeur D'Alene River (Idaho, USA), downstream of a mining district.

    PubMed

    Paulson, A J

    2001-10-20

    The conservative biogeochemical behavior of dissolved Zn and Cd in a 17-km, free-flowing reach of the Coeur d'Alene River downstream of a mining district is typical of watersheds in which suspended matter concentrations are low. For watersheds impacted by acid-rock drainage (ARD), low suspended matter concentrations are more likely to be found when acid rock drainage travels through soils because much of the Fe and Al that could form adsorbing surfaces is retained within the soils. In the absence of additional sources of solid substrates, metals can be transported great distances downstream once this Fe- and Al-poor ARD seeps into surface waters. In a 46-km backwater reach of the Coeur d'Alene River, it appears that biological activity increased pH and provided the organic matter solid substrate which removed approximately 50% of the Zn and Cd. Zn removal was partially reversible as pH decreased. These observations reinforce the concept that both inorganic and organic carbon chemistry must be measured if significant. advances in our understanding of the attenuation of Zn and Cd from ARD sources are to be made. PMID:11669275

  20. 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.

  1. 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.

  2. 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

  3. 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

  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

    2016-01-01

    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. 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

  6. 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

  7. 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).

  8. Environmental lead contamination in the Rudnaya Pristan--Dalnegorsk mining and smelter district, Russian far East.

    PubMed

    von Braun, Margrit C; von Lindern, Ian H; Khristoforova, Nadezhda K; Kachur, Anatoli H; Yelpatyevsky, Pavel V; Elpatyevskaya, Vera P; Spalinger, Susan M

    2002-03-01

    A preliminary survey of a remote mining and smelting region of the Russian Far East (RFE) indicates significant soil lead contamination and a high probability of childhood lead poisoning. Lead concentrations in residential gardens (476-4310 mg/kg, Gmean=1626 mg/kg) and in roadside soils (2020-22900 mg/kg, Gmean=4420 mg/kg) exceed USEPA guidance for remediation. Preliminary biokinetic estimates of mean blood levels suggest that preschool children are at significant risk of lead poisoning from soil/dust ingestion with levels predicted to average 13-27 microg/dl. Samples of other pathways, such as air, water, paint, interior dust, and garden produce, and pediatric and occupational blood lead levels are needed. An assessment of the industry's ability to improve emissions controls and materials handling should also be undertaken. Global lessons in remediating contamination problems and preventing childhood lead poisoning must be applied in innovative ways to meet the logistical, social, and economic challenges in the RFE. PMID:12051794

  9. Assessing the influence of reacting pyrite and carbonate minerals on the geochemistry of drainage in the Coeur d'Alene mining district

    USGS Publications Warehouse

    Balistrieri, L.S.; Box, S.E.; Bookstrom, A.A.; Ikramuddin, M.

    1999-01-01

    The relative abundance of minerals that react to generate or consume acid in mineralized areas is critical in determining the quality of water draining from such areas. This work examines the fundamental reactions that influence the pH and composition of drainage from mine adits and tailings piles. We construct triangle diagrams that predict stoichiometric relationships between concentrations of dissolved SO4 dissolved Ca and Mg, and either alkalinity or acidity by considering reactions involving the oxidation of pyrite, dissolution of carbonate minerals, and precipitation of iron oxide and iron hydroxysulfate minerals. Drainage data from the Coeur d'Alene mining district are used to test our stoichiometric approach. Comparisons between theoretical predictions and drainage data indicate that the range of pH values in the mining district is due to reacting pyrite to carbonate mineral ratios that range from near 0/1 to 1/1. Calcite and ankerite are the dominant carbonate minerals that buffer the acid produced during pyrite oxidation and ferrihydrite or schwertmannite precipitation.The relative abundance of minerals that react to generate or consume acid in mineralized areas is critical in determining the quality of water draining from such areas. This work examines the fundamental reactions that influence the pH and composition of drainage from mine adits and tailings piles. We construct triangle diagrams that predict stoichiometric relationships between concentrations of dissolved SO4, dissolved Ca and Mg, and either alkalinity or acidity by considering reactions involving the oxidation of pyrite, dissolution of carbonate minerals, and precipitation of iron oxide and iron hydroxysulfate minerals. Drainage data from the Coeur d'Alene mining district are used to test our stoichiometric approach. Comparisons between theoretical predictions and drainage data indicate that the range of pH values in the mining district is due to reacting pyrite to carbonate mineral ratios

  10. 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.

  11. Modeling and estimating manganese concentrations in rural households in the mining district of Molango, Mexico.

    PubMed

    Cortez-Lugo, Marlene; Rodríguez-Dozal, Sandra; Rosas-Pérez, Irma; Alamo-Hernández, Urinda; Riojas-Rodríguez, Horacio

    2015-12-01

    Airborne manganese (Mn) is considered the most hazardous route of exposure since Mn particles can enter into the body through the lung and may access the brain directly through olfactory uptake, thereby bypassing homeostatic excretory mechanisms. Environmental indoor and outdoor manganese concentrations in PM2.5 were monitored in ten rural households from two communities of Hidalgo, Mexico, from 2006 to 2007. Indoor and outdoor air samples of PM2.5 were collected using MiniVol samplers, and Mn concentrations in the filters were measured using proton-induced X-ray emission (PIXE). An adjusted generalized linear mixed model was applied and then used for estimating indoor concentrations in non-monitored households. Our monitoring results showed a higher daily average concentration of indoor PM2.5 vs. outdoor PM2.5 (46.4 vs. 36.2 μg/m(3), respectively); however, manganese concentration in PM2.5 indoor and outdoor was 0.09 μg/m(3) in both sceneries. Predictor variables of indoor Mn concentration were outdoor Mn concentration (64.5% increase per 0.1 μg/m(3) change in Mn) and keeping the windows open (4.2% increase). Using these predictors, the average estimated indoor Mn concentration in PM2.5 was 0.07 μg/m(3) (SD = 0.05). Our results confirm the direct effect of outdoor Mn levels, opening house windows, and the distance to the mining chimney in indoor Mn levels in houses. PMID:26573689

  12. 7 CFR 920.131 - Redistricting of kiwifruit districts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... include the counties of San Francisco, San Mateo, Santa Cruz, Contra Costa, Alameda, Santa Clara, Monterey, San Benito, San Joaquin, Calaveras, Alpine, Mono, Tuolumne, Stanislaus, Merced, Mariposa, Madera, and.... (h) District 8 shall include of Kern, San Luis Obispo, Santa Barbara, Ventura, San Bernardino,...

  13. 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

  14. 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

  15. Evaluation of the impact of acid mine drainage on the chemistry and the macrobenthos in the Carolina stream (San Luis, Argentina).

    PubMed

    Tripole, Susana; Gonzalez, Patricia; Vallania, Adriana; Garbagnati, Marcela; Mallea, Miguel

    2006-03-01

    The purpose of this study was to evaluate the impact of acid mine drainage on the chemistry and the macrobenthos of the Carolina stream (San Luis - Argentina). Samples were obtained in the years 1997-1998 at two sites: site C(1), located 200 m upstream of the drainage, and site C(2), located 800 m downstream. The system buffer capacity was evaluated in the non - contaminated site by means of the buffer index calculation. The physico - chemical changes observed as a consequence of the contribution of acid mine drainage (AMD) were: a decreasing of pH and an increase in the ionic concentration, especially sulfate and Fe coming from the oxidation produced by chemiolithotrophic bacteria. The values obtained indicated a low buffer capacity and a high intrinsic vulnerability of the system to resist the impact originated by the AMD, producing a remarkable decreasing of pH of the receiving stream. These changes caused modifications in the original benthic community that was replaced by organisms more tolerant to the acid stress. A reduction in the abundance and in the taxonomic richness of the benthic macroinvertebrates was observed when compared with the reference station. An increase in the proportion of Chironomidae and of Acari and a decrease in the proportion of the remaining taxa were observed. The most sensitive groups were Ephemeroptera, Trichoptera and Mollusca. The community was mostly affected by the following variables: pH, conductivity, sulfate and dissolved total Fe. PMID:16565803

  16. Contextual view of district with Quarters 1, 2, and 3 ...

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

    Contextual view of district with Quarters 1, 2, and 3 in view, as well as Whiting Way, camera facing southwest - Naval Training Station, Senior Officers' Quarters District, Naval Station Treasure Island, Yerba Buena Island, San Francisco, San Francisco County, CA

  17. Alteration and ore distribution in the Proterozoic Mines Series, Tenke-Fungurume Cu-Co district, Democratic Republic of Congo

    NASA Astrophysics Data System (ADS)

    Fay, I.; Barton, M. D.

    2012-06-01

    Two sediment-hosted stratiform Cu-Co deposits in the Tenke-Fungurume district of the Central African Copperbelt were examined to evaluate the alteration history of the ore-hosting Mines Series and its implications for ore distribution and processing. Core logging and petrography, focused on lithology and timing relationships, outlined a complex alteration sequence whose earliest features include formation of anhydrite nodules and laths, followed by precipitation of dolomite. Later alteration episodes include at least two silica introductions, accompanied by or alternating with two dolomite introductions into the existing gangue assemblages. One introduction of Cu-Co sulfides accompanied the last episode of dolomite alteration, overprinting an earlier generation of ore whose gangue association was unidentifiable. Sulfides and some carbonates were subsequently modified by supergene oxidation, transport, and reprecipitation to 100-200 m depth. Present-day ore distribution resulted from these successive processes. Ore is concentrated in two shale-dominated units on either side of a cavernous silicified dolomite, which is interpreted as the main conduit for the mineralizing fluids. Sulfide ores precipitated at the redox or sulfidation contacts between this dolomite and the shales. Later, supergene fluids dissolved and moved some of the metals, redepositing them as oxides and carbonates. Solubility differences between Cu and Co in supergene conditions caused them to precipitate separately. Thus, modern ore distribution at Tenke-Fungurume results both from original hypogene lithology- and contact-related precipitation and from supergene oxidation, transport, and Cu-Co decoupling. The supergene fluid flow also redistributed gangue minerals such as dolomite, which has an economically important influence on the processing costs of supergene ores.

  18. 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.).

  19. 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

    .... SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice... rule after publishing a Notice of Proposed Rulemaking (NPRM) on August 28, 2013 (78 FR 53109). The... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA87 Security Zones; Naval Base Point Loma; Naval Mine...

  20. 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.

  1. Evaluation of 0.46- to 2.36-micrometre multispectral scanner images of the East Tintic mining district, Utah, for mapping hydrothermally altered rocks.

    USGS Publications Warehouse

    Rowan, L.C.; Kahle, A.B.

    1982-01-01

    Airborne multispectral scanner images recorded in the 0.46 to 2.36 micrometre region for the E Tintic mining district, Utah, were evaluated to determine their usefulness for distinguishing six types of hydrothermally altered rocks from a wide range of sedimentary and igneous rock types. The laboratory and field evaluation of a color ratio composite image, supported by in situ spectral reflectance measurements and an alteration map compiled from a published map, shows that silicified, argillized, and pyritized rocks can be mapped in detail utilizing an intense OH absorption band centered near 2.2 micrometre. This absorption band is absent or weak in most of the unaltered rocks. -from Authors

  2. 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

  3. 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.

  4. Fate of arsenic-bearing phases during the suspended transport in a gold mining district (Isle river Basin, France).

    PubMed

    Grosbois, C; Courtin-Nomade, A; Robin, E; Bril, H; Tamura, N; Schäfer, J; Blanc, G

    2011-11-01

    Arsenic-rich (~140-1520 mg x kg(-1)) suspended particulate matter (SPM) was collected daily with an automatic sampler in the Upper Isle River (France) draining a former gold mining district in order to better understand the fate of arsenic during the suspended transport (particles smaller than 50 μm). Various techniques at a micrometric scale (EPMA, quantitative SEM-EDS with an automated particle counting including classification system and μXRD) were used to directly characterize As-bearing phases. The most frequent ones were aggregates of fine clay particles. Their mineralogy varied with particle sources involved. These aggregates were formed by chlorite-phlogopite-kaolinite assemblages during the high flow and chlorite-illite-montmorillonite during the low flow. Among all the observed As-carriers in SPM, these clay assemblages were the least As-rich (0.10 up to 1.58 wt.% As) and their median As concentrations suggested that they were less concentrated during the high flow than during the low flow. Iron oxyhydroxides were evidenced by μXRD in these clay aggregates, either as micro- to nano-sized particles and/or as coating. (Mn, Fe)oxyhydroxides were also present as discrete particles. Manganese oxides (0.14-1.26 wt.% As) transport significantly more arsenic during the low flow than during the high flow (0.16-0.79 wt.% As). The occurrence of Fe oxyhydroxide particles appeared more complex. During the low flow, observations on banks and in wetlands of freshly precipitated Fe hydroxides (ferrihydrite-type) presented the highest As concentrations (up to 6.5 wt.% As) but they were barely detected in SPM at a microscale. During the high flow, As-rich Fe-oxyhydroxides (0.10-2.80 wt.% As) were more frequent, reflecting mechanical erosion and transport when the surface water level increased. Arsenic transfers from SPM to corresponding aqueous fraction mostly depend on As-carrier stability. This study shows the temporal occurrence of each type of As-bearing phases in

  5. 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.

  6. 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.

  7. 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

  8. 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

    2014-06-01

    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. PMID:24793970

  9. 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.

  10. 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. PMID:25636437

  11. 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. PMID:17013679

  12. 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.

  13. Heavy metal contamination in sediments of an artificial reservoir impacted by long-term mining activity in the Almadén mercury district (Spain).

    PubMed

    García-Ordiales, Efrén; Esbrí, José María; Covelli, Stefano; López-Berdonces, Miguel Angel; Higueras, Pablo L; Loredo, Jorge

    2016-04-01

    Sediments from the Castilseras reservoir, located downstream on the Valdeazogues River in the Almadén mercury district, were collected to assess the potential contamination status related to metals(oids) associated with river sediment inputs from several decommissioned mines. Metals(oids) concentrations in the reservoir sediments were investigated using different physical and chemical techniques. The results were analyzed by principal component analysis (PCA) to explain the correlations between the sets of variables. The degree of contamination was evaluated using the enrichment factor (EF) and the geoaccumulation index (Igeo). PCA revealed that the silty fraction is the main metals(oids) carrier in the sediments. Among the potentially harmful elements, there is a group (Al, Cr, Cu, Fe, Mn, Ni, and Zn) that cannot be strictly correlated to the mining activity since their concentrations depend on the lithological and edaphological characteristics of the materials. In contrast, As, Co, Hg, Pb, and S showed significant enrichment and contamination, thus suggesting relevant contributions from the decommissioned mines through fluvial sediment inputs. As far as Hg and S are concerned, the high enrichment levels pose a question concerning the potential environmental risk of transfer of the organic forms of Hg (mainly methylmercury) from the bottom sediments to the aquatic food chain. PMID:26062457

  14. 75 FR 71179 - Environmental Impact Statement: San Diego County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... Federal Highway Administration Environmental Impact Statement: San Diego County, CA AGENCY: Federal... Environmental Impact Statement (EIS) will be prepared ] for a proposed highway project in San Diego County... Hovey, Environmental Analysis Branch Chief, California Department of Transportation, District...

  15. 98. Street view, East San Antonio Ave., looking west northwest, ...

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

    98. Street view, East San Antonio Ave., looking west northwest, Guarantee Shoe Co. is 211 East San Antonio Ave. - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  16. Arsenic Mineralogy of Near-surface Tailings and Soils: Influences on Arsenic Mobility and Bioaccessibility in the Nova Scotia Mining Districts

    SciTech Connect

    Walker, S.; Parsons, M; Jamieson, H; Lanzirotti, A

    2009-01-01

    The mineral form, grain size and texture of As-bearing particles are important factors influencing the risk to human health associated with exposure to As-contaminated soils, sediments and mine wastes. Mining of arsenopyrite-bearing gold ores in Nova Scotia in the late 1800s and early 1900s has left a legacy of weathered, As-rich tailings deposits in more than 60 gold districts across the province. Fourteen samples of near-surface tailings and one of soil from several former gold mines frequented by the public were sieved to <150 {mu}m and characterized using conventional mineralogical techniques (XRD, microscopy and EPMA) and synchrotron micro-analysis ({mu}-X-ray diffraction, {mu}-X-ray fluorescence and {mu}-X-ray absorption spectroscopy). This study is part of a broader coordinated effort by a multi-department federal and provincial advisory committee formed to coordinate the study of ecosystem and human health risks associated with historical gold mine sites in Nova Scotia. Our study shows that (i) the mineralogy of As in weathered tailings is highly variable, with aggregates of more than one As-bearing phase common in a given sample, and (ii) major differences in As mineralogy in the tailings are mainly controlled by factors that influence the weathering history (e.g., presence or absence of mill concentrates, degree of water saturation, and abundance of relict carbonate minerals). The variable solubility of these primary and secondary As-bearing minerals influences both the environmental mobility and the bioaccessibility of As in near-surface tailings and soil samples.

  17. 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

  18. 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.

  19. 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.

  20. Alteration zone Mapping in the Meiduk and Sar Cheshmeh Porphyry Copper Mining Districts of Iran using Advanced Land Imager (ALI) Satellite Data

    NASA Astrophysics Data System (ADS)

    Beiranvand Pour, A.; Hashim, M.

    2015-10-01

    This study evaluates the capability of Earth Observing-1 (EO1) Advanced Land Imager (ALI) data for hydrothermal alteration mapping in the Meiduk and Sar Cheshmeh porphyry copper mining districts, SE Iran. Feature-oriented principal components selection, 4/2, 8/9, 5/4 band ratioing were applied to ALI data for enhancing the hydrothermally altered rocks associated with porphyry copper mineralization, lithological units and vegetation. Mixture-tuned matched-filtering (MTMF) was tested to discriminate the hydrothermal alteration areas of porphyry copper mineralization from surrounding environment using the shortwave infrared bands of ALI. Results indicate that the tested methods are able to yield spectral information for identifying vegetation, iron oxide/hydroxide and clay minerals, lithological units and the discrimination of hydrothermally altered rocks from unaltered rocks using ALI data.

  1. 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.

  2. Structural evolution of the Port Wells gold mining district, Prince William Sound, south central Alaska: Implications for the origin of the gold lodes

    NASA Astrophysics Data System (ADS)

    Stuwe, K.

    1986-10-01

    Data collected in the Port Wells gold mining district, Alaska, indicate several stages in the structural history of the district. The first stage was the accretion and associated deformation of the Valdez group flysch sequence at the end of the Cretaceous. The deformation of the semilithified rocks included two folding phases forming isoclinal NE-SW-striking and SE-vergent folds during a D1 phase, and minor open warps in NW-SE direction during a D2 phase. Intrusion of early Oligocene (36 Ma) calc-alkaline granitoids followed deformation and was terminated by the emplacement of aplitic dikes. The major fracturing processes in both the granitoids and the country rocks occurred subsequently, probably during the uplift of the Chugach mountains in the late Tertiary. Several generations of epigenetic gold-bearing quartz veins were emplaced along the fractures at a later stage. Due to the significant time gap between peak metamorphism and mineralization, the metamorphic secretion model proposed for the vein formation is reconsidered.

  3. 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.

  4. 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.

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

    USGS Publications Warehouse

    Schmitt, C.J.; Whyte, J.J.; Brumbaugh, W.G.; Tillitt, D.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

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

    PubMed

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

    2005-06-01

    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 delta-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 (Icralurus 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

  7. 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

  8. 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

  9. Occurrence and risk assessment of polycyclic aromatic hydrocarbons in soil from the Tiefa coal mine district, Liaoning, China.

    PubMed

    Liu, Jingjing; Liu, Guijian; Zhang, Jiamei; Yin, Hao; Wang, Ruwei

    2012-10-26

    In order to evaluate soil-associated polycyclic aromatic hydrocarbons (PAHs) pollution from coal mine activities in Tiefa coal mine, Northeast China, 16 PAHs identified as priority pollutants by US Environmental Pollution Agency were determined in mining zone soil (MZS), agricultural soil (AS), local lake bank soil (LBS), a vertical soil profile and three coal gangue samples. The total concentration of 16 PAHs (defined as Σ(16)PAH, dry weight) in surface soil ranged from 5.1 to 5642.3 ng g(-1), with an arithmetic mean of 1118.3 ng g(-1). Σ(16)PAH values at the sites from MZS are significantly higher than those found in AS and LBS. The vertical distribution of PAHs indicated that these compounds can penetrate the deeper layers of the soil, especially the low-rings compounds. A complex of petrogenic origin and pyrolytic sources was found within the study area, as suggested by the isomeric ratios of PAHs. According to principal component analysis (PCA), four factors were identified in the source contribution, including coal combustion, unburned coal particulates, coal gangue and vehicular emissions. The degree of contamination and the PAH toxicity assessment suggested that the soils of the study area have been seriously polluted and pose a high potential health risk. PMID:22914869

  10. Metal immobilization in hazardous contaminated minesoils after marble slurry waste application. A field assessment at the Tharsis mining district (Spain).

    PubMed

    Fernández-Caliani, J C; Barba-Brioso, C

    2010-09-15

    A one-year field trial was conducted at the abandoned mine site of Tharsis (Spain) in order to assess the potential value of waste sludge generated during the processing of marble stone, as an additive for assisting natural remediation of heavily contaminated acid mine soils. An amendment of 22 cmol(c) of lime per kilogram of soil was applied to raise the pH level from 3.2 to above 6. The amendment application was effective in reducing concentrations of Al, Fe, Mn, sulfate and potentially hazardous trace elements (mainly Cu, Pb, Zn and Cd) in the most labile metal pools (water-soluble and EDTA-extractable fractions). Geochemical equilibrium calculations indicate that sulfate complexes and free metal ions were the dominant aqueous species in the soil solution. Metal coprecipitation with nanocrystalline ferric oxyhydroxides may be the major chemical mechanism of amendment-induced immobilization. The alleviating effect of the soil amendment on the metal bioavailability and phytotoxicity showed promise for assisting natural revegetation of the mine land. PMID:20541314