MARC全文
02h0025413 20110921133221.0 cr un||||||||| 110921s2002 xx ||||f|||d||||||||eng | AAI3082330 CNY371.35 NGL NGL NGL a875 Montero Sanchez, Irene Carlina. Assessment of the environmental impact of abandoned mines through identification of acid minerals (California) [electronic resource] / Irene Carlina Montero Sanchez. 2002. 95 p. : digital, PDF file. Source: Dissertation Abstracts International, Volume: 64-02, Section: B, page: 0590. ; Chair: George H. Brimhall. Thesis (Ph.D.) -- University of California, Berkeley, 2002. Mapping of the surface distribution of secondary iron minerals created during by the biogenic oxidation of pyrite in abandoned mine waste rock piles can serve to detect sources and sinks of acid mine drainage (AMD), investigate the evolution of AMD fluids, and screen for abandoned mines that are in severe need of remediation. Maps of minerals such as copiapite, coquimbite, jarosite, schwertmannite, goethite, ferrihydrite, and hematite that form at specific pH and sulfate levels reflect the creation and evolution of AMD and serve as a proxy to identify sources and sink of contaminants. The detection of very-low pH hydrated sulfate salt minerals such as copiapite that accumulate from evaporating AMD fluids during the dry California summer is critical for the evaluation of AMD because the rapid dissolution of hydrated sulfate salts during the first storms of the winter season can quickly release highly toxic fluids to surface water bodies.;Multi-platform hyperspectral reflectance VIS/SWIR data in the wavelength range from 0.35μm to 2.5μm was applied to the study of three small abandoned copper mines (Newton, Spenceville, and Dairy Farm mines) in the volcanogenic massive sulfide Cu-Zn belt of the Foothills of the Sierra Nevada, California. Hyperspectral data ranged from high-altitude airborne imaging reflectance spectroscopy (AVIRIS) to very low altitude helicopter-borne and ground-based reflectance spectroscopy integrated into digital mapping systems. The application of hyperspectral VIS/SWIR data to create maps of secondary iron minerals relies on the characterization of absorption features observed in reflectance spectra from 0.4μm to 1.3μm that are caused by electronic transitions of Fe 3+. The program FSTSpecID, created for this application, analyzes and compares subtle differences in spectral shape to a detailed library of reference spectra. The output from FSTSpecID is automatically integrated into a digital mapping system supported by DGPS and Laser range finder to create real-time maps of secondary iron minerals that can be analyzed and refined in the field. Detailed ground-based and very low-altitude hyperspectral mapping methods that integrate existing digital mapping tools and FSTSpecID are proposed as an effective way to accomplish initial screening of abandoned metal mines for the release of AMD. This emerging technology was applied in Spenceville and Dairy Farm Mines and resulted in detailed surface maps that clarified the effect of hydrated sulfate salts on streams adjacent to these mines.;Characterization of the Newton Mine applied a high-altitude 1997 AVIRIS image to map the regional distribution of abandoned mines and the local distribution of secondary iron minerals in inaccessible parts of the mine. Detailed hydrogeochemical studies of Copper Creek, a small intermittent stream that drains Newton Mine, built on results from analysis of the AVIRIS image to determine that dissolution of hydrated iron sulfate salts is the main and most severe source of contamination to Copper Creek. The yearly hydrated sulfate salt formation and release cycle was documented in dissolved metal, sulfate, and pH analysis of Copper Creek. Abandoned mines Environmental aspects California. Electronic books. aeBook. aCN bNGL http://proquest.calis.edu.cn/umi/detail_usmark.jsp?searchword=pub_number%3DAAI3082330&singlesearch=no&channelid=%CF%B8%C0%C0&record=1 NGL Bs945 rCNY371.35 ; h1 bs1107
