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Showing 1 to 20 of 86 for “"Breccia"”.
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Apophyllite weathering and the aqueous geochemistry of a Karoo breccia pipe
… phase occupying fractures in a dolerite breccia pipe on the farm Kopoasfontein, outside Calvinia in the western Karoo, South Africa. Groundwater abstracted from this breccia is uncharacteristically alkaline (pH 10) and high in fluoride (11 mg/L) for a natural water and the link between …
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Geochemistry of artificial groundwater recharge into the Kopoasfontein breccia pipe near Calvinia, Karoo
… would be injected into the Kopoasfontein breccia pipe, a roughly cylindrical body of fractured rock, 12 km east of the town. Subsurface water storage would then mjnjmjse evaporative losses, so that the injected water could be recovered when emergency water supplies are needed. Underground …
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A low - δ 18 O intrusive breccia from the Koegel Fontein complex, South Africa
… the lowest δ 18 O values belong to an intrusive breccia and have a fine - grained, black matrix. The silica content of these breccia rocks ranges between 44 - 68 wt %, their whole - rock δ 18 O values vary between - 5.2 ‰ and +1.8 ‰ , and their water content is between 0.2 - 1.1 wt %. The major …
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Geology of the Alice E. breccia pipe and vicinity, New World mining district, Park County, Montana
The Alice E. breccia pipe occurs in a one square mile area of the New World mining district, Park County, Montana. Porphyry gold type mineralization-alteration is exposed at many prospects within the study area. Rocks exposed in the vicinity of the breccia pipe consist of Precambrian …
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The geology and genesis of iron oxide-copper-gold mineralisation associated with Wernecke Breccia, Yukon, Canada
The large scale Wernecke Breccia system occurs throughout the 13 km-thick Early Proterozoic Wernecke Supergroup (WSG) and is spatially associated with regional-scale faults. Breccia emplacement made use of pre-existing crustal weaknesses and permeable zones; metaevaporitic rocks in the lower WSG …
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Laser induced breakdown spectroscopy of martian breccia Northwest Africa 7034: comparison with Mars Science Laboratory results
… of 1.56-7 meters. At the same time, martian breccia meteorite Northwest Africa (NWA) 7034 was analyzed with the ChemCam engineering model laboratory LIBS instrument at Los Alamos National Laboratory (LANL) at a 1.6 m standoff distance under 7 Torr CO2. Each LIBS location was pulsed with 150 …
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Petrographic Analysis of an Early Cenozoic Breccia from the Tinton Area, Northern Black Hills, South Dakota
<p>The Tinton area breccia crops out in two areas in the northern Black Hills just northwest of Tinton, South Dakota, in an area of Precambrian metamorphic rocks, pegmatites, and Tertiary intrusives. The outcrops are fairly circular, the smaller measuring 150 meters and the larger measuring 400 …
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Petrography and Field Mapping of Eocene Intrusions and Adjacent Breccia Zones at the Scraper Springs Prospect, Elko County, Nevada
… adjacent silicified/advanced argillic lithocap breccias. Petrography and sodium-cobaltinitrite staining supplement field observations to aid in understanding alteration events. Geochemical data from topaz-rich samples are considered to help classify the hydrothermal system present at Scraper in …
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Lithofacies and Microfacies of a Fossil Hot Spring System: McGinness Hills, Nevada
… system in which hydrothermal, eruption breccia is exposed on top of the sinter mound. Based on lithology, macro-features and micro-features the sinter at McGinness Hills was divided into seven microfacies, hydrothermal breccia, massive chalcedonic sinter, flat-laminated sinter, …
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Lithofacies and Microfacies of a Fossil Hot Spring System: McGinness Hills, Nevada
… system in which hydrothermal, eruption breccia is exposed on top of the sinter mound. Based on lithology, macro-features and micro-features the sinter at McGinness Hills was divided into seven microfacies, hydrothermal breccia, massive chalcedonic sinter, flat-laminated sinter, …
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Modeling the diffusion of reactive and nonreactive solutes in cores from the Cannikin Test Site, Amchitka Island, Alaska
… and nonreactive solutes through basalt and breccia cores from the Cannikin Test Site, Amchitka Island, Alaska has been studied. Lead (Pb(II)) and cesium (Cs(I)) were chosen as reactive solutes and bromide (Br-) was chosen as the nonreactive solute. Because retardation due to sorption is …
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A study of the kimberlites, diamonds and associated rocks and minerals from the monastery mine, South Africa. Volume 1: Text
… but is poorly exposed and highly weathered. The breccia kimberlite hosts abundant country rock fragments in a soft serpentinous matrix. It is an opaque oxide-rich phlogopite serpentine kimberlite breccia. The precursor kimberlite dyke associated with the diatreme is an opaque oxide-rich calcite …
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Petrology, geochemistry, stable and radiogenetic isotopy of the Guelb Moghrein iron oxide copper gold cobalt deposit, Mauritania
… the metacarbonate body. The ore bodies occur in breccia zones developed in the metacarbonate and form multiple, up to 30 m wide, tabular, foliation (S2) parallel lenses that dip moderately SW. The breccia zones have a characteristic geometry of central, ductile Fe-Mg clinoamphibole-chlorite …
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Geology, paragenesis, and geochemistry of sphalerite mineralization at the Young mine, Mascot-Jefferson City zinc district, East Tennessee
… Sphalerite mineralization which occurs as a breccia infilling in the Lower Ordovician Knox Group carbonates has been studied in detail at the Young Mine, located in the central portion of the district. The sphalerite occurs as fracture fillings and as rosettes between carbonate breccia blocks …
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Heterotrophic Microbial Colonization of the Interior of Shocked Rocks from the Haughton Impact Structure, Devon Island, Nunavut, Canadian High Arctic
… in the interior of impact-shocked gneiss and breccia samples from Haughton Impact structure on Devon Island, Nunavut, in the Canadian High Arctic. The high-latitude and arid, polar climate at Haughton preclude significant populations of higher-order organisms, naturally restricting the impact …
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Geology of igneous extrusive and intrusive rocks in the Sundance area, Crook County, Wyoming
… Quartz latite occurs as subparallel units of breccia, tuff, and massive flows without any clear cross-cutting relationships. Fragmental types (breccia and cuff) constitute 41 to 76 percent of the rocks, suggesting that Sundance Mountain is a mixed cone. The quartz latite has a pre dominantly …
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The Middle Ordovician Knox unconformity, Virginia Appalachians: transition from passive to convergent margin
… filled with detritus from the unconformity and breccia from host carbonates, and sub-unconformity dolomite breccia bodies that formed by collapse after dissolution of limestone interbeds. Coarse detritus on the unconformity surface formed thin to thick veneers of regolith; locally this material …
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Geology of the Northern Alto Relex Area, Big Bend National Park, Brewster County, Texas
… Distinctive ii reddish-brown knobs of fault breccia on the west side of Alto Relex appear to have been silicified or hydrothermally altered. This breccia probably marks the location of a large basin-bounding normal fault. Both map-scale and outcrop scale folding is present. One map-scale …
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Petrology of the Cenozoic igneous rocks of the Tinton district, Black Hills, South Dakota - Wyoming
… dike complex, lamprophyre dikes and intrusive breccia.</p> <p>Precambrian rocks are represented by a sequence of metapelites thst have been intruded by metabasite and granitic pegmatite dikes. The schistosity of the metapelites strikes NNW with a consistent westerly dip of 28° to 90°. The …
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