Scatterplot by Level Code 6. Analysis of Variance Source Sum of Squares Df Mean Square F-Ratio P-Value Between groups 55, 3 18, 78,09 0, Within groups 5, 24 0, Total Corr. Box-and-Whisker Plot. S1 Sucursal. Other P-values are based on general tables and may be very conservative.
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Sulfur isotope data measured on samples of galena from the main Mississippi Valley- type prospects of the eastern Beni Snassen belt preclude an igneous source for sulfur, pointing instead to a sedimentary source. Mixing of these two fluids resulted in the deposition of the Pb ore.
Application of apatite fission tract analysis to problems of Mississippi Valley- type Pb-Zn ore genesis. Epigenetic, carbonate-hosted Pb-Zn mineralization of the Mississippi Valley- Type MVT is considered to form from warm basinal brines in the temperature range deg. A variety of genetic fluid flow models have been proposed to explain MVT mineralization, but all suffer from a lack of constraint concerning the timing of ore formation. Fission tracks in apatite resulting from the spontaneous decay of trace amounts of U are thermally unstable over the range of temperatures proposed for MVT ore formation, and may therefore record thermal events related to Pb-Zn mineralization provided sufficient time is allowed for track annealing to occur.
Zinc mineralization in Devonian carbonates of the Lennard Shelf, northwest Australia is also considered to be of the Mississippi Valley- type. Mean apatite ages from Precambrian basement and from Devonian carbonates generally average Ma. No difference in apatite annealing effects are observed in the vicinity of zinc mineralization.
Coupled with other evidence, this suggests that the mineralizing episode was of short duration given temperatures of ore formation in the range deg. C indicated by fluid inclusion homogenization temperatures. Hercynian Pb-Zn mineralization types in the Alcudia Valley mining district Spain and their reflect in Pb isotopic signatures. More than ore deposits indexed within the Alcudia Valley of the Central-Iberian Zone Spain may be grouped by their tectonic and lithologic characteristics 1,2 as follows: type A of rare stratabound mineralizations, and types B, C, D and E represented by abundant Hercynian veins post-Namurian.
The origin of the more abundant E type ore bodies has been related to the Hercynian granitic rocks in the area 2, and references therein. Other plutons within this sector of the Central Iberian Zone e.
The isotopic data obtained thus point to a related or common source material for the various types of granites within the area studied. Yet, the Pb isotopic composition of other mineralizations B, C, D , likewise located in Hercynian veins, allow to consider different types of Pb-Zn ore bodies and point therefore to different sources of.
Electron probe microanalysis EPMA results are reported for newly identified silver-bearing minerals from the Xinhua deposit, Yunkaidashan area, South China. The Xinhua deposit is a hydrothermal vein- type Pb-Zn deposit and is hosted in the Pubei Complex, which consists of a cordierite-biotite granite with a U-Pb zircon age of The mineralization process is subdivided into four mineralization stages, characterized by the following mineral associations: mineralization stage I with quartz, pyrite, and sphalerite; mineralization stage II with siderite, galena, and tetrahedrite; mineralization stage III with quartz and galena; and mineralization stage IV with quartz, calcite, and baryte.
Tetrahedrite series minerals, such as freibergite, argentotetrahedrite, and tennantite are the main Ag-bearing minerals in the Xinhua deposit. The greatest concentration of silver occurs in phases from mineralization stage II.
Microscopic observations reveal close relationship between galena and tetrahedrite series minerals that mostly occur as irregular inclusions within galena. The negative correlation between Cu and Ag in the lattices of tetrahedrite series minerals suggests that Cu sites are occupied by Ag atoms. Zn substitution for Fe in argentotetrahedrite and Cd substitution for Pb in tetrahedrite are also observed.
Micro-thermometric data reveal that both homogenization temperatures and calculated salinities of hydrothermal fluids decrease progressively from the early to the later mineralization stages. Bouhlel, Salah; Leach, David L. The ores are unconformity and fault-controlled and occur as subvertical column-shaped bodies developed in dissolution-collapse breccias and in cavities within the Late Aptian platform carbonate rocks, which are covered unconformably by impermeable shales and marls of the Fahdene Formation Late Albian-Cenomanian age.
The host rock is hydrothermally altered to ankerite proximal to and within the ore bodies. Quartz, as fine-grained bipyramidal crystals, formed during hydrothermal alteration of the host rocks. The ore mineral assemblage is composed of barite, fluorite, sphalerite, and galena in decreasing abundance.
The ore zones outline distinct depositional events: sphalerite-galena, barite-ankerite, and fluorite. The salinity of the barite-hosted fluid inclusions is less than obtained simply by the. The ores are unconformity and fault-controlled and occur as subvertical column-shaped bodies developed in dissolution-collapse breccias and in cavities within the Late Aptian platform carbonate rocks, which are covered unconformably by impermeable shales and marls of the Fahdene Formation Late Albian—Cenomanian age.
The salinity of the barite-hosted fluid inclusions is less than obtained. The soils adjacent to an area of historical mining, ore processing and smelting activities reflects the historical background and a mixing of recent contamination sources. The main anthropogenic sources of metals can be connected with historical and recent mine wastes, direct atmospheric deposition from mining and smelting processes and dust particles originating from open tailings ponds.
Contaminated agriculture and forest soil samples with mining and smelting related pollutants were collected at different distances from the source of emission in the Pb-Zn -Ag mining area near Olkusz, Upper Silesia to a compare the chemical speciation of metals in agriculture and forest soils situated at the same distance from the point source of pollution paired sampling design , b to evaluate the relationship between the distance from the polluter and the retention of the metals in the soil, c to describe mineralogy transformation of anthropogenic soil particles in the soils, and d to assess the effect of deposited fly ash vs.
Forest soils are much more affected with smelting processes than agriculture soils. However, agriculture soils suffer from the downward metal migration more than the forest soils. The metal pollutants from smelting processes are less stable under slightly alkaline soil pH then acidic due to the metal carbonates precipitation.
Under relatively comparable pH conditions, the main soil properties influencing metal migration are total organic carbon and cation exchange. The change of tectonic regimes from extension to compression after eruption of basalts of the ELIP, and then to extension during Early Mesozoic, facilitated extraction, migration, and excretion of ore-forming metals and associated fluids. Mixing of fluids and reduction geochemical barrier activated TSR, causing cyclical carbonate dissolution, CO2 degassing and recrystallization namely carbonate buffer.
All these processes triggered continuous precipitation of huge amounts of hydrothermal minerals. Underplating and eruption of ELIP basalts provided heat flow, fluids and volatiles, whereas the basalts acted as an impermeable and protective layer, and even as ore-hosting rocks.
Cu, Ag, Ge, and Cd , and medium-low temperatures usually Yangtze metallogenic province representing to a new type of Pb-Zn deposits that are hosted in platform carbonate sequences and formed within compressional zones of passive margin tectonic settings.
Zn-Pb-Fe ores in the Ali ou Daoud deposit Central High Atlas are found as stratiform levels and as karst fillings in carbonate platforms facies of Bajocian age. Tectonic structures e. The dolomitic ore-related host-rock levels are characterized by the presence of kaolinite enrichment in clay levels in amounts directly related to the proportion of the clay minerals.
The latter is evidenced by correlation between kaolinite and sulphide contents, suggesting that the installation of kaolinite and mineralizations would result from the same hydrothermal fluid. Author 55 refs. Elevated inorganic phosphate Pi concentrations in pore water of amended tailings under direct revegetation may cause toxicity in some native woody species but not native forbs or herb species, all of which are key constituents in target native plant communities for phytostabilizing base metal mine tailings.
As a result, Pi sorption capacity has been quantified by a conventional batch procedure in three types of base metal mine tailings sampled from two copper Cu -lead Pb -zinc Zn mines, as the basis for Pi-fertiliser addition.
It was found that the Pi-sorption capacity in the tailings and local soil was extremely high, far higher than highly weathered agricultural soils in literature, but similar to those of volcanic ash soils. The Langmuir P-sorption maximum was up to 7. Physicochemical factors highly correlated with the high Pi-sorption in the tailings were fine particle distribution, oxalate and dithionite-citrate-bicarbonate extractable Fe FeO and Fed , oxalate-extractable Al and Mn, and the levels of soluble Cd and Zn, and total S and Fe.
Large amounts of amorphous Fe oxides and oxyhydroxides may have been formed from the oxidation of pyritic materials and redox cycles of Fe-minerals such as pyrite FeS2 , ankerite Ca Fe Mg CO3 2 and siderite FeCO3 , as indicated by the extractable FeO values.
As a result, the possibility of P-toxicity in native plant species caused by the addition of soluble phosphate fertilizers would be minimal. Directory of Open Access Journals Sweden. Full Text Available Elevated inorganic phosphate Pi concentrations in pore water of amended tailings under direct revegetation may cause toxicity in some native woody species but not native forbs or herb species, all of which are key constituents in target native plant communities for phytostabilizing base metal mine tailings.
As a result, Pi sorption capacity has been quantified by a conventional batch procedure in three types of base metal mine tailings sampled from two copper Cu-lead Pb-zinc Zn mines, as the basis for Pi-fertiliser addition. Physicochemical factors highly correlated with the high Pi-sorption in the tailings were fine particle distribution, oxalate and dithionite-citrate-bicarbonate extractable Fe FeO and Fed, oxalate-extractable Al and Mn, and the levels of soluble Cd and Zn, and total S and Fe.
Large amounts of amorphous Fe oxides and oxyhydroxides may have been formed from the oxidation of pyritic materials and redox cycles of Fe-minerals such as pyrite FeS2, ankerite Ca Fe Mg CO32 and siderite FeCO3, as indicated by the extractable FeO values.
The Bianjiadayuan Ag- Pb-Zn deposit 4. A subsequent supergene oxidation stage has also been identified. Hydrothermal alteration consists of an early episode of silicification, two intermediate episodes propylitic and phyllic , and a late argillic episode. Silver mineralization primarily belongs to the late paragenetic sequence III. Freibergite is the dominant and most important Ag-mineral in the deposit.
Detailed ore mineralogy of Bianjiadayuan freibergite reveals evidence of chemical heterogeneity down to the microscale. Silver-rich sulfosalts in the late paragenetic sequence III are largely derived from a series of retrograde and solid-state reactions that redistribute Ag via decomposition and exsolution during cooling, illustrating that documentation of post-mineralization processes is essential for understanding silver ore formation.
Sulfur and lead isotope compositions of sulfides, and comparison with those of local various geological units, indicate that the ore-forming fluids, lead, and other metals have a magmatic origin, suggesting a close genetic association between the studied Ag- Pb-Zn veins and the local granitic intrusion.
Fluid cooling coupled with decreases in fO2 and fS2 are the factors inferred to have led to a decrease of silver solubility in the hydrothermal fluid, and successively promoted extensive Ag deposition. This paper studies the petrology and geochemistry of hydrothermal alterations associated with the vein- type Cu- Pb-Zn mineralization hosted by this pluton, focusing on the determination of the mass gains and losses of chemical components, which reflect the chemical exchanges between the host rocks and hydrothermal fluids.
Paragenetic relationships reveal three stages of mineralization: pre-ore, ore, and supergene. The ore mineralogy typically includes hypogene chalcopyrite, sphalerite, galena, and pyrite, with locally supergene covellite, malachite, and azurite. Wall-rock hypogene hydrothermal alterations include pervasive silicification, sulfidation, sericitization, and selective carbonatization and albitization. Metal speciation in agricultural soils adjacent to the Irankuh Pb-Zn mining area, central Iran.
Mining activities are a significant potential source of metal contamination of soils in surrounding areas, with particular concern for metals dispersed into agricultural area in forms that are bioavailable and which may affect human health. Soils in agricultural land adjacent to Pb-Zn mining operations in the southern part of the Irankuh Mountains contain elevated concentrations for a range of metals associated with the mineralization including Pb , Zn and As.
Total and partial geochemical extraction data from a suite of soil samples is used to establish mineralogical controls on ore-related trace elements and help differentiate spatial patterns that can be related to the effects of mining on the agricultural land soils from general geological and environmental controls. Mass change calculations of hydrothermal alterations within the volcanogenic metasediments hosted Cu- Pb - Zn mineralization at Halilar area, NW Turkey. The Halilar Cu- Pb - Zn mineralization that is formed in the volcanogenic metasediments of Bagcagiz Formation at Balikesir province, NW Turkey, represents locally vein- type deposit as well as restricted to fault gouge zone directed NE-SW along with the lower boundary of Bagcagiz Formation and Duztarla granitic intrusion in the study area.
Furthermore, This granite is traversed by numerous mineralized sheeted vein systems, which locally transgress into the surrounding metasediments. Therefore, this mineralization closely associated with intense hydrothermal alteration within brecciation, and quartz stockwork veining. The ore mineral assemblage includes chalcopyrite, galena, and some sphalerite with covellite and goethite formed during three phases of mineralization pre-ore, main ore, and supergene within an abundant gangue of quartz and calcite.
It revealed that the phyllic alteration has enrichments of Si, Fe, K, Ba, and LOI with depletion of Mg, Ca, and Na reflect sericitization of alkali feldspar and destruction of ferromagnesian minerals. This zone has high Cu and Pb with Zn contents represents the main mineralized zone. On the other hand, the propylitic zone is characterized by addition of Ca, Na, K, Ti, P, and Ba with LOI and Cu lower content referring to the replacement of plagioclase and ferromagnesian minerals by albite, calcite, epidote, and sericite.
Thermal analysis and prediction of phase equilibria in ternary Pb-Zn -Ag system. Full Text Available Ternary Pb-Zn -Ag system is typical for some physicochemical processes going on in refining phase in the extractive metallurgy of lead. Therefore, investigation of mentioned system is important from both theoretical and practical research of the phenomena occurring during the lead desilverizing process.
The results of experimental investigation using differential thermal analysis DTA and thermodynamic calculation of phase equilibria in Pb-Zn -Ag system according to CALPHAD method, in the sections with Zn:Ag mass ratio equal to , and , are presented in this paper. Comparative of Quercus spp. Seedlings of three Quercus spp. The root systems showed marked differences between the Quercus spp. The maximum efficiency of photosystem II photochemistry value of the five species showed no differences among the treatments, except for Q.
All species showed low metal translocation factors TFs. However, S.
Resultados Taller Anova Banco
Resultados Taller Anova Banco
Diario de la marina ( 06-12-1951 )