864 resultados para Mining geology


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"Bibliography of selected references": p. 607-609.

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Literature: p. xxxii.

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Includes bibliographical references (p. 456-482) and index.

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Section titles vary slightly.

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Mode of access: Internet.

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Mode of access: Internet.

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Deep sea manganese nodules from the Central Pacific Basin are mainly composed of 10Å manganite and d-MnO2 Two zones equivalent to the minerals are evidently distinguishable according to their optical properties. Microscopic and microprobe analyses revealed quite different chemical compositions and textnral characteristics of the two zones. These different feature of the two zones of nodules suggest the different conditions under which they were formed. Concentrations of 11 metal elements in the zones and inter-element relationships show that the 10Å manganite zone is a monomineralic oxide phase containing a large amount of manganese and minor amounts of useful metals, and that the d-MnO2 zone which is apparently homogeneous under the microscope is a mixture of three or more different minerals. The chemical characteristics of the two zones can explain the variation of bulk composition of deep sea manganese nodules and inter-element relationships previously reported, suggesting that the bulk compositions are attributable to the mixing of the 10Å manganite and d-MnO2 zones in various ratios. Characteristic morphology and surface structure of some types of nodules and their relationships to chemistry are also attribut able to the textural and chemical features of the above mentioned two phases. Synthesis of hydrated manganese oxides was carried out in terms of the formation of manganese minerals in the ocean. The primary product which is an equivalent to d-MnO2 was precipitated from Mn 2+ -bearing alkaline solution under oxigenated condition by air bubbling at one atmospheric pressure and room temperature. The primary product was converted to a l0Å manganite equivalent by contact with Ni 2+, Cu 2++ or CO2+ chloride solutions. This reaction caused the decrease of Ni2+, Cu2+ or CO2+ concentrations and the increase of Na+ concentration in the solution. The reaction also proceeded even in diluted solutions of nickel chloride and resulted in a complete removal of Ni2+ from the solution. Reaction products were exclusively 10Å manganite equivalents and their chemical compositions were very similar to those of 10Å manganite in manganese nodules. The maximum value of(Cu+Ni+Co)/Mn ratio of 10Å manganite zones in manganese nodules is 0.16, and the Ni/Mn ratio of synthetic 10Å manganite ranges from 0.15 to 0.18 with the average of 0.167.

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Petrological, mineralogical and chemical investigations of marine manganese nodules from the West Pacific revealed the intimate relation between the chemical and mineral compositions and the remarkable preferential partitioning of metal elements in the ferromanganese minerals. The microscopic observations of textures of manganese nodules tell the growth history of manganese nodules and the formation conditions of ferromanganese minerals. Chemical compositions of nodules from Komahashi-Daini Seamount are very similar to those of the nodules from marginal banks and seamounts. Compositional variations in the bulk composition of nodules collected from the same dredge haul are considerably small, suggesting the similarity of the growth history of individual nodules, although the contents of metal elements vary remarkably from layer to layer in a single nodule.

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The Cardwell Mining District is part of the greater Whitehall Mining District. The district is situated about four miles to the east and northeast of Whitehall in the southern end of the Bull Mountains which are near the Continental Divide. The first reported production was in 1896 after the dis­covery of the Mayflower Mine. Mining has been carried on in­termittently and on a small scale since that time.

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This report includes the results of geological investigation of a small area in the northern part of the Argenta mining district. Approximately two square miles were mapped. The underground working of the three mines only were accessible: the Goldfinch. Golden Era, and Mayday mines.

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From 1888 until 1893 the district was a booming mining camp. Seven stamp mills were running and ore was be­ing mined from the Independence, King Solomon, Poorman, Golden, Hidden Treasure and Crown claims. The town of Independence, which was on the Boulder River at the fork of Basin Creek, boasted a population of 400 people.