961 resultados para Uranium mines and mining
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This layer is a georeferenced raster image of the historic paper map entitled: North Africa or Barbary : III Tunis and part of Tripoli, Society for the Diffusion of Useful Knowledge ; engraved by J. & C. Walker. This is map 3 of a 5 map set published by George Cox Jan. 1st, 1853. Scale [ca. 1:2,000,000]. Covers portions of Tunisia and Libya, and Malta. The image inside the map neatline is georeferenced to the surface of the earth and fit to a modified 'Europe Lambert Conformal Conic' projection with a central meridian of 12 degrees East. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, aqueducts, cities, villages and other human settlements, roads, trails, territorial boundaries, tribes, mines, and more. Relief shown by hachures. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection as part of the Open Collections Program at Harvard University project: Islamic Heritage Project. Maps selected for the project represent a range of regions, originators, ground condition dates, scales, and purposes. The Islamic Heritage Project consists of over 100,000 digitized pages from Harvard's collections of Islamic manuscripts and published materials. Supported by Prince Alwaleed Bin Talal and developed in association with the Prince Alwaleed Bin Talal Islamic Studies Program at Harvard University.
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We determined the sedimentary concentrations of phosphorus (P), barium (Ba), manganese (Mn), titanium (Ti), aluminum (Al), and uranium (U) for sediment samples from the southeast Pacific Nazca Ridge, Ocean Drilling Program Site 1237. This unique record extends to 31 Ma over 360 meters composite depth (mcd), recording depositional history as the site progressed eastward over its paleohistory. We sampled with a temporal resolution of ~0.2 m.y. throughout the sequence, equivalent to an average spacing of 1.63 m/sample. Concentrations of sequentially extracted components of P (oxide-associated, authigenic, organic, and detrital) increase toward the modern. Al/Ti ratios indicate that the background detrital source material is consistent with upper continental crust. U enrichment factors (U EFs) generally exceed crustal values and indicate slightly reducing environments. However, authigenic U precipitation can also be influenced by the organic carbon rain rate and may not be solely an indicator of redox conditions. Dramatic changes in Mn EFs at ~162 mcd, from values between 12 and 93 to values <12 after this depth, and a sharp color contact boundary lead us to believe that a paleoredox boundary from an oxygenated to a more reducing depositional environment occurred near this depth. Estimates of biogenic barite concentrations from a total sediment digestion technique (Ba excess) are greater than those from a barite extraction (Ba barite) for selected samples across the entire depth range. Applying a range of Ba/Ti ratios from different source materials to correct for detrital inputs does not change the lack of agreement with Ba barite concentrations. Reactive P (P reactive) concentrations (the sum of oxide-associated, authigenic, and organic P concentrations) increase toward the modern with values typically <12 µmol P/g from the base of our record through ~100 mcd, with a gradual increase to concentrations >15 µmol P/g. Ba excess follows the same general trends as Preactive, with concentrations <14 µmol Ba/g in the lower portion of the record to values >15 µmol Ba/g. Accumulation rate records of these proxies will be needed to infer paleoproductivity. P reactive/Ba excess ratios, an indicator of the relative burial of the nutrient P to organic carbon export, exhibit higher values, similar to modern, from the base of our record through ~180 mcd. The remainder of the record exhibits values lower than modern, indicating that organic carbon export to the sediments was higher relative to nutrient burial.
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"October 1982."
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Mode of access: Internet.
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Published in 1929 under title: Agricultural and mineral production in Japan.
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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First vol. (through 1950) compiled by M.R. Burks and J.H. Schilling; 1951-55 and 1956-60 by C.F. and J.H. Schilling: 1961-65 by T. Ray; 1966-70 by M.A. and H.H. Koehn; 1971-75 by J.R. Wright and J.A. Russell; 1976-80 by Dana M. Adkins-Heljeson and Candace L. Holts.
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a At head of title 453, 457-461, 463, 465- :U.S. Department of commerce ... Bureau of mines ...; 455, United States Department of commerce. Bureau of mines; 456, 462, 464, United States Department of commerce ... Bureau of mines ...
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Vita.
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Mode of access: Internet.
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Photocopy. Iowa City, Iowa, University of Iowa Libraries, 1980.
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Mode of access: Internet.