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Academic literature on the topic 'Sedimentasry manganese'

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Published: 10 December 2022
Last updated: 29 January 2023

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Journal articles on the topic "Sedimentasry manganese"

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Romer, Rolf L., and Uwe Kroner. "Reply to the discussion by J.W.F. Waldron and C.E. White on “Geochemical signature of Ordovician Mn-rich sedimentary rocks on the Avalonian shelf”1Appears in Canadian Journal of Earth Sciences, 2012, 49(6): 772–774 [doi: 10.1139/e2012-004]." Canadian Journal of Earth Sciences 49, no. 6 (June 2012): 775–80. http://dx.doi.org/10.1139/e2012-006.

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In their comment, Waldron and White state that manganese-rich sedimentary rocks of Nova Scotia and Wales are Cambrian and were deposited in a deep-water turbidite basin called “Megumia” rather than on the Avalonian shelf. Available geochronological data are not in conflict with an Early Ordovician deposition age for manganese-rich sedimentary rocks north of the Rheic suture, including those of Nova Scotia and northern Wales. “Megumia” is part of the Avalonian plate, and the manganese-rich sediments were deposited on its shelf.
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Bar-Matthews, Miryam. "The genesis of uranium in manganese and phosphorite assemblages, Timna Basin, Israel." Geological Magazine 124, no. 3 (May 1987): 211–29. http://dx.doi.org/10.1017/s0016756800016253.

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AbstractUranium enrichments (up to 4000 ppm) occur in the manganese and phosphorite assemblages of the Lower Cambrian clastic marine sedimentary sequence, Timna Basin, Israel. Two types of mineralization assemblages can be defined. Sedimentary stratabound assemblages consist of uranium-enriched stratiform manganese and phosphatic laminae, diagenetic (type A) manganese nodules composed of pyrolusite and hollandite laminae and phosphorite lenses. Fission-track maps show that the uranium is homogeneously distributed within host manganese and phosphatic minerals of these assemblages. Epigenetic assemblages are mainly composed of manganese- and phosphorite-bearing veins and secondary (type B) manganese nodules with a coronadite dominant mineralogy. Uranium is depleted in these assemblages, relative to the sedimentary stratabound assemblages.The distribution of manganese and phosphorite assemblages has a marked bimodal character. Alternation between manganese and phosphatic laminae in the stratiform deposits reflects cycles of oxidizing and reducing conditions brought about by mixing and stratification of the waters in the Timna semi-closed depositional basins. Compaction of wet sediments led to remobilization and the formation of uranium-enriched manganese nodules at the aerated sediment–water interface, and uranium-enriched phosphorite lenses below the interface in reducing conditions. Epigenesis occurred through the passage of solution fronts which recrystallized the manganese and phosphatic minerals and remobilized metallic elements, particularly uranium which was leached away and is still being remobilized today.The mechanism of uranium uptake in manganese phases is shown most probably to involve adsorbtion of [(UO2)3. (OH)5]+ complexes on precipitating minerals. Uranium is enriched in both the pyrolusite and hollandite laminae of type A nodules, but is particularly concentrated in the former (4000–10000 ppm). Thermodynamic calculations of the relative stabilities of pyrolusite and hollandite suggest that the pH conditions of hollandite formation were close enough to the pH limit of efficient uranium adsorption to inhibit its uptake relative to pyrolusite.
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Costa, Marcondes, Oscar Fernandez, Marlis Requelme, Luiz Cláudio Costa, and Carlos Delgado. "SEDIMENTARY MANGANESE DEPOSITS IN CARAJÁS, BRAZIL." Boletim do Museu de Geociências da Amazônia 9, no. 2 (December 31, 2022): 1–38. http://dx.doi.org/10.31419/issn.2594-942x.v92022i2a3mlc.

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The Carajás Mineral Province in Brazil is actually one of the most important in the world because it contains world-class mineral deposits (Fe, Cu, Au, Ni and Mn), partly enriched by lateritic weathering (Fe, Mn, Ni). It carries at least four manganese ore deposits: Azul, Buritirama, Sereno-Conquista and Buriti, of these Azul and Buritirama are productive mines. The Azul deposit is the earliest known and was initially considered as typically lateritic. Further studies show that much of the reserves are classically associated with carbonaceous gray to black mineralized shales and enriched in manganese oxyhydroxides, where cryptomelane is the major ore mineral, enveloped by thick packets of red siltstones and sandstones of lower age Proterozoic (around 2.1 Ga). The mineralogical composition of rocks and ore, isotopic data, abundance of carbonaceous organic matter and the presence of stromatolite structures show deposition in a shallow platform, where the source of manganese and associated metals were mainly of ocean hydrothermal origin, while the sediments of the rocks would have a main continental source from Archean rocks. Rhodochrosite is restricted and diagenetic, likely pyrite. Tectonic deformations reached the whole package and provided environment and structures for remobilization and reprecipitation of Mn-oxyhydroxides of high content and crystallinity. These two types of ores were the source of lateritic ore and colluvionary, already practically depleted
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Wang, Wenming, Zongze Shao, Yanjun Liu, and Gejiao Wang. "Removal of multi-heavy metals using biogenic manganese oxides generated by a deep-sea sedimentary bacterium – Brachybacterium sp. strain Mn32." Microbiology 155, no. 6 (June 1, 2009): 1989–96. http://dx.doi.org/10.1099/mic.0.024141-0.

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A deep-sea manganese-oxidizing bacterium, Brachybacterium sp. strain Mn32, showed high Mn(II) resistance (MIC 55 mM) and Mn(II)-oxidizing/removing abilities. Strain Mn32 removed Mn(II) by two pathways: (1) oxidizing soluble Mn(II) to insoluble biogenic Mn oxides – birnessite (δ-MnO2 group) and manganite (γ-MnOOH); (2) the biogenic Mn oxides further adsorb more Mn(II) from the culture. The generated biogenic Mn oxides surround the cell surfaces of strain Mn32 and provide a high capacity to adsorb Zn(II) and Ni(II). Mn(II) oxidation by strain Mn32 was inhibited by both sodium azide and o-phenanthroline, suggesting the involvement of a metalloenzyme which was induced by Mn(II). X-ray diffraction analysis showed that the crystal structures of the biogenic Mn oxides were different from those of commercial pyrolusite (β-MnO2 group) and fresh chemically synthesized vernadite (δ-MnO2 group). The biogenic Mn oxides generated by strain Mn32 showed two to three times higher Zn(II) and Ni(II) adsorption abilities than commercial and fresh synthetic MnO2. The crystal structure and the biogenic MnO2 types may be important factors for the high heavy metal adsorption ability of strain Mn32. This study provides potential applications of a new marine Mn(II)-oxidizing bacterium in heavy metal bioremediation and increases our basic knowledge of microbial manganese oxidation mechanisms.
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Gao, Lingfeng, Shan Xu, Xiangyun Hu, Shuang Liu, Qi Zhou, and Bingnan Yang. "Sedimentary Setting and Ore-Forming Model in the Songtao Manganese Deposit, Southwestern China: Evidence from Audio-Frequency Magnetotelluric and Gravity Data." Minerals 11, no. 11 (November 17, 2021): 1273. http://dx.doi.org/10.3390/min11111273.

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The break-up of the supercontinent Rodinia in the late Neoproterozoic led to the formation of the Nanhua rift basin within the South China Block. The Datangpo-type manganese deposit, which developed in the Nanhua rift basin, is one of the most important types of manganese deposits in South China. Although it is widely accepted that deep sedimentary structures significantly affect the manganese ore system, the relationship between the manganese deposits in South China and the Nanhua rifting process is still unclear. The origin of the manganese ore layer remains controversial. In this paper, we integrated the audio-frequency magnetotelluric (AMT) data, gravity data, and comprehensive geological and borehole data analysis to characterize the structure of the Datangpo-type manganese deposit in Songtao, Guizhou Province. The resistivity and density models produced an inclined layered structure, which correlated well with the coeval sediment strata of the Nanhua rift basin. A high-resistivity cap was observed from the surface to a depth of 800 m, corresponding to the Cambrian Loushanguan (ϵ3−4ls) and Palang dolomite formation (ϵ2p), which has helped the storage of the manganese ore. The most significant low-resistivity anomaly (25–40 Ω·m) resides at a depth of 1400 m in the Nantuo (Nh3n) gravel sandstone and Datangpo (Nh2d) silty and carbonaceous shale, corresponding to the ore-forming layer. This distinct low-resistivity layer was possibly produced by aqueous fluids and pyrite in the syn-sedimentary fault and alteration zone. The accumulations of sulfide minerals in the rock samples suggest a possible anoxic-euxinic deposition environment during the manganese mineralization and precipitation. The fault revealed in the resistivity models is perhaps a previous fault zone produced by extension in the Nanhua rifting process, which provided migration and upwelling channels for ore-forming minerals. Based on our resistivity models, density models, and geological survey, the manganese ore-forming model was derived, which can help to provide geophysical evidence for the origin of the Datangpo-type manganese deposit.
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Pattan, J. N. "Manganese micronodules: A possible indicator of sedimentary environments." Marine Geology 113, no. 3-4 (August 1993): 331–44. http://dx.doi.org/10.1016/0025-3227(93)90026-r.

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Johnson, Jena E., Samuel M. Webb, Chi Ma, and Woodward W. Fischer. "Manganese mineralogy and diagenesis in the sedimentary rock record." Geochimica et Cosmochimica Acta 173 (January 2016): 210–31. http://dx.doi.org/10.1016/j.gca.2015.10.027.

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Michel, Magdalena. "A study of application of chalcedonite as a manganese dioxide carrier." Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation 44, no. 1 (January 1, 2012): 63–73. http://dx.doi.org/10.2478/v10060-011-0063-z.

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A study of application of chalcedonite as a manganese dioxide carrier Chalcedonite is a sedimentary siliceous rock, which occurs at four deposits in Poland and is included into a group of unique rocks. Chalcedonite is utilized in water treatment technology, mostly as an effective filtration material due to its mesoporous structure and extended outer surface of the grains. This paper presents three different methods of impregnation of the mineral material (MDMC-1, MDMC-2, MDMC-3) by manganese dioxide. As an oxide carrier chalcedonite was used. The results of the chalcedonite surface modification with SEM-EDS technique were presented. It was found that the chalcedonite is a very good manganese dioxide carrier and the modification of the chalcedonite surface changes its chemical composition, structure and value of the specific surface area.
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Xu, Zhiming, Chengquan Wu, Zhengwei Zhang, Jinhong Xu, Xiyao Li, and Ziru Jin. "Separation of Fe from Mn in the Cryogenian Sedimentary Mn Deposit, South China: Insights from Ore Mineral Chemistry and S Isotopes from the Dawu Deposit." Minerals 11, no. 5 (April 23, 2021): 446. http://dx.doi.org/10.3390/min11050446.

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Manganese and Fe have similar geochemical properties in the supergene environment. Separation of Mn and Fe is an important process for the formation of high-grade sedimentary manganese deposits. Large-scale manganese carbonate deposits (total reserves of approximately 700 Mt) were formed during the interglacial of the Sturtian and Marinoan in South China. The orebodies are hosted in the black rock series at the basal Datangpo Formation of the Cryogenian period. The Fe contents in ores range from 1.15 to 7.18 wt.%, with an average of 2.80 wt.%, and the average Mn/Fe ratio is 8.9, indicating a complete separation of Mn and Fe during the formation of manganese ores. Here, we present element data of manganese carbonates and sulfur isotopes of pyrite from the Dawu deposit, Guizhou, China, aiming to investigate the separation mechanism of Mn and Fe and the ore genesis. The Fe in ores mainly occurs as carbonate (FeCO3) and pyrite (FeS2). The Mn, Ca, Mg and Fe exist in the form of isomorphic substitutions in manganese carbonate. The contents of FeCO3 in manganese carbonates are similar in different deposits, with averages of 2.6–2.8 wt.%. The whole-rock Fe and S contents have an obvious positive correlation (R = 0.69), indicating that the difference of whole-rock Fe content mainly comes from the pyrite content. The δ34SV-CDT of pyrite varies from 40.0 to 48.3‰, indicating that the pyrite formed in a restricted basin where sulfate supply was insufficient and the sulfate concentrations were extremely low. Additionally, the whole-rock Fe content is negatively correlated with the δ34S values of the whole-rock and pyrite, with correlation coefficients of −0.78 and −0.83, respectively. Two stages of separations of Mn and Fe might have occurred during the mineralization processes. The reduced seawater became oxidized gradually after the Sturtian glaciation, and Fe2+ was oxidized and precipitated before Mn2+, which resulted in the first-stage separation of Mn and Fe. The residual Mn-rich and Fe-poor seawater flowed into the restricted rift basin. Mn and Fe were then precipitated in sediments as oxyhydroxide as the seawater was oxidized. At the early stage of diagenesis, organic matter was oxidized, and manganese oxyhydroxide was reduced, forming the manganese carbonate. H2S was insufficient in the restricted basin due to the extremely low sulfate concentration. The Fe2+ was re-released due to the lack of H2S, resulting in the second-stage separation of Mn and Fe. Finally, the manganese carbonate deposit with low Fe and very high δ34S was formed in the restricted basin after the Sturtian glaciation.
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Ostwald, J., and Barrie R. Bolton. "Glauconite formation as a factor in sedimentary manganese deposit genesis." Economic Geology 87, no. 5 (August 1, 1992): 1336–44. http://dx.doi.org/10.2113/gsecongeo.87.5.1336.

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Dissertations / Theses on the topic "Sedimentasry manganese"

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Jacinto, G. S. "Sedimentary geochemistry of cooper and manganese and marine chemistry of platinum." Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384386.

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Terracin, Matthew Theodore. "Petrography, geochemistry and origin of atypical sedimentary-igneous contact relationships at the base of the Hotazel Formation around Middelplaats, Northern Cape Province, RSA." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1012985.

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In the Middelplaats mine area of the Kalahari manganese field, two drill holes (MP53 and MP54) intersected anomalously high-grade manganese ore sitting stratigraphically just above an igneous body (likely a dike or sill). Manganese ore located within approximate 5 meters of the contact with the underlying igneous rocks has been substantially metasomatically upgraded from 25 percent manganese, to over 40 percent whilst the dominant manganese species within the ore has been altered to hausmannite. This report demonstrates the metasomatic alteration is related to devolatilization (removal and/or remobilization of H₂O, CO₂ and CaO) due to contact metamorphism caused by the underlying igneous rocks. The Middelplaats mine is situated in the southwest corner of the Kalahari manganese field where the paleo basin shallows out and ends. Within the mine area, several stratigraphic units pinch out or are truncated by the side of the basin. This pinching out of lithological formations has led to the underlying Ongeluk Formation being in contact with the much younger units of the Hotazel Formation. Therefore, geochemical investigation into the nature and source of the igneous rocks was also undertaken to see if the rocks from the two drill holes were related to one another and/or the underlying Ongeluk Formation. Results of these geochemical studies have demonstrated that the Middelplaats igneous rocks (dolerites) from the two drill holes (MP53 and MP54) share a co-genetic source region. There is also reasonable geochemical evidence that the source region of the Middelplaats igneous rocks was substantially similar to the source region of the Ongeluk Formation. This may indicate that the source region of the Ongeluk Formation was reactivated at some later stage resulting in the emplacement of doleritic dikes or sills in the Middelplaats mine area. The Middelplaats igneous rocks were also found to have undergone a slight but pervasive potassic alteration; with most of the original plagioclase feldspar showing some level of replacement by a potassium enriched feldspar. Although no source for this potassic fluid was found, the devolatilization reaction within the manganese ore appears to have released some potassium into the surrounding rocks. This additional potassium may be responsible for some localized potassic alteration.
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Gregory, Christopher T. "The geology and origin of sedimentary manganese from the Boolcunda, Etna and Muttabee Deposits, central Flinders Ranges, South Australia /." Title page, table of contents and abstract only, 1988. http://web4.library.adelaide.edu.au/theses/09SB/09sbg822.pdf.

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AZZILEY, AZZIBROUCK GEORGES. "Sedimentologie et geochimie du francevillien b (proterozoique inferieur). Metallogenie des gisements de manganese de moanda, gabon." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13041.

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Gregory, C. T. "The geology and origin of sedimentary manganese from the Boolcunda, Etna and Muttabee deposits, central Flinders Ranges, South Australia." Thesis, 1988. http://hdl.handle.net/2440/105734.

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The origin of small manganese deposits from the central Southern Flinders Ranges, has not previously been adequately discussed. The region comprising these sedimentary manganese accumulations incorporates a sinuous folded sequence of thick variegated clastic and carbonate sediments deposited within the Adelaide Geosyncline, the stratotype basin for the Adelaidean sediments delineated. Extended exposure of the craton to the west provided a dominant source of both sedimentary detritus and manganese ore constituent. Paragenesis involved leaching of manganese from this source region, transport into the aqueous system and subsequent precipitation in favourable shallow-marine environments meridionally within the Adelaide Geosyncline. Cyclic eustatic fluctuations increased potential ionic manganese concentration, with remobilization and concentration during transgressive oxygen deficient phases and oxidation and precipitation during alternate regressive more oxygenated phases. The precipitation of particulate manganese-oxides, from pre-existing particulate and dissolved manganese from an enriched reservoir, was controlled by the interactive responses of a number of features: estuarine circulation, anoxic-oxic water stratification, and sediment-water interface relationships, at specific geomorphological sites on a stable shallow-marine continental platform. Retention of the precipitated manganese resulted from rapid burial by regressive sands and silts, with little post-genetic supergene alteration of the deposit observed.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 1988
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Books on the topic "Sedimentasry manganese"

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Golota, V. V. Podgotovitelʹnai︠a︡ stadii︠a︡ osadochnogo margant︠s︡evorudnogo prot︠s︡essa: A pre-stage of sedimentary manganese ore process. Ufa: RNTIK Bashtekhinform, 2000.

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Force, Eric R. Manganese contents of some sedimentary rocks of Paleozoic age in Virginia. [Washington]: U.S. Dept. of the Interior, U.S. Geological Survey, 1991.

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R, Hein James, Koski Randolph A, and Geological Survey (U.S.), eds. Stable-isotope study of volcanogenic- and sedimentary-manganese deposits. Menlo Park, Calif: U.S. Dept. of Interior, Geological Survey, 1985.

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R, Hein James, Koski Randolph A, and Geological Survey (U.S.), eds. Stable-isotope study of volcanogenic- and sedimentary-manganese deposits. Menlo Park, Calif: U.S. Dept. of Interior, Geological Survey, 1985.

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Stable-isotope study of volcanogenic- and sedimentary-manganese deposits. Menlo Park, Calif: U.S. Dept. of Interior, Geological Survey, 1985.

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R, Hein James, Koski Randolph A, and Geological Survey (U.S.), eds. Stable-isotope study of volcanogenic- and sedimentary-manganese deposits. Menlo Park, Calif: U.S. Dept. of Interior, Geological Survey, 1985.

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R, Hein James, Koski Randolph A, and Geological Survey (U.S.), eds. Stable-isotope study of volcanogenic- and sedimentary-manganese deposits. Menlo Park, Calif: U.S. Dept. of Interior, Geological Survey, 1985.

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V, Vitovskai͡a︡ I., and Institut geologii rudnykh mestorozhdeniĭ, petrografii, mineralogii i geokhimii (Akademii͡a︡ nauk SSSR), eds. Vulkanogenno-osadochnye i gidrotermalʹnye margant͡s︡evye mestorozhdenii͡a︡: T͡S︡entralʹnyĭ Kazakhstan, Malyĭ Kavkaz i Eniseĭskiĭ kri͡a︡zh. Moskva: "Nauka", 1985.

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Book chapters on the topic "Sedimentasry manganese"

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Böttcher, Michael E. "Manganese (Sedimentary Carbonates and Sulfides)." In Encyclopedia of Geobiology, 541–42. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-1-4020-9212-1_130.

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Doe, B. R., R. A. Ayuso, Kiyoto Futa, and Z. E. Peterman. "Evaluation of the Sedimentary Manganese Deposits of Mexico and Morocco for Determining Lead and Strontium Isotopes in Ancient Seawater." In Earth Processes: Reading the Isotopic Code, 391–408. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm095p0391.

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"Manganese." In Sedimentary and Diagenetic Mineral Deposits, 147–57. Society of Economic Geologists, 1991. http://dx.doi.org/10.5382/rev.05.11.

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Cronan, D. S. "SEDIMENTARY ROCKS | Oceanic Manganese Deposits." In Encyclopedia of Geology, 113–20. Elsevier, 2005. http://dx.doi.org/10.1016/b0-12-369396-9/00499-8.

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Leenheer, Jerry A., and Gary E. Maciel. "Preparation of Low-Carbon Sediments from the Mississippi River and Certain Tributaries for Solid-state CPMAS 13C NMR Analysis." In Nuclear Magnetic Resonance Spectroscopy in Environment Chemistry. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195097511.003.0024.

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The nature of organic carbon in aquatic sediments and soils with low carbon contents and significant contents of paramagnetic elements such as iron and manganese is difficult to assess by solid-state, cross-polarization magic angle spinning (CPMAS) 13C nuclear magnetic resonance (NMR) spectrometry because of the inherent low sensitivity of 13C NMR analyses, and band broadening and sensitivity losses caused by paramagnetic elements. Other investigators have addressed this problem in the analysis of soils by enriching the organic carbon content by flotation, by magnetic separation of paramagnetic minerals, and by chemical reduction of iron by stannous chloride and sodium dithionite. In this study, they found that satisfactory 13C NMR spectra could be obtained if the C/Fe ratio was greater than 1 wt%. Each of the physical and chemical treatments used to increase the C/Fe ratio resulted in losses of organic matter and changes in the nature of organic matter through physical fractionation and chemical alteration. Suspended stream sediments frequently have equivalent contents of organic carbon and sesquioxide coatings with which the organic matter is associated. These sesquioxide coatings consist predominantly of iron and manganese oxyhydroxides that cause problems with NMR analyses. In this chapter we describe a method to enrich organic matter and remove iron and manganese from low-carbon sediments sampled from the Mississippi, Illinois, and Ohio Rivers with minimal loss and alteration of the organic matter. The second objective is to characterize the sedimentary organic matter by 13C NMR using recent advances that increase instrument sensitivity. Suspended and bed sediments were collected during a sampling cruise on the Mississippi River during May–June 1990. Fine bed sediments were collected in depositional regions of the river or tributaries with a pipe dredge. Suspended silts were collected using a continuous-flow centrifuge operated on board the Research Vessel Acadiana. Both bed sediments and suspended silts were freeze-dried prior to additional treatment procedures and NMR analyses. A flow chart of selective mineral dissolution procedures is presented in Figure 17.1. The acid pyrophosphate treatment6 was placed first in the sequence to remove calcium and magnesium minerals that would form insoluble oxalates in the following extraction.
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Berner, Robert A. "Atmospheric O2 over Phanerozoic Time." In The Phanerozoic Carbon Cycle. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195173338.003.0008.

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The chemical reactions that affect atmospheric O2 on a multimillion-year time scale involve the most abundant elements in the earth’s crust that undergo oxidation and reduction. This includes carbon, sulfur, and iron. (Other redox elements, such as manganese, are not abundant enough to have an appreciable effect on O2.) Iron is the most abundant of the three, but it plays only a minor role in O2 control (Holland, 1978). This is because during oxidation the change between Fe+2 and Fe+3 involves the uptake of only one-quarter of an O2 molecule, whereas the oxidation of sulfide to sulfate involves two O2 molecules, and the oxidation of reduced carbon, including organic matter and methane, involves between one and two O2 molecules. The same stoichiometry applies to reduction of the three elements. Because iron is not sufficiently abundant enough to counterbalance its low relative O2 consumption/release, the iron cycle is omitted in most discussions of controls on atmospheric oxygen. In contrast, the sulfur cycle, although subsidiary to the carbon cycle as to its effect on atmospheric O2, is nevertheless non-negligible and must be included in any discussion of the evolution of atmospheric O2. In this chapter the methods and results of modeling the long-term carbon and sulfur cycles are presented in terms of calculations of past levels of atmospheric oxygen. The modeling results are then compared with independent, indirect evidence of changes in O2 based on paleobiological observations and experimental studies that simulate the response of forest fires to changes in the levels of O2. Because the sulfur cycle is not discussed anywhere else in this book, it is briefly presented first. The long-term sulfur cycle is depicted as a panorama in figure 6.1. Sulfate is added to the oceans, via rivers, originating from the oxidative weathering of pyrite (FeS2) and the dissolution of calcium sulfate minerals (gypsum and anhydrite) on the continents. Volcanic, metamorphic/hydrothermal, and diagenetic reactions add reduced sulfur to the oceans and atmosphere where it is oxidized to sulfate. Sulfur is removed from the oceans mainly via formation of sedimentary pyrite and calcium sulfate.
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Leary, Stephen, Richard H. Sillitoe, Jorge Lema, Fernando Téliz, and Diego Mena. "Chapter 21: Geology of the Fruta del Norte Epithermal Gold-Silver Deposit, Ecuador." In Geology of the World’s Major Gold Deposits and Provinces, 431–50. Society of Economic Geologists, 2020. http://dx.doi.org/10.5382/sp.23.21.

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Abstract Fruta del Norte is a completely concealed and extremely well-preserved, Late Jurassic epithermal gold-silver deposit of both low- and intermediate-sulfidation type, which is located in the remote Subandean mountain ranges of southeastern Ecuador. Currently defined indicated resources are 23.8 million metric tons (Mt) averaging 9.61 g/t Au and the total endowment is 9.48 Moz Au. The deposit, notable for the widespread occurrence of visible gold and bonanza grades, will be bulk mined underground. Fruta del Norte was discovered in 2006 during greenfield exploration and systematic drill testing of a conceptual geologic model, which predicted that auriferous veins would occur in andesitic volcanic rocks inferred to underlie a zone of arsenic- and antimony-anomalous silicification in fluvial conglomerate. The host andesitic volcanic rocks, crosscutting feldspar porphyry, and associated phreatic breccia are part of a roof pendant in the Zamora batholith. Together, they are products of a continental-margin volcanoplutonic arc of Middle to Late Jurassic age. The deposit lies beneath the northern extremity of the ~16-km-long, Suárez pull-apart basin where it is localized by steep, second-order faults within the regionally extensive Las Peñas strike-slip fault zone. The pull-apart basin was progressively filled by fluvial conglomerate, dacitic ignimbrite, finer grained siliciclastic sedimentary rocks, and, finally, andesite flows. The Fruta del Norte deposit comprises a 1.3-km-long and up to >300-m-wide vein stockwork associated with quartz-illite-pyrite alteration. The deposit comprises two principal vein types, one in the south dominated by quartz, manganoan carbonates, and abundant base metal sulfides and the other in the north dominated by manganese- and base metal-poor quartz, chalcedony, and calcite. Adularia is a minor gangue mineral in both. Both vein types are abruptly transitional upward and westward to a third important ore type characterized by intense silicification and chalcedony veining, with disseminated and veinlet marcasite (± pyrite). An extensive silica sinter horizon directly overlies the andesitic rocks and/or occurs as interbeds in the lowermost 20 m of the conglomerate and, consequently, is in unusual proximity to the underlying gold-silver orebody. Much of the conglomerate lacks silicification except for a narrow, steeply inclined zone exposed above the deposit, which led to its discovery.
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Conference papers on the topic "Sedimentasry manganese"

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Sasao, Eiji. "The Long-Term Stability of Geological Environments in the Various Rock Types in Japan From the Perspective of Uranium Mineralization." In ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2010. http://dx.doi.org/10.1115/icem2010-40039.

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Long-term stability of the geological environment is one of the important keys for deep geological disposal of high-level radioactive waste in the Japanese Islands due to their location in a tectonically active island-arc. Uranium occurrences in Japan have been subjected to many geological processes inherent to the island-arc setting. Geological environments associated with uranium mineralization are considered favorable for HLW disposal, because uranium mineralization is considered a natural analogue of the radionuclides in HLW. Studies on the long-term stability of the uranium mineralization in Japan can be instructive as these could provide useful information on the long-term stability of the geological environment. Information on host rock and mode of occurrence of uranium mineralization was compiled from published data. The mineralization occurs in these types of deposits, i.e., sedimentary formations, association with metallic ore mineralization of magmatic origin and stratiform manganese mineralization, pegmatite, and alluvial placer deposit. The mineralization occurs in various geological settings in Japan. This fact suggests that geological environments suitable for geological isolation are widely distributed in the Japanese Islands, despite their location in a geologically active area. This study will support building confidence in HLW disposal in the Japanese Islands.
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Reports on the topic "Sedimentasry manganese"

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Manganese contents of some sedimentary rocks of Paleozoic age in Virginia. US Geological Survey, 1991. http://dx.doi.org/10.3133/b1916.

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