Study on integrated evaluation of sandstone-hosted uranium metallogenic potential in southern Yili basin

International Nuclear Information System (INIS)

Han Shaoyang; Ke Dan; Xu Jianguo; Zheng Enjiu; Li Shengxiang

2008-01-01

Plenty of geological data have been accumulated during mineral resource survey in China; under the guidance of new metallogenic theories, it is an important task of how to use these data most effectively for the new cycle uranium survey. In this paper, the flow of establishing the integrated mineral deposits prospecting model for sandstone-hosted uranium deposits is put forward. Based on studying geologic, hydrogeologic and regional geophysical field characteristics of representative uranium deposits No. 512 in southern Yili basin, its multi-source information descriptive model has been established, from which 512-type integrated prospecting models of sandstone-hosted uranium orefield and deposits are summarized. According to the established integrated prospecting models, the metallogenic information extraction of sandstone-hosted uranium deposits has completed in the study area. Finally, the integrated quantitative evaluation of sandstone-hosted uranium metallogenic potential is performed by using the evidence weighing method to integrate middle scale multi-source metallogenic information in the southern Yili basin, and good prediction effect is obtained. (authors)

Analysis on uranium mineralization-formation condition and prospecting potential in Xidamingshan metallogenic belt

International Nuclear Information System (INIS)

Li Zhixing; Qi Fucheng; He Zhongbo; Zhang Zilong

2012-01-01

There are many different opinions about the source of uranium and metallogenic mechanism in Xidamingshan metallogenic belt. therefore it blocked uranium resources potential evaluation and ore exploration. Through absorb in- formation and investigate Daxin deposit and systematic analysis on samples. It is believed that uranium source mainly came from Cambrian System, a little came from the deep. The Devonian System is favorable room for saving ores in addition to be pre-concentrated room for uranium. Also, there are new cognition about uranium metallogenic mechanism, establish ore-forming series of Xidamingshan metallogenic belt, It is proposed that uranium mineralization have experienced 4 stages; It is cleared that hydrothermal fluid superposition transform type uranium deposit is main genetic type, ancient karst accumulate type is secondary genetic type, the later is formed by leaching the former and then precipitate, enrichment in ancient karst congeries, which is formed nearby faults and with the movement of Xishan structural movement. It is proven that metallogenic potential of Xidamingshan metallogenic belt is good. Tectonic rock controlled by subsidiary fracture nearby regional main fault, which connected with the Cambrian System and the Devonian System, and the deep of the deposit is guideline of mineral prospecting next stage. (authors)

Regional metallogenic essential factor of granite-type uranium deposits in Guangdong province

International Nuclear Information System (INIS)

Pan Yongzheng

1987-12-01

The uranium origin, activation region, red basin, and fault depressed zone constitute the regional metallogenic essential factor of the four united like one granite-type uranium deposits in the post-Caledonian rise area in China. In the development of sub-geosyncline in the Caledonian, the clastic formation with widely deposited carbon, silicon, mud rich bearing organic matter, which drow a great amount of uranium formed the uranium-bearing system in the Sinian-Cambrian period. The magmagranite activation in a large scale in the Indosinian-Yenshanian period caused the continental crust to be suffered strong reformation and the uranium-bearing basement system to be eroded and remelted, and formed the rich uranium granite body. The multiple structure-magmatic movement further made the uranium in the rock body suffered the endogenic, structure, supergene active reformation, and produced mobile uranium concentrated area. Under the dry and hot paleoclimate condition in the Cretaceous-Tertiary period, strong weathering and hot water leaching forced uranium to be concentrated into the 'rock origin activation' type uranium deposits in the fault depressed zone

Granite metallogenic specialization study based on RS information model-A case of hydrothermal uranium and tungsten deposits in Nanling region

International Nuclear Information System (INIS)

Huang Hongye; Qin Qiming

2009-01-01

According to the granite hydrothermal metallogenic principle, metallogenic specialization information model for uranium producing and tungsten producing granites in Nanling region is built up and the group factor system of granite metallogenic specialization is initially proposed by using RS information model. On the basis of the above aspects, the geographical index and coefficients of information model of granite metallogenic specialization are respectively analyzed, metallogenic specialization discrimination criterion is built up. After the non-discriminatory massif is forecasted, the results are basically accordant with geological fact, at the same time they are used in the geological metallogenic research, which indicates that metallogenic specialization information model is objective and operative, realizes quantitative appraisal on metallogenic specialization and provides a scientific basis for further discriminating the ore-forming massif. (authors)

Analysis on tectonomagmatic evolution and metallogenic geological conditions of rich-large uranium deposits in Nanling uranium-polymetal metallogenic belt, South Jiangxi province

International Nuclear Information System (INIS)

Chen Guihua

2001-01-01

Nanling is a complicated tectonomagmatic belt. It is also an important uranium-polymetallic metallogenic belt. On the basis of the research achievements of previous researchers, through the detailed stratigraphic, lithologic, litho-paleo-geographic, geochronologic and geochemical studies and the processing of gravimetric and magnetic data, as well as the information extraction of remote sensing data, the authors come to the following conclusions: (1) The Sannan-Xunwu fault is a long-lived (from the Early Sinian to recent time) EW-trending fault; (2) The earth crust in Nanling experienced three time opening-closing with different scales; (3) The Anyuan-Xunwu area is a large thermo-upwelling extensional structure; (4) The above area is considered to be favourable for the formation of rich-large uranium deposit

Discussion of metallogenic substance source of Xiangshan uranium orefield

International Nuclear Information System (INIS)

Shao Fei; Tang Xiangsheng; Zou Maoqin; Hu Maomei; He Xiaomei; Chen Xiaoming; Xu Hengli

2008-01-01

Analysis of uranium source is a key problem for study on uranium deposit genesis. Based on analysis of general implication for determination of uranium source on distribution characteristics of regional uranium abundance, according to temporal and spatial evolution of regional metallogenic substances in process of geological history, and combining with indication for analysis of uranium source by Pb isotopic composition of ores and REE geochemistry of both rocks and ores in Xiangshan orefield, Lower Cambrian strata are determined as regional uranium source bed, Xiangshan volcanic basin is the accumulation area for regional metallogenic substances, magma and hydrothermal solution of post magmatism are media for uranium. Magmatism realizes uranium migration from 'source' to 'accumulation'. In process of magmatic evolution, uranium transformed into gas phase to provide substance base for uranium mineralization. Fluid-rock interaction of post magmatism also promoted some uranium from schist of the basement and rhyodacite into metallogenic solution. (authors)

Gemstone deposits of Serbia

Directory of Open Access Journals (Sweden)

Miladinović Zoran

2016-06-01

Full Text Available Gemstone minerals in Serbia have never been regarded as an interesting and significant resource. Nevertheless, more than 150 deposits and occurrences have been recorded and some of them preliminarily explored in the last 50 years. The majority of deposits and occurrences are located within the Serbo-Macedonian metallogenic province and the most significant metallogenic units at the existing level of knowledge are the Fruska Gora ore district, Cer ore district, Sumadija metallogenic zone, Kopaonik metallogenic zone and Lece-Halkidiki metallogenic zone. The most important genetic type of deposits is hydrothermal, particularly in case of serpentinite/peridotite as host/parent rock. Placer deposits are also economically important. The dominant gemstones are silica minerals: chalcedony (Chrysoprase, carnelian, bluish chalcedony etc., jasper (picture, landscape, red etc., common opal (dendritic, green, milky white etc., silica masses (undivided, and quartz (rock crystal, amethyst etc.. Beside silica minerals significant gemstones in Serbia include also beryl (aquamarine, garnet (almandine and pyrope, tourmaline, fluorite, rhodochrosite, carbonate-silica breccia, carbonate-silica onyx, silicified wood, howlite, serpentinite, marble onyx, and kyanite. This paper aims to present an overview of Serbian gemstone deposits and occurrences and their position based on a simplified gemstone metallogenic map of Serbia, as well as genetic-industrial classification of gemstone deposits and gemstone varieties.

Gemstone deposits of Serbia

Science.gov (United States)

Miladinović, Zoran; Simić, Vladimir; Jelenković, Rade; Ilić, Miloje

2016-06-01

Gemstone minerals in Serbia have never been regarded as an interesting and significant resource. Nevertheless, more than 150 deposits and occurrences have been recorded and some of them preliminarily explored in the last 50 years. The majority of deposits and occurrences are located within the Serbo-Macedonian metallogenic province and the most significant metallogenic units at the existing level of knowledge are the Fruska Gora ore district, Cer ore district, Sumadija metallogenic zone, Kopaonik metallogenic zone and Lece-Halkidiki metallogenic zone. The most important genetic type of deposits is hydrothermal, particularly in case of serpentinite/peridotite as host/parent rock. Placer deposits are also economically important. The dominant gemstones are silica minerals: chalcedony (Chrysoprase, carnelian, bluish chalcedony etc.), jasper (picture, landscape, red etc.), common opal (dendritic, green, milky white etc.), silica masses (undivided), and quartz (rock crystal, amethyst etc.). Beside silica minerals significant gemstones in Serbia include also beryl (aquamarine), garnet (almandine and pyrope), tourmaline, fluorite, rhodochrosite, carbonate-silica breccia, carbonate-silica onyx, silicified wood, howlite, serpentinite, marble onyx, and kyanite. This paper aims to present an overview of Serbian gemstone deposits and occurrences and their position based on a simplified gemstone metallogenic map of Serbia, as well as genetic-industrial classification of gemstone deposits and gemstone varieties.

ALPINE MAGMATIC-METALLOGENIC FORMATIONS OF THE NORTHWESTERN AND CENTRAL DINARIDES

Directory of Open Access Journals (Sweden)

Jakob Pamić

1997-12-01

Full Text Available In the paper are presented basic geological, petrologieca1, geochemi-cal and mineral deposit data for five main magmatic-metallogenic formations of the northwestern and central Dinarides: (lThe Permo Triassic rifting related andesite-diorite formations; (2 The Jurassic-Lower Cretaceous accretionary (ophiolite formations; (3 The Upper Cretaceous-Paleogene subduction related basalt-rhyohite formations; (4 The Paleogene collisional granite formations, and (5 The Oligo-cene-Neogene postsubduction andesite formations. All these magmatic-metallogenic formations originated in different geotectonic settings during the Alpine evolution of the Dinaridic parts of thc Tethys and the postorogenic evolution of the Paratethys and the Pannonian Basin, respectively.

Complexity and Productivity Differentiation Models of Metallogenic Indicator Elements in Rocks and Supergene Media Around Daijiazhuang Pb–Zn Deposit in Dangchang County, Gansu Province

International Nuclear Information System (INIS)

He, Jin-zhong; Yao, Shu-zhen; Zhang, Zhong-ping; You, Guan-jin

2013-01-01

With the help of complexity indices, we quantitatively studied multifractals, frequency distributions, and linear and nonlinear characteristics of geochemical data for exploration of the Daijiazhuang Pb–Zn deposit. Furthermore, we derived productivity differentiation models of elements from thermodynamics and self-organized criticality of metallogenic systems. With respect to frequency distributions and multifractals, only Zn in rocks and most elements except Sb in secondary media, which had been derived mainly from weathering and alluviation, exhibit nonlinear distributions. The relations of productivity to concentrations of metallogenic elements and paragenic elements in rocks and those of elements strongly leached in secondary media can be seen as linear addition of exponential functions with a characteristic weak chaos. The relations of associated elements such as Mo, Sb, and Hg in rocks and other elements in secondary media can be expressed as an exponential function, and the relations of one-phase self-organized geological or metallogenic processes can be represented by a power function, each representing secondary chaos or strong chaos. For secondary media, exploration data of most elements should be processed using nonlinear mathematical methods or should be transformed to linear distributions before processing using linear mathematical methods.

Tectonic and metallogenic model for northeast Asia

Science.gov (United States)

Parfenov, Leonid M.; Nokleberg, Warren J.; Berzin, Nikolai A.; Badarch, Gombosuren; Dril, Sergy I.; Gerel, Ochir; Goryachev, Nikolai A.; Khanchuk, Alexander I.; Kuz'min, Mikhail I.; Prokopiev, Andrei V.; Ratkin, Vladimir V.; Rodionov, Sergey M.; Scotese, Christopher R.; Shpikerman, Vladimir I.; Timofeev, Vladimir F.; Tomurtogoo, Onongin; Yan, Hongquan; Nokleberg, Warren J.

2011-01-01

This document describes the digital files in this report that contains a tectonic and metallogenic model for Northeast Asia. The report also contains background materials. This tectonic and metallogenic model and other materials on this report are derived from (1) an extensive USGS Professional Paper, 1765, on the metallogenesis and tectonics of Northeast Asia that is available on the Internet at http://pubs.usgs.gov/pp/1765/; and (2) the Russian Far East parts of an extensive USGS Professional Paper, 1697, on the metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera that is available on the Internet at http://pubs.usgs.gov/pp/pp1697/. The major purpose of the tectonic and metallogenic model is to provide, in movie format, a colorful summary of the complex geology, tectonics, and metallogenesis of the region. To accomplish this goal four steps were taken: (1) 13 time-stage diagrams, from the late Neoproterozoic (850 Ma) through the present (0 Ma), were adapted, generalized, and transformed into color static time-stage diagrams; (2) the 13 time-stage diagrams were placed in a computer morphing program to produce the model; (3) the model was examined and each diagram was successively adapted to preceding and subsequent diagrams to match the size and surface expression of major geologic units; and (4) the final version of the model was produced in successive iterations of steps 2 and 3. The tectonic and metallogenic model and associated materials in this report are derived from a project on the major mineral deposits, metallogenesis, and tectonics of the Northeast Asia and from a preceding project on the metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera. Both projects provide critical information on bedrock geology and geophysics, tectonics, major metalliferous mineral resources, metallogenic patterns, and crustal origin and evolution of mineralizing systems for this region. The major

Temporal evolution of granitic magmas in the Luanchuan metallogenic belt, east Qinling Orogen, central China: Implications for Mo metallogenesis

Science.gov (United States)

Li, Dong; Han, Jiangwei; Zhang, Shouting; Yan, Changhai; Cao, Huawen; Song, Yaowu

2015-11-01

The Luanchuan metallogenic belt, located within the eastern part of the Qinling Orogen, central China, hosts a number of world-class Mo deposits that are closely related to small late Mesozoic granitic plutons. Zircon U-Pb dating of distinct plutons in the Luanchuan metallogenic belt has yielded ages of 153 ± 1, 154 ± 2, 152 ± 2, and 148 ± 1 Ma. Molybdenite Re-Os isotopic compositions of Yuku ore district in the southern part of Luanchuan metallogenic belt has yielded an isochron age of 146 ± 1 Ma, which is consistent with the large-scale mineralization ages in the northern part of the Luanchuan metallogenic belt. A combination of previous studies and new geochronological and isotopic data show a concordant temporal and genetic link between granitic magmatism and Mo mineralization in the Luanchuan metallogenic belt, suggesting that this mineralization episode formed the most extensive Mo mineralization belt in the east Qinling Orogen. Zircon grains from Mo-related granitic plutons show similar trace element distributions. High-precision Multi Collector-Inductively Coupled Plasma-Mass Spectrometry (MC-ICP-MS) Pb isotope analysis of K-feldspar megacrysts from mineralization-related granites suggest that they were derived from the lower crust. Similarly, the Pb isotopic compositions of pyrite coprecipitated with molybdenite also suggest that the metals were derived form the lower crust, with probably minor mantle contribution. A continuum mineralization model that describes the sourcing of Mo from an evolving granitic magma over successive differentiation events, possibly in separate but connected magma chambers, could explain the remarkable Mo enrichment in the Luanchuan metallogenic belt. The volatile- and Mo-bearing granitic magmas ascended as diapirs from the deep crust, and were emplaced as dikes in the upper crust. Lithological differences between these Mo-bearing granites may relate to different stages in the evolution of individual magmas. Finally, ore

Metallogenic aspects of Itu intrusive suite

International Nuclear Information System (INIS)

Amaral, G.; Pascholati, E.M.

1990-01-01

The integrated use of geological, geochemical, geophysical and remote sensing data is providing interesting new information on the metallogenic characteristics of the Itu Intrusive Suite. During World War II, up to 1959, a wolframite deposit was mined near the border of the northernmost body (Itupeva Granite). This deposit is formed by greisen veins associated with cassiterite and topaz, clearly linked with later phases of magmatic differentiation. Generally those veins are related to hydrothermal alteration of the granites and the above mentioned shear zone. U, Th and K determinations by field and laboratory gammaspectrometry were used for regional distribution analysis of those elements and its ratios and calculation of radioactivity heat production. In this aspects, the Itupeva Granite is the hottest and presents several anomalies in the Th/U ratio, indicative of late or post magmatic oxidation processes. (author)

Brief analysis on uranium metallogenic potential in Wunikeng area

International Nuclear Information System (INIS)

Wang Binghua

2010-01-01

Through the geological mapping, gamma total equivalent weight survey in Wunikeng area, the tectonics and gamma anomalies discovered in this area are analyzed, uranium metallogenic potential is analyzed by combining the regional metallogenic condition, contrasting the metallogenic geological background, massif condition, tectonic framework from these aspects of the regional geological background, massif condition on the work area, tectonic framework, etc.. (authors)

Investigation on the age of mineralization in the Sungun porphyry Cu-Mo deposit, NW Iran with a regional metallogenic perspective

Science.gov (United States)

Simmonds, Vartan; Moazzen, Mohssen; Mathur, Ryan

2016-04-01

The Sungun porphyry copper deposit (PCD) is located in NW Iran, neighbouring several other PCDs and prospects in the region and the Lesser Caucasus (south Armenia). It lies on the Urumieh-Dokhtar magmatic arc (UDMA), which formed through the northeast-ward subduction of the Neo-Tethyan oceanic crust beneath the Central Iranian plate during late-Mesozoic and early-Cenozoic [1], and hosts the porphyry copper metallogenic belt of Iran. The Sungun PCD is the second largest deposit in Iran with ore reserves of about 850 Mt at 0.62 wt% Cu and 0.01 wt% Mo and probable reserves over 1Gt. The monzonitic to quartz monzonitic porphyry stock intruded the upper Cretaceous carbonates and Eocene volcano-sedimentary rocks. It produced a skarn-type mineralization at its contact zone with the carbonate rocks, as well as vast hydrothermal alteration zones and porphyry-type Cu and Mo mineralization. The zircon U-Pb age of the host porphyry stock is about 22.5±0.4 to 20.1±0.4 Ma [2]. Re-Os dating of four molybdenite separates from this PCD shows ages ranging between 22.9±0.2 to 21.7±0.2 Ma, with an average of 22.57±0.2 Ma, corresponding to the early Miocene (Aquitanian). These ages indicate that both the porphyry stock and the Cu-Mo mineralization are post-collisional events, similar to many other deposits and prospects in NW and central Iran and south Armenia, and the mineralization occurred shortly after the emplacement of the host stock, corresponding better to the ages obtained from the marginal parts of the stock. Magmatism and mineralization in Sungun coincides with the third metallogenic epoch in the Lesser Caucasus (Eocene to Miocene; [3]), though it is considerably younger than all of the dated PCDs and prospects in the south Armenia. It also postdates Cu-Mo mineralizations in the Saheb Divan (35 Ma), Qaradagh batholith (31.22±0.28 to 25.19±0.19 Ma), as well as Haft Cheshmeh PCD (28.18±0.42 to 27.05±0.37 Ma) in NW Iran, while it seems to be coeval with the Kighal

Metallogenic hydrothermal solution system of post volcanic magma in Xiangshan ore field

International Nuclear Information System (INIS)

Xu Hengli; Shao Fei; Zou Maoqin

2009-01-01

This paper has systematically described uranium metallogenic characteristics of Xiangshan ore field.Sources of metallogenic materials are discussed in different temporal and spatial scale. Combining with background analysis of metallogenic tectonic-magmatic-geodynamics, formation and evolution of metallogenic hydrothermal solution system in Xiangshan volcanic basin are studied. Metallogenic hydrothermal solution system in Xiangshan ore field is considered as the objective product of systematic evolution of hydrothermal solution in post volcanic magma constrained by regional tectonic environment. In time scale, metallogenic hydrothermal solution system developed for about 50 Ma, but its active spaces varied in different time domains. So temporal and spatial distribution of uranium mineralization is constrained. Further exploration for the ore field is also suggested in this paper. (authors)

New understanding in genesis of uranium deposit Bashblak in tarim basin

International Nuclear Information System (INIS)

Qin Mingkuan; Zhao Ruiquan

2000-01-01

Using metallogenic theory of hydrogenic uranium deposit and theory of oil-gas reduction, the author makes a re-recognition of the metallogenic mechanism of the biggest uranium deposit in Tarim basin--uranium deposit Bashblak in order to give some reference guide in the prospecting for in-situ leachable sandstone-type uranium deposits in the biggest intra-continental basin in China--Tarim basin

Hydrothermal Evolution of the Giant Cenozoic Kadjaran porphyry Cu-Mo deposit, Tethyan metallogenic belt, Armenia, Lesser Caucasus: mineral paragenetic, cathodoluminescence and fluid inclusion constraints

Science.gov (United States)

Hovakimyan, Samvel; Moritz, Robert; Tayan, Rodrik; Rezeau, Hervé

2016-04-01

The Lesser Caucasus belongs to the Central segment of the Tethyan metallogenic belt and it is a key area to understand the metallogenic evolution between the Western & Central parts of the Tethyan belt and its extension into Iran. Zangezur is the most important mineral district in the southernmost Lesser Caucasus. It is a component of the South Armenian block, and it was generated during the convergence and collision of the southern margin of the Eurasian plate and the northern margin of the Arabian plate, and terranes of Gondwana origin (Moritz et al., in press). The Zangezur ore district consists of the Tertiary Meghri-Ordubad composite pluton, which is characterized by a long-lasting Eocene to Pliocene magmatic, tectonic and metallogenic evolution. It hosts major porphyries Cu-Mo and epithermal Au - polymetallic deposits and occurrences, including the giant world class Kadjaran porphyry Cu-Mo deposit (2244 Mt reserves, 0.3% Cu, 0.05% Mo and 0.02 g/t Au). The Kadjaran deposit is hosted by a monzonite intrusion (31.83±0.02Ma; Moritz et al., in press). Detailed field studies of the porphyry stockwork and veins of the different mineralization stages, their crosscutting and displacement relationships and the age relationship between different paragenetic mineral associations were the criteria for distinction of the main stages of porphyry mineralization at the Kadjaran deposit. The economic stages being: quartz- molybdenite, quartz-molybdenite-chalcopyrite, and quartz-chalcopyrite. The main paragenetic association of the Kadjaran porphyry deposit includes pyrite, molybdenite, chalcopyrite, bornite, chalcocite, pyrrhotite, covellite, sphalerite, and galena. Recent field observations in the Kadjaran open pit revealed the presence of epithermal veins with late vuggy silica and advanced argillic alteration in the north-eastern and eastern parts of the deposit. They are distributed as separate veins and have also been recognized in re-opened porphyry veins and in

Perspective and resource evaluation and metallogenic studies on sandstone-type uranium deposit in Qianjiadian depression of Songliao Basin

Energy Technology Data Exchange (ETDEWEB)

Yuliang, Xia; Jinrong, Lin; Ziying, Li; Shengxiang, Li; Hanbin, Liu; Zhiming, Wang; Guang, Fan [Beijing Research Inst. of Uranium Geology, Beijing (China); Jiwei, Zheng; Zhenji, Li; Mingyu, Zhang [Liaohe Oil Field, Panjin (China)

2003-07-01

The geotectonic evolution history of the southeastern part of Songliao Basin has been clearly described and it is pointed out that both of the provenance rocks and evolution features of the studied area are favorable to the formation of U-rich sandstone bodies, development of interlayered oxidation and providing uranium source for mineralization. Yaojia Formation in Qianjiadian depression has been found out to be the favorable target ore bed for looking for sandstone-type uranium deposit. On the basis of analysis of metallogenetic conditions, the perspective target area has been circled and a sandstone-type uranium deposit with a certain amounts of uranium tonnages has been discovered. The achievements and data have been gotten in the following aspects: constitution and features of ore-forming beds and sandstone bodies, uranium existence forms and mineralogical and chemical compositions of the ores, associated elements and their economic values for comprehensive mining. The study of metallogenetic features and mechanism of the uranium deposit suggested that pre-enrichment of uranium during the depositional-diagenetic stage provide a good basis for uranium mineralization, and hereafter interlayered oxidation as well as oil-gas reduction processes played a decisive role to uranium mineralization. U-Pb isotopic studies indicate that the ores have two isochron ages of 53{+-}3 Ma and 7.0{+-}0 Ma, corresponding to the periods of arid and semiarid paleo-climates which are favorable to interlayered oxidation development and uranium mineralization. It is concluded that the Qianjiadian sandstone-type uranium deposit is genetically related to interlayered oxidation and secondary reduction of oil-gas. The metallogenic model of Qianjiadian uranium deposit was set up. (authors)

Perspective and resource evaluation and metallogenic studies on sandstone-type uranium deposit in Qianjiadian depression of Songliao Basin

International Nuclear Information System (INIS)

Xia Yuliang; Lin Jinrong; Li Ziying; Li Shengxiang; Liu Hanbin; Wang Zhiming; Fan Guang; Zheng Jiwei; Li Zhenji; Zhang Mingyu

2003-01-01

The geotectonic evolution history of the southeastern part of Songliao Basin has been clearly described and it is pointed out that both of the provenance rocks and evolution features of the studied area are favorable to the formation of U-rich sandstone bodies, development of interlayered oxidation and providing uranium source for mineralization. Yaojia Formation in Qianjiadian depression has been found out to be the favorable target ore bed for looking for sandstone-type uranium deposit. On the basis of analysis of metallogenetic conditions, the perspective target area has been circled and a sandstone-type uranium deposit with a certain amounts of uranium tonnages has been discovered. The achievements and data have been gotten in the following aspects: constitution and features of ore-forming beds and sandstone bodies, uranium existence forms and mineralogical and chemical compositions of the ores, associated elements and their economic values for comprehensive mining. The study of metallogenetic features and mechanism of the uranium deposit suggested that pre-enrichment of uranium during the depositional-diagenetic stage provide a good basis for uranium mineralization, and hereafter interlayered oxidation as well as oil-gas reduction processes played a decisive role to uranium mineralization. U-Pb isotopic studies indicate that the ores have two isochron ages of 53±3 Ma and 7.0±0 Ma, corresponding to the periods of arid and semiarid paleo-climates which are favorable to interlayered oxidation development and uranium mineralization. It is concluded that the Qianjiadian sandstone-type uranium deposit is genetically related to interlayered oxidation and secondary reduction of oil-gas. The metallogenic model of Qianjiadian uranium deposit was set up. (authors)

Study on fractal characteristics of remote sensing image in the typical volcanic uranium metallogenic areas

International Nuclear Information System (INIS)

Pan Wei; Ni Guoqiang; Li Hanbo

2010-01-01

Computing Methods of fractal dimension and multifractal spectrum about the remote sensing image are briefly introduced. The fractal method is used to study the characteristics of remote sensing images in Xiangshan and Yuhuashan volcanic uranium metallogenic areas in southern China. The research results indicate that the Xiangshan basin in which lots of volcanic uranium deposits occur,is of bigger fractal dimension based on remote sensing image texture than that of the Yuhuashan basin in which two uranium ore occurrences exist, and the multifractal spectrum in the Xiangshan basin obviously leans to less singularity index than in the Yuhuashan basin. The relation of the fractal dimension and multifractal singularity of remote sensing image to uranium metallogeny are discussed. The fractal dimension and multifractal singularity index of remote sensing image may be used to predict the volcanic uranium metallogenic areas. (authors)

Paired Magmatic-Metallogenic Belts in Myanmar - an Andean Analogue?

Science.gov (United States)

Gardiner, Nicholas; Robb, Laurence; Searle, Michael; Morley, Christopher

2015-04-01

contrasting minerals endowment. The Mogok-Mandalay-Mergui (MMM) Belt hosts crustal-melt S-type granites with significant tin-tungsten mineralization, and contains the historically major tungsten deposit of Mawchi. The Wuntho-Popa Arc comprises I-type granites and granodiorites with porphyry-type copper-gold and epithermal gold mineralization, and includes the world-class Monywa copper mine. Recent U-Pb radiometric age dating has shown the potential for the two belts to be both active from the Late Cretaceous to Eocene. The spatial juxtaposition of these two sub-parallel belts, the implication of contemporary magmatism, and their distinct but consistent metallogenic endowment bears strong similarities to the metallogenic belts of the South American Cordillera. Here we investigate whether they together represent the magmatic and metallogenic expression of an Andean-type setting in Myanmar during the subduction of Neo-Tethys. In this analogue the Wuntho-Popa Arc represents a proximal I-type magmatic belt sited immediately above the eastwards-verging Neo-Tethys subduction zone. Exhibiting porphyry-type copper-gold and epithermal gold mineralization, this would therefore be the Myanmar equivalent of the Andean coastal copper belts. Conversely, the parallel MMM Belt, comprised of more distal crustal-melt S-type tin granites, would have an analogue in the Bolivian tin belt.

Variation of molybdenum isotopes in molybdenite from porphyry and vein Mo deposits in the Gangdese metallogenic belt, Tibetan plateau and its implications

Science.gov (United States)

Wang, Yong; Zhou, Lian; Gao, Shan; Li, Jian-Wei; Hu, Zhi-Fang; Yang, Lu; Hu, Zhao-Chu

2016-02-01

We present Mo isotopic ratios of molybdenite from five porphyry molybdenum deposits (Chagele, Sharang, Jiru, Qulong, and Zhuonuo) and one quartz-molybdenite vein-type deposit (Jigongcun) along the Gangdese metallogenic belt in the Tibetan Plateau. These deposits represent a sequence of consecutive events of the India-Asia collision at different periods. Additional molybdenite samples from the Henderson Mo deposit (USA), the oceanic subduction-related El Teniente (Chile), and Bingham (USA) porphyry Cu-(Mo) deposits were analyzed for better understanding the controls on the Mo isotope systematics of molybdenite. The results show that molybdenite from Sharang, Jiru, Qulong, and Zhuonuo deposits have similar δ97Mo (˜0 ‰), in agreement with the values of the Henderson Mo deposit (-0.10 ‰). In contrast, samples from the Changle and Jigongcun deposit have δ97Mo of 0.85 ‰ to 0.88 ‰ and -0.48 %, respectively. Molybdenite from the El Teniente and Bingham deposits yields intermediate δ97Mo of 0.27 and 0.46 ‰, respectively. The Mo isotopes, combined with Nd isotope data of the ore-bearing porphyries, indicate that source of the ore-related magmas has fundamental effects on the Mo isotopic compositions of molybdenite. Our study indicates that molybdenite related to crustal-, and mantle-derived magmas has positive or negative δ97Mo values, respectively, whereas molybdenite from porphyries formed by crust-mantle mixing has δ97Mo close to 0 ‰. It is concluded that the Mo isotope composition in the porphyry system is a huge source signature, without relation to the tectonic setting under which the porphyry deposits formed.

Metallogenic relationships to tectonic evolution - the Lachlan Orogen, Australia

Science.gov (United States)

Bierlein, Frank P.; Gray, David R.; Foster, David A.

2002-08-01

Placing ore formation within the overall tectonic framework of an evolving orogenic system provides important constraints for the development of plate tectonic models. Distinct metallogenic associations across the Palaeozoic Lachlan Orogen in SE Australia are interpreted to be the manifestation of interactions between several microplates and three accretionary complexes in an oceanic back-arc setting. In the Ordovician, significant orogenic gold deposits formed within a developing accretionary wedge along the Pacific margin of Gondwana. At the same time, major porphyry Cu-Au systems formed in an oceanic island arc outboard of an evolved magmatic arc that, in turn, gave rise to granite-related Sn-W deposits in the Early Silurian. During the ongoing evolution of the orogen in the Late Silurian to Early Devonian, sediment-hosted Cu-Au and Pb-Zn deposits formed in short-lived intra-arc basins, whereas a developing fore-arc system provided the conditions for the formation of several volcanogenic massive sulphide deposits. Inversion of these basins and accretion to the Australian continental margin triggered another pulse of orogenic gold mineralisation during the final consolidation of the orogenic belt in the Middle to Late Devonian.

Magmatism and polymetallic mineralization in southwestern Qinzhou-Hangzhou metallogenic belt, South China

Science.gov (United States)

Huang, Xudong; Lu, Jianjun; Wang, Rucheng; Ma, Dongsheng

2016-04-01

As Neoproterozoic suture zone between the Yangtze Block and Cathaysia Block, Qinzhou-Hangzhou metallogenic belt is one of the 21 key metallogenic belts in China. Intensive multiple-aged felsic magmatism and related polymetallic mineralization take place in this belt. Although Neoproterozoic, Paleozoic, Triassic granites and associated deposits have been found in southwestern Qinzhou-Hangzhou metallogenic belt, Middle-Late Jurassic (150-165 Ma) magmatism and related mineralization is of the most importance. Three major kinds of Middle-Late Jurassic granitoids have been distinguished. (Cu)-Pb-Zn-bearing granitoids are slightly differentiated, calc-alkaline and metaluminous dioritic to granodioritic rocks. Sn-(W)-bearing granites contain dark microgranular enclaves and have high contents of REE and HFSE, suggesting affinities of aluminous A-type (A2) granites. W-bearing granites are highly differentiated and peraluminous rocks. (Cu)-Pb-Zn-bearing granitoids have ɛNd(t) values of -11 ˜ -4 and ɛHf(t) values of -12 ˜ -7, corresponding to TDMC(Nd) from 1.4 to 1.8 Ga and TDMC(Hf) from 1.6 to 2.0 Ga, respectively. The ɛNd(t) values of W-bearing granites vary from -11 to -8 with TDMC(Nd) of 1.6 ˜ 1.9 Ga and ɛHf(t) values change from -16 to -7 with TDMC(Hf) of 1.5 ˜ 2.0 Ga. Compared with (Cu)-Pb-Zn-bearing granitoids and W-bearing granites, the Sn-(W)-bearing granites have higher ɛNd(t) (-8 ˜ -2) and ɛHf(t) (-8 ˜ -2) values and younger TDMC(Nd) (1.1 ˜ 1.6 Ga) and TDMC(Hf) (1.2 ˜ 1.8 Ga) values, showing a more juvenile isotopic character. Sn-(W)-bearing granites originate from partial melting of granulitized lower crust involved with some mantle-derived materials. W-bearing granites are derived from partial melting of crust. (Cu)-Pb-Zn-bearing granitoids are also derived from crust but may be influenced by more mantle-derived materials. For (Cu)-Pb-Zn deposits, skarn and carbonate replacement are the most important mineralization types. Cu ore bodies mainly

Geology of uranium vein-deposits in France

International Nuclear Information System (INIS)

Sarcia, J.A.; Carrat, J.; Poughon, A.; Sanselme, H.

1958-01-01

This paper gives an outline of the characteristics of the main uranium vein deposits in France; it underlines the structural, petrographic and metallogenic similarities of these deposits. (author) [fr

Analysis of uranium metallogenic conditions and prospective prognosis on the south-central part of the Xikang-Yunnan Axis

International Nuclear Information System (INIS)

Guo Baochi; Qian Farong; Cai Yuqi; Zhang Daishi

1996-08-01

Three types of uranium mineralizations (i.e., sandstone type, sodium metasomatite type and Proterozoic epimetamorphic rock type) are distinguished in the south-central part of the Xikang-Yunnan Axis, and their major characteristics are expounded. It is proposed that the Early Proterozoic crust has three elevation stages: primitive old land formation stage, subsidence stage and base mental reconsolidation stage, and that the Middle Proterozoic Kunyang Group is different from typical carbonate-siliceous-politic sedimentary formation which contains many regional uranium-rich horizons. The primitive uranium contents of some rocks in the region have been studied for the first time, and proposed a new knowledge that some relative rocks be recognized as the uranium source rocks of the region. It is pointed out that there are two kinds of hydrothermal alterations, namely, alkaline alteration and acidic alteration, and some areas with development of alkaline alteration have promising uranium-metallogenic potential. As for the U-metallogenic prospect of the region, three conclusions are summarized: (1) This region does not have favourable geologic conditions for the Australian-Canadian type Proterozoic unconformity-related uranium deposit; (2) The Proterozoic unconformity different from that of Australian-Canadian type does not have permission U-metallogenic potential either; (3) The alkaline (sodium) metasomatite type uranium mineralization in the region has some prospecting potential. Therefore on the basis of above-mentioned conclusions five relatively promising uranium-metallogenic prospects are selected. (4 refs.)

Some tentative idea about uranium metallogenic prognosis on the basis of application of GIS

International Nuclear Information System (INIS)

Li Jianwei; Li Xianfu

1998-01-01

Geographic information system (GIS) is a new borderline subject. The principal components of MAPGIS are introduced, and the data needed, main procedures and outstanding advantages in uranium metallogenic prognosis applying MAPGIS are discussed. For uranium metallogenic areas with detailed research basis and abundant data, it is of great prospects to apply MAPGIS for metallogenic prognosis

Analysis of metallogenic conditions of sandstone type uranium deposits in interlayer oxidation zone in the northwest of Junggar basin, Xinjiang

International Nuclear Information System (INIS)

Lin Shuangxing

1997-01-01

From various aspects such as the basin structures, structure features of the sedimentary cover, lithofacies features of basin sediments, geochemical characteristics of sedimentary rocks, regional hydrogeologic conditions and epigenetic reworking of the sedimentary cover and so on, the author analyzes the metallogenic conditions of sandstone type uranium deposits in interlayer oxidation zone in the northwest of Junggar basin. The author proposes that the area has abundant uranium sources, and possesses favourable stratigraphic combinations for the development of interlayer oxidation zone. Secondarily oxidized sandstone bodies present universally at places from the source area to stream channel facies. Reducing beds and secondarily reducing barrier are developed at the front of the secondarily oxidized sandstone body. The tectonic features of the sedimentary cover indicate that the area belongs to a relatively-stable suborogenic region and possesses secondary mobilization and reworking conditions during the uplifting and contraction stage of the basin. Epigenetic metallization is evident in the sedimentary cover of the basin

Discussion on several problems on the mineralization of paleo-channel sandstone type uranium deposits

International Nuclear Information System (INIS)

Huang Shijie

1997-01-01

On the basis of comprehensively analyzing paleo-channel sandstone type uranium deposits at home and abroad, the author discusses the division of mineralization types of paleo-channel sandstone type uranium deposits, and analyzes the metallogenic geologic conditions such as regional geologic background, climatic and geomorphological conditions, basement and sedimentary cover, characteristics of paleo-valley and paleo-channel, mineralization features as well as epigenetic metallogenic process. Future prospecting direction is also proposed

Metallogenic condition and regularity of inter layered oxidation zone-type sandstone uranium deposit in southwestern part of Turpan-Hami basin, Northwestern China

International Nuclear Information System (INIS)

Xiang Weidong; Chen Zhaobo; Chen Zuyi; Yin Jinshuang

2001-01-01

Regional geological surveying and drilling evaluation in recent years show that there are very large potential resources of sandstone-type uranium deposits in the southwestern part of Turpan-Hami basin. According to the characteristics of tectonic evolution and sedimentary cover of the basin, the evolution stages and types of the basin are divided, and the favorable development stages for the ore-bearing formation and the formation of uranium deposits in the evolution process are identified. The metallogenic conditions of uranium deposits are deeply discussed from four aspects: basic tectonics, paleoclimate evolution, hydrogeology and uranium source of the region. All these have laid an important foundation for accurate prediction and evaluation of uranium resources in this region. The research indicates that the uranium metallogeny is a process of long-term, multi-stage and pulsation. The authors try to ascertain the role of organic matter in concentrating uranium. The organic matter is of humic type in sandstone host-rock in the studied area, whose original mother material mainly belongs to terrestrial high plant. The maturity of the organic matter is very low, being in low-grade stage of thermal evolution. Correlation analysis and separation experiments show that uranium concentration is closely related with the organic matter, and the organic matter in uranium ore is mainly in the form of humic acid adsorption and humate. For this reason the total organic carbon content is often increased in the geochemical redox zone in epigenetic sandstone-type uranium deposits. It is suggested that the north of China is of great potential for sandstone-type uranium resources

Geochronology and geochemistry of the Badaguan porphyry Cu-Mo deposit in Derbugan metallogenic belt of the NE China, and their geological significances

Science.gov (United States)

Gao, Bingyu; Zhang, Lianchang; Jin, Xindi; Li, Wenjun; Chen, Zhiguang; Zhu, Mingtian

2016-03-01

The Badaguan porphyry Cu-Mo deposit belongs to the Derbugan metallogenic belt, which is located in the Ergun block, NE China. In the mining area, the Cu-Mo mineralization mainly occurs in quartz diorite porphyry and is hosted within silicified-sericitized and sericite alteration zone. Geochemical results of the host porphyry is characterized by high SiO2, high Al2O3, low MgO, weak positive Eu anomalies and clearly HREE depletion, high Sr, low Y and low Yb, similar to those of adakite. The Sr-Nd isotopic composition of the host porphyry displays an initial (87Sr/86Sr)i ratio of 0.7036-0.7055 and positive Nd( t) values of +0.1 to +0.6, which are similar to the OIB, reflecting the source of the host porphyry may derive from subducted ocean slab, and the new lower crust also had some contribution to the magma sources. The SIMS zircon U-Pb age from the host porphyry is 229 ± 2 Ma. The Re-Os isochron age for the molybdenite in the deposit is 225 ± 2 Ma closed to zircon U-Pb age of the host porphyry, indicating that Cu-Mo mineralization event occurred in Triassic. Combining the geology-geochemistry of the host porphyry and the regional tectonic evolution, we infer that the subduction processes of Mongol-Okhotsk oceanic slab under the Ergun block led to the formation of the Badaguan porphyry Cu-Mo deposit during the Triassic.

Geochronology and petrogenesis of the Qibaoshan Cu-polymetallic deposit, northeastern Hunan Province: Implications for the metal source and metallogenic evolution of the intracontinental Qinhang Cu-polymetallic belt, South China

Science.gov (United States)

Yuan, Shunda; Mao, Jingwen; Zhao, Panlao; Yuan, Yabin

2018-03-01

The recently recognized Qinhang metallogenic belt (QHMB) is an economically important intracontinental Mesozoic porphyry-skarn Cu-polymetallic metallogenic belt in South China. However, the origin of the ore-bearing magma and the major factors controlling the different metal assemblages in the QHMB are still unclear. The Qibaoshan deposit is a large Cu-Au-Pb-Zn-Ag-Fe deposit located at the juncture between the northern and central parts of the QHMB. In this study, new zircon U-Pb ages, Hf-O isotopic data, molybdenite Re-Os ages, and whole-rock geochemical data are combined to constrain the timing of the mineralization and the origin and petrogenesis of the ore-bearing porphyry in the Qibaoshan deposit. The ages obtained from both zircon U-Pb and molybdenite Re-Os dating fall in the Late Jurassic (between 152.7 and 148.3 Ma), revealing that this deposit is significantly younger than previously estimated (227-184 Ma). The Qibaoshan ore-bearing quartz porphyry shows variable negative zircon εHf(t) values (-14.8 to -5.5), high δ18O values (8.4 to 10.8‰), and high Mg# values (69.1 to 73.0), indicating that it formed via the partial melting of ancient crust triggered by the injection of mantle-derived magma. Zircon Hf-O isotopic modeling of the mixing of two extreme endmembers indicates that the magmatic source comprised 70-80% reworked ancient crustal components and 20-30% depleted mantle components. Based on comparisons with other ore-bearing porphyries in the QHMB, a magmatic source dominated by crust-derived material and relatively low oxygen fugacities (ΔFMQ -1.8 to ΔFMQ +0.8) was responsible for the high (Pb + Zn)/Cu ratio in the Qibaoshan deposit, and the Pb, Zn and Ag were mainly derived from the reworked ancient crust. Although four analyses of inherited Neoproterozoic zircons ( 800 Ma) have variable positive εHf(t) values (0.72 to 11.21), indicating that Neoproterozoic juvenile crust was involved in the formation of the Qibaoshan ore-bearing quartz

Integrated prediction based on GIS for sandstone-type uranium deposits in the northwest of Ordos Basin

International Nuclear Information System (INIS)

Han Shaoyang; Ke Dan; Hu Shuiqing; Guo Qingyin; Hou Huiqun

2005-01-01

The integrated prediction model of sandstone-type uranium deposits and its integrated evaluation methods as well as flow of the work based on GIS are studied. A software for extracting metallogenic information is also developed. A multi-source exploring information database is established in the northwest of Ordos Basin, and an integrated digital mineral deposit prospecting model of sandstone-type uranium deposits is designed based on GIS. The authors have completed metallogenic information extraction and integrated evaluation of sandstone-type uranium deposits based on GIS in the study area. Research results prove that the integrated prediction of sandstone-type uranium deposits based on GIS may further delineate prospective target areas rapidly and improve the predictive precision. (authors)

Application of Research on the Metallogenic Background in the Assessment of Mineral Resources Potentiality

Science.gov (United States)

Jia, D.; Feng, Y.; Liu, J.; Yao, X.; Zhang, Z.; Ye, T.

2017-12-01

1. Working BackgroundCurrent Status of Geological Prospecting: Detecting boundaries and bottoms, making ore search nearby; Seeing the stars, not seeing the Moon; Deep prospecting, undesirable results. The reasons of these problems are the regional metallogenic backgroud unclear and the metallogenic backgroud of the exploration regions unknown. Accordingly, Development and Research Center, CGS organized a geological setting research, in detail investigate metallogenic geological features and acquire mineralization information. 2. Technical SchemeCore research content is prediction elements of Metallogenic Structure. Adopt unified technical requirements from top to bottom, and technical route from bottom to top; Divide elements of mineral forecast and characteristics of geological structure into five elements for research and expression; Make full use of geophysical, geochemical and remote sensing inferences for the interpretation of macro information. After eight years the great project was completed. 3. Main AchievementsInnovation of basic maps compilation content of geological background, reinforce of geological structure data base of potentiality valuation. Preparation of geotectonic facies maps in different scales and professions, providing brand-new geologic background for potentiality assessment, promoting Chinese geotectonic research to the new height. Preparation of 3,375 geological structure thematic base maps of detecting working area in 6 kinds of prediction methods, providing base working maps, rock assemblage, structure of the protolith of geologic body / mineralization / ore controlling for mineral prediction of 25 ores. Enrichment and development of geotectonic facies analysis method, establishment of metallogenic background research thoughts and approach system for assessment of national mineral resources potentiality for the first time. 4. Application EffectOrientation——More and better results with less effort. Positioning——Have a definite

Metallogenic epoch of the Jiapigou gold belt, Jilin Province, China

Indian Academy of Sciences (India)

Metallogenic epoch of the Jiapigou gold belt, Jilin Province, China: ... The Jiapigou gold belt is located on the northern margin of the North China Craton, and is one of the ... 29, Xueyuan Road, Beijing 100083, People's Republic of China.

Analysis on metallogenetic conditions of sandstone-type uranium deposit in Minhe Basin

International Nuclear Information System (INIS)

Jiang Minzhong; Wang Huaiwu

2002-01-01

Little uranium prospecting has been performed so far in Minhe basin. However, at the marginal areas of the basin uranium mineralizations and lots of aero-radioactive anomalies have been found before, and the basin shows some prospecting potential. Based on the regional geological setting, by means of interpretation of high-precision aero-magnetic, aero-radiometric and Bouguer gravimetric data, and combined with hydrodynamic, lithofacies-palaeographic and paleo-climatic analyses, authors make a comprehensive evaluation of metallogenic conditions for sandstone-type uranium deposits, and propose metallogenically favourable areas in the basin

U-Pb, Re-Os and Ar-Ar dating of the Linghou polymetallic deposit, Southeastern China: Implications for metallogenesis of the Qingzhou-Hangzhou metallogenic belt

Science.gov (United States)

Tang, Yanwen; Xie, Yuling; Liu, Liang; Lan, Tingguan; Yang, Jianling; Sebastien, Meffre; Yin, Rongchao; Liang, Songsong; Zhou, Limin

2017-04-01

The Qingzhou-Hangzhou metallogenic belt (QHMB) in Southeastern China has gained increasingly attention in recent years. However, due to the lack of reliable ages on intrusions and associated deposits in this belt, the tectonic setting and metallogenesis of the QHMB have not been well understood. The Linghou polymetallic deposit in northwestern Zhejiang Province is one of the typical deposits of the QHMB. According to the field relationships, this deposit consists of the early Cu-Au-Ag and the late Pb-Zn-Cu mineralization stages. Molybdenite samples with a mineral assemblage of molybdenite-chalcopyrite-pyrite ± quartz are collected from the copper mining tunnel near the Cu-Au-Ag ore bodies. Six molybdenite samples give the Re-Os model ages varying from 160.3 to 164.1 Ma and yield a mean age of 162.2 ± 1.4 Ma for the Cu-Au-Ag mineralization. Hydrothermal muscovite gives a well-defined Ar-Ar isochron age of 160.2 ± 1.1 Ma for the Pb-Zn-Cu mineralization. Three phases of granodioritic porphyry have been distinguished in this deposit, and LA-ICP-MS zircon U-Pb dating shows that they have formed at 158.8 ± 2.4 Ma, 158.3 ± 1.9 Ma and 160.6 ± 2.1 Ma, comparable to the obtained ages of the Cu-Au-Ag and Pb-Zn-Cu mineralization. Therefore, these intrusive rocks have a close temporal and spatial relationship with the Cu-Au-Ag and Pb-Zn-Cu ore bodies. The presences of skarn minerals (e.g., garnet) and vein-type ores, together with the previous fluid inclusion and H-O-C-S-Pb isotopic data, clearly indicate that the Cu-Au-Ag and Pb-Zn-Cu mineralization are genetically related to these granodiorite porphyries. This conclusion excludes the possibility that this deposit is of ;SEDEX; type and formed in a sag basin of continental rifts setting as previously proposed. Instead, it is proposed that the Linghou polymetallic and other similar deposits in the QHMB, such as the 150-160 Ma Yongping porphyry-skarn Cu-Mo, Dongxiang porphyry? Cu, Shuikoushan/Kangjiawang skarn Pb

Multiple Stage Ore Formation in the Chadormalu Iron Deposit, Bafq Metallogenic Province, Central Iran: Evidence from BSE Imaging and Apatite EPMA and LA-ICP-MS U-Pb Geochronology

Directory of Open Access Journals (Sweden)

Hassan Heidarian

2018-02-01

Full Text Available The Chadormalu magnetite-apatite deposit in Bafq metallogenic province, Central Iran, is hosted in the late Precambrian-lower Cambrian volcano-sedimentary rocks with sodic, calcic, and potassic alterations characteristic of iron oxide copper-gold (IOCG and iron oxide-apatite (IOA ore systems. Apatite occurs as scattered irregular veinlets and disseminated grains, respectively, within and in the marginal parts of the main ore-body, as well as apatite-magnetite veins in altered wall rocks. Textural evidence (SEM-BSE images of these apatites shows primary bright, and secondary dark areas with inclusions of monazite/xenotime. The primary, monazite-free fluorapatite contains higher concentrations of Na, Si, S, and light rare earth elements (LREE. The apatite was altered by hydrothermal events that led to leaching of Na, Si, and REE + Y, and development of the dark apatite. The bright apatite yielded two U-Pb age populations, an older dominant age of 490 ± 21 Ma, similar to other iron deposits in the Bafq district and associated intrusions, and a younger age of 246 ± 17 Ma. The dark apatite yielded a U-Pb age of 437 ± 12 Ma. Our data suggest that hydrothermal magmatic fluids contributed to formation of the primary fluorapatite, and sodic and calcic alterations. The primary apatite reequilibrated with basinal brines in at least two regional extensions and basin developments in Silurian and Triassic in Central Iran.

Geology of uranium vein-deposits in France; Geologie des gites uraniferes et filoniens en France

Energy Technology Data Exchange (ETDEWEB)

Sarcia, J A; Carrat, J; Poughon, A; Sanselme, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper gives an outline of the characteristics of the main uranium vein deposits in France; it underlines the structural, petrographic and metallogenic similarities of these deposits. (author) [French] La note presente est un expose des caracteres generaux des principaux gites uraniferes filoniens de France; elle insiste sur les similitudes structurales, petrographiques et metallogeniques de ces gisements. (auteur)

Uranium deposit research, 1983

International Nuclear Information System (INIS)

Ruzicka, V.; LeCheminant, G.M.

1984-01-01

Research on uranium deposits in Canada, conducted as a prerequisite for assessment of the Estimated Additional Resources of uranium, revealed that (a) the uranium-gold association in rudites of the Huronian Supergroup preferably occurs in the carbon layers; (b) chloritized ore at the Panel mine, Elliot Lake, Ontario, occurs locally in tectonically disturbed areas in the vicinity of diabase dykes; (c) mineralization in the Black Sturgeon Lake area, Ontario, formed from solutions in structural and lithological traps; (d) the Cigar Lake deposit, Saskatchewan, has two phases of mineralization: monomineralic and polymetallic; (e) mineralization of the JEB (Canoxy Ltd.) deposit is similar to that at McClean Lake; (f) the uranium-carbon assemblage was identified in the Claude deposit, Carswell Structure; and (g) the Otish Mountains area, Quebec, should be considered as a significant uranium-polymetallic metallogenic province

Metallogenetic prospecting in 1:2,000,000 scale for in-situ leachable sandstone type uranium deposit

International Nuclear Information System (INIS)

Wang Zhengbang; Qin Mingkuan; Zhao Ruiquan; Dong Wenming; Li Tiangang; Zheng Dayu; Li Sen; Lin Shuangxing

2002-01-01

By introducing the advanced theory and technology of systematic geo-mapping which is popularized in Central-Asian countries, the project is aimed at metallogenic prospecting in 1:2,000,000 scale for in-situ leachable sandstone type uranium deposits in Xinjiang and its adjacent area. Based on the comprehensive understanding of accumulated data and on the field study in both the work area and the abroad nearby, the authors propose creatively a new concept that the uranium mineralization in the area is controlled by the moderate tectonic movements during the last large-scale orogenic movement, and set up a new epi-genetically metallogenic system of Meso-Cenozoic depositional basins. Furthermore, the temporal-spatial evolution of the ore-controlled Himalaya orogenic movement is brought to light, and a new method to reconstruct the palaeo-tectonic and palaeo-hydrodynamic systems is created. Accordingly, the main differences in metallogenic conditions and prospecting evaluation between the work area and the Central-Asian areas are illustrated, and the favorable and unfavorable influences of the reduction by the exudative oil and gas on the sandstone type uranium mineralization in the work area are explained in detail. Finally, on the basis of compiling the systematic geo-maps and summarizing the assessment criteria, 2 metallogenic provinces and 12 prospecting areas are predicted. This conclusion can provide a scientific foundation for strategic plans to be made by leading groups and other branches. Another achievement of the project is that a guidebook of the systematic geo-mapping theory and technology has been compiled, which is beneficial to the spreading of the method

Application potential of sequence stratigraphy to prospecting for sandstone-type uranium deposit in continental depositional basins

International Nuclear Information System (INIS)

Li Shengxiang; Chen Zhaobo; Chen Zuyi; Xiang Weidong; Cai Yuqi

2001-01-01

Sequence stratigraphy has been widely used in hydrocarbon exploration and development, and great achievements have been achieved. However, its application to the prospecting for sandstone-type uranium deposits is just beginning. The metallogenic characteristics of sandstone-type uranium deposits and those of oil and gas are compared, and the relationship between sandstone-type uranium metallogenesis and the system tracts of sequence stratigraphy is studied. The authors propose that highest and system tracts are the main targets for prospecting interlayer oxidation zone type sandstone uranium deposits, and the incised valleys of low stand system tracts are favourable places for phreatic oxidation zone type sandstone uranium deposits, and transgressive system tracts are generally unfavorable to the formation of in-situ leachable sandstone-type uranium deposits. Finally, the authors look ahead the application potential of sequence stratigraphy to the prospecting for sandstone-type uranium deposits in continental depositional basins

Zircon U-Pb and molybdenite Re-Os geochronology and geological significance of the Baoshan porphyry Cu polymetallic deposit in Jiangxi province

Science.gov (United States)

Jia, Liqiong; Wang, Liang

2017-10-01

Baoshan porphyry Cu polymetallic deposit belongs to Jiujiang-Ruichang Cu-Au ore field, which is a component part of the Middle-Lower Yangtze River Cu-Au metallogenic belt. The U-Pb LA-MC-TCP MS dating of the zircons from Baoshan granodiorite porphyry yields an age of 147.81±0.48Ma (MSWD=1.07). Six molybdenite samples separated from Baoshan deposit are used for Re-Os dating and obtained the weighted average age of 147.42±0.84Ma and an isochron age of 147.7±1.2Ma. These ages suggest that the mineralization in the Baoshan deposit is genetically associated to the granodiorite porphyry, and the process of rock-and ore-forming is continuous. These data indicate that ages of intrusion and ore-body from Baoshan deposit are almost identical to other typical magmatic intrusion and deposits in Jiujiang-Ruichang metallogenic district. Tt is inferred that the Baoshan deposit was formed in the transition from EW-striking Tndosinian tectonic domain to NE-striking Paleo-Pacific tectonic domain.

Remote sensing information acquisition of paleo-channel sandstone-type uranium deposit in Nuheting area

International Nuclear Information System (INIS)

Liu Jianjun

2000-01-01

The author briefly describes the genesis and ore-formation mechanism of paleo-channel sandstone-type uranium deposit in Nuheting area. Techniques such as remote sensing digital image data processing and data enhancement, as well as 3-dimension quantitative analysis of drill hole data are applied to extract information on metallogenic environment of paleo-channel sandstone-type uranium deposit and the distribution of paleo-channel

New idea on the classification of world super-large deposits

International Nuclear Information System (INIS)

Tong Hangshou

2012-01-01

According to the theory of 'multi factors and compound genesis', 'complexity of mineralization' and 'metallogenic series', this paper proposed a new classification idea on the world super-large deposits with the combination of new results on the study of global background for super-large deposits and the model of 'conjugation of multi-source and focus of multi-factors'. 15 super-large deposits with the reserve over 50000 t were studied as the ases, 6 types and 13 sub-types of economics-genesis have been divided for the super-large deposit. The classification is discoursed with symbols and worlds and brief introduction on typical deposit. (authors)

The mineralization and mechanism of the endogenetic mineral deposit in China

International Nuclear Information System (INIS)

Jiang Yonghong

2010-01-01

In the process of mineralization, due to the difference in rank, scale and order of structures orebody, mine colomn or rich ore bag are often produced in the specific structural parts. Obviously, it is controlled by favourite structure. The important and direct control of the structure to metal endogenetic mineralization evolution are representative on the affect of pulse action of structure to the multi-stage of mineralization evolution. According to the formation environment of the mineralization, it can be classified as collision orogeny mineralization, release(extension)mineralization, slide draw-division basin mineralization and shear zone extension mineralization. Throng the discuss of endogenetic deposit in the geological evolution, structure and formation machenism, the metallogenic model was preliminary established,and the criteria for delineating favourable metallogenic area was identified. (authors)

The siliceous-calcareous-argillaceous rock type uranium deposit in south subzone of Western Qinling

International Nuclear Information System (INIS)

Qian Farong; Zhou Dean; Ji Hongfang

1995-11-01

The siliceous-calcareous-argillaceous rock type uranium deposit in south subzone of western Qinling is an inland found type deposit with specific mineralization and good potentiality. The mineralization distributes along definite horizons and occurs in siliceous layer and lenses of siliceous-calcareous rocks. Orebody presents in forms of stratoid, lenticular and irregular veins and controlled by factorial structures. Ore is identified as massive and sandy and each characterized by various mineral compositions and element associations. The study shows that the mineralizing materials are mainly derived from ore-bearing strata. The metallogenic environment has characteristics of middle-low temperature and supergene The metallogenesis underwent three stages: (1) Sedimentation-diagenesis of the ore-bearing strata led to preliminary concentration of uranium; (2) Polytectonic activities accompanied by underground hydrothermal process resulted in the industrial concentration of uranium; and (3) Orebody reworked by oxidation-denudation and leaching, locally has taken place secondary concentration. The deposit in origin attributes to polygenesis dominated by underground hydrothermal metallogenesis. Main metallogenic epoch happens during the periods of Late Yanshan and Himalayan. According to the geological-tectonic conditions the further prospecting direction in study area is proposed. (3 refs., 5 figs., 9 tabs.)

Recent exploration progresses on sandstone-hosted uranium deposits in north-western China

International Nuclear Information System (INIS)

Li, Z.

2014-01-01

The metallogenic target selection using multiple exploration techniques and drilling program for sandstone-hosted uranium deposits have been intensively carried out for recent years, and big progresses on new discoveries of uranium reserve/resource have been made in the Mesozoic sedimentary basins such as in Yili, Ordos etc. in North-western China The Yili basin is a depression one within the Tianshan Mountain belt in the western part of China. Its basement is composed of Proterozoic-Paleozoic metamorphic and sedimentary rocks, and covers of Mesozoic sediments. The early-middle Jurassic Shuixigou Group is major uranium-productive beds which are composed of three Formations such as Badaowan, Sangonghe, Xisanyao and eight sedimentary cycles. Uranium deposits are found in the south margin of the Basin and controlled by the redox zone. The combined exploration techniques of detailed sedimentary facies study, Rn-survey, high-precision magnetic and soil geochemical and seismic surveys have been successfully used to have locate the potential targets and mineralization zones. The enlargement of uranium reserve/resources in the known deposits and new resources in the selected new targets and cycles have been achieved through further drilling programs. The Ordos basin is a large Meso-Cenozoic basin developed in North China Platform, with its size of approximately 250,000 km"2 and is well known as an important “energy resources basin” because of abundance of coal, oil and gas deposits. The Dongsheng sandstone type uranium deposit is a large one discovered in recent years in northeastern Ordos basin. It is a special kind of sandstone type uranium deposit, different from other ordinary sandstone type deposits because of its unique signatures. It is generally controlled by a transitional zone between greenish and grayish sandstones, both of those two kinds of sandstones now indicate reduced geochemical environments. The greenish color of the paleooxidized sandstones mainly

An exploration systems approach to the Copper Mountain uranium deposits, Wyoming, USA

International Nuclear Information System (INIS)

Babcock, L.L.; Sayala, D.

1982-01-01

This study of Copper Mountain uranium deposits entailed the examination, interpretation, and synthesis of geological, geochemical, geophysical, and emanometric results. Regional, structural, and metallogenic syntheses yielded criteria concerning the occurrence of anomalously radioactive granites and associated uranium deposits. Geochemical surveys indicated various pathfinder elements for uranium deposits and defined the extent of the anomalous granites. Subsurface spectral radiometrics outlined high K-Th zones which contain secondary uranium deposits. Aerial spectral radiometric and magnetic surveys delineated the Copper Mountain uranium district. Ground water helium and U-234/U-238 activity ratios are the most effective emanometric and isotopic techniques. Based on the systems approach employed and logistical considerations, a five-phase exploration strategy is suggested for Copper Mountain-type deposits

Discussion on spatial emplacement of exogenic-epigenetic infiltration-type uranium deposit

International Nuclear Information System (INIS)

Zhao Fengmin

2005-01-01

Exogenic-epigenetic infiltration-type uranium deposit is a kind of deposit with large resources, low exploitation cost, and less environmental pollution being the recent important prospecting target in China. Prospecting practice for uranium during recent decade indicates that the metallogenic model and prospecting-evaluation criteria obtained from sandstone-hosted uranium deposits in Middle Asia are not applicable to the case in China. China is a country which has been subject to intense neotectonism, and Meso-Cenozoic basins in China have experienced various tectonic reworking. According to the spatial relation to orogenic belts sedimentary basins may be divided into: basins in orogenic belt; basins near orogenic belt and basins with weak tectonic activation far away from orogenic belt. Then, based on the structural features, basins may be further divided into corresponding subtypes. The author discusses the favourability of each type basin for the formation of exogenic-epigenetic uranium mineralization, as well as the paleo-climatic conditions for uranium ore-formation. Then, the author proposes that, for small intracontinental basins recharged by natural groundwater, the arid climatic period is not totally a favourable factor for uranium ore-formation, it even could be an unfavourable factor. In contrast, basins located in humid climatic region may be advantageous to uranium ore-formation. For improving the prospecting efficiency, a metallogenic model for exogenic-epigenetic infiltration uranium deposits and corresponding prospecting-evaluation criteria suitable for geologic situation of China have to be established as soon as possible. (authors)

Prospecting ideas for mesozoic granite-type, volcanics-type and exo-contact-type uranium deposits in South China. Pt.1

International Nuclear Information System (INIS)

Yu Dagan

2001-01-01

The Mesozoic uranium ore-formation process in South China resulted from the intense volcanic magmatism, the crust-mantle interaction and the fluidization in Yanshanian period, and there is great prospect for large-scale uranium concentration and ore-formation. Therefore, during the prospecting for Mesozoic granite-type, volcanics-type and exo-contact-type uranium deposits it is necessary to introduce deep-source metallogenic theory, to 'desalt' metallogenic theory of epithermal activation, to fully realize that uranium deposits may be formed not only at shallow depth, but also in conditions of deep-source, great depth and high temperature, as well as in environments of deep-source, shallow depth and median temperature, to give emphasis to the early-stage (130-95 Ma) uranium mineralization, to break the man-made boundary in prospecting for uranium only based on host rock type, to strengthen the research on Cretaceous magmatic system

The controlling role of positive structures over the metallogenesis and emplacement of inter layer oxidation sandstone type uranium deposits

International Nuclear Information System (INIS)

Gu Kangheng; Chen Zuyi

2010-01-01

The positive structures in this paper mean the geological structures related to the occurrence of U-metallogenic zones or U-deposit such as anticlines, uplifts and uplifted fault-blocks. Occurrence features of interlayer oxidation sandstone type deposit at the southern margin of Yili basin and southwestern margin of Turpan-Hami basin, the northeastern margin of Jiudong basin illustrate that the sandstone-hosted uranium deposits, the U-mineralized sections and the uranium occurrences are always selectively emplaced on/in positive structures. The reasons for this lie in the formation mechanism of sandstone-hosted U-deposits. The positive structures raised the elevation of ore-hosting sandstone horizon and make it close to ground surface or exposed at the ground surface, which result in the infiltration of uranium and oxygen bearing groundwater from recharge area into host sandstone horizon, and the interlayer oxidation of host sandstone, as well as the dissolution and the migration of uranium in host sandstone, and the reduction mineralization at the oxidation-reduction interface. Sufficient attention should be paid to the controlling role of positive structures over the metallogenesis and emplacement of sandstone-hosted uranium deposits. They could act as an important criterion for recognizing and prognosticating potential uranium mineralized areas in uranium metallogenic zones or uranium-productive sedimentary basins. (authors)

Preliminary discussion on prospecting potential for sandstone-type uranium deposits in meso-cenozoic basins, northern Ordos

International Nuclear Information System (INIS)

Di Yongqiang

2002-01-01

Characteristics of the regional stratigraphy, tectonic movement, geologic evolution and hydrogeology are briefly introduced. Using the metallogenic theory and prospecting criteria for interlayer oxidation zone sandstone-type uranium deposits, the author analyses the prospecting potential and main prospecting targets in the region, and proposes suggestions for further prospecting work as well

Preliminary discussion on deep-sourced uranium metallogenesis and deep prospecting

International Nuclear Information System (INIS)

Huang Shijie

2006-01-01

Prospecting for hydrothermal type uranium deposits should be aimed at medium-to large-sized deposits, and be guided by mantle-sourced, superimposed, deep-sourced metallogenic theory and the establishment of a multifactor, composite, deep-sourced metallogenic model. The author suggests that hydrothermal uranium deposits may be classified into three genetic types, i.e. hydrothermal circulation concentration, postmagmatic hydrothermal and mantle fluid concentration. These types of uranium deposits are characterized by their own metallogenic features and are concentrated in the same mineralization-concentrated area forming a metallogenic series. Large-sized uranium ore fields and rich-large uranium deposits are usually closely associated with mantle-sourced metallogenesis and the formation of such uranium ore fields and deposits is characterized by specific and unique regional geologic environments. Recognition criteria of mantle-sourced metallogenesis are preliminarily proposed in the paper. It is pointed out that prospecting in the future should follow the metallogenic model proper for the specific genetic type, and the establishment of operable prospecting model to realize the model-guided prospecting. (authors)

Age, genesis and exploration for mineral deposits: the possibilities offered by lead isotopes

International Nuclear Information System (INIS)

Marcoux, E.; Calvez, J.Y.

1985-01-01

After a brief theoretical survey of the subject, the paper discusses the assistance that lead isotopes can bring to solving problems of metallogenesis and mineral exploration. Lead isotopes act as a true geologic clock when radioactive decay of lead takes place in a closed U-Th-Pb system, or when these conditions have been recreated by homogenization of a large crustal segment. The lead clock is thus reliable for deposits whose process of formation was part of a hydrothermal event that affected a significant part of the crust, most importantly in island-arc volcanosedimentary deposits, much less so for deposits formed by spatially restricted hydrothermal activity such as the emplacement of veins. Very interesting possibilities are also to be found in the capacity of lead isotopes to act as geochemical tracers. In conjunction with paragenetic and gitologic studies, determination of the isotopic composition of lead allows the sources of metals to be identified and permits an approach to the understanding of inheritance phenomena in a mineral deposit or province. This information also assists in unravelling the successive metallogenic processes in a region, thus contributing to refinement of the concept of a metallogenic province. Lastly lead isotopes provide an additional factor in assessing the economic potential of a deposit undergoing exploration. The method is based on a comparison of the isotopic signature of the deposit with that of economic mineralization occuring elsewhere in the circa. Examples of stratiform deposits and the gold-bearing veins of Limousin are described. The application of this method to gossans can provide additional information to standard geochemistry and thus assist in grading of targets [fr

Analysis of Characteristics of Ore about Iron Deposit of Da Hong Mountain in Yun Nan Province

Directory of Open Access Journals (Sweden)

Zhang Yuefeng

2016-01-01

Full Text Available This thesis aims to analyse the deposit characteristics about Da Hong Mountains Iron ore in Yunnan province. The texture and structure, especially the chemical composition, is different in every section of deposit after comparing. Moreover, the content of SiO2 is much higher than general iron ore. However, the content of other noble metals cannot reach the lowest industrial grade. Da Hong Mountains Iron ore has unique features because of metallogenic periods.

Uranium mineralization environment and prospecting potential of Dawan ore field in Nanling metallogenic belt

International Nuclear Information System (INIS)

Yang Shanghai

2011-01-01

Located in the middle part of Jiuyishan complex pluton, Nanling metallogenic belt, Dawan uranium ore field in Hunan Province is an important uranium-producing and rare metal, nonferrous metal cluster area due to the favourable mineralization environment. The Cambrian is the main uranium source bed and their contact zone to the pluton is the favorable part for mineralization. The uranium deposits which have been explored are all located in the exocontact zone of Jinjiling pluton in the middle part of Jiuyishan complex pluton which is composed of the independent eastern and western magma evolution centers. In the west center, Jinjiling pluton is closely related to uranium mineralization where the trinity geologic setting was formed with magma evolution, hydrothermal fluid action and mineralization. The deep slitted and large faults provide the pathway and thermodynamic source for circulating migration of mineralizing fluid. The uranium mineralization mainly occurred in crustal stress conversion period of Late Cretaceous and related to the tensive NW extending fault and deep originated fluid. The gravity, aero magnetic, airborne gamma-ray spectrometry anomalies and radioactivity hydrochemical anomaly are important criteria for uranium prospecting. Based on the analysis of regional uranium mineralization environment, the prospecting potential is forecasted. (authors)

Recent Exploration Progresses on Sandstone-Hosted Uranium Deposits in Northwestern China

International Nuclear Information System (INIS)

Li Ziying

2014-01-01

Conclusions: 1. China nuclear power development is stimulating exploration for uranium resources. 2. Big progress on exploration for sandstonehosted uranium deposits have been made for recent years. 3. The combined exploration techniques are effectively used for locating ore beds and targeting uranium mineralization. 4. Metallogenic models have played important roles in expansion and new discoveries of u-deposits. 5. Uranium is very mobile and can be enriched in the different types of rocks. 6. Greenish sandstone is due to chlorite alteration by secondary reduction process related to oil and gas and can be used to indicate uranium mineralization.

Metallogenic specialization of supercontinent cycles: A case study of silver deposits

Science.gov (United States)

Tkachev, A. V.; Rundqvist, D. V.; Vishnevskaya, N. A.

2017-07-01

The distribution of integrated resources of large and superlarge mineral deposits (LSLDs) of silver, where the main part of industrially recoverable silver reserves is concentrated, is compared with the existing model of supercontinent cyclicity over the geological history of the Earth. It is found that each supercontinent cycle (Kenoran, Columbian, Rodinian, Pangean, and Amasian) is particularly expressed in the silver metallogeny. The significant intercycle variations in the numbers of LSLDs, diversity of types of these deposits, accumulated resources, mean tenors of silver in ores, and some other numerically expressible characteristics are revealed. These variations correlate with a number of geohistorical changes in the conditions under which endogenous and exogenous geological processes run.

Magmatism and tertiary mineralization of the Kozuf metallogenetic district, the Republic of Macedonia with particular reference to the Alsar deposit

International Nuclear Information System (INIS)

Jankovikj, Slobodan; Boev, Blazho; Serafimovski, Todor

1997-01-01

The Kozhuf metallogenetic district is formed in the marginal parts between the Republic of Macedonia and Aridai region in northern Greece. Hence, the most appropriate name for this metallogenetic unit would be Kozhuf - Aridai area. This Monograph presents, in a synthesized manner, results of investigations carried out so far in the territory of the Republic of Macedonia. The part that is situated in the terrane of Greece is poorly investigated and studied, particularly in the domain of its ore mineralization. Some investigations, however, were carried out in the sector of Voros. The Monograph includes detailed investigations of petrologic features of the Kozhuf magmatic complexes, as well as regional features of the metallogeny in Kozhuf as part of a larger metallogenic unit in south-east Europe. Particular reference is given to the geochemical metallogenetic features of the Sb-As-Tl-Au Alshar deposit that belongs to this metallogenic district and shows a number of specific mineralogic, geochemical and metallogenetic features that make it a unique deposit in the world. Since the Alshar deposit is insufficiently investigated, results presented in this Monograph should be considered as preliminary. Detailed and systematic examinations are in progress. (author)

Analysis on paleo-hydrogeological conditions of uranium formation in Sawafuqi uranium deposit

International Nuclear Information System (INIS)

Lin Xiaobin; Hao Weilin; Wang Zhiming

2013-01-01

Sawafuqi uranium deposit is located in Kuergan intermontane basin of the South Tianshan (STS) fold belt. On the basis of regional tectonics, paleogeography, paleoclimate and related data, the evolution of intermontane basin could be divided into three hydrogeological cycles. The relationship of uranium mineralization to each cycle was analyzed from the perspective of the evolution of palaeo-hydrogeological conditions, and the uranium metallogenic model in palaeohydrogeology under strongly constructive background was established. (authors)

Uranium metallogenic geological conditions in the south central section of da hinggan mountains

International Nuclear Information System (INIS)

Wang Qing; Liu Qing

2014-01-01

The south central section of Da Hinggan Mountains, where the Zha Lantun prospecting zones of volcanic type uranium ore, is a high density concentrated distribution area of uranium and polymetallic mineral. This article elaborated uranium metallogenic geological conditions in the south central section of Da Hinggan Mountain, from the tectonic conditions, the source of uranium, the heat source, the space for ore-forming, hydrothermal alteration, the mineralization, and ect. This area has a good prospecting foreground and potentiality. (authors)

Sequence stratigraphy and uranium metallogenic characteristics in Xinminpu group, lower cretaceous, in Gongpoquan basin

International Nuclear Information System (INIS)

Gong Binli; Wang Jingping

2006-01-01

Characteristics of sequence stratigraphy, the distribution and the geologic time of sequence, boundary features and internal composition, the sedimentary facies, as well as the characteristics of interlayer oxidation zone and U-mineralization are expounded. It is suggested that the Gongpoquan area is of certain prospect for U-prospecting, and uranium metallogenic conditions are not favorable in the Beiluotuoquan area, and the Nalinsuhuai area has no prospect either. (authors)

Reviews on the metallogenic and geological features of sandstone-type uranium deposits in Japan

International Nuclear Information System (INIS)

Pei Chengkai; Huang Xianfang; Zhang Baoju

2006-01-01

Regional geologic settings of sandstone-type uranium deposits in Japan are firstly analyzed. The regional tectonic evolution characteristics of 'Green tuff region' and 'Non green tuff region' and their relationship with uranium mineralization are elaborated in depth. Based on those mentioned above, the uranium sources of sandstone-type uranium deposits in Japan are discussed deeply and the most favorable uranium sources are considered to come from the basement and the surrounding granites. Their intrusive epochs range from Later Cretaceous to Palaeogene (about 60 to 70 Ma ago). The characteristics of ore-bearing host rocks, matter compositions of the deposits, ore formation enrichment factors, the hydrogeologic conditions and so on are described by taking Ningyo-Toge and Tono deposits as examples. Finally, the prospecting measures for the palaeo-channel sandstone-type uranium deposits (basal type) are reviewed. (authors)

Petrographic study of hypo-thermal and pyro-metasomatic deposits on the oriental border of Tichka mountain (Occidental High Atlas, Morocco); Contribution a l'etude des gites hypothermaux et pyrometasomatiques en fonction de la petrographie dans la bordure orientale du Massif du Tichka (Haut Atlas occidental)

Energy Technology Data Exchange (ETDEWEB)

Bizard, C; Ziegler, V [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

It describes the petrographic and metallogenic study of the oriental side of Tichka mountain (Occidental High Atlas, Morocco) which is the center of an anticlinal system, strongly folded, and approximately SW-NE oriented. The main object of this study is the description of its metallogenic activity and in particular the large variety of paragenesis which have been observed in the oriental part of Tichka mountain where the metamorphism is intense. This area presents a large abundance and diversity of deposits. The structural aspect of the oriental part of the Tichka mountain is described. The petrographic study of the complex structure of the oriental border, in particular the studies of the leucocratic complex of veins and apophyses and of the schistous and calcareous metamorphic complex, leads to make assumptions on the relationship between terminal phase of the metamorphism and the hypo-thermal paragenesis. The abundance of facies and the intensity of metamorphism also give the possibility to establish relationships between the different minerals deposits. The metallogenic study shows that mineralization are all peripheral on the Tichka mountain and increase with the number and size of the apophysis which is observed on the east side. The various hypo-thermal paragenesis are studied in the same order of the associated apophysis. The peripheral meso-thermal deposits of the north area are briefly described to complete the metallogenic aspects of the oriental border of the Tichka mountain. This study shows the nature of the two main factors which originate different types of paragenesis: one is the intrusion deep of the mineralizer, the second is the physical and chemical nature of the medium where the paragenesis occurred. (M.P.)

Intermediate sulfidation type base metal mineralization at Aliabad-Khanchy, Tarom-Hashtjin metallogenic belt, NW Iran

Science.gov (United States)

Kouhestani, Hossein; Mokhtari, Mir Ali Asghar; Chang, Zhaoshan; Johnson, Craig A.

2018-01-01

The Aliabad-Khanchy epithermal base metal deposit is located in the Tarom-Hashtjin metallogenic belt (THMB) of northwest Iran. The mineralization occurs as Cu-bearing brecciated quartz veins hosted by Eocene volcanic and volcaniclastic rocks of the Karaj Formation. Ore formation can be divided into five stages, with most ore minerals, such as pyrite and chalcopyrite being formed in the early stages. The main wall-rock alteration is silicification, and chlorite, argillic and propylitic alteration. Microthermometric measurements of fluid inclusion assemblages show that the ore-forming fluids have eutectic temperatures between −30 and −52 °C, trapping temperatures of 150–290 °C, and salinities of 6.6–12.4 wt% NaCl equiv. These data demonstrate that the ore-forming fluids were medium- to high-temperature, medium- to low-salinity, and low-density H2O–NaCl–CaCl2 fluids. Calculated δ18O values indicate that ore-forming hydrothermal fluids had δ18Owater ranging from +3.6‰ to +0.8‰, confirming that the ore–fluid system evolved from dominantly magmatic to dominantly meteoric. The calculated 34SH2S values range from −8.1‰ to −5.0‰, consistent with derivation of the sulfur from either magma or possibly from local volcanic wall-rock. Combined, the fluid inclusion and stable isotope data indicate that the Aliabad-Khanchy deposit formed from magmatic-hydrothermal fluids. After rising to a depth of between 790 and 500 m, the fluid boiled and subsequent hydraulic fracturing may have led to inflow and/or mixing of early magmatic fluids with circulating groundwater causing deposition of base metals due to dilution and/or cooling. The Aliabad-Khanchy deposit is interpreted as an intermediate-sulfidation style of epithermal mineralization. Our data suggest that the mineralization at Aliabad-Khanchy and other epithermal deposits of the THMB formed by hydrothermal activity related to shallow late Eocene magmatism. The altered Eocene volcanic and

Regional evaluation and primary geological structural and metallogenical research of great Kavir basin as view of possibility formation of sedimentary-surficial Uranium mineralization

International Nuclear Information System (INIS)

Kamali Sadr, S.

2006-01-01

Great Kavir basin is the largest inner basin in Iran that extended about 90000 km 2. This basin is situated in the centre of lran , to the south from Alborz mountain range and elongated in the sub- latitudinal trend and its construction is asymmetric. The basin cover consists generally of complicated sequence of continental - marine Oligocene - Miocene molasses. According to drainage systems - conditions, molassoid cycles, alluvial, alluvial - deltaic and lacustrine sediments, climate, morphological conditions and metallogenic and structural features, Great Kavir depression generally is favorable for exigence and surficial uranium deposits (vally - fill, flood plain, deltaic and playa). Uranium occurrences that are Known in the southern and north eastern part of the margent Great Kavir basin, are Arosan, Irekan and Mohammad Abad. Similar geological - structural conditions for uranium mineralization is possible in the margent of Great Kavir basin

The Mianhuakeng deposit no. 9 with -50 m to -150 m middle production prospecting practice some understanding

International Nuclear Information System (INIS)

Bi Yide; Tan Zhongyin; Kuang Zhengping; Hou Zhiyong; Qiu Huiyuan

2014-01-01

The production prospecting is an extension of prospecting, it can identify deposits occurrence conditions in the main deposits mined, geological factors, ore grade distribution characteristics of type and So on, it can provide a reliable geological data for the development plan of the section and the quasi - Design in order to reduce mining costs and improve economic benef. This article through to the Mianhuakeng Deposit No. 9 with -50 m to -150 m middle production prospecting practice some understanding, sum up the metallogenic conditions, ore controlling factors, ore characteristics, to realize the optimization of production prospecting, so as to lower the cost for the better prospecting effect. (authors)

Uranium metallogenic model related to CO2 and hydrocarbon in granite type uranium deposits

International Nuclear Information System (INIS)

Ou Guangxi; Chen Anfu; Cui Jianyong; Xu Yinhuan; Wang Chunhua; Xu Yan

2001-01-01

The report is concerned with the inseparable connections between the uranium migration, enrichment rule and the geochemical characteristics of CO 2 and hydrocarbon gas, as well as the relations between the deposit locations and the gas abnormal distribution in rocky body, which are based on the analysis of some data and phenomena in 11 typical deposits in 2 granite type uranium ore fields, including the observations of 250 rocky fluid inclusion sections and the analyzed data of which 2470 are in gas composition, 200 in uranium content, 50 in thermometry. All the conclusions are drawn from different angles for the first time and this new exploration and advancement fills up the blank of gas geochemistry study in uranium deposits or other metal deposits

Characteristics and model of sandstone type uranium deposit in south of Songliao basin

International Nuclear Information System (INIS)

Yu Wenbin; Yu Zhenqing

2010-01-01

Through analyzing the uranium deposit tectonic environment, upper cretaceous sequence stratigraphy, depositional system, evolutionary characteristics of sand bodies, the effect of subsequent transformation and the characteristic of uranium deposit, the sandstone type uranium deposit in southern basin is different from typical interlayer oxidation zone sandstone type uranium deposit. The formation and evolution of sandstone-type uranium deposit are controlled by structure fensters; the favorable sedimentary facies type is braided river facies, and the ore body is braided river sand body. The size of uranium deposits is controlled by the local oxidation zone with the characteristics of sandstone type uranium deposit in partial oxidation zone. Uranium ore bodies which distribute in the roof wings of structure fenstes, and occur in gray layers between the upper and lower oxidation zone, showing tabular, and the plate of uranium ore body is controlled by the local oxidation zone. Based on the geological features of sandstone-type uranium deposits, the metallogenic model of local oxidation zones sandstone-type uranium deposits has been set up in the south of Songliao Baisn. (authors)

Metallogenic aspects of the feldspars and micas geochemistry in pegmatite from Alto-Ligonha (Mocambique)

International Nuclear Information System (INIS)

Neves, J.M.C.

1990-01-01

This paper deals with metallogenic aspects concerning the huge Alto Ligonha pegmatite Province. The geological setting of the pegmatites is briefly reviewed and the metamorphic grade of the country rocks of the pegmatites, ranging from granulitic to greenschist facies, has been considered. The economically most interesting pegmatites are those emplaced within rocks with lighter metamorphism. The available geochronological data allow us to link, the most interesting pegmatites from Alto Ligonha, to the Pan-African granitoid magmatism, about 500 Ma ago. (author)

Distribution regularities and prospecting of carbonate-siliceous-argillitic rock type uranium deposit in China

International Nuclear Information System (INIS)

Zhao Fengmin; Pan Yan

2012-01-01

The carbonate-siliceous-argillitic rock type uranium deposit is one of the important types of uranium deposits in China. Exogenic permeability type and hydrothermal type are dominated in genetic type. Four mineralization zones, two independent mineralization districts, two potential mineralization zones can be classified in China, uranium mineralization districts can be classified further. They are classified as four levels through the potential metallogenic evaluation on the mineralization districts, an important prospective area in the near future. In order to develop and make use of carbonate-siliceous-argillitic rock type uranium resources, exploration and study should be listed in the development planning on uranium geology. (authors)

Main types and metallogenetic characteristics of sandstone-type uranium deposits in central asian mobile belt and its neighbouring area, and the study on prospecting direction of northwest China

International Nuclear Information System (INIS)

Fu Chengming

2007-01-01

Based on the study of geotectonic setting, formation evolution model and metallogenic characteristics of uranium productive basins, important sandstone-type uranium deposits in Central Asian mobile belt and neighbouring area are divided into five types. The statial distribution pattern of different sandstone-type uranium deposits is analyzed in detail. Geotectonic setting and metallogenetic characteristics are discussed. Finally, the characteristics of basin geodynamics, prospecting type and ore-bearing stratigraphy in Northwest China have been proposed. (authors)

Analysis on uranium resource situations and metallogenic potential of Heyuan mineralization belt of Guangdong province

International Nuclear Information System (INIS)

Chen Zhuhai; Zheng Mingliang; Song Shizhu; Liang Yewu; Zhao Wei

2008-01-01

Heyuan mineralization belt is a structure-magmatic activities belt which is charcterized by strong plastic deformation and shearing. The squeeze (overthrust) structure is formed early. Later stretch produced slide shovel-shaped normal fault which control the red basin and uranium mineralization. Comprehensive study shows that this area is of favorable uranium metallogenic condition due to the rich uranium source and higher degree of geology work, it is a target for the new round resources exploration. (authors)

Phanerozoic Rifting Phases And Mineral Deposits

Science.gov (United States)

Hassaan, Mahmoud

2016-04-01

In North Africa occur Mediterranean and Red Sea metallogenic provinces. In each province distribute 47 iron- manganese- barite and lead-zinc deposits with tectonic-structural control. The author presents in this paper aspects of position of these deposits in the two provinces with Phanerozoic rifting . The Mediterranean Province belongs to two epochs, Hercynian and Alpine. The Hercynian Epoch manganese deposits in only Moroccoa- Algeria belong to Paleozoic tectonic zones and Proterozoic volcanics. The Alpine Epoch iron-manganese deposits are of post-orogenic exhalative-sedimentary origin. Manganese deposits in southern Morocco occur in Kabil-Rief quartz-chalcedony veins controlled by faults in andesitic sheets and in bedded pelitic tuffs, strata-form lenses and ore veins, in Precambrian schist and in Triassic and Cretaceous dolomites. Disseminated manganese with quartz and barite and effusive hydrothermal veins are hosted in Paleocene volcanics. Manganese deposits in Algeria are limited and unrecorded in Tunisia. Strata-form iron deposits in Atlas Heights are widespread in sub-rift zone among Jurassic sediments inter-bedding volcanic rocks. In Algeria, Group Beni-Saf iron deposits are localized along the Mediterranean coast in terrigenous and carbonate rocks of Jurassic, Cretaceous and Eocene age within faults and bedding planes. In Morocco strata-form hydrothermal lead-zinc deposits occur in contact zone of Tertiary andesite inter-bedding Cambrian shale, Lias dolomites and Eocene andesite. In both Algeria and Tunisia metasomatic Pb-Zn veins occur in Campanian - Maastrichtian carbonates, Triassic breccia, Jurassic limestone, Paleocene sandstones and limestone and Neogene conglomerates and sandstones. The Red Sea metallogenic province belongs to the Late Tertiary-Miocene times. In Wadi Araba hydrothermal iron-manganese deposits occur in Cretaceous sediments within 320°and 310 NW faults related to Tertiary basalt. Um-Bogma iron-manganese deposits are closely

LA-ICP-MS U-Th-Pb Dating and Trace Element Geochemistry of Allanite: Implications on the Different Skarn Metallogenesis between the Giant Beiya Au and Machangqing Cu-Mo-(Au Deposits in Yunnan, SW China

Directory of Open Access Journals (Sweden)

Yu Fu

2017-12-01

Full Text Available The giant Beiya Au skarn deposit and Machangqing porphyry Cu-Mo-(Au deposit are located in the middle part of the Jinshajiang–Ailaoshan alkaline porphyry metallogenic belt. The Beiya deposit is the largest Au skarn deposit in China, whilst the Machangqing deposit comprises a well-developed porphyry-skarn-epithermal Cu-Mo-(Au mineral system. In this paper, we present new allanite U-Th-Pb ages and trace element geochemical data from the two deposits and discuss their respective skarn metallogenesis. Based on the mineral assemblage, texture and Th/U ratio, the allanite from the Beiya and Machangqing deposits are likely hydrothermal rather than magmatic. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS allanite U-Th-Pb dating has yielded Th-Pb isochron ages of 33.4 ± 4.6 Ma (MSWD = 0.22 (Beiya and 35.4 ± 9.8 Ma (MSWD = 0.26 (Machangqing, representing the retrograde alteration and magnetite skarn mineralization age of the two deposits. The Beiya and Machangqing alkali porphyry-related mineralization are synchronous and genetically linked to the magmatic hydrothermal activities of the Himalayan orogenic event. Major and trace element compositions reveal that the Beiya allanite has higher Fe3+/(Fe3+ + Fe2+ ratios, U content and Th content than the Machangqing allanite, which indicate a higher oxygen fugacity and F content for the ore-forming fluids at Beiya. Such differences in the ore-forming fluids may have contributed to the different metallogenic scales and metal types in the Beiya and Machangqing deposit.

Application of soil radon survey to searching for sandstone-type uranium deposit at western margin of Ordos basin

International Nuclear Information System (INIS)

Liu Hanbin; Yin Jinshuang; Cui Yonghui

2006-01-01

On the basis of condition tests of soil radon survey at certain uranium deposit in Ordos basin, regional soil radon survey was carried but in a study area of western margin of Ordos basin. By processing of soil radon survey data, five anomalous areas with certain metallogenic potential have been delineated. Then, discovered anomalies have been interpreted and evaluated for providing important reference for further drilling work. Research results indicate that by soil radon survey, anomalies may be distinguished in a basin, and soil radon survey could be an important geochemical prospecting method for rapid evaluation of sandstone-type uranium deposit in basin areas. (authors)

Tempo of magma degassing and the genesis of porphyry copper deposits.

Science.gov (United States)

Chelle-Michou, Cyril; Rottier, Bertrand; Caricchi, Luca; Simpson, Guy

2017-01-12

Porphyry deposits are copper-rich orebodies formed by precipitation of metal sulphides from hydrothermal fluids released from magmatic intrusions that cooled at depth within the Earth's crust. Finding new porphyry deposits is essential because they are our largest source of copper and they also contain other strategic metals including gold and molybdenum. However, the discovery of giant porphyry deposits is hindered by a lack of understanding of the factors governing their size. Here, we use thermal modelling and statistical simulations to quantify the tempo and the chemistry of fluids released from cooling magmatic systems. We confirm that typical arc magmas produce fluids similar in composition to those that form porphyry deposits and conclude that the volume and duration of magmatic activity exert a first order control on the endowment (total mass of deposited copper) of economic porphyry copper deposits. Therefore, initial magma enrichment in copper and sulphur, although adding to the metallogenic potential, is not necessary to form a giant deposit. Our results link the respective durations of magmatic and hydrothermal activity from well-known large to supergiant deposits to their metal endowment. This novel approach can readily be implemented as an additional exploration tool that can help assess the economic potential of magmatic-hydrothermal systems.

Application research on remote sensing geology of sandstone-type uranium deposit in Yili basin

International Nuclear Information System (INIS)

Wang Huaiwu

2002-01-01

Based on remote sensing images and practical materials, and new ideas of laying particular emphasis on the research of regional geologic structures, and large in-situ leachable sandstone-type uranium deposits, applying the theory of plate tectonics, the author makes a comprehensive analysis on the uranium metallogenic environments, characteristics of regional geologic structures, the ore-controlling mechanism and factors, and uranium metallogeny. Authors propose that large interlayer oxidation zone sandstone-type uranium deposits are controlled by the combination of the stable block in Meso-Cenozoic compressive-shearing faulted subsided basin on the Yili multiphase massif in Tianshan paleo-island arc system, and the specific paleo-geographic environments and its' structural terrace'. The origin of hydrogenic sandstone-type uranium deposits is summarized by the authors as the 'mixing and neutralization' genetic model, and the 'eight ore-controlling factors merge into an organic whole' prospecting model. The above mentioned provides clear prospecting direction and new ideas for the forecasting direction for prospecting large sandstone-type uranium deposits

Correlations between the North China Craton and the Indian Shield: Constraints from regional metallogeny

Directory of Open Access Journals (Sweden)

Caifeng Li

2015-11-01

Full Text Available The correlation between the North China Craton (NCC and the Indian Shield (IND has been a hot topic in recent years. On the basis of ore deposit databases, the NCC and IND have shown broad similarity in metallogenesis from the middle Archaean to the Mesoproterozoic. The two blocks both have three major metallogenic systems: (1 the Archaean BIF metallogenic system; (2 the Paleoproterozoic Cu-Pb-Zn metallogenic system; and (3 the Mesoproterozoic Fe-Pb-Zn system. In the north margin of the NCC and the west margin of the IND, the Archaean BIF-Au-Cu-Pb-Zn deposits had the same petrogenesis and host rocks, the Paleoproterozoic Cu-Pb-Zn deposits were controlled by active belts, and the Mesoproterozoic Fe-Pb-Zn deposits were mainly related to multi-stage rifting. Matching regional mineralization patterns and geological features has established the continental assembly referred to as “NCWI”, an acronym for the north margin of the NCC (NC and the west margin of the IND (WI during the middle Archaean to the Mesoproterozoic. In this assembly, the available geological and metallogenic data from the Eastern Block and active belts of NC fit those from the Dharwar craton and the Aravalli–Delhi–Vindhyan belt of WI, respectively. Moreover, the depositional model and environment of Paleoproterozoic metasedimentary manganese deposits in NCWI implied that the assembly may be located at low latitudes, where the conditions were favorable for dissolving ice and precipitating manganese deposits.

The lithosphere structure and deep processes of the Mesozoic metallogenic belt in eastern China: constraints from passive and active seismic methods

Science.gov (United States)

Lu, Q.; Shi, D.; Jiang, G.; Yan, J.

2013-12-01

The lithosphere structure and deep processes are keys to understanding mineral system and ore-forming processes. Lithosphere-scale process could create big footprints or signatures which can be observed by geophysics methods. SinoProbe-03 has conducted a Transect exploration across middle and lower Yangtze Metallogenic Belt (YMT) in Eastern China. Broadband seismic, reflection seismic, wide-angle reflection and magnetotellurics survey were carried out along the Transect. Seismic reflection profiles and MT survey were also performed in Luzong, Tongling and Ningwu ore districts to construct 3D geological model. The resulting geophysical data provides new information which help to better understanding the lithosphere structure, deep processes and deformation history of the Metallogenic Belt. The major results are: (1) Lower velocity body at the top of upper mantle and a SE dipping high velocity body were imaged by teleseismic tomography beneath YMB; (2) Shear wave splitting results show NE parallel fast-wave polarization direction which parallel with tectonic lineament; (3) The reflection seismic data support the crustal-detachment model, the lower and upper crust was detached during contraction deformation near Tanlu fault and Ningwu volcanic basin; (4) Broadband and reflection seismic confirm the shallow Moho beneath YMB; (5) Strong correlation of lower crust reflectivity with magmatism; (6) The lower crust below Luzong Volcanics shows obvious reflective anisotropy both at the crust-mantle transition and the brittle-ductile transition in the crust. All these features suggest that introcontinental subduction, lithosphere delamination, mantle sources magmatic underplating, and MASH process are responsible for the formation of this Mesozoic metallogenic belt. Acknowledgment: We acknowledge the financial support of SinoProbe by the Ministry of Finance and Ministry of Land and Resources, P. R. China, under Grant sinoprobe-03, and financial support by National Natural

The lithosphere architecture and geodynamic of the Middle and Lower Yangtze metallogenic belt in eastern China: constraints from integrated geophysical data

Science.gov (United States)

Lü, Qingtian; Shi, Danian; Jiang, Guoming; Dong, Shuwen

2014-05-01

The lithosphere structure and deep processes are keys to understanding mineral system and ore-forming processes. Lithosphere-scale process could create big footprints or signatures which can be observed by geophysics methods. SinoProbe has conducted an integrated deep exploration across middle and lower reaches of Yangtze Metallogenic Belt (YMB) in Eastern China, these included broadband seismic, reflection seismic, wide-angle reflection and magnetotellurics survey. Seismic reflection profiles and MT survey were also performed in Luzong, Tongling and Ningwu ore districts to construct 3D geological model. The resulting geophysical data provides new information which help to better understanding the lithosphere structure, geodynamic, deformation and heat and mass transportation that lead to the formation of the Metallogenic Belt. The major results are: (1) Lower velocity body at the top of upper mantle and a SE dipping high velocity body were imaged by teleseismic tomography beneath YMB; (2) Shear wave splitting results show NE parallel fast-wave polarization direction which parallel with tectonic lineament; (3) The reflection seismic data support the crustal-detachment model, the lower and upper crust was detached during contraction deformation near Tanlu fault and Ningwu volcanic basin; (4) Broadband and reflection seismic confirm the shallow Moho beneath YMB; (5) Strong correlation of lower crust reflectivity with magmatism; (6) The lower crust below Luzong Volcanics shows obvious reflective anisotropy both at the crust-mantle transition and the brittle-ductile transition in the crust. All these features suggest that introcontinental subduction, lithosphere delamination, mantle sources magmatic underplating, and MASH process are responsible for the formation of this Mesozoic metallogenic belt. Acknowledgment: We acknowledge the financial support of SinoProbe by the Ministry of Finance and Ministry of Land and Resources, P. R. China, under Grant sinoprobe-03, and

An review on geology study of carbonaceous-siliceous-pelitic rock type uranium deposit in China and the strategy for its development

International Nuclear Information System (INIS)

Zhao Fengmin

2009-01-01

Carbonaceous-siliceous-pelitic rock type uranium deposit was founded by Chinese uranium geologist, it refers to the uranium deposit hosted by non or light metamophosed carbonate,siliceous rock, pelitic rock and their intermediates. It is one of the important types uranium deposit in China. A lot of this type deposits have been discovered in China and their temporal-spatial distribution pattern and mineralization features have been basically identified, and the rich experience have layed a good foundation for the future exploration. Although the ore of this type is not favourable economically, it is still available. Because carbonaceous-siliceous-pelitic rock type uranium deposit has great resource potential, metallogenic study and exploration efforts should be projected differentially according to their economic profit so as to meet the uranium resource demand of nuclear power development in China. (authors)

Devonian through early Carboniferous (Mississippian) metallogenesis and tectonics of northeast Asia, Chapter 6 in Metallogenesis and tectonics of northeast Asia

Science.gov (United States)

Badarch, Gombosuren; Dejidmaa, Gunchin; Gerel, Ochir; Obolenskiy, Alexander A.; Prokopiev, Andrei V.; Timofeev, Vladimir F.; Nokleberg, Warren J.

2010-01-01

The major purposes of this chapter are to provide (1) an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia for readers who are unfamiliar with the region, (2) a general scientific introduction to the succeeding chapters of this volume, and (3) an overview of the methodology of metallogenic and tectonic analysis used in this study. We also describe how a high-quality metallogenic and tectonic analysis, including construction of an associated metallogenic-tectonic model will greatly benefit other mineral resource studies, including synthesis of mineral-deposit models; improve prediction of undiscovered mineral deposit as part of a quantitative mineral-resource-assessment studies; assist land-use and mineral-exploration planning; improve interpretations of the origins of host rocks, mineral deposits, and metallogenic belts, and suggest new research. Research on the metallogenesis and tectonics of such major regions as Northeast Asia (eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (the Russian Far East, Alaska, and the Canadian Cordillera) requires a complex methodology including (1) definitions of key terms, (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions, (3) compilation of a mineral-deposit database that enables a determination of mineral-deposit models and clarification of the relations of deposits to host rocks and tectonic origins, (4) synthesis of a series of mineral-deposit models that characterize the known mineral deposits and inferred undiscovered deposits in the region, (5) compilation of a series of metallogenic-belt belts constructed on the regional geologic base map, and (6) construction of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis presented here is based on publications of the major international collaborative studies of the metallogenesis and

Dazai super-large uranium-bearing germanium deposit in western Yunnan region metallogenic geological conditions and prospect

International Nuclear Information System (INIS)

Han Yanrong; Yuan Qingbang; Li Yonghua; Zhang Ling; Dai Jiemin

1995-05-01

The Dazai super-large uranium-bearing germanium deposit is located in Bangmai Fault Basin, Western Yunnan, China. The basin basement is migmatitic granite and the cover is miocene coal-bearing clastics, Bangmai Formation. The basin development had undergone faulted rhombus basin forming, synsedimentary structure-developing and up-lifted-denuded stages. Synsedimentary faults had controlled distribution of sedimentary formation and lithofacies, and uranium and germanium mineralization. Germanium ore-bodies occur mainly in master lignite-bed of lower rhythmite. Hosted germanium-lignite is taken as main ore-type. Germanium occurs in vitrinite of lignite in the form of metal-organic complex. The metallogenetic geological conditions of the deposit are that ground preparation is uplift zone-migmatitic granite-fault basin-geothermal anomaly area, rich and thick ore-body is controlled by synsedimentary fault, peat-bog phase is favorable to accumulation for ore-forming elements, and unconformity between overlying cover and underlying basement is a channel-way of mineralizing fluid. A multiperiodic composite, being regarded sedimentation and diagenesis as a major process, uranium and germanium ore deposit has been formed through two mineralization. Four prospecting areas have been forecasted and two deposits have been accordingly discovered again. Technical-economic provableness shows that the deposit is characterized by shallow-buried, rich grade, large scale, easy mining and smelting. (9 figs.)

Mineralogy, occurrence of mineralization and temperature-pressure conditions of the Agh-Daragh polymetallic deposit in the Ahar-Arasbaran metallogenic area

Directory of Open Access Journals (Sweden)

Heydar Asgharzadeh Asl

2017-07-01

Full Text Available Introduction The Ahar-Arasbaran metallogenic area (Qara Dagh zone is located in the northwest of Iran and the western part of the Mazandaran Sea. At the base of the structural classification from Nabavi (1976, this area is situated in the Alborz-Azerbijan magmatic belt. Sheviar Dagh (Ahar batholite intrusive suite, subvolcanic and volcanic accompanied rocks with east-west trending and 30 km long serves as the main Eocene-Oligocene magmatic event in the north of the Ahar province. Considering geochemistry, this assemblage includes two shoshonitic and calc-alkaline to high-K calc-alkaline series which are the shoshonitic series in the central part and the calc-alkaline series outcrop in the western and eastern part (Aghazadeh, 2009. Textural characteristic, mineral chemistry and fluid inclusion studies were carried out at the tree part of the Agh-Daragh prospecting area. Material and methods A total of 50 samples were collected from the host rocks (including 4 trench and 250 m, ore deposit and altered rocks. Ten altered samples were analyzed for their mineral recognition by X-ray diffraction in the Iran Mineral Process and Research Center (IMPRC. Electron microprobe analyses (EMPA and backscattered electron (BSE images of minerals were obtained using a Cameca SX100 electron microprobe in the Iran Mineral Process and Research Center (IMPRC. An accelerating voltage of 15 to 25 kV and beam current of 20 mA was used for all analyses. Typical spot sizes ranged from 2 to 5 μm. A total of 5 double-polish thin sections representative of quartz samples were selected from mineralized veins after petrographic and field studies. Fluid inclusion microthermometry was conducted using a Linkam THMS600 heating–freezing stage (-190°C to +600°C mounted on a ZEISS Axioplan2 microscope in the fluid inclusion laboratory of the school of Earth Sciences of the Kharazmi University. The heating rate was 5–10 °C/min at higher temperatures (>100°C, with a

Using ASD data to identify the altered minerals for exploring of gold deposit in the Beishan area, North China

Science.gov (United States)

Ren, G. L.; Yi, H.; Yang, M.; Liang, N.; Li, J. Q.; Yang, J. L.

2016-11-01

Hyperspectral information of altered minerals plays an important role in the identifications of mineralized zones. In this study, the altered minerals of two gold deposits from Fangshankou-Laojinchang regions of Beishan metallogenic belt were measured by ASD field Spectrometer. Many gold deposits would have a close relationship with Variscan magma intrusion, which have been found in study region. The alteration minerals have been divided six types by the spectral results, i.e. sericite, limonite, dolomite, chlorite, epidote and calcite. The distribution characteristics and formations of altered minerals were discussed here. By the ASD, the spectral curve of different geological units in the Jintanzi and Fangshankou gold deposits were analysed and summarized. The results show that the sericite and limonite are mainly related with the gold mineralization and widely occurred in the gold deposits. Therefore, we proposed that the sericite and limonite are the iconic alteration mineral assemblages for gold mineralization and the models of altered minerals for gold deposits could be established in this region.

Complex mineralization at large ore deposits in the Russian Far East

Science.gov (United States)

Schneider, A. A.; Malyshev, Yu. F.; Goroshko, M. V.; Romanovsky, N. P.

2011-04-01

Genetic and mineralogical features of large deposits with complex Sn, W, and Mo mineralization in the Sikhote-Alin and Amur-Khingan metallogenic provinces are considered, as well as those of raremetal, rare earth, and uranium deposits in the Aldan-Stanovoi province. The spatiotemporal, geological, and mineralogical attributes of large deposits are set forth, and their geodynamic settings are determined. These attributes are exemplified in the large Tigriny Sn-W greisen-type deposit. The variation of regional tectonic settings and their spatial superposition are the main factor controlling formation of large deposits. Such a variation gives rise to multiple reactivation of the ore-magmatic system and long-term, multistage formation of deposits. Pulsatory mineralogical zoning with telescoped mineral assemblages related to different stages results in the formation of complex ores. The highest-grade zones of mass discharge of hydrothermal solutions are formed at the deposits. The promising greisen-type mineralization with complex Sn-W-Mo ore is suggested to be an additional source of tungsten and molybdenum. The Tigriny, Pravourminsky, and Arsen'evsky deposits, as well as deposits of the Komsomol'sk and Khingan-Olonoi ore districts are examples. Large and superlarge U, Ta, Nb, Be, and REE deposits are localized in the southeastern Aldan-Stanovoi Shield. The Ulkan and Arbarastakh ore districts attract special attention. The confirmed prospects of new large deposits with Sn, W, Mo, Ta, Nb, Be, REE, and U mineralization in the south of the Russian Far East assure expediency of further geological exploration in this territory.

Long-term evolution of radio-active waste storage in geological formations: analogy with the weathering of mineral deposits

International Nuclear Information System (INIS)

Cantinolle, P.; Griffault, L.; Jebrak, M.

1986-01-01

The aim of this study was to select examples of mineral deposits and their weathering environment, showing the long-term behaviour, in geological time, measuring (area, volume) some constituent elements of radio-active waste storage subject to the hazards of hydrogeochemical weathering. Initially, a feasibility study was made to collate data available within the BRGM (mining group and public service) and from literature dealing with weathering of deposits. It was thus discovered that the analogy between radio-active waste storage and mineral deposits could be approached in two different yet complementary ways: - one approach is to observe the behaviour of a mineral deposit in relation to the country rocks. For this a bibliographic metallogenic study was made. The other approach is to observe the behaviour of chemical elements during deposition of a mineral deposit whose genesis is similar to the spatial and thermal environment of a deposit of radio-active waste in a geological formation. For this two sites were selected corresponding to hydrothermal systems showing strong analogies to those expected in the neighbourhood of the storage sites. These two sites, Langenberg in the Vosges and La Telhaie in Brittany, were the subject of complementary analytical work [fr

The Bairendaba silver polymetallic deposit in Inner Mongolia, China: characteristics of ore-forming fluid and genetic type of ore deposit

Science.gov (United States)

Wang, Ying; Xie, Yuling; Wu, Haoran

2018-02-01

Bairendaba silver-polymetallic deposit is located in the middle south of the Xing Meng orogenic belt, and in the silver-polymetallic metallogenic belt on the west slope of the southern of Great Xing’an Range. Based on studying of the fluid inclusion, we discuss the characteristics of ore-forming fluid and the metallic genesis of the Bairendaba silver-polymetallic deposit. By means of the analysis of the fluid inclusions, homogenization temperature, salinity and composition were studied in quartz and fluorite. The result is as the follows: with homogenization temperatures of fluid inclusions in quartz veins being 196∼312 °C, the average 244.52 °C, and fluid salinity 2.90∼9.08 wt%NaCl; with homogenization temperatures of fluid inclusions in fluorite being 127∼306 °C, the average 196.92 °C, and fluid salinity 2.90∼9.34 wt% NaCl. The ore-forming fluid is mainly composed of water and the gas. The results of laser Raman analysis show that the gas phase is mainly CH4. It shows that the ore-forming fluid is characterized by medium-low temperature and low-salinity system. The temperature of ore-forming fluid is from high to low, and the salinity from high to low, and the meteoric water or metamorphic water is added during deposit. According to the geological characteristics of the mining area, it is considered that the genetic type of the ore deposit should be the fault-controlled and the medium-low temperature hydrothermal deposit related to magmatic hydrothermal activities.

Current status and prospects of uranium geology developments of foreign in-situ leachable sandstone type uranium deposits

International Nuclear Information System (INIS)

Wang Zhengbang

2002-01-01

Firstly, with emphasis on in-situ leachable sandstone-type uranium deposits, the prospecting history of uranium deposits worldwide and its scientific research development are generally reviewed in four steps, and their basic historical experience is also summarized. Secondly, based on the detailed description of current development status of uranium geology of foreign in-situ leachable sandstone-type uranium deposits the important strategic position of sandstone-type uranium deposits in overall uranium resources all-over-the-world and its classification, spatial-temporal distribution and regulation, and metallogenic condition of sandstone-type uranium deposits are analysed thoroughly in five aspects: techtonics, paleo-climate, hydrogeology, sedimentary facies and lithology, as well as uranium sources: Afterwards, evaluation principles of three type of hyper-genic, epigenetic infiltrated sandstone-type uranium deposits are summarized. Based on sandstone-type uranium deposits located two important countries: the United States and Russia, the current development status of prospecting technology for in-situ leachable sandstone-type uranium deposits in foreign countries is outlined. Finally, according to the prospects of supply-demand development of global uranium resources, the author points out seriously that Chinese uranium geology is faced with a severe challenge, and proposes directly four strategic measures that should be taken

Genesis of the Bangbule Pb-Zn-Cu polymetallic deposit in Tibet, western China: Evidence from zircon U-Pb geochronology and S-Pb isotopes

Science.gov (United States)

Kan, Tian; Zheng, Youye; Gao, Shunbao

2016-04-01

The Banbule Pb-Zn-Cu skarn deposit is located in the Longger-Gongbujiangda volcanic magma arc in the Gangdese-Nyainqentanglha Plate. It is the only lead-zinc polymetallic deposit discovered in the westernmost Nyainqentanglha metallogenic belt. The measured and indicated resources include 0.9 Mt of Pb+Zn (4.77% Pb and 4.74% Zn, respectively), 6499 t of Cu, and 178 t of Ag (18.75g/t Ag). The orebodies mainly occur as lenses, veins and irregular shapes in the contact zone between the quartz-porphyry and limestone of the Upper Permian Xiala Formation, or in the boundaries between limestone and sandstone. Pb-Zn-Cu mineralization in the Banbule deposit is closely associated with skarns. The ore minerals are dominated by galena, sphalerite, chalcopyrite, bornite, and magnetite, with subordinate pyrite, malachite, and azurite. The gangue minerals are mainly garnet, actinolite, diopside, quartz, and calcite. The ore-related quartz-porphyry displays LA-ICP-MS zircon U-Pb age of 77.31±0.74 Ma. The δ34S values of sulfides define a narrow range of -0.8 to 4.7‰ indicating a magmatic source for the ore-forming materials. Lead isotopic systematics yield 206Pb/204Pb of 18.698 to 18.752, 207Pb/204Pb of 15.696 to 15.760, and 208Pb/204Pb of 39.097 to 39.320. The data points are constrained around the growth curves of upper crust and orogenic belt according to the tectonic discrimination diagrams. The calculated Δβ - Δγ values plot within the magmatic field according to the discrimination diagram of Zhu et al. (1995). The S-Pb isotopic data suggest that Bangbule is a typical skarn deposit, and the Pb-Zn-Cu mineralization is genetically related to the quartz-porphyry in the mining district. The discovery of the Bangbule deposit indicates that there is metallogenic potential in the westernmost Nyainqentanglha belt, which is of great importance for the exploration work in this area.

The genesis of the Hashitu porphyry molybdenum deposit, Inner Mongolia, NE China: constraints from mineralogical, fluid inclusion, and multiple isotope (H, O, S, Mo, Pb) studies

Science.gov (United States)

Zhai, Degao; Liu, Jiajun; Tombros, Stylianos; Williams-Jones, Anthony E.

2018-03-01

The Hashitu porphyry molybdenum deposit is located in the Great Hinggan Range Cu-Mo-Pb-Zn-Ag polymetallic metallogenic province of NE China, in which the Mo-bearing quartz veins are hosted in approximately coeval granites and porphyries. The deposit contains more than 100 Mt of ore with an average grade of 0.13 wt.% Mo. This well-preserved magmatic-hydrothermal system provides an excellent opportunity to determine the source of the molybdenum, the evolution of the hydrothermal fluids and the controls on molybdenite precipitation in a potentially important but poorly understood metallogenic province. Studies of fluid inclusions hosted in quartz veins demonstrate that the Hashitu hydrothermal system evolved to progressively lower pressure and temperature. Mineralogical and fluid inclusion analyses and physicochemical calculations suggest that molybdenite deposition occurred at a temperature of 285 to 325 °C, a pressure from 80 to 230 bars, a pH from 3.5 to 5.6, and a Δlog fO2 (HM) of -3.0, respectively. Results of multiple isotope (O, H, S, Mo, and Pb) analyses are consistent in indicating a genetic relationship between the ore-forming fluids, metals, and the Mesozoic granitic magmatism (i.e., δ 18OH2O from +1.9 to +9.7‰, δDH2O from -106 to -87‰, δ 34SH2S from +0.3 to +3.9‰, δ 98/95Mo from 0 to +0.37‰, 206Pb/204Pb from 18.2579 to 18.8958, 207Pb/204Pb from 15.5384 to 15.5783, and 208Pb/204Pb from 38.0984 to 42.9744). Molybdenite deposition is interpreted to have occurred from a low-density magmatic-hydrothermal fluid in response to decreases in temperature, pressure, and fO2.

Geological and Geochemical Characteristics of Skarn Type Lead-Zinc Deposit in Baoshan Block, Yunnan Province

Science.gov (United States)

Yao, Xue; Wang, Peng

2017-11-01

Baoshan block is an important Pb-Zn-Fe-Cu polymetallic ore-concentration area which is located in southern of the Sanjiang metallogenic belt in western Yunnan. The article is studying about the geological and geochemical characteristics of the skarn type lead-zinc deposit in Baoshan block. The skarn-type lead-zinc deposit Baoshan block is characterized by skarn and skarn marble, and the orebodies are layered, or bedded along the interlayer fault, which are significantly controlled by structure. The research about Stable isotope S, H and O indicates that the ore-forming fluids are mainly derived from magmatic water, partly mixed with parts of metamorphic water and atmospheric precipitation. The initial Sr isotopic Sr87/Sr86 ratio suggests that the ore-forming materials derived from deep concealed magmatic rock, age of Rb-Sr mineralization is similar to that of Yanshanian granite. In conclusion, the Yanshanian tectonic-magmatic-fluid coupling mineralization of Yanshan formation is the main reason for the skarn-type lead-zinc deposit in the Baoshan block.

The Berezitovoe gold-polymetallic deposit (Upper Amur region, Russia: Structure, mineralogy and genetic aspects

Directory of Open Access Journals (Sweden)

Alexandr S. Vakh

2016-05-01

Full Text Available The Berezitovoe deposit in the Sergachi volcano-plutonic and metallogenic belt preserves evidence for polymetallic mineralization of multiple stages. The steeply dipping garnet-tourmaline-muscovite-quartz metasomatites (with K-Ar ages of 132 ± 2.9 and 127 ± 4.4 Ma carry two distinct stages of mineralization developed at different times: (1 polymetallic mineralization and (2 gold-quartz. The deposit is located within Paleozoic gneissose granitoids of the Pikansky complex (dated as 379 ± 1.1 Ma by zircon U-Pb method intruded by early Cretaceous porphyry-like granites of the Haikta pluton (dated as 137 ± 0.67 Ma by zircon U-Pb method and late Cretaceous dikes of porphyrites, porphyries, and lamprophyres. Evidence suggests the action of late gold-bearing hydrothermal fluids on the early polymetallic ores and the selective mobilization of some elements from these lead to redeposition together with complex sulphosalts.

Relationship between uranium-molybdenum, fluorite and gold deposits within provinces of continental volcanicity

International Nuclear Information System (INIS)

Modnikov, I.S.; Skvortsova, K.V.; Chesnokov, L.V.

1974-01-01

The article gives a comparative description of and the age relationships between uranium-molybdenum, gold and fluorite mineralizations in the areas of development of adhesite-diorite and liparite-granite vulcanoplutonic formations, which are most fully and intensively manifest in the intra-anticlinal and median blocks of folded regions in the final stages of geosynclinal development or during the final stages of tectono-magmatic activation. These formations usually fill vulcano-tectonic depression structures - overlaid troughs and inherited delections. The geological and geochemical data are evidence of the close temporal link between the hydrothermal process of ore formation and the type and scale of manifestations of the vulcano-plutonic magmatism that is responsible for the general geochemical features of the ores of deposits of various types. The formation of gold, fluorite and uranium-molybdenum deposits occurred immediately after the completion of effusive and intrusive magmatism during a single metallogenic cycle. The spatial distribution of the ore fields and deposits depends chiefly on the peculiarities of the tectonic make-up of the depression structures, and also on the type and scale of the manifestations of vulcano-plutonic magmatism. (B.Ya.)

Formation mechanism of self-potential at ISL-amenable interlayer oxidation zone sandstone-type uranium deposit and the simulation and application of self-potential anomalies

International Nuclear Information System (INIS)

Tang Hongzhi; Liu Qingcheng; Su Zhaofeng; Gong Yuling

2006-01-01

Based on the analysis of geochemical characteristics and metallogenic physico-chemical conditions of ISL-amenable sandstone-type uranium deposits, the formation mechanism of self-potential field is discussed, a mathematic calculation model has been set up, and the simulation calculation has been performed for self-potential anomalies above uranium ore bodies of ordinary form, features of survey curve are analysed and methods for correcting topography at self-potential anomalies are discussed, and a simulation curve of self-potential in the area of slope topography has been presented. Finally, the availability of the method is demonstrated by an example. (authors)

Isotopic data from proterozoic sediment-hosted sulfide deposits of Brazil: Implications for their metallogenic evolution and for mineral exploration

International Nuclear Information System (INIS)

Misi, Aroldo; Coelho, Carlos E.S.; Franca Rocha, Washington J.S.; Gomez, Adriana S.R.; Cunha, Iona A.; Iyer, Sundaram S.; Tassinari, Colombo C.G.; Kyle, J. Richard

1998-01-01

Geological, petrographic, fluid inclusions studies and isotopic data of seven Proterozoic sediment-hosted Pb-Zn-Ag sulfide deposits of Brazil, permit the estimation of the age of the hosting sequence and the mineralization, the nature of the sulfur and metal sources, the temperature range of sulfide formation and the environment of deposition of the mineral deposits. The studies suggest that they were formed during periods of extensional tectonics: Growth faults or reactivated basement faults were responsible for localized circulation of metal-bearing fluids within the sedimentary sequences. In most cases, sulfides were formed by the reduction of sedimentary sulfates. Linear structures are important controls for sulfide concentration in these Proterozoic basins. (author)

The metallogenic model of volcanic-hosted large deposit rich in U in the Northeast Asia

International Nuclear Information System (INIS)

Peng Zhidong

2001-01-01

During the evolution of ridge-basin tectonic system occurred in Northeast Asia area, the U-rich fluid was formed with intense tectonic-magmatic activities and the fixed fluid of crust-mantle upwelling, shallow structural coupling and deep or shallow derived heat fluid has been established. Using the geologic theory of deep-shallow structure, the U-deposits in this area have been divided into collapsed-basin type, divergent belt type, fissure type and sub-volcanics type, the favorable region for uranium also has been predicted

Granite-related Yangjiashan tungsten deposit, southern China

Science.gov (United States)

Xie, Guiqing; Mao, Jingwen; Li, Wei; Fu, Bin; Zhang, Zhiyuan

2018-04-01

The Yangjiashan scheelite-bearing deposit (38,663 metric tons of WO3 with an average ore grade of 0.70% WO3) is hosted in quartz veins in a biotite monzogranite intrusion and surrounding slate in the Xiangzhong Metallogenic Province of southern China. The monzogranite has a zircon SHRIMP U-Pb age of 406.6 ± 2.8 Ma (2σ, n = 20, MSWD = 1.4). Cassiterite coexisting with scheelite yields a weighted mean 206Pb/238U age of 409.8 ± 5.9 Ma (2σ, n = 30, MSWD = 0.20), and molybdenite intergrown with scheelite yields a weighted mean Re-Os age of 404.2 ± 3.2 Ma (2σ, n = 3, MSWD = 0.10). These results suggest that the Yangjiashan tungsten deposit is temporally related to the Devonian intrusion. The δD and calculated δ18OH2O values of quartz intergrown with scheelite range from - 87 to - 68‰, and - 1.2 to 3.4‰, respectively. Sulfides have a narrow range of δ34S values of - 2.9 to - 0.7‰ with an average value of - 1.6‰ (n = 16). The integration of geological, stable isotope, and geochronological data, combined with the quartz-muscovite greisen style of ore, supports a magmatic-hydrothermal origin for the tungsten mineralization. Compared to the more common tungsten skarn, quartz-wolframite vein, and porphyry tungsten deposits, as well as orogenic gold deposits worldwide, the Yangjiashan tungsten deposit is an unusual example of a granite-related, gold-poor, scheelite-bearing quartz vein type of deposit. The calcium needed for the formation of scheelite is derived from the sericitization of calcic plagioclase in the monzogranite and Ca-bearing psammitic country rocks, and the relatively high pH, reduced and Ca-rich mineralizing fluid may be the main reasons for the formation of scheelite rather than wolframite at Yangjiashan.

The origin of the Avram Iancu U-Ni-Co-Bi-As mineralization, Băiţa (Bihor) metallogenic district, Bihor Mts., Romania

Science.gov (United States)

Zajzon, Norbert; Szentpéteri, Krisztián; Szakáll, Sándor; Kristály, Ferenc

2015-10-01

The Băiţa metallogenic district in the Bihor Mountains is a historically important mining area in Romania. Uranium mining took place between 1952 and 1998 from various deposits, but very little is known about the geology and mineralogy of these deposits. In this paper, we describe geology and mineralogy of uranium mineralization of the Avram Iancu uranium mine from waste dump samples collected before complete remediation of the site. Texturally and mineralogically complex assemblages of nickeline, cobaltite-gersdorffite solid solution, native Bi, Bi-sulfosalts, molybdenite, and pyrite-chalcopyrite-sphalerite occur with uraninite, "pitchblende," and brannerite in most of the ore samples. The association of nickel, cobalt, and arsenic with uranium is reminiscent of five-element association of vein type U-Ni-Co-Bi-As deposits; however, the Avram Iancu ores appear to be more replacement-type stratiform/stratabound. Avram Iancu ore samples contain multistage complex, skarn, uranium sulfide, arsenide assemblages that can be interpreted to have been formed in the retrograde cooling stages of the skarn hydrothermal system. This mineralizing system may have built-up along Upper Cretaceous-Paleogene "Banatite" intrusions of diorite-to-granite composition. The intrusions crosscut the underlying uraniferous Permian formations in the stacked NW-verging Biharia Nappe System. The mineralization forms stacked, multilayer replacement horizons, along carbonate-rich lithologies within the metavolcanic (tuffaceous) Muncel Series. Mineral paragenesis and some mineral chemistry suggest moderate-to-high <450, i.e., 350-310 °C, formation temperatures for the uranium sulfide stage along stratigraphically controlled replacement zones and minor veins. Uranium minerals formed abundantly in this early stage and include botryoidal, sooty and euhedral uraninite, brannerite, and coffinite. Later and/or lower-temperature mineral assemblages include heterogeneous, complexly zoned arsenide

Zircon U-Pb dating of Maherabad porphyry copper-gold prospect area: evidence for a late Eocene porphyry-related metallogenic epoch in east of Iran

Directory of Open Access Journals (Sweden)

Azadeh Malekzadeh Shafaroudi

2011-04-01

Full Text Available Eastern Iran has great potential for porphyry copper deposits, as a result of its past subduction zone tectonic setting that lead to extensive alkaline to calc-alkaline magmatic activity in Tertiary time. Maherabad is the first porphyry Cu-Au prospecting area which is discovered in eastern Iran. This is related to a succession o f monzonitic to dioritic porphyries stocks that were emplaced within volcanic rocks. Monzonitic porphyries have basic role in mineralization. Hydrothermal alteration zones are well developed including potassic, sericitic-potassic, quartz-sericite-carbonate-pyrite, quartz-carbonate-pyrite, silicified-propylitic, propylitic, carbonate and silicified zones. Mineralization occurs as Disseminated, stockwork and hydrothermal breccia. Based on early stage of exploration, Cu is between 179- 6830 ppm (ave. 3200 ppm and Au is up to 1000 ppb (ave. 570 ppb. This prospect is gold- rich porphyry copper deposit. Laser-ablation U-Pb dating of two samples from ore-related intrusive rocks indicate that these two monzonitic porphyries crystallized at 39.0 ± 0.8 Ma to 38.2 ± 0.8 Ma, within a short time span of less than ca. 1 Ma during the middle Eocene. This provides the first precise ages for metallogenic episode of porphyry-type mineralization. Also, the initial 87Sr/86Sr and (143Nd/144Ndi was recalculated to an age of 39 Ma. Initial 87Sr/86Sr ratios for monzonitic rocks are 0.7047-0.7048. The (143Nd/144Ndi isotope composition are 0.512694-0.512713. Initial ε Nd isotope values 1.45-1.81. Based on isotopic data the magma had originated beyond the continental crust. The study will be used for tectonic-magmatic setting and evolution of eastern Iran. Keywords: Lut block, Middle Eocene, Zircon, Geochronology, Laser ablation ICP-MS,

Development of data processing system for regional geophysical and geochemical exploration of sandstone-hosted uranium deposits based on ArcGIS Engine

International Nuclear Information System (INIS)

Han Shaoyang; Ke Dan; Hou Huiqun; Hu Shuiqing

2010-01-01

According to the data processing need of geophysical and geochemical exploration of sandstone-hosted uranium deposits, the function design of the regional geophysical and geochemical data processing system is completed in the paper. The geophysical and geochemical data processing software with powerful functions is also developed based on ArcGIS Engine which remedies the shortage of GIS software for performing the geophysical and geochemical data processing. The development technique route of system software and key techniques are introduced, and the development processes of system software are showed through some development examples. Application practices indicate that the interface of developed system software with friendly interface and utility functions, may quickly perform the data processing of regional geophysical and geochemical exploration and provide the helpful deep information for predicting metallogenic prospective areas of sandstone-hosted uranium deposits. The system software is of a great application foreground. (authors)

Uranium deposits in the Nord-Limousin; Les gites d'uranium du Nord-Limousin

Energy Technology Data Exchange (ETDEWEB)

Sarcia, J A; Sarcia, J A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The authors briefly consider the region in its geographical and geological setting. They describe the main petrographic, metallogenic and tectonic characteristics of the sector investigated by the Atomic Energy Commission since 1947, stressing the form of uraniferous mineral deposits. This short account is intended as a general presentation of the detailed studies which will follow, of which that dealing with the mine Henriette is the first to be published. (author) [French] Les auteurs replacent rapidement la region dans son cadre geographique et geologique. Ils decrivent les principales caracteristiques petrographiques, metallogeniques et tectoniques du secteur etudie par le Commissariat a I'Energie atomique depuis 1947, en insistant sur le mode de gisement des mineralisations uraniferes. Ces quelques pages sont destinees a la presentation generale des etudes de detail qui suivront, dont celle qui concerne la Mine Henriette est la premiere publiee. (auteur)

Scientific communications: Re-Os sulfide (bornite, chalcopyrite, and pyrite) systematics of the carbonate-hosted copper deposits at ruby creek, southern brooks range, Alaska

Science.gov (United States)

Selby, D.; Kelley, K.D.; Hitzman, M.W.; Zieg, J.

2009-01-01

New Re-Os data for chalcopyrite, bornite, and pyrite from the carbonate-hosted Cu deposit at Ruby Creek (Bornite), Alaska, show extremely high Re abundances (hundreds of ppb, low ppm) and contain essentially no common Os. The Re-Os data provide the first absolute ages of ore formation for the carbonate-hosted Ruby Creek Cu-(Co) deposit and demonstrate that the Re-Os systematics of pyrite, chalcopyrite, and bornite are unaffected by greenschist metamorphism. The Re-Os data show that the main phase of Cu mineralization pre dominantly occurred at 384 ?? 4.2 Ma, with an earlier phase possibly at ???400 Ma. The Re-Os data are consistent with the observed paragenetic sequence and coincide with zircon U-Pb ages from igneous rocks within the Ambler metallogenic belt, some of which are spatially and genetically associated with regional volcanogenic massive sulfide deposits. The latter may suggest a temporal link between regional magmatism and hydrothermal mineralization in the Ambler district. The utility of bornite and chalcopyrite, in addition to pyrite, contributes to a new understanding of Re-Os geochronology and permits a refinement of the genetic model for the Ruby Creek deposit. ?? 2009 Society of Economices Geologists, Inc.

Characteristics of chlorites from Huangnihu uranium deposit and their implications in uranium metallogenic environment in the southern part of Jiangxi Province

International Nuclear Information System (INIS)

Hu Zhihua; Lin Jinrong; Pang Yaqing; Gao Fei; Rong Jiashu; Guo Shuying

2013-01-01

Chlorite is genetically related to uranium mineralization in Huangnihu uranium deposit. By means of microscopic and electronic microprobe analysis, the authors investigated chemical composition and texture of the chlorite and found that chlorite in Huangnihu deposit has the following characteristics: 1. they are mainly Fe-rich chlorite composed of chamosite and brunsvigite, of which chemical composition is mainly affected by mud and mafic rock; 2. the Fe-Mg and Al"I"V-Si substitution dominates the octahedral substitution supplemented by Al"V"I-Fe substitution; the oolitic chlorite and biotite feinted chlorite closely associated with uranium were formed at temperatures of 216.23 ∼ 256.73℃ (average 228.6℃). The chemical composition and forming environment of the oolitic chlorite and biotite illusion chlorite suggests that Huangnihu uranium deposit is a low-moderate temperature hydrothermal uranium deposit formed in a reducing environment and iron-rich formation, the ore-forming fluid mainly originated from shale rock, partly from ultramafic or mafic liquid. (authors)

Molybdenum mineralization related to the Yangtze's lower crust and differentiation in the Dabie Orogen: Evidence from the geochemical features of the Yaochong porphyry Mo deposit

Science.gov (United States)

Liu, Qing-Quan; Li, Bin; Shao, Yong-Jun; Lu, An-Huai; Lai, Jian-Qing; Li, Yong-Feng; Luo, Zheng-Zhuan

2017-06-01

The Dabie Orogen is a world-class case for large amounts of Mo mineralization in that it contains at least 10 porphyry Mo deposits with Mo metal reserves over 3 Mt from the time period of 156-110 Ma. However, the principal mechanism for the Mo mineralization remains controversial due to the lack of a precise definition of its source and shallow ore-forming process, which is essential to understand these rare large Mo deposits. Detailed geochronology, geochemistry, and isotopic data for ore-related granites and minerals were analyzed in order to place constraints on the massive Mo mineralization in the Dabie Orogen in eastern China. The Yaochong molybdenum orebodies were hosted in the transition belt and alteration zone between the granitic stocks and the Dabie Complex and were characterized as numerous veinlets with potassic, phyllic and propylitic alterations. The buried Yaochong granitic intrusions and associated molybdenum mineralization yield Early Cretaceous ages of magmatic activities at ca. 138 Ma and extremely similar Re-Os isotope ages for the corresponding Mo metallogenic event at ca. 137 Ma. The Yaochong monzogranite and granite porphyry belong to the highly fractionated I-type granites, which are believed to be derived from the dominantly Yangtze's lower crust mixed with the Northern Dabie Complex due to their geochemical and isotope features. The elemental diversity and isotopic homogeneity suggest that the formation of the Yaochong monzogranite involved the fractionation of biotite, garnet and minor feldspar and accessory minerals combined with a weak crustal assimilation process. In contrast, the granite porphyry was possibly generated by the partial melting of the same mixed lower continental crust via the differentiation process involving the fractionation of feldspar, apatite, and/or titanite. Fractional crystallization processes can significantly elevate the molybdenum concentration in the residual melts. The biotite fractional crystallization

Modeling of Paleo Heat-and-Mass Trasport for Prognosys of Mineral Deposits Using GIS

International Nuclear Information System (INIS)

Cherkasov, Sergei; Vishnevskaya, Natalia; Cassard, Daniel; Sterligov, Boris; Arbuzova, Ekaterina

2008-01-01

The heat-and-mass flow from the mantle to the surface can be characterized by the three basic models. The first one represents just a convective heating of the crust by the hot mantle. Two other kinds of the heat-and-mass flow system are rather anomalous and sometimes serve as an engine for launching ore-forming processes. The second model describes a pipe-like conductive heat-and-flow system reasoning appearance of mafic-ultramafic intrusions coming to the surface directly from the upper mantle. The third model corresponds with a complicated convective-conductive process involving melting of crustal rocks, and forming magmatic chambers inside the crust. Analysis of gravimetric and seismic data using geographic informational systems allows us to locate elements of the anomalous heat-and-flow systems. Some of the elements (their projection on the surface) correlate with position of the known deposits of gold, silver, tungsten, tin, sometimes--molybdenum and base metals. The results of studies conducted by the Russian-French Metallogenic Laboratory in the frames of crystalline shields of Russia demonstrate location of 87% of the known gold-bearing deposits inside the zones defined by such analysis

Metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera

Science.gov (United States)

Nokleberg, Warren J.; Bundtzen, Thomas K.; Eremin, Roman A.; Ratkin, Vladimir V.; Dawson, Kenneth M.; Shpikerman, Vladimir I.; Goryachev, Nikolai A.; Byalobzhesky, Stanislav G.; Frolov, Yuri F.; Khanchuk, Alexander I.; Koch, Richard D.; Monger, James W.H.; Pozdeev, Anany I.; Rozenblum, Ilya S.; Rodionov, Sergey M.; Parfenov, Leonid M.; Scotese, Christopher R.; Sidorov, Anatoly A.

2005-01-01

The Proterozoic and Phanerozoic metallogenic and tectonic evolution of the Russian Far East, Alaska, and the Canadian Cordillera is recorded in the cratons, craton margins, and orogenic collages of the Circum-North Pacific mountain belts that separate the North Pacific from the eastern North Asian and western North American Cratons. The collages consist of tectonostratigraphic terranes and contained metallogenic belts, which are composed of fragments of igneous arcs, accretionary-wedge and subduction-zone complexes, passive continental margins, and cratons. The terranes are overlapped by continental-margin-arc and sedimentary-basin assemblages and contained metallogenic belts. The metallogenic and geologic history of terranes, overlap assemblages, cratons, and craton margins has been complicated by postaccretion dismemberment and translation during strike-slip faulting that occurred subparallel to continental margins. Seven processes overlapping in time were responsible for most of metallogenic and geologic complexities of the region (1) In the Early and Middle Proterozoic, marine sedimentary basins developed on major cratons and were the loci for ironstone (Superior Fe) deposits and sediment-hosted Cu deposits that occur along both the North Asia Craton and North American Craton Margin. (2) In the Late Proterozoic, Late Devonian, and Early Carboniferous, major periods of rifting occurred along the ancestral margins of present-day Northeast Asia and northwestern North America. The rifting resulted in fragmentation of each continent, and formation of cratonal and passive continental-margin terranes that eventually migrated and accreted to other sites along the evolving margins of the original or adjacent continents. The rifting also resulted in formation of various massive-sulfide metallogenic belts. (3) From about the late Paleozoic through the mid-Cretaceous, a succession of island arcs and contained igneous-arc-related metallogenic belts and tectonically paired

Using apatite to discriminate synchronous ore-associated and barren granitoid rocks: A case study from the Edong metallogenic district, South China

Science.gov (United States)

Duan, Deng-Fei; Jiang, Shao-Yong

2018-06-01

In order to find criteria to discriminate the synchronous ore-associated and barren granitoid rocks, we have determined apatite chemistry associated with ore-associated (Cu-Au) and barren granitoid rocks in the Edong district of the Middle and Lower Yangtze River metallogenic belt, South China. Both rock types give zircon U-Pb ages between 135.0 and 138.7 Ma. Apatite has a higher volatile and Li content (Cl: 0.19-0.57 wt%, average 0.35 wt%, SO3: 0.08-0.71 wt%, average 0.32 wt%, Li: 0.49-7.99 ppm, average 3.23 ppm) in ore-associated rocks than those in barren rocks (Cl: 0.09-0.31 wt%, average 0.16 wt%, SO3: 0.06-0.28 wt%, average 0.16 wt%, Li: 0.15-0.89 ppm, average 0.36 ppm). Apatite (La/Yb)N ratios and Eu/Eu* values are relatively high and show wider variation in ore-associated rocks than those in barren rocks. Apatite (La/Sm)N and (Yb/Sm)N show positive correlation in ore-associated rocks but negative in barren rocks. The higher volatile content occurs in ore-associated magma, favoring Cu-Au transportation and deposition. Furthermore, amphibole fractional crystallization in ore-associated magma further enriched the ore elements in the residual melt. Barren rocks may have undergone fluid exsolution before emplacement, which makes it barren in Cl, S and ore elements (Cu, S). These signatures emphases the significance of volatile and magma evolution in mineralization and indicate that analyses of magmatic apatite can serve to distinguish ore-associated from barren intrusions.

A synthesis of mineralization styles and geodynamic settings of the Paleozoic and Mesozoic metallic ore deposits in the Altay Mountains, NW China

Science.gov (United States)

Yang, Fuquan; Geng, Xinxia; Wang, Rui; Zhang, Zhixin; Guo, Xuji

2018-06-01

The Altay Mountains within the Xinjiang region of northwestern China hosts major metallic ore deposits. Here we review the geological characteristics, metallogenic features and tectonic settings of these deposits. The metallic ore deposits in the Altay Mountains occur mainly within four regions: North Altay, Central Altay, South Altay and Erqis. We recognize seven types of metallic ore deposits in the Altay Mountains: VMS, submarine volcanogenic iron, magmatic, skarn, pegmatite, hydrothermal vein (Cu-Zn, Fe) and orogenic gold. Among these types, the VMS, pegmatite, orogenic gold and skarn deposits are the most common. Most of the rare metal pegmatite deposits are distributed in Central Altay, with only a few in South Altay. The VMS, submarine volcanogenic type iron and skarn-type deposits are distributed in South Altay, whereas the orogenic-type gold deposits are distributed in the Erqis Fault belt. The hydrothermal vein-type deposits occur in the Erqis Fault belt and Chonghu'er Basin in South Altay. Magmatic-type deposits are mostly in the Erqis Fault belt and Central Altay. Based on isotopic age data, the VMS, submarine volcanogenic-type Fe and skarn-type Cu, Pb, Zn, Fe mineralization occurred during Early-Middle Devonian (∼410-377 Ma), orogenic-type Au, magmatic-type Cu-Ni, and a small number of skarn-type Fe, hydrothermal vein-type Cu-Zn, pegmatite-type rare-metal deposits in Early-Middle Permian (293-261 Ma), pegmatite-type rare-metal deposits, few skarn-type Fe deposit in Early-Middle Triassic (248-232 Ma), and dominantly represented by pegmatite-type rare-metal deposits in Late Triassic-Early Jurassic (223-180 Ma). The metallic ore deposits in the Altay Mountains formed in various tectonic settings, such as the Early-Middle Devonian continental arc and oceanic island arc, Early-Middle Permian post-collisional extensional setting, and Triassic-Early Jurassic intracontinental setting.

The regional metallogenesis and optimum selection of prospecting target for superlarge uranium deposit in metallogenic area of erguna

International Nuclear Information System (INIS)

Luo Yi; Wang Zhengbang; Hou Huiqun; Zhou Dean; Qi Fucheng; Xiao Xiangping

1995-06-01

The study area, an activation zone of the median Massif in Xingmeng geosynclinal area, geologically underwent the multiple tectono-magmatic reworking of granitizations during Shinagan, Caledonia and Hercynian periods and of continental rift volcanism in the Mesozoic-Cenozoic era. It is an important potential area for uranium metallogenesis in volcanic basin in North China. The study identifies that four stages of uranium preconcentration and three phases of hydrothermal superimposed-reworking uranium metallogenesis occurred along with the regional geological elevation process. Studies on the U-Pb isotope and induced fission track of various kinds of basement rocks from the area indicate that the basement composed of crustal source remelting type Caledonian and Hercynian granites is favourable for uranium metallogenesis in volcanic basin, and that the late Jurassic intermediate-acid volcano-rock directly act as the source of uranium and that Cretaceous-Tertiary extension-rift basalt magmatic activation supply an important hydrothermal reworking condition for the uranium metallogenesis in volcanic basin. Based on comparative study on the metallogenetic conditions of typical large-scale volcanic uranium deposits at home and abroad, nine prospecting criteria are summarized, the polygenetic mixing hydrothermal uranium metallogenetic model for penetrable volcano-collapse basin is presented, and the main prospecting targets of uranium deposits are pointed out. (2 figs.)

Tianmujian caldera. A potential area for locating rich and large uranium deposit

International Nuclear Information System (INIS)

Lin Ziyu; Xu Jinshan; Chen Mingzhuo; Jiang Jinyuan; Fan Honghai; Cheng Qi

2001-01-01

Based on the comprehensive analysis on geologic, remote sensing, gravimetric, magnetic and geochemical data, and the field geologic investigation, the author has preliminarily ascertained the formation and the distribution characteristics of the Tianmujian caldera, and recognized the porphyroclastic lava system which is extensively distributed in the area. The authors suggest that the Tianmujian volcanic basin experienced two evolution stages--the thermal uplifting and the formation of caldera, that large concealed uranium-rich granitic massif occurs in the area, and during the vertical evolution process the uranium showed its concentration in the lower part and depletion in the upper part, and large amount of ore-forming material moved upward along with the magmatic hydrothermals entering the caldera to form uranium deposit. In addition, it is clarified that the NE-NW rhombic-formed basement structural pattern is predominated by the NE-trending fault. At the same time, the important role of the basement faults in controlling the magmatic activities, in the formation of volcanic basins, as well as the formation of uranium mineralization is emphasized. On the basis of the above comprehensive analysis the authors suggest that the Tianmujian caldera is a quite favourable potential area for possessing the basic conditions necessary for the formation of rich and large uranium deposit including uranium 'source, migration, concentration, preservation' and favourable multiple metallogenic information is displayed in the Tianmujian area

The study on the characteristic of Shuangqiao fault and the ore-control action of it in Daqiaowu deposit

International Nuclear Information System (INIS)

Han Xiaozhong; Hui Xiaochao; Wang Mingtai; Liu Rongrong; Liu Quan; Tang Jiangwei; Jin Miaozhang

2012-01-01

Shuangqiao fault is the most important one to control uranium ore bodies in Daqiaowu district of Quzhou area, Zhejiang province, but there is the obvious argument about the attitude which results in the restriction of the U- prognosis in the area. It aims at finding out the movement and ore-control action of the fault by the study on the characteristic of geometry and kinematics. and combining with geophysics in the depth. The Shuangqiao fault's trend is SE instead of NW by researching, and it has the polygenetic movement. There are two obvious stages of tension about the Shuangqiao fault which tally with the two stages of mineralization in Daqiaowu deposit to show the controlled action to ore bodies by it. By the study in-depth, the Shuangqiao fault can lead the metallogenic hydrothermal, and the secondary faults which connect with it can store the ore bodies. The point that the hanging side of fault can control the ore bodies is put forward by making a synthesis of tectonic assembled form and ore-control factors in Daqiaowu deposit. This view is approved by exploration to provide the reference for disposition of uranium prospecting. (authors)

The deposit of Oklo and its natural nuclear reactors

International Nuclear Information System (INIS)

Gauthier-Lafaye, F.; Weber, F.; Pfiffelmann, J.P.; Chauvet, R.; Michel, B.; Reboul, J.C.

1980-01-01

In the uranium deposit of Oklo (Republic of Gabon), seven zones have been discovered since 1972, in which natural fission reactions took place. Since 1974, a thorough geological study of these zones has been undertaken. It includes field studies, observations of drilled samples and laboratory studies. These studies permit the authors to define the geological environment of the reactors and to point out the influence of nuclear reactions on the surrounding formations. All this work was completed by a geological and metallogenic study of the deposit of Oklo and of the uraniferous basin of Franceville. The deposit of Oklo is situated in a detrital, sandstone-like and pelitic series belonging to the Francevillian. The Francevillian and the mineralization are dated as Middle Precambrian (1800-2000 M.A.). The ore of Oklo is the result of two concentration stages. In the first, uranium seems to have been fixed by hydrocarbons that were concentrated in oil traps. After a tectonic event, circulations of oxidizing solutions generated reconcentrations that are associated with hematite and have contents of UO 2 between 1 and 20%. The fission reactions developed in the high-graded ores which had formed during the last phase of UO 2 concentration. A thorough tectonic analysis of the ore deposit shows that high-graded ores and fission reactors are controlled by fractures. The working of nuclear reactors results in a local increase of temperature which gave a rise to circulation of warm water. The results of this hydrothermal circulation and of the neutron bombardment are seen in a succession of facies surrounding the reactors. At the centre of the reactor all sedimentary structures have been destroyed; within the reaction zone the following clays mineral zones are founded: (1) 1 Md illite and ferrous chlorite corresponding to the common Francevillian sediment; (2) 2 Md illite, (3) magnesium chlorite and (4) 1 Md illite and chlorite-vermiculite in the very rich uraninite ore

Re-Os dating of mineralization in Siah Kamar porphyry Mo deposit (NW Iran) and investigating on its temporal relationship with porphyry Cu-Mo deposits in the southern Lesser Caucasus, NW and central Iran

Science.gov (United States)

Simmonds, Vartan; Moazzen, Mohssen; Selby, David

2017-04-01

The Neo-Tethyan basin closure in Iran is characterized by the Urumieh-Dokhtar magmatic arc (UDMA), formed by north-eastward subduction of the Neo-Tethyan oceanic crust during the Alpine orogeny. This belt also coincides with the porphyry copper metallogenic belt of Iran, which hosts many porphyry Cu-Mo deposits (PCDs) and prospects, such as Sungun (NW Iran) and Sarcheshmeh (central Iran). The Siah Kamar porphyry Mo deposit (PMD) is the first discovered porphyry molybdenum deposit on this belt, which is located 10 km west of Mianeh (NW Iran), with 39.2 Mt proved reserves @ 539 ppm Mo and 66.4 Mt probable reserves @ 266 ppm Mo. The host porphyry stock has quartz-monzonitic composition, which intruded the volcanic and pyroclastic rocks of Eocene age. Re content of molybdenites is about 10.44-41.05 ppm which, considering the several tens of ppm concentration, is comparable with porphyry Mo deposits (e.g., Climax in USA), being clearly distinguished from porphyry Cu-Mo deposits. Re-Os dating of molybdenites from this PMD has given model ages between 28.1±0.15 to 29.06±0.2 Ma, and isochron age of 28.0±2.1 Ma, corresponding to the middle Oligocene (upper part of Rupelian). Comparing the ages determined for Siah Kamar PMD with porphyry Cu-Mo mineralizations in the Lesser Caucasus indicates that it is younger than most of the dated PCDs and prospects there, especially those of upper Eocene, while it is a little older than Paragachay and first-stage Kadjaran PCDs [1]. In a regional scale of NW Iran, it shows a narrow overlap with vein-type Cu-Mo-Au mineralizations in Qarachilar (Qaradagh batholith) and is nearly coeval with Haftcheshmeh PCD, indicating that mineralization in the Siah Kamar PMD corresponds to the second porphyry mineralization epoch in NW Iran, proposed by [2]. Meanwhile, mineralization in Siah Kamar is older than all the porphyry Cu-Mo mineralizations along the central and SE parts of the UDMA, except the Bondar Hanza PCD in Kerman zone, which nearly

Uranium deposits in France and in French overseas territories; Les gisements d'uranium de la France metropolitaine et des territoires francais d'Outre-Mer

Energy Technology Data Exchange (ETDEWEB)

Roubault, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The discover of radium element by Pierre and Marie Curie in 1898 activated the uranium ores prospecting in France and its overseas territories. Before 1945, rare and poor deposits were found with only one being operated in Madagascar and the production of nobiantalates from washing of pegmatitic eluvium. Since the setting up of the Research and Mines Department in the C.E.A. and the training of specialized exploration teams as well as the use of Geiger counters, the uranium ores prospecting has been largely developed in France. The mineralogical data resulting from studies during the pre-war period led to the discover of four main uranium ores content areas: La Crouzille deposit in Limousin characterized by large presence of pitchblende, the Bauzot deposit with massive presence of pitchblende as well, discover of mineralization traces in the Bois Noirs area where a rich uranium ore lodes were discovered afterwards and finally the madagascar deposit. Few other areas have been prospected and have got good evidences of uranium ores presence. The majority of French uranium deposits have got an 'hydrothermal' vein type with localized pitchblende or a secondary mineralization type. It described the different deposits by region and in chronological order of discover. The structural aspect and petrographic studies are discussed. The metallogenic study shows the presence of large mineralization in the French Hercynian massif. After ten years of uranium ores prospecting and mines work, it shows that France possesses numerous uranium deposits which can be qualified as large deposits and the minerals ores prospecting revealed that many deposits sites would be payable in the near future. (M.P.)

Contribution of geological and geophysical 3D models to the development of the polymetallic deposit of Draa Sfar (Hercinian Massif of Central Jebilets, Morocco); Apport du modele geologique et geophysique 3D dans le developpement du gisement polymetallique de Draa Sfar (Massif hercynien des Jebilet centrales, Maroc)

Energy Technology Data Exchange (ETDEWEB)

Rziki, S.; Alansari, A.; Mouguina, E. M.; Simard, J.; Zouhair, M.; Maacha, L.

2012-11-01

The compilation of geological and geophysical (magnetic and gravity) data and the development of the corresponding three-dimensional models have allowed the recognition of the deep mineralized structures, and helped the reopening of the mining after 23 years of inactivity. Geological resources were increased tenfold in three years to reach 10Mt at 5.39% Zn, 1.94% Pb and 0.34% Cu. This exploration methodology based on three-dimensional geological and geophysical models becomes increasingly used in mining exploration strategy after the improvement in the computing capacities of the modelling tools. The results from this study could be helpful for the development of mining massive sulphide deposits in the Jebilet province of Guemassa and by extension to other deposits with similar geological and metallogenic characteristics. (Author) 17 refs.

Mise en place syntectonique des minéralisations cuprifères du gîte d'Ifri (district du Haut Seksaoua, Haut Atlas occidental, Maroc)Syntectonic emplacement of the Ifri copper mineralization (High Seksaoua, western High Atlas, Morocco)

Science.gov (United States)

Gaouzi, Abdelaziz; Chauvet, Alain; Barbanson, Luc; Badra, Lakhlifi; Touray, Jean-Claude; Oukarou, Saı̈d; El Wartiti, Mohamed

2001-09-01

Structural and metallogenic studies of the Ifri copper deposit (western High Atlas, Morocco) demonstrate that a great part of the mineralization was linked to a stockwork developed during a Late-Variscan NNW-verging shearing event. With this significant result, the until now accepted syngenetic character for this mineralization has to be reconsidered and allows to suggest a new guide of prospection for this kind of deposit.

A new edition global map - Uranium deposits of the world

International Nuclear Information System (INIS)

Fairclough, M.

2014-01-01

In 1995 The International Atomic Energy Agency published a hard copy map entitled “World Distribution of Uranium Deposits” at a scale of 1:30 000 000. The map displayed data from agency information that was to become UDEPO database of uranium deposits, overlaid on a generalised geological map supplied by the Geological Survey of Canada. At that time, the database contained 582 deposits with a cut-off of 500 t U at an average grade of 0.03% U, and was generated over a period of half a decade by small group external experts. The experts developed a revised deposit classification scheme displayed on the map and in the accompanying guidebook in 1996. A revised and expanded UDEPO database was made widely available on the internet from 2004, and contained additional deposit information and a constantly increasing number of deposits (874 by the end of 2008 coinciding with a new UDEPO guidebook in 2009). Enhanced efforts by the IAEA and consultants of the UDEPO Working Group have now generated a database that has 1526 deposits with a more detailed classification subdivision utilised in a forthcoming IAEA UDEPO publication. The establishment of this classification scheme and the completion of a major phase of updating UDEPO has created an opportunity for creating a completely new edition of the Uranium Deposits Of The World Map using modern GIS techniques. Cartographic tools within GIS software have become very sophisticated, allowing better display of variably dense data through real-time manipulation of layers and symbology with the GIS dataset. Moreover, some of the results of this functionality can then be transferred to the data display aspects the online version of UDEPO as well as distributed as scale-independent digital version of the map. In parallel, a planned IAEA publication regarding global uranium provinces allows a more rigorous clustering of deposits for the purposes of showing particular metallogenic aspects in more detail. This also has an important

Discussions of the uranium geology working groups IGC, Sydney

International Nuclear Information System (INIS)

1978-01-01

The report is divided into six working group discussions on the following subjects: 1) Chemical and physical mechanisms in the formation of uranium mineralization, geochronology, isotope geology and mineralogy; 2) Sedimentary basins and sandstone-type uranium deposits; 3) Uranium in quartz-pebble conglomerates; 4) Vein and similar type deposits (pitchblende); 5) Other uranium deposits; 6) Relation of metallogenic, tectonic and zoning factors to the origin of uranium deposits. Each working group paper contains a short introductory part followed by a discussion by the working group members

Geological and geochemical studies of the Shujiadian porphyry Cu deposit, Anhui Province, Eastern China: Implications for ore genesis

Science.gov (United States)

Wang, Shiwei; Zhou, Taofa; Yuan, Feng; Fan, Yu; White, Noel C.; Lin, Fengjie

2015-05-01

Most porphyry deposits in the world occur in magmatic arc settings and are related to subduction of oceanic plates. A small proportion of porphyry deposits occur in intracontinental settings, however they are still poorly understood. Shujiadian, a newly-discovered porphyry Cu deposit, is located in the Middle-Lower Yangtze River Valley metallogenic belt and belongs to the intracontinental class. The deposit has classic alteration zones defined by a core of potassic alteration and local Ca-silicate alteration, which is overprinted by a feldspar-destructive alteration zone and cut by veins containing epidote and chlorite. Wallrocks of the deposit are unreactive quartz-rich sedimentary rocks. Three main paragenetic stages have been recognized based on petrographic observations; silicate stage, quartz-sulfide stage, and sulfide-carbonate stage. Quartz + pyrite + chalcopyrite ± molybdenite veins, and quartz + chalcopyrite + pyrite veins of the quartz-sulfide stage contribute most of the copper, and chalcopyrite + chlorite ± pyrite ± pyrrhotite ± quartz ± illite veins of the sulfide-carbonate stage also contribute part of the copper; all the mineralized veins are associated with feldspar-destructive alteration. Investigations on the fluid inclusions in Shujiadian indicate that the ore-forming fluids had four evolutionary episodes: immiscibility and overpressure in the silicate stage, boiling in the quartz-sulfide stage and mixing with meteoric water in the sulfide-carbonate stage. Sulfur and strontium isotope studies suggest that ore metals were mainly derived from magmatic-hydrothermal fluids, and combined with our study of fluid inclusions, we infer that decompression, changes in oxygen fugacity and sulfur content were the main factors that caused Cu precipitation. Compared with porphyry deposits in magmatic arc settings, there are some differences in the ore-bearing rock, alteration, and the composition of ore-forming fluids.

Analysis on uranium metallogenetic conditions of granite pluton in Ulan Uzhur

International Nuclear Information System (INIS)

Lu Yaozu

2014-01-01

Qimantage area in Qinghai province is one of the important exploration areas in the present China, Ulan Uzhur complex pluton, located in the compound tectonic magmatic belt of Qimantage, is the main cluster area with uranium mineralization. This paper describes the petrochemical, geochemical, petrophysical and Heishan uranium deposit mineralization characteristics of rocks formed at the different tectonic-magmatic cycles in Ulan Uzhur complex pluton. Uranium metallogenic conditions in Ulan Uzhur complex pluton were analyzed from uranium source, magmatic activity and structure. The research shew that the Ulan Uzhur complex pluton has the petrochemical characteristics of uranium rock and Cisuralian monzonitic granite has the most significant relationship to uranium mineralization, it has the characteristics of high background radiation, many anomalies and pronounced ore-control structure, Heishan uranium deposit was controlled by factors such as pronounced northeast and the northwest structure and alteration. To conclude, Ulan Uzhur complex pluton possesses good uranium metallogenic prospect. (author)

Remote sensing and GIS-based prediction and assessment of copper-gold resources in Thailand

International Nuclear Information System (INIS)

Yang, Shasha; Wang, Gongwen; Du, Wenhui; Huang, Luxiong

2014-01-01

Quantitative integration of geological information is a frontier and hotspot of prospecting decision research in the world. The forming process of large scale Cu-Au deposits is influenced by complicated geological events and restricted by various geological factors (stratum, structure and alteration). In this paper, using Thailand's copper-gold deposit district as a case study, geological anomaly theory is used along with the typical copper and gold metallogenic model, ETM+ remote sensing images, geological maps and mineral geology database in study area are combined with GIS technique. These techniques create ore-forming information such as geological information (strata, line-ring faults, intrusion), remote sensing information (hydroxyl alteration, iron alteration, linear-ring structure) and the Cu-Au prospect targets. These targets were identified using weights of evidence model. The research results show that the remote sensing and geological data can be combined to quickly predict and assess for exploration of mineral resources in a regional metallogenic belt

Nonlinear metallogeny and the depths of the earth

Science.gov (United States)

Shcheglov, A. D.; Govorov, I. N.

This book is concerned with the basic relations regarding a new approach in the field of knowledge of metallogenesis, taking into account the complex character of the mutual dependence between ore deposits, the structure of the earth's crust, and depth relations. The principles of nonlinear metallogeny are examined, giving attention to the development of the metallogenic science during the past few years, the formation of the concept 'nonlinear metallogeny', the main aspects of nonlinear metallogeny, the origin of the ore deposits and the characteristics of ore formations in the mantle, the parallel manifestation of ore-forming processes in the crust, sedimentary-hydrothermal ore formations and their place in nonlinear metallogeny, and various types of rock and ore formations. The structure, composition, and metalliferous characteristics found at various depth zones of the tectonosphere are discussed along with the geochemical and metallogenic heterogeneity in the mantle. General questions of nonlinear metallogeny are also investigated.

Gravity data processing and research in potential evaluation of uranium resource in China

International Nuclear Information System (INIS)

Liu Hu; Zhao Dan; Ke Dan; Li Bihong; Han Shaoyang

2012-01-01

Through data processing, anomaly extraction, geologic structure deduction from gravity in 39 uranium metallogenic zones and 29 prediction areas, the predicting factors such as tectonic units, faults, scope and depth of rocks, scope of basins and strata structure were provided for the evaluation of uranium resources potential. Gravity field features of uranium metallogenic environment were summarized for hydrothermal type uranium deposits (granite, volcanic and carbonate-siliceous-argillaceous type) as regional gravity transition from high to the low field or the region near the low field, and the key metallogenic factors as granite rocks and volcanic basins in the low gravity field. It was found that Large-scale sandstone type uranium mineralization basins are located in the high regional gravity field, provenance areas are in the low field, and the edge and inner uplift areas usually located in the high field of the residual gravity. Faults related to different type uranium mineralization occur as the gradient zones, boundaries, a string of bead anomalies and striped gravity anomalies in the gravity field. (authors)

Geochronology, petrogenesis and metallogeny of Piaotang granitoids in the tungsten deposit region of South China

International Nuclear Information System (INIS)

He Zhenyu; Xu Xisheng; Wang Xudong; Yu Yao; Zou Haibo

2010-01-01

stages of magmatism and W mineralization in the Piaotang tungsten deposit, and the similarities with other granite related W-Sn deposits in the same region, it is proposed that the regional tectonic setting and lithosphere dynamics are the key factors controlling the metallogenic capacity of granitoids in South China. (author)

Main types of rare-metal mineralization in Karelia

Science.gov (United States)

Ivashchenko, V. I.

2016-03-01

Rare-metal mineralization in Karelia is represented by V, Be, U deposits and In, Re, Nb, Ta, Li, Ce, La, and Y occurrences, which are combined into 17 types of magmatic, pegmatite, albitite-greisen, hydrothermal-metasomatic, sedimentary, and epigenetic groups. The main vanadium resources are localized in the Onega ore district. These are deposits of the Padma group (556 kt) and the Pudozhgorsky complex (1.5 Mt). The REE occurrences are primarily characterized by Ce-La specialization. The perspective of HREE is related to the Eletozero-Tiksheozero alkaline and Salmi anorthosite-rapakivi granite complexes. Rare-metal pegmatites bear complex mineralization with insignificant low-grade resources. The Lobash and Jalonvaara porphyry Cu-Mo deposits are potential sources of rhenium: Re contents in molybdenite are 20-70 and 50-246 ppm and hypothetical resources are 12 and 7.5 t, respectively. The high-grade (˜100 ppm) and metallogenic potential of indium (˜2400 t) make the deposits of the Pitkäranta ore district leading in the category of Russian ore objects most prospective for indium. Despite the diverse rare-metal mineralization known in Karelia, the current state of this kind of mineral commodities at the world market leaves real metallogenic perspective only for V, U, Re, In, and Nb.

Geochronology and geochemistry constraints of the Early Cretaceous Taibudai porphyry Cu deposit, northeast China, and its tectonic significance

Science.gov (United States)

Zhou, Zhen-Hua; Mao, Jing-Wen; Wu, Xin-Li; Ouyang, Hen-Gen

2015-05-01

The southern Great Xing'an Range (SGXR), located in the southeastern part of Inner Mongolia, China, shows intense Mesozoic tectono-magmatic activity and hosts economically important polymetallic (Cu-Pb-Zn-Sn-Fe-Ag-Au-Mo) mineralization. Here, we present new zircon U-Pb ages, whole-rock geochemical data, Nd-Sr-Hf isotopic data and Re-Os ages for the Taibudai deposit in the SGXR. The Taibudai granitoids show high SiO2 (70.62-72.13 wt.%) and alkali (Na2O + K2O = 7.04-8.60 wt.%) concentrations, low MgO (0.89-1.37 wt.%) and Al2O3 (∼14 wt.%), ASI ratios molybdenite from the deposit yield an ore-forming age of 137.1 ± 1.4 Ma. Re contents range from 4.37 to 41.77 ppm, implying ore material components have a mixed crust-mantle origin. SHRIMP analysis of zircons show that the monzogranitic porphyry and biotite granite in the Taibudai deposit were formed at 137.0 ± 0.9 Ma and 138.3 ± 0.9 Ma, respectively, indicating a temporal link between granitic magmatism and Cu mineralization. This result, combined with the regional geology, tectonic evolution, and age data from the literature, suggests that the Early Cretaceous (∼140 Ma) was the peak metallogenic epoch for the Great Xing'an Range, and the mineralization in this period generally takes the form of porphyry, skarn, or hydrothermal polymetallic ore deposits in an active extensional continental margin environment. The Taibudai porphyry and associated mineralization provides a typical example of magmatism and metallogeny associated with a Paleo-Pacific plate subduction, continental margin, back-arc extensional setting.

Timing of multiple hydrothermal events in the iron oxide-copper-gold deposits of the Southern Copper Belt, Carajás Province, Brazil

Science.gov (United States)

Moreto, Carolina P. N.; Monteiro, Lena V. S.; Xavier, Roberto P.; Creaser, Robert A.; DuFrane, S. Andrew; Melo, Gustavo H. C.; Delinardo da Silva, Marco A.; Tassinari, Colombo C. G.; Sato, Kei

2015-06-01

The Southern Copper Belt, Carajás Province, Brazil, hosts several iron oxide-copper-gold (IOCG) deposits, including Sossego, Cristalino, Alvo 118, Bacuri, Bacaba, Castanha, and Visconde. Mapping and U-Pb sensitive high-resolution ion microprobe (SHRIMP) IIe zircon geochronology allowed the characterization of the host rocks, situated within regional WNW-ESE shear zones. They encompass Mesoarchean (3.08-2.85 Ga) TTG orthogneiss, granites, and remains of greenstone belts, Neoarchean (ca. 2.74 Ga) granite, shallow-emplaced porphyries, and granophyric granite coeval with gabbro, and Paleoproterozoic (1.88 Ga) porphyry dykes. Extensive hydrothermal zones include albite-scapolite, biotite-scapolite-tourmaline-magnetite alteration, and proximal potassium feldspar, chlorite-epidote and chalcopyrite formation. U-Pb laser ablation multicollector inductively coupled mass spectrometry (LA-MC-ICP-MS) analysis of ore-related monazite and Re-Os NTIMS analysis of molybdenite suggest multiple Neoarchean (2.76 and 2.72-2.68 Ga) and Paleoproterozoic (2.06 Ga) hydrothermal events at the Bacaba and Bacuri deposits. These results, combined with available geochronological data from the literature, indicate recurrence of hydrothermal systems in the Southern Copper Belt, including 1.90-1.88-Ga ore formation in the Sossego-Curral ore bodies and the Alvo 118 deposit. Although early hydrothermal evolution at 2.76 Ga points to fluid migration coeval with the Carajás Basin formation, the main episode of IOCG genesis (2.72-2.68 Ga) is related to basin inversion coupled with Neoarchean (ca. 2.7 Ga) felsic magmatism. The data suggest that the IOCG deposits in the Southern Copper Belt and those in the Northern Copper Belt (2.57-Ga Salobo and Igarapé Bahia-Alemão deposits) do not share a common metallogenic evolution. Therefore, the association of all IOCG deposits of the Carajás Province with a single extensive hydrothermal system is precluded.

Some metallogenic features of the Huronian and post-Huronian uraniferous conglomerates

International Nuclear Information System (INIS)

Ruzicka, V.

1981-01-01

Uraniferous conglomerates with syngenetic mineralization are restricted to lower Proterozoic sediments. The depositional environment was near volcanic centres; excessive sulfur, a product a volcanic and postvolcanic activity, apparently caused sulfurization of some minerals and of hydrocarbon. The sedimentary syngenetic origin of uranium mineralization may be illustrated. The cycle starts with deposition of coarse grains of quartz, continues with the deposition of a mixture of finer grains of quartz and pyrite with distinct graded bedding, is followed by deposition of monazite and brannerite, and ends with deposition of fragmented fine grains of uraninite embedded in sulfur-rich hydrocarbon. This situation apparently testifies to the fact that the carbonaceous material is a product of algal mats that existed in quiet times between cycles of sedimentation. The succeeding cycle again starts with the deposition of coarse grains of quartz. Uraniferous conglomerates with epigenetic mineralization are localized in regions containing rocks with higher contents of uranium. Primary concentration of uranium minerals in these source rocks can also be syngenetic. Deposition of uranium took place by one or more epigenetic processes: adsorption, complexing, precipitation, or redox changes according to the degrees of solubility and stability of uranium compounds. Evidence of these mentioned features is based upon studies on the Huronian uraniferous conglomerate from Elliot Lake, Canada, and on the late Precambrian and Paleozoic radioactive conglomerates from the eastern Ural Mountains and Enisey Crest region, USSR

Study on geochronology and uranium source of sandstone-type uranium deposit in Dongsheng area

International Nuclear Information System (INIS)

Liu Haibin; Xia Yuliang; Tian Shifeng

2007-01-01

This paper studied the geochronology of sandstone-type uranium deposit in the Dongsheng area of Ordos Basin. In eastern segment, ages of mineralization at the wing of the ore-roll are found to be 120 ± 5 Ma and 80 ± 5 Ma, and at the front of the ore-roll are 20 ± 2 Ma and 8 ± 1 Ma; While in middle segment, ages of mineralization are 124 ± 6 Ma and 80 ± 5 Ma. This means that the main mineralization in Dongsheng area were formed at early Jurassic and late Cretaceous, and correspondent to the time of structure uplift. Mineralization of roll-front (rich ore) which formed in Miocene and Pliocene may related to tectonic-thermal event taken place at that time and reformed the early mineralization in this area. The isochron line age of sample with uranium grade 0 ) in the sandbody is 24.64 x 10 -6 also shows the uranium pre-concentration in the strata. The even value of ΔU of rocks in Zhiluo formation is -70.2%, this shows that non-mineralized rocks have migrated uranium and acted as important metallogenic uranium sources. (authors)

International Project - Atlas of Geological Maps of Central Asia and Adjacent Territories 1:2 500 000 Scale - the Status and the Development Prospects

Science.gov (United States)

Leonov, Y.; Petrov, O. V.; Dong, S.; Morozov, A.; Shokalsky, S.; Pospelov, I.; Erinchek, Y.; Milshteyn, E.

2011-12-01

This project is launched by geological surveys of Russia, China, Mongolia, Kazakhstan and the Republic of Korea with participation of National Academies of Sciences under the aegis of the Commission for the Geological Map of the World since 2004. The project goal is the compilation and subsequent monitoring of the set of digital geological maps for the large part of the Asian continent (20 million km2). Each country finances its own part of the project while all the issues concerning methods and technologies are discussed collectively during annual meetings and joint filed excursions. At the 33d IGC, were shown 4 digital maps of the Atlas at 1: 2,5M - geological, tectonic, metallogenic and energy resources. Geological and energy resources maps were compiled and published by the Chinese part while tectonic and metallogenic maps by Russian side (VSEGEI, Saint-Petersburg). The geological map was also used as the base for the compilation of the other maps of the Atlas. On the tectonic map colours indicate several stages of the continental crust consolidation within fold belts, their tectonic reworking and rifting. The map also shows rock complexes-indicators of geodynamic settings. In the platform areas, the colour reflects the time of beginning of the sedimentary cover formation while its shades reflect the thickness of the sediments. The metallogenic map of the Atlas depicts 1380 objects of metallogenic zoning (from super-provinces to ore clusters) and is accompanied with a database (more than 5000 ore deposits). The map of energy resources with the database contains information on the of coal- and oil-and-gas-bearing basins and main coal and hydrocarbon deposits. In 2009 the study area was extended to the North, East and South in order to embrace bigger territory with ore-bearing Mesozoic-Cenozoic volcanic belts of the Asian continent's Pacific margin. According to nearest plans, discussed with the head of Rosnedra Dr. Anatoliy Ledovskikh and the director of the

Sandstone uranium deposits of Eurasia – from genetic concepts to forecasting and new discoveries

International Nuclear Information System (INIS)

Pechenkin, I.

2014-01-01

the location of infiltration uranium deposits of the Tien Shan megaprovince and the pattern of development of the Pacific Plate subduction. In both cases young sandstone deposits tend to be situated close to the zone of subsiding geodynamic activity. Endogene uranium bodies can be found near the contact area of collision plates. The size of both endogene and exogene objects in the south and east of the Eurasian Plate differ considerably. The given material bears evidence of a close spacial connection between part of sandstone uranium deposits and endogene uranium deposits. Both types of uranium deposits belong to the same ore metallogenic zoning which is entirely dependent on the global geodynamic processes taking place in the crust and mantle on the fringes of the Eurasian continent. This makes it possible to increase the prospects for the future of many parts of the world. (author)

Geochemistry and Fuid-Inclusion Microthermometry of the Farsesh Barite Deposit, Iran

Directory of Open Access Journals (Sweden)

Zarasvandi Alireza

2014-10-01

Full Text Available The Permian carbonate-hosted Farsesh barite deposit is located southeast of the City of Aligudarz in the province of Lorestan, Iran. Structurally, this deposit lies in the Zagros metallogenic belt and the Sanandaj-Sirjan Zone. Barite mineralisations occur as open-space flling veins, and as massive and replacement ores along fractures, faults and shear zones of the Permian carbonate host rocks. In order to determine the structure, in addition to pe-trographic and fuid-inclusions studies, an ICP-MS analysis was carried out in order to measure the major as well as the trace and rare earth elements. The Farsesh barite deposit has a simple mineralogy, of which barite is the main mineral, followed by calcite, dolomite, quartz, and opaque minerals such as Fe-oxides. Replacement of bar-ite by calcite is common and is more frequent than space-flling mineralisation. Sulphide minerals are minor and mainly consist of chalcopyrite and pyrite, which are altered by weathering to covellite, malachite and azurite. Petrographic analysis and micro-thermometry were carried out on the two-phase liquid/vapour inclusions in ellipsoidal or irregularly shaped minerals ranging in size from 5–10 µm. The measurements were conducted on fuid inclusions during the heating and subsequent homogenisation in the liquid phase. The low homogenisation temperatures (200–125°C and low to moderate salinity (4.2–20 eq wt% NaCl indicate that the barite had precipitated from hydrothermal basinal water with low to moderate salinity. It appears from the major and trace elements that geochemical features such as Ba and Sr enrichment in the barite samples was accompanied by depletion of Pb, Zn, Hg, Cu and Sb. The geochemistry of the rare earth elements, such as low σREE concentrations, LREE-enrichment chondrite-normalised REE patterns, the negative Ce and positive Eu anomalies, the low Ce/La ratio and the positive La and Gd anomalies, suggest that the Farsesh barite was deposited

Environmental risk assessment of lead-zinc mining: a case study of Adudu metallogenic province, middle Benue Trough, Nigeria.

Science.gov (United States)

Igwe, Ogbonnaya; Una, Chuku Okoro; Abu, Ezekiel; Adepehin, Ekundayo Joseph

2017-09-07

Assessment of the impacts of lead-zinc mining in Adudu-Imon metallogenic province was carried out. Reconnaissance and detailed field studies were done. Lithologies, stream sediments, farmland soils, mine tailings, artificial pond water, stream water, well water, and borehole water were collected and subjected to atomic absorption spectrometry (AAS) and X-ray fluorescence (XRF) analyses. Geochemical maps were generated using ArcGIS 10.1. Significant contamination with cadmium (Cd), iron (Fe), and lead (Pb) was recorded in the collected water samples. Virtually all collected soil samples were observed to be highly contaminated when compared with the European Union environmental policy standard. The discharge of mining effluents through farmlands to the Bakebu stream, which drains the area, further exposes the dwellers of this environment to the accumulation of potentially harmful metals (PHMs) in their bodies through the consumption of food crops, aquatic animals, and domestic uses of the water collected from the stream channels. The study revealed non-conformity of past mining operations in the Adudu-Imon province to existing mining laws in Nigeria. Inhabitants of this region should stop farming in the vicinity of the mines, fishing from the Bakebu stream channels should be discouraged, and domestic use of the water should be condemned, even as concerned government agencies put necessary mercenaries in place to ensure conformity of miners to standard mining regulations in Nigeria.

Minerageny and potential of the mineral-raw base development. Pt. 2

International Nuclear Information System (INIS)

Bespaev, Kh.A.

1999-01-01

The second part of the book is dedicated to the 100-anniversary of academician K.I.Satpaev. It is opened out by the paper on genetic classification of petroleums of the Caspian basin and their forecast. The group of papers are devoted to new types of gold containing ores in Kazakhstan. In other papers rare earths, rhenium and osmium, titanium, iron, manganese, aluminium of Kazakhstan are characterized. Stratiform copper deposits metallogeny and condition of formation of Zhezkazgan deposit ores are discussed, metallogenic stages of the Earth evolution are considered

Application of anatectic mineralization to prospecting in-situ leachable sandstone type uranium ore in South Songliao Basin

International Nuclear Information System (INIS)

Zhao Zhonghua

2001-01-01

The deep ore-forming origin is a new theory for prospecting in-situ leachable sandstone type uranium. Tectonics, lithologic and geochemistry are basic forecasting criteria. Previous unconsolidated sand, source area and geochemical barrier are three essential conditions for forming uranium deposit. Metallogenic environment and prospective region are found. Tertiary system is prospective layer for prospecting in-situ leachable sandstone type uranium ore in south Songliao Basin

Meeting of the French geological society - Uranium: geology, geophysics, chemistry. Book of abstracts; Reunion de la Societe Geologique de France - Uranium: geologie, geophysique, chimie. Recueil des resumes

Energy Technology Data Exchange (ETDEWEB)

Zakari, A.A.; Mima, S.; Bidaud, A.; Criqui, P.; Menanteau, P.; David, S.; Pagel, M.; Chagnes, A.; Cote, G.; Courtaud, B.; Thiry, J.; Miehe, J.M.; Gilbert, F.; Cuney, M.; Bruneton, P.; Ewington, D.; Vautrin-Ul, C.; Cannizzo, C.; Betelu, S.; Chausse, A.; Ly, J.; Bourgeois, D.; Maynadie, J.; Meyer, D.; Clavier, N.; Costin, D.T.; Cretaz, F.; Szenknect, S.; Ravaux, J.; Poinssot, C.; Dacheux, N.; Durupt, N.; Blanvillain, J.J.; Geffroy, F.; Aparicio, B.; Dubessy, J.; Nguyen-Trung, C.; Robert, P.; Uri, F.; Beaufort, D.; Lescuyer, J.L.; Morichon, E.; Allard, T.; Milesi, J.P.; Richard, A.; Rozsypal, C.; Mercadier, J.; Banks, D.A.; Boiron, M.C.; Cathelineau, M.; Dardel, J.; Billon, S.; Patrier, P.; Wattinne, A.; Vanderhaeghe, O.; Fabre, C.; Castillo, M.; Salvi, S.; Beziat, D.; Williams-Jones, A.E.; Trap, P.; Durand, C.; Goncalves, P.; Marquer, D.; Feybesse, J.L.; Richard, Y.; Orberger, B.; Hofmann, A.; Megneng, M.; Orberger, B.; Bouttemy, M.; Vigneron, J.; Etcheberry, A.; Perdicakis, M.; Prignon, N.; Toe, W.; Andre-Mayer, A.S.; Eglinger, A.; Jordaan, T.; Hocquet, S.; Ledru, P.; Selezneva, V.; Vendryes, G.; Lach, P.; Cuney, M.; Mercadier, J.; Brouand, M.; Duran, C.; Seydoux-Guillaume, A.M.; Bingen, B.; Parseval, P. de; Guillaume, D.; Bosse, V.; Paquette, J.L.; Ingrin, J.; Montel, J.M.; Giot, R.; Maucotel, F.; Hubert, S.; Gautheron, C.; Tassan-Got, L.; Pagel, M.; Barbarand, J.; Cuney, M.; Lach, P.; Bonhoure, J.; Leisen, M.; Kister, P.; Salaun, A.; Villemant, B.; Gerard, M.; Komorowski, J.C.; Michel, A.; Riegler, T.; Tartese, R.; Boulvais, P.; Poujols, M.; Gloaguen, E.; Mazzanti, M.; Mougel, V.; Nocton, G.; Biswas, B.; Pecaut, J.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Galoisy, L.; Calas, G.; Fayek, M.

2010-11-15

This document brings together the abstracts of the 39 presentations given at this meeting days on uranium, organized by the French geological society, and dealing with: 1 - Prospective study of the electronuclear technological transition; 2 - The front-end of the nuclear cycle: from the molecule to the process; 3 - Geophysics: recent changes; 4 - Use of well logging in uranium exploration; 5 - Genetical classification of thorium deposits; 6 - Genetical nomenclature of uranium sources; 7 - Uranium deposits linked to a Proterozoic discordance - retrospective; 8 - The use of spectral analysis techniques in uranium exploration: real-time mapping of clay alteration features; 9 - Development of functionalized silk-screened carbon electrodes for the analysis of uranium trace amounts; 10 - Study of the actinides solvation sphere in organic environment; 11 - Thermodynamic of uraniferous phases of interest for the nuclear cycle; 12 - Heap leaching of marginal minerals at Somair: from lab studies to the production of 700 t of uranium/year; 13 - Agglomeration phenomenology and role of iron in uranium heap leaching; 14 - Chloride uranyl complexes up to 300 deg. C along the saturation vapour curve: Raman spectroscopy analysis and metallogenic consequences; 15 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): vertical variability of argillaceous weathering; 16 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): contribution of irradiation defects in clays to the tracing of past uranium migrations; 17 - Uranium concentrations in mineralizing fluids of the Athabasca basin: analytical and experimental approach; 18 - Paleo-surfaces and metallic rooting: the autochthonous uranium of pre-Athabasca paleo-alterites, Canada; 19 - Distribution of argillaceous parageneses in the Imouraren deposit - Niger; 20 - Heat flux and radioelements concentration (U, Th, K) of precambrian basements: implications in terms of crust growth mechanisms, paleo

Meeting of the French geological society - Uranium: geology, geophysics, chemistry. Book of abstracts

International Nuclear Information System (INIS)

Zakari, A.A.; Mima, S.; Bidaud, A.; Criqui, P.; Menanteau, P.; David, S.; Pagel, M.; Chagnes, A.; Cote, G.; Courtaud, B.; Thiry, J.; Miehe, J.M.; Gilbert, F.; Cuney, M.; Bruneton, P.; Ewington, D.; Vautrin-Ul, C.; Cannizzo, C.; Betelu, S.; Chausse, A.; Ly, J.; Bourgeois, D.; Maynadie, J.; Meyer, D.; Clavier, N.; Costin, D.T.; Cretaz, F.; Szenknect, S.; Ravaux, J.; Poinssot, C.; Dacheux, N.; Durupt, N.; Blanvillain, J.J.; Geffroy, F.; Aparicio, B.; Dubessy, J.; Nguyen-Trung, C.; Robert, P.; Uri, F.; Beaufort, D.; Lescuyer, J.L.; Morichon, E.; Allard, T.; Milesi, J.P.; Richard, A.; Rozsypal, C.; Mercadier, J.; Banks, D.A.; Boiron, M.C.; Cathelineau, M.; Dardel, J.; Billon, S.; Patrier, P.; Wattinne, A.; Vanderhaeghe, O.; Fabre, C.; Castillo, M.; Salvi, S.; Beziat, D.; Williams-Jones, A.E.; Trap, P.; Durand, C.; Goncalves, P.; Marquer, D.; Feybesse, J.L.; Richard, Y.; Orberger, B.; Hofmann, A.; Megneng, M.; Orberger, B.; Bouttemy, M.; Vigneron, J.; Etcheberry, A.; Perdicakis, M.; Prignon, N.; Toe, W.; Andre-Mayer, A.S.; Eglinger, A.; Jordaan, T.; Hocquet, S.; Ledru, P.; Selezneva, V.; Vendryes, G.; Lach, P.; Cuney, M.; Mercadier, J.; Brouand, M.; Duran, C.; Seydoux-Guillaume, A.M.; Bingen, B.; Parseval, P. de; Guillaume, D.; Bosse, V.; Paquette, J.L.; Ingrin, J.; Montel, J.M.; Giot, R.; Maucotel, F.; Hubert, S.; Gautheron, C.; Tassan-Got, L.; Pagel, M.; Barbarand, J.; Cuney, M.; Lach, P.; Bonhoure, J.; Leisen, M.; Kister, P.; Salaun, A.; Villemant, B.; Gerard, M.; Komorowski, J.C.; Michel, A.; Riegler, T.; Tartese, R.; Boulvais, P.; Poujols, M.; Gloaguen, E.; Mazzanti, M.; Mougel, V.; Nocton, G.; Biswas, B.; Pecaut, J.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Galoisy, L.; Calas, G.; Fayek, M.

2010-11-01

This document brings together the abstracts of the 39 presentations given at this meeting days on uranium, organized by the French geological society, and dealing with: 1 - Prospective study of the electronuclear technological transition; 2 - The front-end of the nuclear cycle: from the molecule to the process; 3 - Geophysics: recent changes; 4 - Use of well logging in uranium exploration; 5 - Genetical classification of thorium deposits; 6 - Genetical nomenclature of uranium sources; 7 - Uranium deposits linked to a Proterozoic discordance - retrospective; 8 - The use of spectral analysis techniques in uranium exploration: real-time mapping of clay alteration features; 9 - Development of functionalized silk-screened carbon electrodes for the analysis of uranium trace amounts; 10 - Study of the actinides solvation sphere in organic environment; 11 - Thermodynamic of uraniferous phases of interest for the nuclear cycle; 12 - Heap leaching of marginal minerals at Somair: from lab studies to the production of 700 t of uranium/year; 13 - Agglomeration phenomenology and role of iron in uranium heap leaching; 14 - Chloride uranyl complexes up to 300 deg. C along the saturation vapour curve: Raman spectroscopy analysis and metallogenic consequences; 15 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): vertical variability of argillaceous weathering; 16 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): contribution of irradiation defects in clays to the tracing of past uranium migrations; 17 - Uranium concentrations in mineralizing fluids of the Athabasca basin: analytical and experimental approach; 18 - Paleo-surfaces and metallic rooting: the autochthonous uranium of pre-Athabasca paleo-alterites, Canada; 19 - Distribution of argillaceous parageneses in the Imouraren deposit - Niger; 20 - Heat flux and radioelements concentration (U, Th, K) of precambrian basements: implications in terms of crust growth mechanisms, paleo

Granite-related hypothermal uranium mineralization in South China

International Nuclear Information System (INIS)

Liu, X.; Wu, J.; Pan, J.; Zhu, M.

2014-01-01

As one of the important geological types, granite-related uranium deposits account for about 29% of the total discovered natural uranium resources in China. Most of the granite-related uranium deposits located in Taoshan - Zhuguang uranium metallogenic belt, South China. In addition to the typical pitchblende vein-type uranium mineralization of epithermal metallogenic system, a new type of granite-related uranium mineralization with characteristics of hypothermal matallogenic system was discovered in South China by current studies. However, hypothermal is contact thermal to epithermal mineralization, and not the conventional intrusive high temperature mineralization. Hypothermal uranium mineralization is presented by disseminated uraninite or pitchblende stockwork in fissures in granites normally with extensive alkaline alteration. The high temperature mineral assemblage of uraninite associate with scheelite and tourmaline was identified in hypothermal uranium mineralization. Fluid inclusion studies on this type mineralization indicated the middle to high temperature (>250℃) mineralization with the mixing evidence of ore forming solution derived from deep level, and the boiling and mixing of ore forming solution are regarded as the dominant mineralization mechanism for the precipitating of uranium. In contrast to the mineralization ages of 67 Ma to 87 Ma for typical pitchblende vein mineralization of epithermal metallogenic system, the mineralization age is older than 100 Ma for hypothermal uranium mineralization in granite. In the Shituling deposit, Xiazhuang uranium ore field, uraninite and pitchblende micro veins with extensive potassic alteration, chloritization and sericitization are hosted in fissures of Indo-Chinese epoch granites with the uranium mineralization age of 130 Ma to 138 Ma with a mineralization temperature of 290℃ to 330℃ indicated. Other examples sharing the similar characters of hypothermal uranium mineralization have been recognized in

The Shah-Ali-Beiglou Zn-Pb-Cu (-Ag Deposit, Iran: An Example of Intermediate Sulfidation Epithermal Type Mineralization

Directory of Open Access Journals (Sweden)

Khadijeh Mikaeili

2018-04-01

Full Text Available The Shah-Ali-Beiglou epithermal base metal-silver deposit is located in the Tarom-Hashjin metallogenic province (THMP in northwestern Iran. This deposit is hosted by quartz monzonite dikes of Oligocene age and surrounded by andesite to trachyandesite volcanic and volcaniclastic rocks of Eocene age. The subvolcanic rocks in the study area vary in composition from quartz-monzonite to monzonite and have metaluminous, calc-alkaline to shoshonitic affinity. These rocks have I-type geochemical characteristic and are related to post-collisional tectonic setting. The mineralization occurs as NE-SW and E-W-trending brecciated veins controlled by strike-slip and normal faults, which are associated to the Late Oligocene compressional regime. The mineral paragenesis of the vein mineralization is subdivided into pre-ore stage, ore stage, post-ore stage, and supergene stage. Pre-ore stage is dominated by quartz, sericite, and subhedral to anhedral pyrite as disseminated form. Ore-stage is represented by quartz, sphalerite (from 0.1 mol % to 4 mol % FeS, galena, chalcopyrite, tetrahedrite-tennantite, minor seligmannite and enargite, as vein-veinlet, cement and clast breccias. Post-ore stage is defined by deposition of quartz and carbonate along with minor barite, and supergene stage is characterized by bornite, chalcocite, covellite, hematite, goethite, and jarosite. The ore mineralization is associated with the silicic alteration. The styles of alteration are silicic, carbonate, sericitic, chloritic, and propylitic. Fluid inclusions in sphalerite have a wide range of salinities between 0.35 wt % and 21.4 wt % NaCl equivalent and homogenization temperatures range from 123 to 320 °C. The isotopic values of sulfides vary from 2.8‰ to 6.7‰ suggesting a magmatic source for the sulfur. In the present study, based on geological setting, alteration style of the host and wall rocks, main textures, mineral assemblages, composition of ore minerals, and structural

Geochronology and Genesis of the Xitian W-Sn Polymetallic Deposit in Eastern Hunan Province, South China: Evidence from Zircon U-Pb and Muscovite Ar-Ar Dating, Petrochemistry, and Wolframite Sr-Nd-Pb Isotopes

Directory of Open Access Journals (Sweden)

Jingya Cao

2018-03-01

Full Text Available The recently explored Xitian tungsten-tin (W-Sn polymetallic ore field, located in Hunan province, South China, is one of the largest ore fields in the Nanling Range (NLR. Two major metallogenic types appeared in this ore field, skarn- and quartz vein-type. They are distributed within Longshang, Heshuxia, Shaiheling, Hejiangkou, Goudalan, and so on. Hydrothermal zircons from two altered granites yielded U-Pb ages of 152.8 ± 1.1 Ma, and 226.0 ± 2.8 Ma, respectively. Two muscovite samples from ore-bearing quartz vein yielded 40Ar/39Ar plateau ages of 156.6 ± 0.7 Ma, 149.5 ± 0.8 Ma, respectively. Combined with the geological evidence, two metallogenic events are proposed in the Xitian ore field, with skarn-type W-Sn mineralization in Late Triassic (Indosinian and quartz vein/greisen type W-Sn mineralization in Late Jurassic (Yanshanian. The relatively low Ce/Ce* ratios and high Y/Ho ratios in zircons from two altered granites indicate that the hydrothermal fluids of two metallogenic events are characterized by low oxygen fugacities and enrichment in F. The similar chondrite-normalized patterns between the skarn and Xitian Indosinian granites and Sr-Nd-Pb isotopic compositions of wolframite suggest that the metal sources for both types W-Sn mineralization are derived from a crustal source.

Implication of Spectral Characteristic of Chlorite Based on Spectrums SWIR in Nuri Deposit of Tibet

Science.gov (United States)

Huang, Z.

2017-12-01

This contribution reports the spectral characterization of chlorite in Nuri deposit of Tibet. Nuri Cu polymetallic deposit locates in south rim of Eastern of Gangdise in Tibet. It is presented for large metallogenic scale and special mineralized combination. The study area is underlain extensively by lower Cretaceous rocks of Bima Formation, upper Cretaceous to Paleogene Danshiting Formation and the Quaternary Aeolian Sand. Intrusive bodies, which mainly are quartz diorite, granodiorite, monzonitic granitite, moyite, granite porphyry and so on, feature growth gigantic composite granitic batholith. Distribution of Chlorite is very significant for range and degree of influence of hydrothermal alteration in magmatic hydrothermal deposit. From measuring the spectral of rock and mineral using SVC portable spectrograph, it derived consequence of exists some main altered mineral chlorite. The spectra of chlorite show the absorption features at 1390, 2000, 2250, 2340nm which reflect either O-H stretching vibrations and/or Fe-OH and Mg-OH bending vibrations. Chlorite with Mg-rich shows a strong band at 2324 with a shoulder at 2245nm. The iron-rich chlorite has two absorption features which occur at 2356 and 2256nm. From 110 samples containing chlorite which measured in situ using SVC portable spectrometer, the secondary characteristic absorption wavelengths of chlorite were extracted using TSG software and the diagnosis absorption characteristic of chlorite near 2250nm wavelength is from 2232 to 2266nm. According to the absorption characteristics wavelength position near 2250nm, the samples containing chlorite divided into four categories, i.e. Mg-chlorite whose wavelength less than 2245nm, MgFe-chlorite whose wavelength between 2245 and 2250nm, FeMg-chlorite whose wavelength between 2250 and 2258nm, and Fe-chlorite whose wavelength greater than 2258nm. And then chemical composition of chlorite is analyzed by electron probe with JXA-8230 device which shows that the Fe and

Geochemistry and geochronology of ore-bearing and barren intrusions in the Luanchuan ore fields of East Qinling metallogenic belt, China: Diverse tectonic evolution and implications for mineral exploration

Science.gov (United States)

Xue, Fei; Wang, Gongwen; Santosh, M.; Yang, Fan; Shen, Zhiwei; Kong, Liang; Guo, Nana; Zhang, Xuhuang; Jia, Wenjuan

2018-05-01

The Luanchuan ore fields form part of the East Qinling metallogenic belt in central China. In this study, we compare two ore-bearing intrusions, the Shibaogou granitic pluton (SBG) and the Zhongyuku granitic pluton (ZYK), with the ore-barren Laojunshan intrusion (LJS) from the Luanchuan ore field. Geochemically, all the three intrusions are characterized by high-Si, high-K, and alkalis, together with moderate-ASI, exhibiting I-type granite features. The rocks, especially the ore-related plutons also show enrichment in LREEs. Mineral chemistry of biotite from the intrusions exhibits similar features of high Si and Mg, and low Al and Fe. Zircon grains from the ZYK intrusion yielded a U-Pb age of 149.6 ± 2.4 Ma. The zircon grains show εHf (t) values and two stage model ages (TDM2) in the range of -16.8 to -19.7 and 1998-2156 Ma respectively. The biotite composition and Hf isotopic data indicate that the magma was derived by re-melting of deep crustal material with minor input of mantle components. We evaluate the results to understand the physico-chemical conditions, petrogenesis, and tectonic setting, and their implications for mineral exploration. The ore-bearing plutons show wide ranges of temperature and oxygen fugacity, favoring Mo-W mineralization. In addition, estimates on pressure and depth of emplacement suggest that lower solidification pressure in a decompressional setting contributed to the evolution of magmatic hydrothermal deposits. Our data suggest that the ZYK has the highest potential for Mo-W mineralization. The ore-bearing plutons of ZYK and SBG were formed in a transitional tectonic setting from compression to extension, with the large-scale metallogeny triggered by slab melts at ca. 145 Ma. However, the ore-barren LJS batholith formed in an extension-related geodynamic setting at ∼115 Ma. Our study shows that different tectonic settings and consequent physico-chemical conditions dictated the ore potential of the intrusions in the Luanchuan ore

GEOLOGICAL FEATURES OF NEOGENE BASINS HOSTING BORATE DEPOSITS: AN OVERVIEW OF DEPOSITS AND FUTURE FORECAST, TURKEY

Directory of Open Access Journals (Sweden)

Cahit HELVACI

2015-12-01

Full Text Available The geometry, stratigraphy, tectonics and volcanic components of the borate bearing Neogene basins in western Anatolia offer some important insights into on the relationship between basin evolution, borate formation and mode of extension in western Anatolia. Some of the borate deposits in NE-SW trending basins developed along the İzmir-Balıkesir Transfer Zone (İBTZ (e.g. Bigadiç, Sultançayır and Kestelek basins, and other deposits in the NE-SW trending basins which occur on the northern side of the Menderes Core Complex (MCC are the Selendi and Emet basins. The Kırka borate deposit occurs further to the east and is located in a completely different geological setting and volcanostratigraphic succession. Boron is widely distributed; including in soil and water, plants and animals. The element boron does not exist freely by itself in nature, but rather it occurs in combination with oxygen and other elements in salts, commonly known as borates. Approximately 280 boron-bearing minerals have been identified, the most common being sodium, calcium and magnesium salts. Four main continental metallogenic borate provinces are recognized at a global scale. They are located in Anatolia (Turkey, California (USA, Central Andes (South America and Tibet (Central Asia. The origin of borate deposits is related to Cenozoic volcanism, thermal spring activity, closed basins and arid climate. Borax is the major commercial source of boron, with major supplies coming from Turkey, USA and Argentina. Colemanite is the main calcium borate and large scale production is restricted to Turkey. Datolite and szaibelyite are confined to Russia and Chinese sources. Four Main borax (tincal deposits are present in Anatolia (Kırka, California (Boron, and two in the Andes (Tincalayu and Loma Blanca. Kırka, Boron and Loma Blanca have similarities with regard to their chemical and mineralogical composition of the borate minerals. Colemanite deposits with/without probertite and

Some problems on target-area selection for searching interstratified infiltration sandstone-type uranium deposits suitable to in-situ leaching

International Nuclear Information System (INIS)

Hu Shaokang

2005-01-01

The sandstone-type uranium deposits are widely distributed in the world, but only 3 regions where deposits reach uranium province size and are suitable for in-situ leaching have been found. Deposits are all of the interstratified-oxidation type, and developed at the combination sites of the most recent orogenic belt with young or old platforms in form of 'branching, inclining and disappearing' of the former. Geomorphologically, these regions consist of 3 big 'steps' from high mountain regions through lower mountains or hills to the margins of the basin, which are in form of declining slope and form a good hydrodynamic conditions. Climatically, an arid climate was always required for the period of sandstone-type uranium ore formation, while annual evaporation is higher than the annual precipitation, the high mountain regions with high potential energy of water melted from glacier and snow which is thought to be a long-term and steady underground water supplier for lower mountains or hill regions and the margins of the basin. However, in orogenic belt there is a good number of inter-mountain basins with at least two big 'steps' indicating a good potential to discover interstratified-oxidation sandstone-type uranium deposits in coal-bearing basins. Many Chinese and foreign uranium geologists have noticed that there is an east-west oriented Hercynian uranium mineralization belt lying across the middle of Europe, the eastern section is superimposed on the Ural-Tianshan-Mongolian mobile belt and together with the latter it was infected by the Alpine-Himalayan movement in Meso-Cenozoic. This resulted in a complicated metallogenic scene with different ore-forming times, multiple types of deposits, and spatial concentration. In addition, a sub-meridional-oriented 'Vebris belt' running through the eastern part of Asia is considered as combination part of the Central Asian mobile belt with the Western Pacific mobile belt which reflects inhomogeneity in crustal construction of

Localization of mineralization, its age, and relationship to magmatism at the Mogot silver-base-metal deposit, North Stanovoi metallogenic zone in the southeastern framework of the North Asian Craton

Science.gov (United States)

Buchko, I. V.; Buchko, Ir. V.; Sorokin, A. A.; Ponomarchuk, V. A.; Travin, A. V.

2014-03-01

The results of studying the Mogot silver-base-metal deposit located in the Dzhugdzhur-Stanovoi Superterrane are discussed in this paper. The main ore-controlling structural elements of the studied district are near-latitudinal and NE-trending faults, which are accompanied by zones of hydrothermal metasomatic potassic, propylitic, and argillic alterations, breccias with quartz and quartz-carbonate cement replacing metamorphic rocks and granitoids of the Late Stanovoi Complex. The total sulfide content in ore is 2-3%. The high Ag, Pb, and Zn contents in ore allow us to consider the Mogot deposit as silver-base-metal, since except of orebody 4, there are no silver minerals proper. This indicates that silver is incorporated into crystalline lattice of sulfides. The results of 40Ar/39Ar geochronological investigations show that the hydrothermal ore deposition dated at 127-125 Ma was related to emplacement of intrusions pertaining to the Tynda-Bakaran Complex.

Contribution to a summary of the results obtained in the field of geology on the Oklo natural reactors and their environment

International Nuclear Information System (INIS)

Weber, F.

1978-01-01

The very special characteristics of the ore in the reaction zones may be attributed to the effects of the nuclear reactions themselves: de-structuration of the gangue by neutronic effects and hydrothermal leaching due to the generation of a true thermal syphon by the nuclear reactions. This mechanism contributes to the propagation of reactions from a number of initial reaction sites. The latter were initiated in certain parts of the deposit, enriched as a result of a tectonic episode, by oxidizing currents in the shear troughs. These enriched zones occur as anomalies within a pre-existent deposit, the formation of which still poses many questions of a metallogenic nature. (author)

Evaluation of mineral resource potential of the Finnish precambrian

International Nuclear Information System (INIS)

Peltonen, K.

1993-05-01

In the report the undiscovered mineral resource potential of metallogenic regions in Finland is evaluated. The evaluation is based on known deposits. The criteria of the evaluation were: ore and mineral deposit density, regional distribution of valuable metals, and the amount and the nature of prospecting methods used. The information for the study has been collected from the data base for ore minerals maintained by the Geological Survey of Finland. Regions with mineral resource potential conclusively under national average are Presvecokarelidic and Svecokarelidic granitoids and rapakivi Massif. The mineral resource potential of basic rocks in relation to their surface area is multiple compared to non-basic rocks

Uranium provinces and the exploration industry

International Nuclear Information System (INIS)

Hunter, J.; Michie, U.McL.

1988-01-01

There is little doubt that exploration by mining companies in established districts or 'provinces' has led to the discovery of substantial additional ore reserves. However, the competition for, and expenses of, land acquisitions in these known districts often prompts companies to search further afield. In some cases, new discoveries can merely be regarded as extensions of known provinces while others are located in completely new areas. Whether the explorers utilized concepts of metallogenic provinces in the course of such discoveries is questionable; rather, they would have sought the particular combinations of geological circumstances required by the model. Once a new deposit is found, however, the concept of a province, whether correct in that situation or not, is usually responsible for stimulating further activity. Recent examples of such behaviour are the Arizona Strip and NE Nebraska (USA) in provincial extensions and Roxby Downs, Lone Gull (NW Territories, Australia) and Lagoa Real (Brazil) in new areas. More routine and scientific application of metallogenic province theory by the uranium exploration industry would require evidence that not only the bulk of the world's uranium reserves but also the majority of the individual world-class deposits fall into geologically definable provinces. Such evidence should include the demonstration that particular areas of the Earth's crust had been enriched in uranium (with or without related elements) and that this enrichment had persisted through periods of crustal reworking and been responsible for concentrations of the metal ore deposits. The evidence described in the volume is critically reviewed in this context. (author). Refs, 4 figs

Pb-Pb and U-Pb zircon ages of archean syntetocnic granites of the Carajas metallogenic province, northern Brazil

International Nuclear Information System (INIS)

Barros, Carlos Eduardo de Mesquita; Sardinha, Alex Souza; Barbosa, Jaime dos Passos de Oliveira; Krimski, Robert; Macambira, Moacir Jose Buenano

2001-01-01

The Carajas Metallogenic Province is located in the southeastern Amazonian Craton. It has been divided in two domains, the southernmost comprises the Rio Maria region and the northernmost corresponds to Caraj region (Souza et al. 1996). The former domain is made up of Archean greenstone sequences (2,97 Ga), TTG (2,9 Ga) and calc-alkaline granitoids (2,87 Ga) (Macambira and Lafon 1995, Leite et al. 1999, Althoff et al. 2000). The Carajas block is constituted of minor mafic granulites (3,00 Ga) and quartzofeldspathic gneisses (2,81 Ga), metavolcanosedimentary sequences (2,76 Ga) and granites (2,76 to 2,56 Ga) (Machado et al. 1991; Huhn et al. 1999, Pidgeon et al. 2000). Widespread anorogenic A-type granites are found in both areas (Docegeo 1988; Dall'Agnol et al. 1994). In the last two decades several authors (Lindenamyer et al. 1994, Barros and Barbey 1998, Huhn et al. 1999 and others) have emphasized the role of the Archean granite magmatism in the tectonicthermal evolution in the Carajas Province. In this paper we discuss the tectonic significance of the Pb- Pb and U-Pb ages obtained in some granitoids from the Carajas region. The Estrela Granite Complex and the granitoids located to the north of Parauapebas were dated by Pb- Pb evaporation zircon method (cf. Kober 1987). Data are presented considering 2σ ∼ . The Pb corrections have been done in the basis of the evolution model of Pb in double stage (cf. Stacey and Kramers 1975). U-Pb zircon method (cf. Krogh 1973, Stacey and Kramers 1975, Parrish 1987, Ludwuig 1999), recently put on routine in the Para-Iso laboratories, was employed to date the granite from the Serra do Rabo area. Analyses were carried on the Finnigan Mat 262 spectrometer (au)

Uranium favourability and evaluation in Mongolia (phase II), recent events in uranium resources and production in Mongolia

International Nuclear Information System (INIS)

Batbold, T.

2001-01-01

Uranium exploration in Mongolia covered a period of over 5 decades. The main results of these activities were the discoveries of 6 uranium deposits and about 100 occurrences as well as numerous favourable indications. Sizable resources are found mainly in deposits of the sandstone, volcanic and alkaline intrusive types. Of these, the first two are considered to be of economic importance. Uranium production in Mongolia started in 1989 with the exploitation of volcanic type uranium deposits of the Mongol-Priargun metallogenic province, known as the Dornot Mine. Due to political and economic changes in the country and neighbouring areas of the Russian Federation, this uranium production was terminated in 1995. A new plan to restart production at the Mardai-gol deposits as a joint venture between Mongolia, the Russian Federation and a US company is being considered. (author)

Research on ore-controlling factors and prospecting targets in Shihongtan uranium deposit area, turpan-hami basin

International Nuclear Information System (INIS)

Fu Chengming

2005-01-01

Based on analyzing the controlling role of geologic structure, host formation and hydrodynamic environments on interlayer oxidation zone and uranium mineralization, the author suggests that the Aiding structural slope, block-faulting structure, and subsidiary faults and folds are indications of uranium mineralization emplacement, sand bodies of braided stream facies provide favorable space for the development of interlayer oxidation zone and uranium mineralization, and variation sites of interlayer artesian water and geochemical environments are important places for the precipitation of ore material. Based on the above-mentioned a prediction of favorable metallogenic targets is made. (author)

Le gisement Ag sbnd Hg de Zgounder (Jebel Siroua, Anti-Atlas, Maroc) : un épithermal néoprotérozoïque de type Imiter

Science.gov (United States)

Marcoux, Éric; Wadjinny, Ahmed

2005-12-01

The Zgounder ore deposit (Anti-Atlas, Morocco), is hosted in a PII-PIII Proterozoic volcanosedimentary series. Disseminated mineralization is dominated by mercuriferous native silver (2 to 30 wt.% Hg), with few silver sulfosalts (acanthite, pearceite), arsenopyrite and base-metal sulfides. Arsenic grade of arsenopyrite and homogenisation temperatures of fluid inclusions indicate initial conditions of high temperature (above 400 °C). Lead isotope compositions comfort a Late-Proterozoic age and a crustal origin for metals. Similarities are obvious with the neighbouring silver ore deposit of Imiter and lead to consider Zgounder as another example of Neoproterozoic epithermal deposit in the Anti-Atlas of Morocco, a region that appears more and more as a silver metallogenic province. To cite this article: É. Marcoux, A. Wadjinny, C. R. Geoscience 337 (2005).

The metallogeny of Late Triassic rifting of the Alexander terrane in southeastern Alaska and northwestern British Columbia

Science.gov (United States)

Taylor, C.D.; Premo, W.R.; Meier, A.L.; Taggart, J.E.

2008-01-01

A belt of unusual volcanogenic massive sulfide (VMS) occurrences is located along the eastern margin of the Alexander terrane throughout southeastern Alaska and northwestern British Columbia and exhibits a range of characteristics consistent with a variety of syngenetic to epigenetic deposit types. Deposits within this belt include Greens Creek and Windy Craggy, the economically most significant VMS deposit in Alaska and the largest in North America, respectively. The occurrences are hosted by a discontinuously exposed, 800-km-long belt of rocks that consist of a 200- to 800-m-thick sequence of conglomerate, limestone, marine elastic sedimentary rocks, and tuff intercalated with and overlain by a distinctive unit of mafic pyroclastic rocks and pillowed flows. Faunal data bracket the age of the host rocks between Anisian (Middle Triassic) and late Norian (late Late Triassic). This metallogenic belt is herein referred to as the Alexander Triassic metallogenic belt. The VMS occurrences show systematic differences in degree of structural control, chemistry, and stratigraphic setting along the Alexander Triassic metallogenic belt that suggest important spatial or temporal changes in the tectonic environment of formation. At the southern end of the belt, felsic volcanic rocks overlain by shallow-water limestones characterize the lower part of the sequence. In the southern and middle portion of the belt, a distinctive pebble conglomerate marks the base of the section and is indicative of high-energy deposition in a near slope or basin margin setting. At the northern end of the belt the conglomerates, limestones, and felsic volcanic rocks are absent and the belt is composed of deep-water sedimentary and mafic volcanic rocks. This northward change in depositional environment and lithofacies is accompanied by a northward transition from epithermal-like structurally controlled, discontinuous, vein- and pod-shaped, Pb-Zn-Ag-Ba-(Cu) occurrences with relatively simple mineralogy

Geology, mineralization, and fluid inclusion characteristics of the Skrytoe reduced-type W skarn and stockwork deposit, Sikhote-Alin, Russia

Science.gov (United States)

Soloviev, Serguei G.; Kryazhev, Sergey G.

2017-08-01

The Skrytoe deposit (>145 Kt WO3, average grade 0.449% WO3) in the Sikhote-Alin orogenic system (Eastern Russia) is situated in a metallogenic belt of W, Sn-W, Au, and Au-W deposits formed in a late to post-collisional tectonic environment after cessation of active subduction. It is localized within a mineralized district of reduced-type skarn W and veined Au (±W) deposits and occurrences related to the Early Cretaceous ilmenite-series plutonic suite. The deposit incorporates large stockworks of scheelite-bearing veinlets related to propylitic (amphibole, chlorite, quartz) and phyllic (quartz, sericite, albite, apatite, and carbonate) hydrothermal alteration. The stockwork cuts flat-lying mafic volcanic rocks and limestone partially replaced by pyroxene skarn that host the major W orebodies. Scheelite is associated with pyrrhotite and/or arsenopyrite, with minor chalcopyrite and other sulfide minerals; the late phyllic stage assemblages hosts Bi and Au mineralization. The fluid evolution included low-salinity moderate-temperature, moderate-pressure (˜370-390 °C, ˜800 bars) methane-dominated carbonic-aqueous fluids that formed post-skarn propylitic alteration assemblages. Then, at the phyllic stage, there has been an evolution from methane-dominated, moderate-temperature (330-360 °C), low-salinity (<12.3 wt% NaCl equiv.) fluids forming the early quartz-sericite-albite-arsenopyrite assemblage, through lower temperature (290-330 °C) methane-dominated, low-salinity (˜9-10 wt% NaCl equiv.) fluids forming the intermediate quartz-sericite-albite-scheelite-pyrrhotite assemblage, to yet lower temperature (245-320 °C) CO2-dominated carbonic-aqueous low-salinity (˜1-7 wt% NaCl equiv.) fluids forming the late quartz-sericite-sulfide-Bi-Au assemblage. Recurrent fluid immiscibility (phase separation) and cooling probably affected W solubility and promoted scheelite deposition. The stable isotope data support a sedimentary source of carbon (δ13Cfluid = ˜-21 to -10 �

Some geological effects of the search for radioactive minerals in the Canadian shield

International Nuclear Information System (INIS)

Lang, A.H.; Ruzicka, V.

1979-01-01

Priorities for funds and personnel to provide field and laboratory work related to finding and evaluating radioactive deposits, mainly those of uranium, also led directly and indirectly to greatly increased knowledge of the general geology of the Canadian Shield. The paper outlines some of the main advances made in these ways, as well as some minor ones. Main examples are: the acceleration of geological mapping and special studies of stratigraphy, structure and other aspects of several parts of the Shield, including the Archaean-Proterozoic boundary; the acquisition of modern equipment capable of making large numbers of isotope age determinations, which was soon applied to general problems in the Shield, including revision of its regional provinces and sub-provinces and the subdivision of Proterozoic time; the obtaining of modern equipment for X-ray identification of minerals and for several kinds of rock and mineral analyses, which soon allowed more advanced and more extensive mineral, petrological and trace element studies of various parts of the Shield and a general study of metallogenic provinces, illustrated by metallogenic maps, which stemmed from a metallogenic map for uranium. The development of Geiger counters and other detectors is outlined because of their relation to the map for uranium and so to aeroradiometric surveys. By 1960, 26 producing uranium mines had been developed from an estimated 12 000 occurrences carrying more than 0.05% U 3 O 8 equivalent. Current activities of the Geological Survey of Canada for radioactive minerals are summarized for whatever hints this may provide regarding further indirect effects

Architecture and mineral deposit settings of the Altaid orogenic collage: a revised model

Science.gov (United States)

Yakubchuk, Alexander

2004-09-01

of the Paleo-Pacific Ocean. Several world-class Cu-(Mo)-porphyry, Cu-Pb-Zn VMS and intrusion-related Au mineral camps, which formed in the Altaids at this stage, coincided with the episodes of plate reorganization and oroclinal bending of magmatic arcs. Major Pb-Zn and Cu sedimentary rock-hosted deposits of Kazakhstan and Central Asia formed in backarc rifts, which developed on the earlier amalgamated fragments. Major orogenic gold deposits are intrusion-related deposits, often occurring within black shale-bearing sutured backarc basins with oceanic crust. After amalgamation of the western Altaids, this part of the collage and adjacent cratons were affected by the Siberian superplume, which ascended at the Permian-Triassic transition. This plume-related magmatism produced various deposits, such as famous Ni-Cu-PGE deposits of Norilsk in the northwest of the Siberian craton. In the early Mesozoic, the eastern Altaids were oroclinally bent together with the overlapping Transbaikal magmatic arc in response to the northward migration and anti-clockwise rotation of the North China craton. The following collision of the eastern portion of the Altaid collage with the Siberian craton formed the Mongol-Okhotsk suture zone, which still links the accretionary wedges of central Mongolia and Circum-Pacific belts. In the late Mesozoic, a system of continent-scale conjugate northwest-trending and northeast-trending strike-slip faults developed in response to the southward propagation of the Siberian craton with subsequent post-mineral offset of some metallogenic belts for as much as 70-400 km, possibly in response to spreading in the Canadian basin. India-Asia collision rejuvenated some of these faults and generated a system of impact rifts.

Forecasting sandstone uranium deposits in oil-and-gas bearing basins

International Nuclear Information System (INIS)

Pechenkin, I.

2014-01-01

The interrelation between oxidation and reduction processes in the carbonaceous strata of Paleogene age was first studied in the 1950s in deposit of the Fergana depression. The presence of pre-ore and post-ore epigenesis of petroleum series was established. Part of uranium mineralization was found to be covered with fluid oil. In the middle of the 1960s in the Sabirsay deposit (Uzbekistan) in primary red-coloured continental sediment of Cretaceous age were studied pre-ore reduction changes, which caused economic uranium mineralization in contrasting geochemical barrier. Further research showed that multidirectional epigenetic processes had changed repeatedly. Later, in the 1970s, American geologists studying uranium deposits in the oil-and-gas bearing Texas Plain reached similar conclusions. From their point of view, in the Benevides deposit the main zones of mineralization tend to be located near the boundary where the zones of oxidation in the strata wedge in, developing in epigenetically reduced formations. A second post-mineral reduction was registered in a number of rock bodies. The complexity of the processes is determined by the double role of hydrocarbon fluids and the products of their dissolution. On the one hand, bituminization of permeable strata as well as pyritization, chloritization, dolomitization and other alterations associated with it create favourable geochemical conditions of a reducing character for a subsequent concentration of ore and nonmetal raw materials. On the other hand, intrusion of bitumen and its dissolution in the aeration zone leads to the burial of the mineralization which formed earlier and disappearance of all traces of its formation (epigenetic oxidation zoning). Thus forecasting and subsequent prospecting become impeded. The established sequence of epigenetic alterations allows us to carry out specialized mapping in productive regions, uncovering hidden parts of epigenetic oxidation zoning and “buried” mineralization

Uranium mineralization possibilities in metamorphic Massif of Isla de Juventud, Cuba

International Nuclear Information System (INIS)

Gongora Dominguez, L.E.; Llanes Castro, A.I.; Pena Fortes, B.; Capote Rodriguez, G.

1996-01-01

The geologic and metallogenic characteristic of the metamorphic Massif shows the presence of possible uranium vein type mineralization as a result of a hidrotermal genetic process. Metalliferous fluids rising along the fault system were responsible for the deposition of the uranium in the reduction zones, i.e. presence of pyrite, organic matter and others. This type of uranium minerization is proposed for the Bibijagua area and for the Revolucion and Lela area the same type is expected. The gamma spectrometric analysis was used to evaluate the geological samples

Prospects of uranium in Baluchistan

International Nuclear Information System (INIS)

Aslam, M.; Rehman, M.A.

1981-01-01

A review of the geology of Baluchistan indicates that sedimentary rocks consisting of sandstones and conglomerates ranging from Paleocene to Miocene age were formed under the fluviatile conditions. The region underwent Late Cretaceous-Early Cenozic continent to continent collision resulting in varied metallogenic environments. Considering the criteria of favourability for the environments of uranium deposition, it is found that these rocks and the acidicigneous rocks of Cretaceous age are favourable for the occurrence of uranium. A radiometric prospecting programme is suggested to locate possible mineralization in the region. (author)

Investigation on uranium resources of Qinling region

International Nuclear Information System (INIS)

Peng Daming

1999-01-01

The Qinling Mountains straddle China from the west to the east with the length of more than 1300 km covering Anhui, Hubai, Hunan, Shanxi, Guansu, Qinghai and Sichuan provinces. Up to now, 20 uranium deposits have been discovered in the region and all discovered deposits can be classified into 3 type (granite type, sedimentation-reworking type and hydrothermal alteration type) and 9 subtypes including 15 uranium deposits discovered in Qinling geosyncline area. Main uranium deposits are concentrated in Danfeng and Shangnan counties, southern Shanxi, lantian county, central Shanxi and Lixian County, Southern Gansu. Of the above listed uranium deposits, the granite-hosted deposits are most important, and characterized by large resources, high grade of ore and easiness in hydrometallurgy. Sedimentation-reworking type deposits are less important. The main U-metallogenic epoch is the Caledonian and the Yanshanian is the second. A prognosis for uranium deposits in Qinling region is made in the paper which proposes that the belt from Dangchuan in the west, via Jiamusi, Gepai and Fenshuling to Longquanping in the east is a most favorable area for location granite type uranium deposits

Contrasting Cu-Au and Sn-W Granite Metallogeny through the Zircon Geochemical and Isotopic Record

Science.gov (United States)

Gardiner, Nicholas; Hawkesworth, Chris; Robb, Laurence; Whitehouse, Martin; Roberts, Nick; Kirkland, Chris

2017-04-01

Magmatic genesis and evolution - mediated by geodynamic setting - exert a primary control on the propensity of granites to be metal fertile. A revolution in our understanding of these petrogenetic processes has been made through a range of mineral-based tools, most notably the common accessory mineral zircon. There is consequently considerable interest in whether the geochemical and isotopic compositions of zircon can be applied to metallogenic problems. The paired magmatic belts of Myanmar have broadly contrasting metallogenic affinities (Sn-W versus Cu-Au), and are interpreted to have formed on the accretionary margin of the subducting Neo-Tethys Ocean. They therefore present the opportunity to geochemically compare and contrast the zircon compositions in two end-member types of granite-hosted mineral deposits generated in collisional settings. We present an integrated zircon isotope (U-Pb, Lu-Hf, O) and trace element dataset that fingerprint: (a) source; (b) redox conditions; and (c) degree of fractionation. These variables all impact on magma fertility, and our key question to address is whether they can be reliably traced and calibrated within the Myanmar zircon record. Granitoid-hosted zircons from the I-type copper arc have juvenile ɛHf (+7 to +12) and mantle-like δ18O (5.3 ‰), whereas zircons from the S-type tin belt have low ɛHf (-7 to -13) and heavier δ18O (6.2-7.7 ‰). Plotting Hf versus U/Yb reaffirms that the tin belt magmas contain greater crustal contributions than the copper arc rocks. Links between whole rock Rb/Sr and zircon Eu/Eu* highlights that the latter can be used to monitor magma fractionation in systems that crystallize plagioclase (low Sr/Y). Ce/Ce* and Eu/Eu* in zircon are thus sensitive to redox and fractionation respectively, and can be used to evaluate the sensitivity of zircons to the metallogenic affinity of their host rocks. Tin contents that exceed the solubility limit are required in order to make a magmatic

Analysis on geology condition of uranium mineralization and the exploration orientation for Baixingtu district southwestern Songliao basin

International Nuclear Information System (INIS)

She Xinmin; Cui Jiahua; Gong Wenjie; Li Zeming; Li Changhua; Zhao Junlong

2007-01-01

The paper mainly analyses the uranium mineralization conditions at Baixingtu district of southwestern Songliao basin. The research is focused on the characteristic of braided stream faces grey sandbody of Yaojia formation and the feature of epigenetic deoxidation and oxidization features of uranium mineralization abnormity, relation of uranium mineralization abnormity to fault, relation of uranium mineralization abnormity to interval oxidation, genesis of uranium mineralization and their controlling factors. It is considered that there are favorable metallogenic conditions in the Baixingtu-Donghuagen district of the east edge of Baixingtu denuded structure window for the formation of Qianjiadian type uranium deposit. (authors)

Geology, mineralization, and fluid inclusion characteristics of the Kashkasu W-Mo-Cu skarn deposit associated with a high-potassic to shoshonitic igneous suite in Kyrgyzstan, Tien Shan: Toward a diversity of W mineralization in Central Asia

Science.gov (United States)

Soloviev, Serguei G.; Kryazhev, Sergey G.

2018-03-01

The Kashkasu deposit is part of the subduction-related Late Paleozoic (Late Carboniferous) metallogenic belt of Tien Shan. It is associated with a multiphase monzodiorite-monzonite-granodiorite-granite pluton of the magnetite-series high-K calc-alkaline to shoshonitic igneous suite. The deposit contains zones of W-Mo-Cu oxidized prograde and retrograde skarns, with abundant andraditic garnet, magnetite, locally scapolite and K-feldspar, as well as scheelite, chalcopyrite, and molybdenite. Skarns are overprinted by quartz-carbonate-sericite (phyllic alteration) zones with scheelite and sulfides. Prograde calcic skarn and initial retrograde skarns were formed from a high temperature (650 °C to 450-550 °C), high pressure (2000 bars to 600-900 bars) magmatic-hydrothermal low- to high-salinity aqueous chloride fluid. The gradual fluid evolution was interrupted by the intrusion of granodiorite and likely associated release of low-salinity (∼7-8 wt% NaCl equiv.) fluid. Ascent of this fluid to shallower levels and/or its cooling to 400-500 °C has resulted in phase separation into low-salinity (2.1-3.1 wt% NaCl equiv.) vapor and coexisting brine (35-40 wt% NaCl equiv.). The boiling was coincident with most intense scheelite deposition in retrograde skarn. Later retrograde skarn assemblages were formed from a gaseous, low- to moderate-salinity (3.4-8.1 wt% NaCl equiv.) fluid and then from high salinity (37-42 wt% NaCl equiv.) aqueous chloride fluids, the latter being enriched in Ca (17-20 wt% CaCl2) that could also affect scheelite deposition. Another cycle of fluid exsolution from crystallizing magma corresponded to quartz-carbonate-sericite-scheelite-sulfide (phyllic) alteration stage, with the early low-salinity (5.3-8.4 wt% NaCl-equiv.) fluid followed by later high-salinity (33.5-38.2 wt% NaCl-equiv.) fluid. The sulfur isotope data (δ34S = +5.1 to +9.0) suggest significant sulfur sourcing from sedimentary rocks enriched in seawater sulfate, possibly evaporites.

Nature and Evolution of the Ore-Forming Fluids from Nanmushu Carbonate-Hosted Zn-Pb Deposit in the Mayuan District, Shaanxi Province, Southwest China

Directory of Open Access Journals (Sweden)

Suo-Fei Xiong

2017-01-01

Full Text Available The Nanmushu carbonate-hosted Zn-Pb deposit is located in the Mayuan district of Shaanxi Province, a newly discovered metallogenic district next to the Sichuan Basin, in the northern margin of the Yangtze Block, which is the largest and the only one that is currently mined in this district. The δ34S values of sulfides are characterized by positive values with a peak around +18‰, and the reduced sulfur may have derived from reduction of SO42- from paleoseawater or evaporitic sulfates that have possibly been leached by basinal brines during mineralization stage. Detailed fluid inclusion study shows two types of fluids in the sphalerite, quartz, dolomite, calcite and barite, that is, aqueous-salt dominant inclusions (type I and hydrocarbon-bearing inclusions (type II. The Laser Raman spectroscopy study shows occurrence of certain amount of CH4, C4H6, and bitumen. The salinities show similar values around 6 to 12 wt% NaCl equivalent but a decreasing temperature from early to late stages (typically 200° to 320°C in stage I, 180° to 260°C in stage II, and 140° to 180°C in stage III. These features may be related to basinal brines mixing between an external higher salinity CaCl2  ±  MgCl2-rich fluid and a local H2O-NaCl methane-rich fluid.

Presenting a mapping method based on fuzzy Logic and TOPSIS multi criteria decision-making methods to detect promising porphyry copper mineralization areas in the east of the Sarcheshmeh copper metallogenic district

Directory of Open Access Journals (Sweden)

Shokouh Riahi

2017-11-01

through applying the multi-criteria decision-making method. Finally, the selected favorable areas in the metallogenic strip located at the south to the south-east of the Sarcheshmeh porphyry copper deposit are prioritized and introduced for further follow up ground exploration operations. Methodology In order to solve complex decision-making problems like the problem of mapping favorable porphyry copper mineralization zones under great uncertainties, the TOPSIS method is considered as an appropriate approach offering significant simplicity, flexibility and capability (Ataei., 2010. The TOPSIS method is considered to be an efficient method due to having very high accuracy, speed, sensitivity as well as being easy to implement and interpret the outputted results (Hwang and Yoon, 1981. It has found many applications in important areas of mining industry where there is a need to make decisions under risky conditions and data uncertainties. One basic issue in applying decision-making methods in the field of mineral exploration is to rank and propose the best possible candidates among all potentially favorable areas for the next stage of mineral exploration. In this regard, the best favorable areas are selected based on exploratory data layers including favorable lithologies, alterations, structures plus geochemical and geophysical anomalies (Pazand et al., 2012. Results and discussion In the first step, the area located south to the southeast of one the largest porphyry copper deposits in Iran known as Sarcheshmeh was investigated for favorable areas using all available exploratory data as mentioned in the previous section using fuzzy logic integration approach in the GIS environment. Evaluating the highly favorable areas presented by the fuzzy logic approach showed great consistency with the already known copper mineralization prospects. Next, the first 20 priorities obtained from the fuzzy logic approach were chosen as the best candidates to be ranked using the TOPSIS multi

Hyperspectral information identification for characterizing metallogenic factors of Taoshan uranium ore-field

International Nuclear Information System (INIS)

Zhang Jielin

2007-01-01

The application of high resolution remote sensing technology to uranium mineralization is discussed in detail. By utilizing field hyperspectrum measurement method (VIS/NIR-SWIR-FIR) and fusion technology of ETM image and Radarsat data, the spectral characteristic of uranium mineralization factors including rock mass, ore-control fault and hydrothermal alteration are studied in Taoshan granite type uranium deposits. The main ore-control structure has been identified based on remote sensing image feature. Those results and experiences provide the new remote sensing approaches to the prospecting and evaluation of uranium resources. (authors)

Element migration of pyrites during ductile deformation of the Yuleken porphyry Cu deposit (NW-China)

Science.gov (United States)

Hong, Tao; Xu, Xing-Wang; Gao, Jun; Peters, Stephen; Li, Jilei; Cao, Mingjian; Xiang, Peng; Wu, Chu; You, Jun

2017-01-01

The strongly deformed Yuleken porphyry Cu deposit (YPCD) occurs in the Kalaxiangar porphyry Cu belt (KPCB), which occupies the central area of the Central Asian Orogenic Belt (CAOB) between the Sawu’er island arc and the Altay Terrane in northern Xinjiang. The YPCD is one of several typical subduction-related deposits in the KPCB, which has undergone syn-collisional and post-collisional metallogenic overprinting. The YPCD is characterized by three pyrite-forming stages, namely a hydrothermal stage A (Py I), a syn-ductile deformation stage B (Py II) characterized by Cu-Au enrichment, and a fracture-filling stage C (Py III). In this study, we conducted systematic petrographic and geochemical studies of pyrites and coexist biotite, which formed during different stages, in order to constrain the physicochemical conditions of the ore formation. Euhedral, fragmented Py I has low Pb and high Te and Se concentration and Ni contents are low with Co/Ni ratios mostly between 1 and 10 (average 9.00). Py I is further characterized by enrichments of Bi, As, Ni, Cu, Te and Se in the core relative to the rim domains. Anhedral round Py II has moderate Co and Ni contents with high Co/Ni ratios >10 (average 95.2), and average contents of 46.5 ppm Pb and 5.80 ppm Te. Py II is further characterized by decreasing Bi, Cu, Pb, Zn, Ag, Te, Mo, Sb and Au contents from the rim to the core domains. Annealed Py III has the lowest Co content of all pyrite types with Co/Ni ratios mostly <0.1 (average 1.33). Furthermore, Py III has average contents of 3.31 ppm Pb, 1.33 ppm Te and 94.6 ppm Se. In addition, Fe does not correlate with Cu and S in the Py I and Py III, while Py II displays a negative correlation between Fe and Cu as well as a positive correlation between Fe and S. Therefore, pyrites which formed during different tectonic regimes also have different chemical compositions. Biotite geothermometer and oxygen fugacity estimates display increasing temperatures and oxygen

Study on remote sensing geologic information of uranium metallogeny in western Liaoning-northern Hebei region

International Nuclear Information System (INIS)

Yu Baoshan

1998-01-01

Based on the study on geologic metallogenic environment, temporal and spatial distribution and deposit features of uranium deposits in western Liaoning-northern Hebei region, summarizing mainly remote sensing information and synthesizing geologic, geophysical and geochemical as well as hydrological data, the author has implemented all-region joint-quadrangle analysis, composite mapping and applications, set up interpretation criteria for circular and arcuate structures of different lithological areas, and then expounded their geologic meaning. Volcanic apparatuses, small close sedimentary basins and magmatic rockbodies closely associated with uranium mineralizations, especially the altitude and types of ore-controlling structures and mineralized alteration zones have been interpreted. 'Heat halo spot' has also been interpreted on the satellite image and its geologic meaning and relation to uranium metallization have been discussed. Finally, remote sensing geologic prospecting model and comprehensive prediction model have been established

Geology, mineralization, and fluid inclusion study of the Kuru-Tegerek Au-Cu-Mo skarn deposit in the Middle Tien Shan, Kyrgyzstan

Science.gov (United States)

Soloviev, Serguei G.; Kryazhev, Sergey; Dvurechenskaya, Svetlana

2018-02-01

The Kuru-Tegerek Cu-Au-Mo deposit is situated in a system of Late Carboniferous subduction-related magmatic arcs of the Middle Tien Shan, which together constitute a metallogenic belt of Cu-Au-Mo (±W) porphyry, with local skarns, deposits. The deposit is related to magnetite-series gabbro-diorite to tonalite intrusion. It contains prograde magnesian and calcic skarns with abundant magnetite, associated with gabbro-diorite, and retrograde skarn with Cu mineralization, formed after intrusion of tonalite. Subsequent propylitic alteration introduced abundant chalcopyrite and pyrrhotite, and native Au culminating in zones overprinting magnetite and garnet skarn. Later quartz-muscovite-carbonate veins, formed after intrusion of late mafic quartz monzogabbro dikes, contain chalcopyrite, pyrite, arsenopyrite and other sulfides and sulfosalts, tellurides, and native Au. The earliest retrograde skarn garnet contains gaseous low-salinity (1.7-3.4 wt.% NaCl eq.) fluid inclusions homogenizing at 460-500 °C into vapor, indicating that the early fluid released from crystallizing magma was a low-density vapor. It was followed by more saline (4.0-5.0 wt.% NaCl eq.), high-temperature (400-440 °C) aqueous fluid, as fluid release from the magma progressed. Boiling of this fluid at temperatures of 420 to 370 °C and a pressure of 350-300 bar produced a low-salinity (0.6-1.2 wt.% NaCl eq.), essentially gaseous, and high-salinity (from 39 to 31 wt.% NaCl eq.) brine, with possible metal (including Cu) partitioning into both gaseous and aqueous-saline phases. Boiling was coeval with sulfide deposition in the retrograde skarn. The latest episode of the retrograde skarn stage included direct separation of saline ( 40-42 wt.% NaCl eq.) fluid from crystallizing magma. The separation of saline ( 40 to 14 wt.% NaCl eq.) fluids from a crystallizing magmatic melt continued during the propylitic stage, when fluid cooling from 370 to 320 °C, together with decreasing fO2, caused Cu and especially

20 CFR 703.306 - Kinds of negotiable securities that may be deposited; conditions of deposit; acceptance of deposits.

Science.gov (United States)

2010-04-01

... the Act in the amount fixed by the Office under the regulations in this part shall deposit any... deposited; conditions of deposit; acceptance of deposits. 703.306 Section 703.306 Employees' Benefits... negotiable securities that may be deposited; conditions of deposit; acceptance of deposits. A self-insurer or...

Tsunami deposits

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-15

The NSC (the Nuclear Safety Commission of Japan) demand to survey on tsunami deposits by use of various technical methods (Dec. 2011), because tsunami deposits have useful information on tsunami activity, tsunami source etc. However, there are no guidelines on tsunami deposit survey in JAPAN. In order to prepare the guideline of tsunami deposits survey and evaluation and to develop the method of tsunami source estimation on the basis of tsunami deposits, JNES carried out the following issues; (1) organizing information of paleoseismological record and tsunami deposit by literature research, (2) field survey on tsunami deposit, and (3) designing the analysis code of sediment transport due to tsunami. As to (1), we organize the information gained about tsunami deposits in the database. As to (2), we consolidate methods for surveying and identifying tsunami deposits in the lake based on results of the field survey in Fukui Pref., carried out by JNES. In addition, as to (3), we design the experimental instrument for hydraulic experiment on sediment transport and sedimentation due to tsunamis. These results are reflected in the guideline on the tsunami deposits survey and evaluation. (author)

Tsunami deposits

International Nuclear Information System (INIS)

2013-01-01

The NSC (the Nuclear Safety Commission of Japan) demand to survey on tsunami deposits by use of various technical methods (Dec. 2011), because tsunami deposits have useful information on tsunami activity, tsunami source etc. However, there are no guidelines on tsunami deposit survey in JAPAN. In order to prepare the guideline of tsunami deposits survey and evaluation and to develop the method of tsunami source estimation on the basis of tsunami deposits, JNES carried out the following issues; (1) organizing information of paleoseismological record and tsunami deposit by literature research, (2) field survey on tsunami deposit, and (3) designing the analysis code of sediment transport due to tsunami. As to (1), we organize the information gained about tsunami deposits in the database. As to (2), we consolidate methods for surveying and identifying tsunami deposits in the lake based on results of the field survey in Fukui Pref., carried out by JNES. In addition, as to (3), we design the experimental instrument for hydraulic experiment on sediment transport and sedimentation due to tsunamis. These results are reflected in the guideline on the tsunami deposits survey and evaluation. (author)

Electrophoretic Deposition of Gallium with High Deposition Rate

Directory of Open Access Journals (Sweden)

Hanfei Zhang

2014-12-01

Full Text Available In this work, electrophoretic deposition (EPD is reported to form gallium thin film with high deposition rate and low cost while avoiding the highly toxic chemicals typically used in electroplating. A maximum deposition rate of ~0.6 μm/min, almost one order of magnitude higher than the typical value reported for electroplating, is obtained when employing a set of proper deposition parameters. The thickness of the film is shown to increase with deposition time when sequential deposition is employed. The concentration of Mg(NO32, the charging salt, is also found to be a critical factor to control the deposition rate. Various gallium micropatterns are obtained by masking the substrate during the process, demonstrating process compatibility with microfabrication. The reported novel approach can potentially be employed in a broad range of applications with Ga as a raw material, including microelectronics, photovoltaic cells, and flexible liquid metal microelectrodes.

20 CFR 703.207 - Kinds of negotiable securities that may be deposited; conditions of deposit; acceptance of deposits.

Science.gov (United States)

2010-04-01

... amount fixed by the Office under the regulations in this part shall deposit any negotiable securities... deposited; conditions of deposit; acceptance of deposits. 703.207 Section 703.207 Employees' Benefits... AND RELATED STATUTES INSURANCE REGULATIONS Insurance Carrier Security Deposit Requirements § 703.207...

The giant Upper Yangtze Pb-Zn province in SW China: Reviews, new advances and a new genetic model

Science.gov (United States)

Zhou, Jia-Xi; Xiang, Zhen-Zhong; Zhou, Mei-Fu; Feng, Yue-Xing; Luo, Kai; Huang, Zhi-Long; Wu, Tao

2018-04-01

In the western margin of the Yangtze Block, SW China, the Emeishan large igneous province (ELIP) is spatially associated with >400 carbonate-hosted epigenetic Pb-Zn deposits. These deposits form the giant Upper Yangtze Pb-Zn metallogenic province with >20 Mt base metals. In the southeastern part of this province, the important Pb-Zn deposits include those of the Yinchangpo, Yunluhe, Maozhachang, Tianqiao, Banbanqiao, Mangdong, Shaojiwan, Liangyan, Qingshan, Shanshulin, Nayongzhi and Guanziyao deposits. Sulfide ore bodies in these deposits are (i) hosted in late Ediacaran to middle Permian limestone, dolomitic limestone and dolostone; (ii) structurally controlled by reverse fault-anticline tectonic systems; and (iii) spatially associated with the ELIP flood basalts and mafic dikes, and early Permian, early Carboniferous and early Cambrian organic matter-rich black shales. C-O isotopic compositions suggest that dolostone and limestone, mantle-derived rocks of the ELIP, and sedimentary organic matters supplied C-O to the hydrothermal systems through water/rock (W/R) interaction. New and existing S isotopic compositions of sulfides imply multiple sources of S and the reduction of sulfate through both abiotic thermochemical (TSR) and bacterially mediated (BSR) processes. Zn isotopes indicate that the sources of Zn were most likely related to the ELIP with various contributions from sediments and basements locally. Pb isotope signatures are suggestive of derivation of Pb from basements and sedimentary rocks with variable influences from the ELIP. Sr isotopes support that mantle-derived rocks, sediments and basements were involved in Pb-Zn mineralization, and they have various contributions in different deposits. We consider that the Pb-Zn deposits in the Upper Yangtze province are the mixed products of multiple S species-bearing solutions and metal-rich fluids, both of which were derived from, flowed through or interacted with multiple lithostratigraphic units in the

Some new tendencies in uranium exploration of Russia

International Nuclear Information System (INIS)

Chen Zuyi

2005-01-01

Russia is a country with abundant uranium resources. However, the uranium production in Russia can meet neither the recent nor the long term demands of nuclear power in the country. In addition, the market price of uranium product during the last two years has been going up continuously. The above facts force Russia to adjust its policy for the exploration and the development of uranium resources in the country, such as to strengthen the prospecting and exploration of the unconformity-related uranium deposit, to try to expand new target stratigraphic horizons of paleo-valley type sandstone-hosted uranium deposit and to discover new uranium-mineralized areas, to do economic-technical re-evaluation of previously explored uranium deposits, and to discover new ore-concentrated regions in known U-metallogenic belts. In order to guarantee the successful performance of the above policy, numerous scientific-technological measures have been taken including intensified research on regional metallogeny of uranium. Based on the above situation, the author proposes some corresponding suggestions for uranium prospecting and exploration in China in the future. (authors)

Recent U.S. Geological Survey Studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada-Results of a 5-Year Project

Science.gov (United States)

Gough, Larry P.; Day, Warren C.

2010-01-01

This report presents summary papers of work conducted between 2002 and 2007 under a 5-year project effort funded by the U.S. Geological Survey Mineral Resources Program, formerly entitled 'Tintina Metallogenic Province: Integrated Studies on Geologic Framework, Mineral Resources, and Environmental Signatures.' As the project progressed, the informal title changed from 'Tintina Metallogenic Province' project to 'Tintina Gold Province' project, the latter being more closely aligned with the terminology used by the mineral industry. As Goldfarb and others explain in the first chapter of this report, the Tintina Gold Province is a convenient term used by the mineral exploration community for a 'region of very varied geology, gold deposit types, and resource potential'. The Tintina Gold Province encompasses roughly 150,000 square kilometers, bounded by the Kaltag-Tintina fault system on the north and the Farewell-Denali fault system on the south. It extends westward in a broad arc, some 200 km wide, from northernmost British Columbia, through the Yukon, through southeastern and central Alaska, to southwestern Alaska. The climate is subarctic and, in Alaska, includes major physiographic delineations and ecoregions such as the Yukon-Tanana Upland, Tanana-Kuskokwim Lowlands, Yukon River Lowlands, and the Kuskokwim Mountains. Although the Tintina Gold Province is historically important for some of the very first placer and lode gold discoveries in northern North America, it has recently seen resurgence in mineral exploration, development, and mining activity. This resurgence is due to both new discoveries (for example, Pogo and Donlin Creek) and to the application of modern extraction methods to previously known, but economically restrictive, low-grade, bulk-tonnage gold resources (for example, Fort Knox, Clear Creek, and Scheelite Dome). In addition, the Tintina Gold Province hosts numerous other mineral deposit types, possessing both high and low sulfide content, which

[Spatial distribution and ecological significance of heavy metals in soils from Chatian mercury mining deposit, western Hunan province].

Science.gov (United States)

Sun, Hong-Fei; Li, Yong-Hu; Ji, Yan-Fang; Yang, Lin-Sheng; Wang, Wu-Yi

2009-04-15

Ores, waste tailings and slag, together with three typical soil profiles (natural soil profiles far from mine entrance and near mine entrance, soil profile under slag) in Chatian mercury mining deposit (CMD), western Hunan province were sampled and their concentrations of mercury (Hg), arsenic (As), lead (Pb), cadmium (Cd), zinc (Zn) were determined by HG-ICP-AES and ICP-MS. Enrichment factor and correlation analysis were taken to investigate the origins, distribution and migration of Hg, as well as other heavy metals in the CMD. The results show that Hg is enriched in the bottom of the soil profile far from mine entrance but accumulated in the surface of soil profiles near mine entrance and under slag. The soil profiles near mine entrance and under slag are both contaminated by Hg, while the latter is contaminated more heavily. In the soil profile under slag, Hg concentration in the surface soil, Hg average concentration in the total profile, and the leaching depth of soil Hg are 640 microg x g(-1), (76.74 +/- 171.71) microg x g(-1), and more than 100 cm, respectively; while 6.5 microg x g(-1), (2.74 +/- 1.90) microg x g(-1), and 40 cm, respectively, are found in the soil profile near mine entrance. Soil in the mercury mine area is also polluted by Cd, As, Pb, Zn besides metallogenic element Hg, among which Cd pollution is relatively heavier than others. The mobility of the studied heavy metals in soil follows the order as Hg > Cd > As > Zn approximately equal to Pb. The leaching depth of the heavy metals is influenced by total concentration in the surface soil and soil physico-chemical parameters. The origins, distribution and migration of heavy metals in soil profile in the mining area are related to primary geological environment, and strongly influenced by human mining activities.

The latest study on development of metallogenic mechanism of Baimianshi uranium field, Jiangxi Province, China

International Nuclear Information System (INIS)

Fan, H.; He, D.; Wang, F.

2009-01-01

It has been considered that deposits in Baimianshi uranium field have similar features and ore-forming type, it is the syngenetic sedimentation that caused some U-bearing minerals to concentrate, and as a result of the enrichment in the late lithogenetic stage the deposit formed which is separate genesis to sandstone type and volcanic hydrothermal sub-type. This paper takes Huangnihu deposit in Baimianshi field as an example, and regards Baimianshi field as hydrothermal type according to research on intergrowth assemblage, fluid inclusions, U-Pb isotopic dating and Nd-Sr isotopic tracing. Ore minerals are mainly uraninite, brannerite, coffinite, etc, while the assistant gangue minerals are mainly galena, hematite, marcasite, blende, etc. The materials for uranium mineralization are mainly crust-derived rocks. Continuous extraction of uranium from the upper crust and basement granite by mantle-derived fluids with little of ore-forming elements may be responsible for the remobilization and transformation of uranium. Mixing of ore-enriched fluid with groundwater in some enclosed places overlain by basalt leads to the precipitation of ore-forming materials from the mixed fluid. There are three episodes of uranium mineralization: The first one is 160.4±0.5Ma, related to double-peak type volcanism, with basalt lithogenetic age of 172.8±7.7Ma and rhyolite lithogenetic age of 164.8±0.57Ma (from Chen Peirong, etc., 1999). The second one is 128±0.8Ma, related to Yanshanian Magmatic activities, for example, Danguanzhang rock mass and several phases of complements. The third one is about 100Ma, related to sub-volcanic rocks and dykes, namely quartz porphyry (99Ma) and diabase (105Ma). The above achievements will play an important part in the guidance of future prospecting in the deeper in that area. (author)

Cobalt—Styles of deposits and the search for primary deposits

Science.gov (United States)

Hitzman, Murray W.; Bookstrom, Arthur A.; Slack, John F.; Zientek, Michael L.

2017-11-30

Cobalt (Co) is a potentially critical mineral. The vast majority of cobalt is a byproduct of copper and (or) nickel production. Cobalt is increasingly used in magnets and rechargeable batteries. More than 50 percent of primary cobalt production is from the Central African Copperbelt. The Central African Copperbelt is the only sedimentary rock-hosted stratiform copper district that contains significant cobalt. Its presence may indicate significant mafic-ultramafic rocks in the local basement. The balance of primary cobalt production is from magmatic nickel-copper and nickel laterite deposits. Cobalt is present in several carbonate-hosted lead-zinc and copper districts. It is also variably present in Besshi-type volcanogenic massive sulfide and siliciclastic sedimentary rock-hosted deposits in back arc and rift environments associated with mafic-ultramafic rocks. Metasedimentary cobalt-copper-gold deposits (such as Blackbird, Idaho), iron oxide-copper-gold deposits, and the five-element vein deposits (such as Cobalt, Ontario) contain different amounts of cobalt. None of these deposit types show direct links to mafic-ultramafic rocks; the deposits may result from crustal-scale hydrothermal systems capable of leaching and transporting cobalt from great depths. Hydrothermal deposits associated with ultramafic rocks, typified by the Bou Azzer district of Morocco, represent another type of primary cobalt deposit.In the United States, exploration for cobalt deposits may focus on magmatic nickel-copper deposits in the Archean and Proterozoic rocks of the Midwest and the east coast (Pennsylvania) and younger mafic rocks in southeastern and southern Alaska; also, possibly basement rocks in southeastern Missouri. Other potential exploration targets include—The Belt-Purcell basin of British Columbia (Canada), Idaho, Montana, and Washington for different styles of sedimentary rock-hosted cobalt deposits;Besshi-type VMS deposits, such as the Greens Creek (Alaska) deposit and

Upper Paleozoic mafic and intermediate volcanic rocks of the Mount Pleasant caldera associated with the Sn-W deposit in southwestern New Brunswick (Canada): Petrogenesis and metallogenic implications

Science.gov (United States)

Dostal, Jaroslav; Jutras, Pierre

2016-10-01

Upper Paleozoic ( 365 Ma) mafic and intermediate volcanic rocks of the Piskahegan Group constitute a subordinate part of the Mount Pleasant caldera, which is associated with a significant polymetallic deposit (tungsten-molybdenum-bismuth zones 33 Mt ore with 0.21% W, 0.1% Mo and 0.08% Bi and tin-indium zones 4.8 Mt with 0.82% Sn and 129 g/t In) in southwestern New Brunswick (Canada). The epicontinental caldera complex formed during the opening of the late Paleozoic Maritimes Basin in the northern Appalachians. The mafic and intermediate rocks make up two compositionally distinct associations. The first association includes evolved rift-related continental tholeiitic basalts, and the second association comprises calc-alkaline andesites, although both associations were emplaced penecontemporaneously. The basalts have low Mg# 0.34-0.40, smooth chondrite-normalized REE patterns with (La/Yb)n 5-6, primitive mantle-normalized trace element patterns without noticeable negative Nb-Ta anomalies, and their ɛNd(T) ranges from + 2.5 to + 2.2. The basalts were generated by partial melting of a transition zone between spinel and garnet mantle peridotite at a depth of 70-90 km. The calc-alkaline andesites of the second association have chondrite-normalized REE patterns that are more fractionated, with (La/Yb)n 7-8.5, but without significant negative Eu anomalies. Compared to the basaltic rocks, they have lower ɛNd(T) values, ranging from + 0.5 to + 1.9, and their mantle-normalized trace element plots show negative Nb-Ta anomalies. The ɛNd(T) values display negative correlations with indicators of crustal contamination, such as Th/La, Th/Nb and SiO2. The andesitic rocks are interpreted to have formed by assimilation-fractional crystallization processes, which resulted in the contamination of a precursor basaltic magma with crustal material. The parent basaltic magma for both suites underwent a different evolution. The tholeiitic basalts experienced shallow-seated fractional

Study on the remote sensing geological information of uranium mineralization in Western Liaoning and Northern Hebei

International Nuclear Information System (INIS)

Yu Baoshan; Wang Dianbai; Jin Shihua; Qiao Rui

1996-01-01

Based on the whole areal geological map joint application rd exploitation, composite forming map, generalization analysis and field examination in detail of key region that mainly depend on remote sensing information and generalize the data of geology, geophysical and geochemical prospecting, and geohydrology, this paper reveals the structure framework, regional geological background, uranium metallogenic condition and space time distribution rule of orustal evolution and its result, and set up the interpretation marks of arc-shaped structure in different of rock area and discusses its geological genesis. The author also interprets volcanic apparatus, small type closed sedimentary basin, magmatic rock body which relate closely to uranium deposit, ore control structure and occurrence and type of mineralization alteration envelope. The thermal halo point of satellite image is emphatically interpreted and its geological meaning and its relation to uranium deposit is discussed. Remote sensing geological prospecting ore model and synthetic provision model is determined lastly

Application of isotope techniques to groundwater pollution research for Xiangshan uranium ore field, China

International Nuclear Information System (INIS)

Liu Fulin; Liu Peilun; Zhu Chuande; Wu Xiaowei; Zeng Yinsheng

1998-01-01

The investigation of groundwater pollution due to uranium deposits focused on the most important uranium metallogenic area-Zhoujiashan district of Xiangshan uranium ore field, China. Groundwater collected from five completed exploration boreholes in the area is regarded as the pollution source and is traced and analysed by using isotope as well as radio-hydrochemical techniques. In addition, the pollution situation of a small uranium ore pile for heap-leaching and a big uranium ore open pit are monitored by the same techniques. It has been experimentally proven that the uranium concentration and the uranium isotope ratio 234 U/ 238 U in natural waters are two sensitive indicators of radioactive pollution in natural waters. It was concluded that under present conditions, exploration of uranium deposits may not cause serious groundwater pollution of radioactive elements (U, Ra, Rn and Th), however, it is difficult to avoid the serious surface water pollution coming from the exploitation of uranium ore by a big open pit. (author)

Acid Deposition Phenomena

International Nuclear Information System (INIS)

Ramadan, A.E.K.

2004-01-01

Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H 2 SO 4 ) and nitric acids (HNO 3 ), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

Local deposition of high-purity Pt nanostructures by combining electron beam induced deposition and atomic layer deposition

NARCIS (Netherlands)

Mackus, A.J.M.; Mulders, J.J.L.; Sanden, van de M.C.M.; Kessels, W.M.M.

2010-01-01

An approach for direct-write fabrication of high-purity platinum nanostructures has been developed by combining nanoscale lateral patterning by electron beam induced deposition (EBID) with area-selective deposition of high quality material by atomic layer deposition (ALD). Because virtually pure,

DepositScan, a Scanning Program to Measure Spray Deposition Distributions

Science.gov (United States)

DepositScan, a scanning program was developed to quickly measure spray deposit distributions on water sensitive papers or Kromekote cards which are widely used for determinations of pesticide spray deposition quality on target areas. The program is installed in a portable computer and works with a ...

The current situation of uranium resources exploration in East China: Problems, thought and countermeasure

International Nuclear Information System (INIS)

He Xiaomei; Mao Mengcai

2014-01-01

Based on analyzing the current situation of uranium resources and exploration effort in East China, the main existing problems, technical thought and countermeasure for the future exploration in East China are discussed in this paper. The degree of both uranium exploration and study in East China is relatively high, philosophy of scientific mineral-prospecting should be established in the new round of mineral prospecting. Under guidance of metallogenic theory of large mineralization cluster area and uranium metallogenic theory of multi-sources, previous data and research achievement should be analyzed and summarized. With the help of metallogenic model, useful methods and means should be applied to set up exploration model in order to realize news phase of model exploration, comprehensive exploration, 3D exploration and quantitative exploration. Efficiency of exploration of uranium resources should be strugglingly increased. High profitable uranium resources will be actively found with rich, shallow, near and easy features. The prospecting targets and strategy reserves of uranium resources will be increased in East China. (authors)

78 FR 56583 - Deposit Insurance Regulations; Definition of Insured Deposit

Science.gov (United States)

2013-09-13

... as a potential global deposit insurer, preserve confidence in the FDIC deposit insurance system, and... the United States.\\2\\ The FDIC generally pays out deposit insurance on the next business day after a... since 2001 and total approximately $1 trillion today. In many cases, these branches do not engage in...

Deposition characteristics of titanium coating deposited on SiC fiber by cold-wall chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Luo, Xian, E-mail: luo_shenfan@hotmail.com; Wu, Shuai; Yang, Yan-qing; Jin, Na; Liu, Shuai; Huang, Bin

2016-12-01

The deposition characteristics of titanium coating on SiC fiber using TiCl{sub 4}-H{sub 2}-Ar gas mixture in a cold-wall chemical vapor deposition were studied by the combination of thermodynamic analysis and experimental studies. The thermodynamic analysis of the reactions in the TiCl{sub 4}-H{sub 2}-Ar system indicates that TiCl{sub 4} transforms to titanium as the following paths: TiCl{sub 4} → TiCl{sub 3} → Ti, or TiCl{sub 4} → TiCl{sub 3} → TiCl{sub 2} → Ti. The experimental results show that typical deposited coating contains two distinct layers: a TiC reaction layer close to SiC fiber and titanium coating which has an atomic percentage of titanium more than 70% and that of carbon lower than 30%. The results illustrate that a carbon diffusion barrier coating needs to be deposited if pure titanium is to be prepared. The deposition rate increases with the increase of temperature, but higher temperature has a negative effect on the surface uniformity of titanium coating. In addition, appropriate argon gas flow rate has a positive effect on smoothing the surface morphology of the coating. - Highlights: • Both thermodynamic analysis and experimental studies were adopted in this work. • The transformation paths of TiCl{sub 4} to Ti is: TiCl{sub 4} → TiCl{sub 3} → Ti, or TiCl{sub 4} → TiCl{sub 3} → TiCl{sub 2} → Ti. • Typical deposited Ti coating on SiC fiber contained two distinct layers. • Deposition temperature is important on deposition rate and morphologies. • Appropriate argon gas flow rate has a positive effect on smoothing of the coating.

Deposition of Boron in Possible Evaporite Deposits in Gale Crate

Science.gov (United States)

Gasda, P. J.; Peets, E.; Lamm, S. N.; Rapin, W.; Lanza, N.; Frydenvang, J.; Clark, B. C.; Herkenhoff, K. E.; Bridges, J.; Schwenzer, S. P.; Haldeman, E. B.; Wiens, R. C.; Maurice, S.; Clegg, S. M.; Delapp, D.; Sanford, V.; Bodine, M. R.; McInroy, R.

2017-12-01

Boron has been previously detected in Gale crater using the ChemCam instrument on board the NASA Curiosity rover within calcium sulfate fracture fill hosted by lacustrine mudstone and eolian sandstone units. Recent results show that up to 300 ppm B is present in the upper sections of the lacustrine unit. Boron has been detected in both the groundwater-emplaced calcium sulfate fracture fill materials and bedding-parallel calcium sulfate layers. The widespread bedding-parallel calcium sulfate layers within the upper strata of the lacustrine bedrock that Curiosity has encountered recently could be interpreted as primary evaporite deposits. We have two hypotheses for the history of boron in Gale crater. In both hypotheses, borates were first deposited as lake water evaporated, depositing primary evaporates that were later re-dissolved by groundwater, which redistributed the boron into secondary evaporitic calcium sulfate fracture fill deposits. In the first scenario, Gale crater may have undergone a period of perennial lake formation during a drier period of martian history, depositing layers of evaporitic minerals (including borates) among lacustrine mudstone layers. In the second scenario, lake margins could have become periodically exposed during cyclic drops in lake level and subsequently desiccated. Evaporites were deposited and desiccation features were formed in lowstand deposits. Either hypothetical scenario of evaporite deposition would promote prebiotic chemical reactions via wet-dry cycles. Boron may be an important prebiotic element, and as such, its presence in ancient martian surface and groundwater provides evidence that important prebiotic chemical reactions could occur on Mars if organics were present. The presence of boron in ancient Gale crater groundwater also provides additional evidence that a habitable environment existed in the martian subsurface well after the expected disappearance of liquid water on the surface of Mars. We will report on the

Metallogenic geologic conditions and prospecting direction of sandstone type uranium mineralizations in Yili basin of Xinjiang

International Nuclear Information System (INIS)

Chen Daisheng; Wang Ruiying; Li Shengxiang; Zhang Kefang

1994-09-01

Yili basin is a Mesozoic down-warped basin superimposed on the late Paleozoic volcanic taphrogenic basin. Uranium mineralizations are hosted in the Middle-Lower Jurassic coal-bearing series. The depositions environment in the basin is turbulent in the east and relatively stable in the west. It is characterized by coarse-grained sequence with thin thickness in the eastern part and fine-grained with thick thickness in the western part. On the analytical basis of sedimentary facies indices, it is the first time to present a sedimentary model of 'alluvial fan-braided stream-(narrow) lakeshore delta-lacustrine facies and marsh facies' for the coal-bearing series. The authors have summarized the basic geologic features of U-mineralizations in the interlayer oxidation zone, analyzed the difference and cause of U-mineralizations between the south and north, as well as the east and west. The genetic mechanism of U-mineralizations in the basin is discussed. Finally, seven items of geologic prerequisites for the formation of in-situ leachable sandstone type uranium deposits have been suggested and the potential of sandstone type U-mineralizations in the basin has been evaluated. Four promising target areas are selected

Economical Atomic Layer Deposition

Science.gov (United States)

Wyman, Richard; Davis, Robert; Linford, Matthew

2010-10-01

Atomic Layer Deposition is a self limiting deposition process that can produce films at a user specified height. At BYU we have designed a low cost and automated atomic layer deposition system. We have used the system to deposit silicon dioxide at room temperature using silicon tetrachloride and tetramethyl orthosilicate. Basics of atomic layer deposition, the system set up, automation techniques and our system's characterization are discussed.

Achieving uniform layer deposition by atmospheric-pressure plasma-enhanced chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae-Ok [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Kang, Woo Seok, E-mail: kang@kimm.re.kr [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of); Hur, Min; Lee, Jin Young [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Song, Young-Hoon [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of)

2015-12-31

This work investigates the use of plasma-enhanced chemical vapor deposition under atmospheric pressure for achieving uniform layer formation. Electrical and optical measurements demonstrated that the counterbalance between oxygen and precursors maintained the homogeneous discharge mode, while creating intermediate species for layer deposition. Several steps of the deposition process of the layers, which were processed on a stationary stage, were affected by flow stream and precursor depletion. This study showed that by changing the flow streamlines using substrate stage motion uniform layer deposition under atmospheric pressure can be achieved. - Highlights: • Zirconium oxide was deposited by atmospheric-pressure plasma-enhanced chemical vapor deposition. • Homogeneous plasma was maintained by counterbalancing between discharge gas and precursors. • Several deposition steps were observed affected by the gas flow stream and precursor depletion. • Thin film layer was uniformly grown when the substrate underwent a sweeping motion.

Pulsed laser deposition in Twente: from research tool towards industrial deposition

NARCIS (Netherlands)

Blank, David H.A.; Dekkers, Jan M.; Rijnders, Augustinus J.H.M.

2014-01-01

After the discovery of the perovskite high Tc superconductors in 1986, a rare and almost unknown deposition technique attracted attention. Pulsed laser deposition (PLD), or laser ablation as it was called in the beginning, became popular because of the possibility to deposit complex materials, like

Effects of deposition time in chemically deposited ZnS films in acidic solution

Energy Technology Data Exchange (ETDEWEB)

Haddad, H.; Chelouche, A., E-mail: azeddinechelouche@gmail.com; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.

2015-08-31

We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

Uraniferous surficial deposits

International Nuclear Information System (INIS)

Toens, P.D.; Hambleton-Jones, B.B.

1980-10-01

As a result of the discovery of uranium in surficial deposits of Tertiary to Recent age, in Australia and Southern Africa, increasing attention is being paid to the location and understanding of the genesis of these deposits. The paper discusses the definitions and terminology currently in use and a classification of these deposits is presented. It is concluded that in order to obtain a measure of clarity, the terms calcrete, gypcrete and dolocrete should not be used to describe the uraniferous valley-fill deposits of Southern Africa and Australia [af

Sandstone-type uranium deposits

International Nuclear Information System (INIS)

Austin, S.R.; D'Andrea, R.F. Jr.

1978-01-01

Three overall factors are necessary for formation of uranium deposits in sandstone: a source of uranium, host rocks capable of transmitting uranium-bearing solutions, and a precipitant. Possible sources of uranium in sandstone-type deposits include groundwaters emanating from granitic highlands, arkosic sediments, tuffaceous material within or overlying the host rocks, connate fluids, and overlying black shales. The first three sources are considered the most likely. Host rocks are generally immature sandstones deposited in alluvial-fan, intermontane-basin or marginal-marine environments, but uranium deposits do occur in well-winnowed barrier-bar or eolian sands. Host rocks for uranium deposits generally show coefficients of permeability on the order of 1 to 100 gal/day/ft 2 . Precipitants are normally agents capable of reducing uranium from the uranyl to the uranous state. The association of uranium with organic matter is unequivocal; H 2 S, a powerful reductant, may have been present at the time of formation of some deposits but may go unnoticed today. Vanadium can serve to preserve the tabular characteristics of some deposits in the near-surface environment, but is considered an unlikely primary precipitant for uranium. Uranium deposits in sandstone are divided into two overall types: peneconcordant deposits, which occur in locally reducing environments in otherwise oxidized sandstones; and roll-type deposits, which occur at the margin of an area where an oxidized groundwater has permeated an otherwise reduced sandstone. Uranium deposits are further broken down into four subclasses; these are described

Polymer deposition morphology by electrospray deposition - Modifications through distance variation

International Nuclear Information System (INIS)

Altmann, K.; Schulze, R.-D.; Friedrich, J.

2014-01-01

Electrospray deposition (ESD) of highly diluted polymers was examined with regard to the deposited surface structure. Only the flight distance (flight time) onto the resulting deposited surface was varied from 20 to 200 mm. An apparatus without any additional heating or gas flows was used. Polyacrylic acid (PAA) and polyallylamine (PAAm) in methanol were deposited on Si wafers. The polymer layers were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, derivatization reactions and Fourier transform infrared spectroscopy using a grazing incidence unit. SEM images illustrated the changing structures of PAA and PAAm. For PAA the deposited structure changed from a smooth film (20 mm) to a film with individual droplets on the coated surface (100 mm and 200 mm), while for PAAm individual droplets can be seen at all distances. The ESD process with cascades of splitting droplets slows down for PAA after distances greater than 40 mm. In contrast, the ESD process for PAAm is nearly stopped within the first flight distance of 20 mm. Residual solvent analysis showed that most of the solvent evaporated within the first 20 mm capillary-sample distance. - Highlights: • We deposited polyacrylic acid and polyallylamine by electrospray ionization (ESI). • The morphology in dependence of flight distance (20 mm to 200 mm) was analyzed. • The amount of residual solvent after deposition was determined. • ESI-process slows down for polyacrylic acid after 40 mm flight distance. • ESI-Process is complete for polyallylamine within the first 20 mm

How deposition parameters control growth dynamics of nc-Si deposited by hot-wire chemical vapor deposition

International Nuclear Information System (INIS)

Moutinho, H.R.; To, B.; Jiang, C.-S.; Xu, Y.; Nelson, B.P.; Teplin, C.W.; Jones, K.M.; Perkins, J.; Al-Jassim, M.M.

2006-01-01

We studied the growth of silicon films deposited by hot-wire chemical vapor deposition under different values of filament current, substrate temperature, and hydrogen dilution ratio. The physical and electrical properties of the films were studied by Raman spectroscopy, x-ray diffraction, atomic force microscopy, conductive-atomic force microscopy, and transmission electron microscopy. There is an interdependence of the growth parameters, and films grown with different parameters can have similar structures. We discuss why this interdependence occurs and how it influences the properties of the deposited films, as well as the deposition rate. In general, the films have a complex structure, with a mixture of amorphous (220)-oriented crystalline and nanocrystalline phases present in most cases. The amount of each phase can be controlled by the variation of one or more of the growth parameters at a time

Patterned deposition by atmospheric pressure plasma-enhanced spatial atomic layer deposition

NARCIS (Netherlands)

Poodt, P.; Kniknie, B.J.; Branca, A.; Winands, G.J.J.; Roozeboom, F.

2011-01-01

An atmospheric pressure plasma enhanced atomic layer deposition reactor has been developed, to deposit Al2O3 films from trimethyl aluminum and an He/O2 plasma. This technique can be used for 2D patterned deposition in a single in-line process by making use of switched localized plasma sources. It

MAPLE deposition of nanomaterials

International Nuclear Information System (INIS)

Caricato, A.P.; Arima, V.; Catalano, M.; Cesaria, M.; Cozzoli, P.D.; Martino, M.; Taurino, A.; Rella, R.; Scarfiello, R.; Tunno, T.; Zacheo, A.

2014-01-01

The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

MAPLE deposition of nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Caricato, A.P., E-mail: annapaola.caricato@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Arima, V.; Catalano, M. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Cesaria, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Cozzoli, P.D. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Martino, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Taurino, A.; Rella, R. [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, I-73100 Lecce (Italy); Scarfiello, R. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Tunno, T. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Zacheo, A. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy)

2014-05-01

The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

ITO thin films deposited by advanced pulsed laser deposition

International Nuclear Information System (INIS)

Viespe, Cristian; Nicolae, Ionut; Sima, Cornelia; Grigoriu, Constantin; Medianu, Rares

2007-01-01

Indium tin oxide thin films were deposited by computer assisted advanced PLD method in order to obtain transparent, conductive and homogeneous films on a large area. The films were deposited on glass substrates. We studied the influence of the temperature (room temperature (RT)-180 deg. C), pressure (1-6 x 10 -2 Torr), laser fluence (1-4 J/cm 2 ) and wavelength (266-355 nm) on the film properties. The deposition rate, roughness, film structure, optical transmission, electrical conductivity measurements were done. We deposited uniform ITO thin films (thickness 100-600 nm, roughness 5-10 nm) between RT and 180 deg. C on a large area (5 x 5 cm 2 ). The films have electrical resistivity of 8 x 10 -4 Ω cm at RT, 5 x 10 -4 Ω cm at 180 deg. C and an optical transmission in the visible range, around 89%

Impurities in chromium deposits produced by electroplating and physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Dini, J.W.

1994-05-01

Impurity contents in electrodeposited (hexavalent and trivalent) chromium deposits and physically vapor deposited (thermal evaporation, electron beam evaporation and rf-sputtering) were compared. Oxygen is the key impurity obtained in electrodeposited films but it can be minimized in hexavalent plating solutions by operating at high temperature, e. g., 85 C. Electrodeposits produced in trivalent chromium plating solutions and physically vapor deposited films have much higher oxygen contents than electrodeposits produced in hexavalent chromium solutions operated at temperatures around 85 C. Depending on the target material used for physically vapor deposited films, these films can also have high amounts of other impurities.

Oxygen Barrier Coating Deposited by Novel Plasma-enhanced Chemical Vapor Deposition

DEFF Research Database (Denmark)

Jiang, Juan; Benter, M.; Taboryski, Rafael Jozef

2010-01-01

We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This confi......We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source...... effect of single-layer coatings deposited under different reaction conditions was studied. The coating thickness and the carbon content in the coatings were found to be the critical parameters for the barrier property. The novel barrier coating was applied on different polymeric materials...

Deposition Measurements in NSTX

Science.gov (United States)

Skinner, C. H.; Kugel, H. W.; Hogan, J. T.; Wampler, W. R.

2004-11-01

Two quartz microbalances have been used to record deposition on the National Spherical Torus Experiment. The experimental configuration mimics a typical diagnostic window or mirror. An RS232 link was used to acquire the quartz crystal frequency and the deposited thickness was recorded continuously with 0.01 nm resolution. Nuclear Reaction Analysis of the deposit was consistent with the measurement of the total deposited mass from the change in crystal frequency. We will present measurements of the variation of deposition with plasma conditions. The transport of carbon impurities in NSTX has been modelled with the BBQ code. Preliminary calculations indicated a negligible fraction of carbon generated at the divertor plates in quiescent discharges directly reaches the outer wall, and that transient events are responsible for the deposition.

Shedding of ash deposits

DEFF Research Database (Denmark)

Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt

2009-01-01

Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

Urban wet deposition nitrate: a comparison to non-urban deposition

International Nuclear Information System (INIS)

Schultz, J.A.M.

1994-01-01

The concentration of nitrate in both wet and dry deposition has both increased historically and currently, and recently parallels emissions in NO x . Since NO x is produced in amounts comparable to SO 2 , it is an important contributor to acid deposition, and is produced in higher amounts in urban areas due to concentrated sources. Prior to to this study, national acid deposition monitoring networks in the United States have been and remain established in non-urban areas. This research study consisted of a comparison of precipitation sampling and analysis of wet deposition nitrate and pH for each deposition event in each of two urban sites over a 15 mo period. Also, a comparison of urban data and data generated at a nearby non-urban NADP site was made by examination of both monthly and seasonal data. This research suggests that national monitoring programs should consider inclusion of urban and non-urban monitoring sites in order to achieve a more representative regional assessment. 24 refs., 2 figs., 2 tabs

76 FR 41392 - Interest on Deposits; Deposit Insurance Coverage

Science.gov (United States)

2011-07-14

... banks' funding costs and also allow them to plan business growth more dependably and rigorously... of business deposits by offering continually higher rates of interest. Three of the four contended... deposits. They reasoned that large banks will offer high rates of interest and lure away business...

Atmospheric deposition 2000. NOVA 2003; Atmosfaerisk deposition 2000. NOVA 2003

Energy Technology Data Exchange (ETDEWEB)

Ellermann, T.; Hertel, O.; Hovmand, M.F.; Kemp, K.; Skjoeth, C.A.

2001-11-01

This report presents measurements and calculations from the atmospheric part of NOVA 2003 and covers results for 2000. It summarises the main results concerning concentrations and depositions of nitrogen, phosphorus and sulphur compounds related to eutrophication and acidification. Depositions of atmospheric compounds to Danish marine waters as well as land surface are presented. Measurements: In 2000 the monitoring program consisted of eight stations where wet deposition of ammonium, nitrate, phosphate (semi quantitatively) and sulphate were measured using bulk precipitation samplers. Six of the stations had in addition measurements of atmospheric content of A, nitrogen, phosphorus, and sulphur compounds in gas and particulate phase carried out by use of filter pack samplers. Filters were analysed at the National Environmental Research Institute. Furthermore nitrogen dioxide were measured using nitrogen dioxide filter samplers and monitors. Model calculations: The measurements in the monitoring program were supplemented with model calculations of concentrations and depositions of nitrogen and sulphur compounds to Danish land surface, marine waters, fjords and bays using the ACDEP model (Atmospheric Chemistry and Deposition). The model is a so-called trajectory model and simulates the physical and chemical processes in the atmosphere using meteorological and emission data as input. The advantage of combining measurements with model calculations is that the strengths of both methods is obtained. Conclusions concerning: 1) actual concentration levels at the monitoring stations, 2) deposition at the monitoring stations, 3) seasonal variations and 4) long term trends in concentrations and depositions are mainly based on the direct measurements. These are furthermore used to validate the results of the model calculations. Calculations and conclusions concerning: 1) depositions to land surface and to the individual marine water, 2) contributions from different emission

Mechanical characteristics of a tool steel layer deposited by using direct energy deposition

Science.gov (United States)

Baek, Gyeong Yun; Shin, Gwang Yong; Lee, Eun Mi; Shim, Do Sik; Lee, Ki Yong; Yoon, Hi-Seak; Kim, Myoung Ho

2017-07-01

This study focuses on the mechanical characteristics of layered tool steel deposited using direct energy deposition (DED) technology. In the DED technique, a laser beam bonds injected metal powder and a thin layer of substrate via melting. In this study, AISI D2 substrate was hardfaced with AISI H13 and M2 metal powders for mechanical testing. The mechanical and metallurgical characteristics of each specimen were investigated via microstructure observation and hardness, wear, and impact tests. The obtained characteristics were compared with those of heat-treated tool steel. The microstructures of the H13- and M2-deposited specimens show fine cellular-dendrite solidification structures due to melting and subsequent rapid cooling. Moreover, the cellular grains of the deposited M2 layer were smaller than those of the H13 structure. The hardness and wear resistance were most improved in the M2-deposited specimen, yet the H13-deposited specimen had higher fracture toughness than the M2-deposited specimen and heat-treated D2.

Exogenous deposits

International Nuclear Information System (INIS)

Khasanov, A.Kh.

1988-01-01

Exogenous deposits forming as a result of complex exogenous processes, passed under the influence of outside forces on the Earth surface. To them relate physical and chemical weathering, decomposition and decay of mineral masses, redistribution and transportation of material, forming and deposit of new minerals and ores steady on the earth surface conditions

Tectono-sedimentary evolution of Erlian basin since late mesozoic and sandstone-hosted uranium metallogenesis

International Nuclear Information System (INIS)

Wei Sanyuan; Qin Mingkuan; Li Yuexiang; He Zhongbo; Chen Anping; Shen Kefeng; Cao Jianying

2006-01-01

Various mineral resources in a basin are associated with its tectono-sedimentary evolution. Based on the analysis of the tectono-sedimentary evolution of Erlian basin, three evolutional stages of Erlian basin are classified, they are: the continental extensional down-faulting stage, the transitional stage from down-faulting to down-warping in Early Cretaceous, and slightly compressional differentiated uplifting-subsidence since Late Cretaceous. According to the mechanism of sandstone-hosted uranium metallogenesis it is suggested that the grey clastic rock series deposited at the stage of down-faulting down-warping transition must be the important target for uranium prospecting, and the differentiated uplifting-subsidence offers necessary conditions for sandstone-hosted uranium ore-formation. Then, types of uranium mineralization that could occur in Erlian basin are discussed, and uranium metallogenic model has been preliminarily summarized. (authors)

Analysis of geological condition of uranium mineralization in the Xiangshan northern uranium orefield in central region of Jiangxi Province

International Nuclear Information System (INIS)

Zhou Yulong; Liu Yunlang; Gao Yan

2013-01-01

According to the basic conditions of 'source, guide, transportation, storage' for uranium mineralization in strata and different types of geological structure, departure from the condition, the coupling effect of stratigraphy, lithology and structure are studied in the process of uranium mineralization in northern Xiangshan volcanic basin. Studies show that the northern ore field are of good metallogenic geological conditions and the uranium rich ancient land mass and uranium rich magma generated by the melting of deep metamorphic rocks. The main geologic events are volcanic eruptions, accompanied by repeated subvolcanic magma intrusion and strong faults and nappe tectonics which result in volcanic collapse and volcanic ring structures. These ore-forming geological condition control the structural frame for the formation of main uranium deposit type-subvolcanic rocks in northern Xiangshan ore field. (authors)

Investigation on distribution of paleo-channels and prospect of uranium metallogenesis in Erlian basin, inner mongolia

International Nuclear Information System (INIS)

Dong Tingkuan; Kang Xiuping

2001-01-01

According to the characteristics of paleo-channel sedimentary evolution in Erlian Basin, the authors investigate the geomorphological forms, regional hydrogeological conditions, the distribution of recent and paleo-stream channels and alluvial-proluvial fans, the hydrodynamic conditions of recharge-run off-discharge for phreatic water and interlayer ground water, as well as the spatial distribution of local discharge areas applying the satellite image analysis techniques. Guided by the theory of hydrogenetic uranium deposit, and using geological, geophysical, hydrogeological data and materials of uranium occurrences and anomalies obtained by previous researchers the environmental relation between the distribution of paleo-channels-alluvial proluvial fans and the dispersion-concentration of uranium are synthesized and analysed. As a result, 19 uranium metallogenic prospective areas are delineated, and the direction for further uranium prospecting is proposed

Geology and metallogeny of the volcanic complex of Rio Blanco Ullum. Province of San Juan. Republica Argentina

International Nuclear Information System (INIS)

Mendoza, N.; Weidmann, N.; Puigdomenech, H.; Weidmann, R.

2007-01-01

Preliminary results of a research carried out at the Complejo Rio Blanco de Ullum, San Juan. Argentina are summarized in the present paper. These studies are focused on geological and metallogenic features o f this unit. The study area is located 20 km. WNW of San Juan city with geographic coordinates of 31grades 30' South latitude and 68 grades 52' West longitude. The older rocks aotcroping in the area correspond to limestones of Ordovician San Juan Formation, the chronologic succession continues with sales and siltstones of Silurian Tambolar Formation, pelites and subgraywackes of Devonian Punta Negra Formation and finally a 1500 m thick package of piroclastics and sediments of Albarracin Formation of Tertiary age. Albarracin Formation is composed pf a Basal Member (sandstones and stilstones), a Tuffaceous Member (tuffs, tuffites and oligomictic breccia s with conglomerate interbed dings in the upper part) and a Conglomeratic Member (polimictic para conglomerates). According to piroclastics facies, relationships and spreading area of piroclastics deposits a c olapsed dome and avalanche model is proposed to be the main process for the piroclastics package outcropping in the area.Sedimentary and piroclastics rocks are intruded by five sub volcanic units as noted by Leveratto (1968) which are composed by different lithologies such as: Altered Da cite - Rhyolite, Ullum Da cite, Cerro Blanco de Zonda Andesite, Ullum Andesite and Hybrid Andesite.Detailed work on alteration assemblages and metallogenic features in the southwestern sector of the Complejo resulted in the identification of three alteration zones with characteric features of potassic, argillic and propyllitic signature. (author)

Electro-Deposition Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The electro-deposition laboratory can electro-deposit various coatings onto small test samples and bench level prototypes. This facility provides the foundation for...

Athabasca basin unconformity-type uranium deposits. A special class of sandstone-type deposits

International Nuclear Information System (INIS)

Hoeve, J.

1980-01-01

Two major episodes of uranium metallogenesis are recognized in Northern Saskatchewan. The first is of late-Hudsonian age and gave rise to metamorphic-hydrothermal pitchblende deposits of simple mineralogy at Beaverlodge (primary mineralization: 1780+-20 m.y.). The second and more important episode of approximately Grenvillian age rendered unconformity-type deposits in the Athabasca Basin (primary mineralization: 1000-1300 m.y.). The late-Hudsonian deposits at Beaverlodge were overprinted by this second event and new deposits of complex mineralogy were formed in that area. The metallogenetic importance of a third and much later episode which gave rise to mineralization within the Athabasca Formation is uncertain at the moment. With regards to metallogenesis of the unconformity-type deposits, presently available evidence favours a diagenetic-hydrothermal rather than a near-surface supergene or a magmatic/metamorphic hydrothermal model. The diagenetic-hydrothermal model relates uranium mineralization to 'red bed-type' diagenetic processes in the Athabasca Formation involving post-depositional oxidation and leaching, which continued for several hundred million years after deposition. Ore deposits were formed by interaction, under conditions of deep burial at elevated temperatures and pressures, of a uraniferous oxidizing Athabasca aquifer with reducing, graphite-bearing, metamorphic rocks of the basin floor. The large-scale convection required for such interaction may have been induced by mafic magmatic activity coeval with the episode of mineralization. The diagenetic-hydrothermal model displays close similarities with metallogenetic models developed for certain sandstone-type deposits. (author)

World Distribution of Uranium Deposits (UDEPO) with uranium deposit classification. 2009 ed

International Nuclear Information System (INIS)

2009-10-01

The World Distribution of Uranium Deposits (UDEPO) database provides general, technical and geological information, including references, about the worldwide uranium deposits. UDEPO has been published on the internet which allows the users to register freely and to work with datasets (http://www-nfcis.iaea.org). The UDEPO web site is designed to allow users to retrieve data sets on a variety of deposit related topics ranging from specific information on individual uranium deposits to statistical information on uranium deposits worldwide. The basic building blocks for the UDEPO database are the more than 900 individual deposits for which information is available in the database. The database is arranged in a relational database format which has one main table and a number of associated tables. Structured nature of the database allows filtering and querying the database in more systematic way. The web site provides filtering and navigation to the data from the database. It has also a statistical tool which provides summary information on number of deposits and uranium resources by type and status, and by country and status. In this respect and with regard to the data presented, the UDEPO database is a unique database which provides freely accessible information on worldwide uranium deposits. Although a great effort is spent to have complete and accurate database, the users should take into consideration that there still might be missing or outdated data for individual deposits due to the rapid changes in the uranium industry due to the new exploration works which are ongoing everyday. This document and its supplementary CD-ROM represent a snapshot of the status of the database as of the end of 2008. However, the database is being continuously updated and the latest updates and additions can be accessed from the database web site (http://wwwnfcis.iaea.org)

Geological factors of deposit formation

International Nuclear Information System (INIS)

Grushevoj, G.V.

1980-01-01

Geologic factors of hydrogenic uranium deposit formation are considered. Structural, formation and lithological-facies factors of deposit formation, connected with zones of stratal oxidation, are characterized. Peculiarities of deposit localization, connected with orogenic structures of Mesozoic and lenozoic age, are described. It is noted that deposits of anagenous group are widely spread in Paleozoic formations, infiltration uranium deposits are localized mainly in Cenozoic sediments, while uranium mineralization both anagenous and infiltration groups are widely developed in Mesozoic sediments. Anagenous deposits were formed in non-oxygen situation, their age varies from 200 to 55 mln years. Infiltration deposit formation is determined by asymmetric oxidation zonation, their age varies from 10 - 40 mln years to dozens of thousand years [ru

Deposit3D: a tool for automating structure depositions to the Protein Data Bank

Energy Technology Data Exchange (ETDEWEB)

Badger, J., E-mail: jbadger@active-sight.com; Hendle, J.; Burley, S. K.; Kissinger, C. R. [SGX Inc., 10505 Roselle Street, San Diego, CA 92121 (United States)

2005-09-01

This paper describes a Python script that may be used to gather all required structure-annotation information into an mmCIF file for upload through the RCSB PDB ADIT structure-deposition interface. Almost all successful protein structure-determination projects in the public sector culminate in a structure deposition to the Protein Data Bank (PDB). In order to expedite the deposition proces, Deposit3D has been developed. This command-line script calculates or gathers all the required structure-deposition information and outputs this data into a mmCIF file for subsequent upload through the RCSB PDB ADIT interface. Deposit3D might be particularly useful for structural genomics pipeline projects because it allows workers involved with various stages of a structure-determination project to pool their different categories of annotation information before starting a deposition session.

Deposit3D: a tool for automating structure depositions to the Protein Data Bank

International Nuclear Information System (INIS)

Badger, J.; Hendle, J.; Burley, S. K.; Kissinger, C. R.

2005-01-01

This paper describes a Python script that may be used to gather all required structure-annotation information into an mmCIF file for upload through the RCSB PDB ADIT structure-deposition interface. Almost all successful protein structure-determination projects in the public sector culminate in a structure deposition to the Protein Data Bank (PDB). In order to expedite the deposition proces, Deposit3D has been developed. This command-line script calculates or gathers all the required structure-deposition information and outputs this data into a mmCIF file for subsequent upload through the RCSB PDB ADIT interface. Deposit3D might be particularly useful for structural genomics pipeline projects because it allows workers involved with various stages of a structure-determination project to pool their different categories of annotation information before starting a deposition session

Stratigraphic implications of uranium deposits

International Nuclear Information System (INIS)

Langford, F.F.

1980-01-01

One of the most consistent characteristics of economic uranium deposits is their restricted stratigraphic distribution. Uraninite deposited with direct igneous affiliation contains thorium, whereas chemical precipitates in sedimentary rocks are characterized by thorium-free primary uranium minerals with vanadium and selenium. In marine sediments, these minerals form low-grade disseminations; but in terrestrial sediments, chiefly fluvial sandstones, the concentration of uranium varies widely, with the high-grade portions constituting ore. Pitchblende vein deposits not only exhibit the same chemical characteristics as the Colorado-type sandstone deposits, but they have a stratigraphically consistent position at unconformities covered by fluvial sandstones. If deposits in such diverse situations have critical features in common, they are likely to have had many features of their origin in common. Thus, vein deposits in Saskatchewan and Australia may have analogues in areas that contain Colorado-type sandstone deposits. In New Mexico, the presence of continental sandstones with peneconformable uranium deposits should also indicate good prospecting ground for unconformity-type vein deposits. All unconformities within the periods of continental deposition ranging from Permian to Cretaceous should have uranium potential. Some situations, such as the onlap of the Abo Formation onto Precambrian basement in the Zuni Mountains, may be directly comparable to Saskatchewan deposition. However, uranium occurrences in the upper part of the Entrada Sandstone suggest that unconformities underlain by sedimentary rocks may also be exploration targets

Mineralogical and Geochemical Characterization of the Kimmeria Intrusion-Related Deposit, Xanthi, NE Greece

Science.gov (United States)

Theodoridou, Stella; Melfos, Vasilios; Voudouris, Panagiotis; Miskovic, Aleksandar

2016-04-01

Although intrusion-related systems have not been previously recognized in the European segment of the Tethyan Metallogenic Belt, the Rhodope metallogenic province of SE Balkan peninsula hosts numerous such occurrences. The Kimmeria hydrothermal system incorporates two styles of ore mineralization: i) a massive Au-bearing magnetite-pyrrhotite skarn and ii) a Mo-Cu-Bi-W quartz vein-hosted mineralization, both of which are related to the Oligocene Xanthi pluton (25.5±1.2 to 30±1 My, K-Ar in hornblende and biotite). The Xanthi pluton, consisting of I-type gabbros, monzonites and amphibole-biotite granodiorites, intrudes the basement gneisses, mica schists, amphibolites and marbles of the Southern Rhodope Core Complex; a dome that has gradually exhumed from Paleocene/mid Eocene to Miocene (starting between 65 and >42 to 10 My). The Xanthi pluton emplacement and the magmatically derived hydrothermal fluid circulation were controlled by two major regional structures: the low-angle Kavala-Xanthi-Komotini detachment fault and the Nestos thrust fault. The Kimmeria Au-Cu-Fe skarn mineralization features a well-preserved aureole at the contact between the granodiorite and the surrounding marbles. It consists of two paragenetic stages comprising magnetite and pyrrhotite-rich assemblages. Alteration minerals comprise chlorite and sericite. Bulk chemical analyses of the skarn mineralization revealed relatively high concentration of Cu (1 wt.%), Pb (288 ppm) and Zn (0.74 wt.%). The mineralization is also enriched in As (molybdenite as dominant sulfides. Minor sphalerite, tetrahedrite-tennantite, galena and rutile are also present, while sericite and chlorite as the alteration minerals. The Cu and Mo content of the vein type mineralization exceed 1.0 and 0.2 wt.% respectively, along with < 2.7 ppm Au, 1.3 to 79.5 ppm W and 0.6 to 456 ppm Bi. A first approach fluid study has revealed small variations in δ34S values of sulfides (0 - 2.3 ‰ VCDT) from both types of mineralization

Mineral deposits of Central America, with a section on manganese deposits of Panama

Science.gov (United States)

Roberts, Ralph Jackson; Irving, Earl Montgomery; Simons, F.S.

1957-01-01

The mineral deposits of Central America were studied between 1942 and 1945, in cooperation with the United States Department of State and the Foreign Economic Administration. Emphasis was originally placed on the study of strategic-mineral deposits, especially of antimony, chromite, manganese, quartz, and mica, but deposits of other minerals that offered promise of significant future production were also studied. A brief appraisal of the base-metal deposits was made, and deposits of iron ore in Honduras and of lead and zinc ores in Guatemala were mapped. In addition, studies were made of the regional geology of some areas, data were collected from many sources, and a new map of the geology of Central America was compiled.

Tandem solar cells deposited using hot-wire chemical vapor deposition

NARCIS (Netherlands)

Veen, M.K. van

2003-01-01

In this thesis, the application of the hot-wire chemical vapor deposition (HWCVD) technique for the deposition of silicon thin films is described. The HWCVD technique is based on the dissociation of silicon-containing gasses at the catalytic surface of a hot filament. Advantages of this technique

In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

KAUST Repository

Avila-Avendano, Jesus

2016-04-09

In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

KAUST Repository

Avila-Avendano, Jesus; Mejia, Israel; Alshareef, Husam N.; Guo, Zaibing; Young, Chadwin; Quevedo-Lopez, Manuel

2016-01-01

In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

Reactive polymer fused deposition manufacturing

Science.gov (United States)

Kunc, Vlastimil; Rios, Orlando; Love, Lonnie J.; Duty, Chad E.; Johs, Alexander

2017-05-16

Methods and compositions for additive manufacturing that include reactive or thermosetting polymers, such as urethanes and epoxies. The polymers are melted, partially cross-linked prior to the depositing, deposited to form a component object, solidified, and fully cross-linked. These polymers form networks of chemical bonds that span the deposited layers. Application of a directional electromagnetic field can be applied to aromatic polymers after deposition to align the polymers for improved bonding between the deposited layers.

Arc-related porphyry molybdenum deposit model: Chapter D in Mineral deposit models for resource assessment

Science.gov (United States)

Taylor, Ryan D.; Hammarstrom, Jane M.; Piatak, Nadine M.; Seal, Robert R.

2012-01-01

This report provides a descriptive model for arc-related porphyry molybdenum deposits. Presented within are geological, geochemical, and mineralogical characteristics that differentiate this deposit type from porphyry copper and alkali-feldspar rhyolite-granite porphyry molybdenum deposits. The U.S. Geological Survey's effort to update existing mineral deposit models spurred this research, which is intended to supplement previously published models for this deposit type that help guide mineral-resource and mineral-environmental assessments.

Low-pressure chemical vapor deposition as a tool for deposition of thin film battery materials

NARCIS (Netherlands)

Oudenhoven, J.F.M.; Dongen, van T.; Niessen, R.A.H.; Croon, de M.H.J.M.; Notten, P.H.L.

2009-01-01

Low Pressure Chemical Vapor Deposition was utilized for the deposition of LiCoO2 cathode materials for all-solid-state thin-film micro-batteries. To obtain insight in the deposition process, the most important process parameters were optimized for the deposition of crystalline electrode films on

Quartz-pebble-conglomerate gold deposits: Chapter P in Mineral deposit models for resource assessment

Science.gov (United States)

Taylor, Ryan D.; Anderson, Eric D.

2018-05-17

Quartz-pebble-conglomerate gold deposits represent the largest repository of gold on Earth, largely due to the deposits of the Witwatersrand Basin, which account for nearly 40 percent of the total gold produced throughout Earth’s history. This deposit type has had a controversial history in regards to genetic models. However, most researchers conclude that they are paleoplacer deposits that have been modified by metamorphism and hydrothermal fluid flow subsequent to initial sedimentation.The deposits are found exclusively within fault-bounded depositional basins. The periphery of these basins commonly consists of granite-greenstone terranes, classic hosts for lode gold that source the detrital material infilling the basin. The gold reefs are typically located along unconformities or, less commonly, at the top of sedimentary beds. Large quartz pebbles and heavy-mineral concentrates are found associated with the gold. Deposits that formed prior to the Great Oxidation Event (circa 2.4 giga-annum [Ga]) contain pyrite, whereas younger deposits contain iron oxides. Uranium minerals and hydrocarbons are also notable features of some deposits.Much of the gold in these types of deposits forms crystalline features that are the product of local remobilization. However, some gold grains preserve textures that are undoubtedly of detrital origin. Other heavy minerals, such as pyrite, contain growth banding that is truncated along broken margins, which indicates that they were transported into place as opposed to forming by in situ growth in a hydrothermal setting.The ore tailings associated with these deposits commonly contain uranium-rich minerals and sulfides. Oxidation of the sulfides releases sulfuric acid and mobilizes various metals into the environment. The neutralizing potential of the tailings is minimal, since carbonate minerals are rare. The continuity of the tabular ore bodies, such as those of the Witwatersrand Basin, has allowed these mines to be the deepest in

Urban acid deposition

Energy Technology Data Exchange (ETDEWEB)

Conlan, D.E.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E.

1991-07-01

In this document results from the Greater Manchester Acid Deposition Survey (GMADS), an urban precipitation chemistry network, for 1990 are presented. Full analytical methods are described along with the precision and accuracy of the methods used. The spatial variability of precipitation chemistry and deposition over this urban region was investigated using a network of twenty collectors. Concentrations of non marine sulphate, ammonium, calcium and hydrogen, and nitrogen dioxide gas concentrations all show significant spatial variability. The spatial variability of the deposition rates of non marine sulphate, nitrate, ammonium, hydrogen and calcium were significant. (Author).

Post-depositional fracturing and subsidence of pumice flow deposits: Lascar Volcano, Chile.

Science.gov (United States)

Whelley, Patrick L; Jay, J; Calder, E S; Pritchard, M E; Cassidy, N J; Alcaraz, S; Pavez, A

Unconsolidated pyroclastic flow deposits of the 1993 eruption of Lascar Volcano, Chile, have, with time, become increasingly dissected by a network of deeply penetrating fractures. The fracture network comprises orthogonal sets of decimeter-wide linear voids that form a pseudo-polygonal grid visible on the deposit surface. In this work, we combine shallow surface geophysical imaging tools with remote sensing observations and direct field measurements of the deposit to investigate these fractures and their underlying causal mechanisms. Based on ground penetrating radar images, the fractures are observed to have propagated to depths of up to 10 m. In addition, orbiting radar interferometry shows that deposit subsidence of up to 1 cm/year -1 occurred between 1993 and 1996 with continued subsidence occurring at a slower rate thereafter. In situ measurements show that 1 m below the surface, the 1993 deposits remain 5°C to 15°C hotter, 18 years after emplacement, than adjacent deposits. Based on the observed subsidence as well as estimated cooling rates, the fractures are inferred to be the combined result of deaeration, thermal contraction, and sedimentary compaction in the months to years following deposition. Significant environmental factors, including regional earthquakes in 1995 and 2007, accelerated settling at punctuated moments in time. The spatially variable fracture pattern relates to surface slope and lithofacies variations as well as substrate lithology. Similar fractures have been reported in other ignimbrites but are generally exposed only in cross section and are often attributed to formation by external forces. Here we suggest that such interpretations should be invoked with caution, and deformation including post-emplacement subsidence and fracturing of loosely packed ash-rich deposits in the months to years post-emplacement is a process inherent in the settling of pyroclastic material.

Low-fluorine Stockwork Molybdenite Deposits

Science.gov (United States)

Ludington, Steve; Hammarstrom, Jane; Piatak, Nadine M.

2009-01-01

Low-fluorine stockwork molybdenite deposits are closely related to porphyry copper deposits, being similar in their tectonic setting (continental volcanic arc) and the petrology (calc-alkaline) of associated igneous rock types. They are mainly restricted to the Cordillera of western Canada and the northwest United States, and their distribution elsewhere in the world may be limited. The deposits consist of stockwork bodies of molybdenite-bearing quartz veinlets that are present in and around the upper parts of intermediate to felsic intrusions. The deposits are relatively low grade (0.05 to 0.2 percent Mo), but relatively large, commonly >50 million tons. The source plutons for these deposits range from granodiorite to granite in composition; the deposits primarily form in continental margin subduction-related magmatic arcs, often concurrent with formation of nearby porphyry copper deposits. Oxidation of pyrite in unmined deposits or in tailings and waste rock during weathering can lead to development of acid-rock drainage and limonite-rich gossans. Waters associated with low-fluorine stockwork molybdenite deposits tend to be nearly neutral in pH; variable in concentrations of molybdenum (10,000 ug/L); below regulatory guidelines for copper, iron, lead, zinc, and mercury; and locally may exceed guidelines for arsenic, cadmium, and selenium.

Development and evaluation of a long-term deposit probe for on-line monitoring of deposit growth

Energy Technology Data Exchange (ETDEWEB)

Brink, Anders; Lauren, Tor; Yrjas, Patrik; Hupa, Mikko [Process Chemistry Centre, Aabo Akademi University, Biskopsgatan 8, FI-20540 Turku (Finland); Friesenbichler, Joachim [Institute for Resource Efficient and Sustainable Systems, Technical University Graz Inffeldg. 21b, A-8010 Graz (Austria)

2007-12-15

A newly designed air-cooled probe for on-line monitoring of deposition growth has been tested in a boiler firing three woody fuels. Thermocouples are mounted on both sides of the tube wall enabling measurements of the heat flux through the probe wall. Knowing the heat flux through the probe wall, it is possible to measure the additional heat transfer resistance caused by the deposit and to estimate the properties of the deposit. Calculating the deposit thickness using the collected temperature data indicated the thinnest deposit when wood was fired, followed by bark and waste wood. The calculated deposit thickness was larger than those found when analysing the deposit thickness after the probe had been removed. Nevertheless, the ranking of fuels by deposit build-up rate was the same. (author)

Dry deposition on urban surfaces

International Nuclear Information System (INIS)

Roed, J.

1985-01-01

In order to facilitate developing a model for deposition in urban areas, beryllium-7, created by cosmic radiation and fall-out cesium-137, have been used as tracers in measurements designed to find the dry deposition velocity on building surfaces. A literature review has revealed that very little work has been done on deposition in urban areas; therefore, a major effort on meausring the deposition parameter is needed to construct reliable models in this field. Deposition velocities in the range from 0.001-0.04 cm/s have been found. (author)

A special issue devoted to gold deposits in northern Nevada: Part 2. Carlin-type Deposits

Science.gov (United States)

Hofstra, Albert H.; John, David A.; Theodore, Ted G.

2003-01-01

This is the second of two special issues of Economic Geology devoted to gold deposits in northern Nevada. Readers interested in a general overview of these deposits, their economic significance, their context within the tectonic evolution of the region, and synoptic references on each gold deposit type are directed to the preface of the first special issue (John et al., 2003). Volume 98, issue 2, contains five papers that address regional aspects important to the genesis of gold deposits in northern Nevada and five papers that present detailed studies of epithermal deposits and districts. All of the regional papers are pertinent to Carlin-type gold deposits, because they address the age of mineralization (Arehart et al., 2003), origin and evolutionary history of the northwest-striking mineral belts that localize many deposits (Grauch et al., 2003), nature of the middle and lower crust below these mineral belts (Howard, 2003), district- to deposit-scale stream sediment and lithogeochemical anomalies (Theodore et al., 2003), and stratigraphy and structure of a district located along a northeast-striking lineament (Peters et al., 2003).

Deposits of the Peruvian Pisco Formation compared to layered deposits on Mars

Science.gov (United States)

Sowe, M.; Bishop, J. L.; Gross, C.; Walter, S.

2013-09-01

Deposits of the Peruvian Pisco Formation are morphologically similar to the mounds of Juventae Chasma at the equatorial region on Mars (Fig. 1). By analyzing these deposits, we hope to gain information about the environmental conditions that prevailed during sediment deposition and erosion, hence conditions that might be applicable to the Martian layered and hydrated deposits. Mariner 9 data of the Martian mid-latitudes have already shown evidence of the wind-sculptured landforms that display the powerful prevailing eolian regime [1]. In addition, [2] reported on similarities between Martian erosional landforms and those of the rainless coastal desert of central Peru from the Paracas peninsula to the Rio Ica. As indicated by similar erosional patterns, hyper-arid conditions and unidirectional winds must have dominated at least after deposition of the sediments, which are intermixed volcaniclastic materials and evaporate minerals at both locations. Likewise, variations in composition are displayed by alternating layers of different competence. The Pisco formation bears yardangs on siltstones, sandstones and clays with volcaniclastic admixtures [3] whereas the presence of sulphate minerals and the omnipresent mafic mineralogy has been reported for the layered mounds of Juventae Chasma equally [4]. Likewise, a volcanic airfall deposition and lacustrine formation have been proposed for the sulphate-rich deposits of Juventae Chasma [5,6]. In order to find out about potential spectral similarities, we performed a detailed spectral analysis of the surface by using LANDSAT and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) VNIR/ SWIR data (visible to near-infrared and shortwave infrared region).

NURE uranium deposit model studies

International Nuclear Information System (INIS)

Crew, M.E.

1981-01-01

The National Uranium Resource Evaluation (NURE) Program has sponsored uranium deposit model studies by Bendix Field Engineering Corporation (Bendix), the US Geological Survey (USGS), and numerous subcontractors. This paper deals only with models from the following six reports prepared by Samuel S. Adams and Associates: GJBX-1(81) - Geology and Recognition Criteria for Roll-Type Uranium Deposits in Continental Sandstones; GJBX-2(81) - Geology and Recognition Criteria for Uraniferous Humate Deposits, Grants Uranium Region, New Mexico; GJBX-3(81) - Geology and Recognition Criteria for Uranium Deposits of the Quartz-Pebble Conglomerate Type; GJBX-4(81) - Geology and Recognition Criteria for Sandstone Uranium Deposits in Mixed Fluvial-Shallow Marine Sedimentary Sequences, South Texas; GJBX-5(81) - Geology and Recognition Criteria for Veinlike Uranium Deposits of the Lower to Middle Proterozoic Unconformity and Strata-Related Types; GJBX-6(81) - Geology and Recognition Criteria for Sandstone Uranium Deposits of the Salt Wash Type, Colorado Plateau Province. A unique feature of these models is the development of recognition criteria in a systematic fashion, with a method for quantifying the various items. The recognition-criteria networks are used in this paper to illustrate the various types of deposits

Fingerprinting the Hydrothermal Fluid Characteristics from LA-ICP-MS Trace Element Geochemistry of Garnet in the Yongping Cu Deposit, SE China

Directory of Open Access Journals (Sweden)

Yu Zhang

2017-10-01

Full Text Available The large Yongping Cu deposit is situated in the eastern Qin-Hang Metallogenic Belt, Southeast China and on the southern side of the Yangtze—Cathaysia suture zone, and is characterized by large stratiform orebodies. Garnet represents the main non-metallic mineral at Yongping, and shows variations in color from dark red to green to light brown with distance from the Shizitou porphyritic biotite granite stock. An in situ elemental analysis using EPMA and LA-ICP-MS and fluid inclusions microthermometric measurement on the Yongping garnet were conducted to constrain the hydrothermal and physicochemical mineralization conditions and the ore origin. The Yongping garnet ranges from nearly pure to impure andradite, is characterized by low concentrations of MnO (0.11–0.71 wt % with a wide range of Y/Ho (2.1–494.9 and does not exhibit any melting inclusions or fluid-melt inclusions, indicating that they are likely to be resulted from hydrothermal replacements. The Yongping garnet is rich in LREEs, Cs, Th, U and Pb; relatively depleted in HREEs, Rb, Sr and Ba; but exhibits distinct Eu anomalies (δEu of the dark red, green and light brown garnet range 2.12–20.54, 0.74–1.70 and 0.52–0.85, respectively with the homogenization temperatures and salinities of the fluid inclusions principally ranging from 387–477 °C and 7.8–16.0 wt % NaCl equivalent, respectively. The distinct trace elements and microthermometric characteristics reveal that the garnet was formed in a physicochemical conditions of medium-high temperature, 44–64 MPa pressures, mildly acidic pH levels, and unstable oxygen fugacity, and indicate that they were primarily formed by infiltration metasomatism, quite fitting with the scenario that the preferential entrance of magmatic-hydrothermal fluids derived from the Shizitou stock into the relatively low-pressure fracture zones between the limestone and quartz sandstone in the Yejiawan Formation, and further led to the formation

Vapor deposition of large area NpO2 and UO2 deposits

International Nuclear Information System (INIS)

Adair, H.L.; Gibson, J.R.; Kobisk, E.H.; Dailey, J.M.

1976-01-01

Deposition of NpO 2 and UO 2 thin films over an area of 7.5 to 10 cm diam has become a routine operation in preparation of fission chamber plates. Vacuum evaporation or electroplating has been used for this purpose. The ''paint brush'' technique has been used as well; however, uniformity requirements normally eliminate this procedure. Vapor deposition in vacuum appears to be the most suitable technique for preparing NpO 2 and UO 2 deposits of >200 cm 2 . This paper describes the procedures used in preparing uniform large area deposits of NpO 2 (approximately 300 cm 2 ) and UO 2 (approximately 2000 cm 2 ) by vacuum evaporation using electron bombardment heating and several substrate motion and heating methods to achieve uniformity and adhesion

Precambrian uranium deposits as a possible source of uranium for the European Variscan deposits

International Nuclear Information System (INIS)

Mineeva, I.G.; Klochkov, A.S.

2002-01-01

The Precambrian uranium deposits have been studied on the territory of Baltic and Ukrainian shields. The primary Early Proterozoic complex Au-U deposits originated in granite-greenstone belts as a result of their evolution during continental earth crust formation by prolonged rift genesis. The greenstone belts are clues for revealing ancient protoriftogenic structures. The general regularities of uranium deposition on Precambrian shields are also traceable in Variscan uranium deposits from the Bohemian massif. The Variscan period of uranium ore formation is connected with a polychronous rejuvenation of ancient riftogenous systems and relatively younger processes of oil and gas formation leading to the repeated mobilization of U from destroyed Proterozoic and Riphean uranium deposits. (author)

Uranium deposits in granitic rocks

International Nuclear Information System (INIS)

Nishimori, R.K.; Ragland, P.C.; Rogers, J.J.W.; Greenberg, J.K.

1977-01-01

This report is a review of published data bearing on the geology and origin of uranium deposits in granitic, pegmatitic and migmatitic rocks with the aim of assisting in the development of predictive criteria for the search for similar deposits in the U.S. Efforts were concentrated on the so-called ''porphyry'' uranium deposits. Two types of uranium deposits are primarily considered: deposits in pegmatites and alaskites in gneiss terrains, and disseminations of uranium in high-level granites. In Chapter 1 of this report, the general data on the distribution of uranium in igneous and metamorphic rocks are reviewed. Chapter 2 contains some comments on the classification of uranium deposits associated with igneous rocks and a summary of the main features of the geology of uranium deposits in granites. General concepts of the behavior of uranium in granites during crustal evolution are reviewed in Chapter 3. Also included is a discussion of the relationship of uranium mineralization in granites to the general evolution of mobile belts, plus the influence of magmatic and post-magmatic processes on the distribution of uranium in igneous rocks and related ore deposits. Chapter 4 relates the results of experimental studies on the crystallization of granites to some of the geologic features of uranium deposits in pegmatites and alaskites in high-grade metamorphic terrains. Potential or favorable areas for igneous uranium deposits in the U.S.A. are delineated in Chapter 5. Data on the geology of specific uranium deposits in granitic rocks are contained in Appendix 1. A compilation of igneous rock formations containing greater than 10 ppM uranium is included in Appendix 2. Appendix 3 is a report on the results of a visit to the Roessing area. Appendix 4 is a report on a field excursion to eastern Canada

Enhanced nitrogen deposition over China

Energy Technology Data Exchange (ETDEWEB)

Liu, Xuejun; Zhang, Ying; Han, Wenxuan; Tang, Aohan; Shen, Jianlin; Cui, Zhenling; Christie, Peter; Zhang, Fusuo [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Vitousek, Peter [Department of Biology, Stanford University, Stanford, California 94305 (United States); Erisman, Jan Willem [VU University Amsterdam, 1081 HV Amsterdam (Netherlands); Goulding, Keith [The Sustainable Soils and Grassland Systems Department, Rothamsted Research, Harpenden AL5 2JQ (United Kingdom); Fangmeier, Andreas [Institute of Landscape and Plant Ecology, University of Hohenheim, 70593 Stuttgart (Germany)

2013-02-28

China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s, before the introduction of mitigation measures. Nitrogen from ammonium (NH4+) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3-), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.

Breakthrough to Non-Vacuum Deposition of Single-Crystal, Ultra-Thin, Homogeneous Nanoparticle Layers: A Better Alternative to Chemical Bath Deposition and Atomic Layer Deposition

Directory of Open Access Journals (Sweden)

Yu-Kuang Liao

2017-04-01

Full Text Available Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new ”paradigm shift” non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD and chemical bath deposition (CBD as used by the Cu(In,GaSe2 (CIGS thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase.

Dual Nitrate Isotopes in Dry Deposition: Utility for Partitioning Nox Source Contributions to Landscape Nitrogen Deposition

Science.gov (United States)

Dry deposition is a major component of total nitrogen deposition and thus an important source of bioavailable nitrogen to ecosystems. However, relative to wet deposition, less is known regarding the sources and spatial variability of dry deposition. This is in part due to diffi...

CTS and CZTS for solar cells made by pulsed laser deposition and pulsed electron deposition

DEFF Research Database (Denmark)

Ettlinger, Rebecca Bolt

This thesis concerns the deposition of thin films for solar cells using pulsed laser deposition (PLD) and pulsed electron deposition (PED). The aim was to deposit copper tin sulfide (CTS) and zinc sulfide (ZnS) by pulsed laser deposition to learn about these materials in relation to copper zinc tin...... time. We compared the results of CZTS deposition by PLD at DTU in Denmark to CZTS made by PED at IMEM-CNR, where CIGS solar cells have successfully been fabricated at very low processing temperatures. The main results of this work were as follows: Monoclinic-phase CTS films were made by pulsed laser...... deposition followed by high temperature annealing. The films were used to understand the double band gap that we and other groups observed in the material. The Cu-content of the CTS films varied depending on the laser fluence (the laser energy per pulse and per area). The material transfer from...

Laboratory Deposition Apparatus to Study the Effects of Wax Deposition on Pipe Magnetic Field Leakage Signals

Directory of Open Access Journals (Sweden)

Karim Mohd Fauzi Abd

2014-07-01

Full Text Available Accurate technique for wax deposition detection and severity measurement on cold pipe wall is important for pipeline cleaning program. Usually these techniques are validated by conventional techniques on laboratory scale wax deposition flow loop. However conventional techniques inherent limitations and it is difficult to reproduce a predetermine wax deposit profile and hardness at designated location in flow loop. An alternative wax deposition system which integrates modified pour casting method and cold finger method is presented. This system is suitable to reproduce high volume of medium hard wax deposit in pipe with better control of wax deposit profile and hardness.

The influences of target properties and deposition times on pulsed laser deposited hydroxyapatite films

International Nuclear Information System (INIS)

Bao Quanhe; Chen Chuanzhong; Wang Diangang; Liu Junming

2008-01-01

Hydroxyapatite films were produced by pulsed laser deposition from three kinds of hydroxyapatite targets and with different deposition times. A JXA-8800R electron probe microanalyzer (EPMA) with a Link ISIS300 energy spectrum analyzer was used to give the secondary electron image (SE) and determine the element composition of the films. The phases of thin film were analyzed by a D/max-γc X-ray diffractometer (XRD). The Fourier-transform infrared spectroscopy (FT-IR) was used to characterize the hydroxyl, phosphate and other functional groups. The results show that deposited films were amorphous which mainly composed of droplet-like particles and vibration of PO 4 3- groups. With the target sintering temperature deposition times increasing, the density of droplets is decreased. While with deposition times increasing, the density of droplets is increased. With the target sintering temperature and deposition time increasing, the ratio of Ca/P is increasing and higher than that of theoretical value of HA

Advanced deposition model for thermal activated chemical vapor deposition

Science.gov (United States)

Cai, Dang

Thermal Activated Chemical Vapor Deposition (TACVD) is defined as the formation of a stable solid product on a heated substrate surface from chemical reactions and/or dissociation of gaseous reactants in an activated environment. It has become an essential process for producing solid film, bulk material, coating, fibers, powders and monolithic components. Global market of CVD products has reached multi billions dollars for each year. In the recent years CVD process has been extensively used to manufacture semiconductors and other electronic components such as polysilicon, AlN and GaN. Extensive research effort has been directed to improve deposition quality and throughput. To obtain fast and high quality deposition, operational conditions such as temperature, pressure, fluid velocity and species concentration and geometry conditions such as source-substrate distance need to be well controlled in a CVD system. This thesis will focus on design of CVD processes through understanding the transport and reaction phenomena in the growth reactor. Since the in situ monitor is almost impossible for CVD reactor, many industrial resources have been expended to determine the optimum design by semi-empirical methods and trial-and-error procedures. This approach has allowed the achievement of improvements in the deposition sequence, but begins to show its limitations, as this method cannot always fulfill the more and more stringent specifications of the industry. To resolve this problem, numerical simulation is widely used in studying the growth techniques. The difficulty of numerical simulation of TACVD crystal growth process lies in the simulation of gas phase and surface reactions, especially the latter one, due to the fact that very limited kinetic information is available in the open literature. In this thesis, an advanced deposition model was developed to study the multi-component fluid flow, homogeneous gas phase reactions inside the reactor chamber, heterogeneous surface

Effect of post-deposition implantation and annealing on the properties of PECVD deposited silicon nitride films

International Nuclear Information System (INIS)

Shams, Q.A.

1988-01-01

Recently it has been shown that memory-quality silicon nitride can be deposited using plasma enhanced chemical vapor deposition (PECVD). Nitrogen implantation and post-deposition annealing resulted in improved memory properties of MNOS devices. The primary objective of the work described here is the continuation of the above work. Silicon nitride films were deposited using argon as the carrier gas and evaluated in terms of memory performance as the charge-trapping layer in the metal-nitride-oxide-silicon (MNOS) capacitor structure. The bonding structure of PECVD silicon nitride was modified by annealing in different ambients at temperatures higher than the deposition temperature. Post-deposition ion implantation was used to introduce argon into the films in an attempt to influence the transfer, trapping, and emission of charge during write/erase exercising of the MNOS devices. Results show that the memory performance of PECVD silicon nitride is sensitive to the deposition parameters and post-deposition processing

Reaction kinetics of metal deposition via surface limited red-ox replacement of underpotentially deposited metal monolayers

International Nuclear Information System (INIS)

Gokcen, Dincer; Bae, Sang-Eun; Brankovic, Stanko R.

2011-01-01

The study of the kinetics of metal deposition via surface limited red-ox replacement of underpotentially deposited metal monolayers is presented. The model system was Pt submonolayer deposition on Au(1 1 1) via red-ox replacement of Pb and Cu UPD monolayers on Au(1 1 1). The kinetics of a single replacement reaction was studied using the formalism of the comprehensive analytical model developed to fit the open circuit potential transients from deposition experiments. The practical reaction kinetics parameters like reaction half life, reaction order and reaction rate constant are determined and discussed with their relevance to design and control of deposition experiments. The effects of transport limitation and the role of the anions/electrolyte on deposition kinetics are investigated and their significance to design of effective deposition process is discussed.

Thermal plasma chemical vapor deposition

International Nuclear Information System (INIS)

Heberlein, J.; Pfender, E.

1993-01-01

Thermal plasmas, with temperatures up to and even exceeding 10 4 K, are capable of producing high density vapor phase precursors for the deposition of relatively thick films. Although this technology is still in its infancy, it will fill the void between the relatively slow deposition processes such as physical vapor deposition and the high rate thermal spray deposition processes. In this chapter, the present state-of-the-art of this field is reviewed with emphasis on the various types of reactors proposed for this emerging technology. Only applications which attracted particular attention, namely diamond and high T c superconducting film deposition, are discussed in greater detail. (orig.)

Uranium deposits in Africa

International Nuclear Information System (INIS)

Wilpolt, R.H.; Simov, S.D.

1979-01-01

Africa is not only known for its spectacular diamond, gold, copper, chromium, platinum and phosphorus deposits but also for its uranium deposits. At least two uranium provinces can be distinguished - the southern, with the equatorial sub-province; and the south Saharan province. Uranium deposits are distributed either in cratons or in mobile belts, the first of sandstone and quartz-pebble conglomerate type, while those located in mobile belts are predominantly of vein and similar (disseminated) type. Uranium deposits occur within Precambrian rocks or in younger platform sediments, but close to the exposed Precambrian basement. The Proterozoic host rocks consist of sediments, metamorphics or granitoids. In contrast to Phanerozoic continental uranium-bearing sediments, those in the Precambrian are in marginal marine facies but they do contain organic material. The geology of Africa is briefly reviewed with the emphasis on those features which might control the distribution of uranium. The evolution of the African Platform is considered as a progressive reduction of its craton area which has been affected by three major Precambrian tectonic events. A short survey on the geology of known uranium deposits is made. However, some deposits and occurrences for which little published material is available are treated in more detail. (author)

Experimental measurements of the thermal conductivity of ash deposits: Part 2. Effects of sintering and deposit microstructure

Energy Technology Data Exchange (ETDEWEB)

A. L. Robinson; S. G. Buckley; N. Yang; L. L. Baxter

2000-04-01

The authors report results from an experimental study that examines the influence of sintering and microstructure on ash deposit thermal conductivity. The measurements are made using a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. The technique is designed to minimize the disturbance of the natural deposit microstructure. The initial stages of sintering and densification are accompanied by an increase in deposit thermal conductivity. Subsequent sintering continues to densify the deposit, but has little effect on deposit thermal conductivity. SEM analyses indicates that sintering creates a layered deposit structure with a relatively unsintered innermost layer. They hypothesize that this unsintered layer largely determines the overall deposit thermal conductivity. A theoretical model that treats a deposit as a two-layered material predicts the observed trends in thermal conductivity.

To what extent can intracrater layered deposits that lack clear sedimentary textures be used to infer depositional environments?

Science.gov (United States)

Cadieux, Sarah B.; Kah, Linda C.

2015-03-01

Craters within Arabia Terra, Mars, contain hundreds of meters of layered strata showing systematic alternation between slope- and cliff-forming units, suggesting either rhythmic deposition of distinct lithologies or similar lithologies that experienced differential cementation. On Earth, rhythmically deposited strata can be examined in terms of stratal packaging, wherein the interplay of tectonics, sediment deposition, and base level (i.e., the position above which sediment accumulation is expected to be temporary) result in changes in the amount of space available for sediment accumulation. These predictable patterns of sediment deposition can be used to infer changes in basin accommodation regardless of the mechanism of deposition (e.g. fluvial, lacustrine, or aeolian). Here, we analyze sedimentary deposits from three craters (Becquerel Crater, Danielson Crater, Crater A) in Arabia Terra. Each crater contains layered deposits that are clearly observed in orbital images. Although orbital images are insufficient to specifically determine the origin of sedimentary deposits, depositional couplets can be interpreted in terms of potential accommodation space available for deposition, and changes in the distribution of couplet thickness through stratigraphy can be interpreted in terms of changing base level and the production of new accommodation space. Differences in stratal packaging in these three craters suggest varying relationships between sedimentary influx, sedimentary base level, and concomitant changes in accommodation space. Previous groundwater upwelling models hypothesize that layered sedimentary deposits were deposited under warm climate conditions of early Mars. Here, we use observed stacking patterns to propose a model for deposition under cold climate conditions, wherein episodic melting of ground ice could raise local base level, stabilize sediment deposition, and result in differential cementation of accumulated strata. Such analysis demonstrates that

Seasonal atmospheric deposition variations of polychlorinated biphenyls (PCBs) and comparison of some deposition sampling techniques.

Science.gov (United States)

Birgül, Askın; Tasdemir, Yücel

2011-03-01

Ambient air and bulk deposition samples were collected between June 2008 and June 2009. Eighty-three polychlorinated biphenyl (PCB) congeners were targeted in the samples. The average gas and particle PCB concentrations were found as 393 ± 278 and 70 ± 102 pg/m(3), respectively, and 85% of the atmospheric PCBs were in the gas phase. Bulk deposition samples were collected by using a sampler made of stainless steel. The average PCB bulk deposition flux value was determined as 6,020 ± 4,350 pg/m(2) day. The seasonal bulk deposition fluxes were not statistically different from each other, but the summer flux had higher values. Flux values differed depending on the precipitation levels. The average flux value in the rainy periods was 7,480 ± 4,080 pg/m(2) day while the average flux value in dry periods was 5,550 ± 4,420 pg/m(2) day. The obtained deposition values were lower than the reported values given for the urban and industrialized areas, yet close to the ones for the rural sites. The reported deposition values were also influenced by the type of the instruments used. The average dry deposition and total deposition velocity values calculated based on deposition and concentration values were found as 0.23 ± 0.21 and 0.13 ± 0.13 cm/s, respectively.

Geochronology of the Thompson Creek Mo Deposit: Evidence for the Formation of Arc-related Mo Deposits

Science.gov (United States)

Lawrence, C. D.; Coleman, D. S.; Stein, H. J.

2016-12-01

The Thompson Creek Mo deposit in central ID, has been categorized as an arc-related Mo deposit due to the location, grade of Mo, and relative lack of enrichments in F, Rb, and Nb, compared to the Climax-type Mo deposits. Geochronology from this arc-related deposit provides an opportunity to compare and contrast magmatism, and mineralization to that in Climax-type deposits. Distinct pulses of magmatism were required to form the Thompson Creek Mo deposit, which is consistent with recent geochronology from Climax-type deposits. Molybdenite Re-Os geochronology from five veins requires at least three pulses of magmatism and mineralization between 89.39 +/- 0.37 and 88.47 +/- 0.16 Ma. Zircon U-Pb ages from these mineralized samples overlap with molybdenite mineralization, but show a much wider range (91.01 +/- 0.37 to 87.27 +/- 0.69). Previous work from Climax-type Mo deposits suggest a correlation between a super eruption, and the subsequent rapid (<1 Ma) onset, and completion of Mo mineralizing intrusions. The longer life (3-4 Ma) for the Thompson Creek Mo deposit suggests that the mineralizing intrusions for arc-related Mo deposits may not need to have as high [Mo] as the Climax-type deposits. This study also finds a shift in the source of magmatism from the pre- to syn-mineralizing intrusions. Zircons from pre-mineralizing intrusions have much higher (15-60 pg) concentrations of radiogenic Pb than zircons from mineralized intrusions, which all have less than 15 pg, though whole rock [U] are similar.

Uranium geology of the eastern Baker Lake basin, District of Keewatin, Northwest Territories

International Nuclear Information System (INIS)

Miller, A.R.

1980-01-01

Proterozoic sequences associated with major unconformities are potential uranium metallogenic provinces. Late Aphebian to Paleohelikian Dubawnt Group contintental clastic sedimentary and subaerial alkaline volcanic rocks and underlying Archean gneisses, District of Keewatin, Northwest Territories, represent one such uraniferous metallogenic province. Three types of uranium mineralization are present in the eastern Baker Lake basin, which extends from Christopher Island at the eastern end of Baker Lake southwestwards to the western limit of Thirty Mile Lake. The three uranium associations are: 1) fracture controlled mineralization in the Dubawnt Group and basement gneisses (U-Cu-Ag-Au-Se or U-Cu-Pb-Mo-Zn), 2)diatreme breccia mineralization in basement gneisses (U-Cu-Zn), and 3) impregnation and microfracture mineralization in altered arkose peripheral to lamprophyre dykes(U-Cu-Ag). Hydrothermal fracture related mineralization is controlled by northwest- and east-northeast-trending fault-fracture zones. Diatreme breccia mineralization results from the channelling of groundwaters through highly permeable brecciated gneiss. Mineralization within the altered Kazan arkose peripheral to alkaline dyke complexes formed by a two stage process. Iron and copper sulphides and silver were deposited within the outer portions of the thermal aureole in response to a temperature and Eh gradient across a convective cell created by the thermal anomaly of the dyke complex. The epigenetic sulphide mineralization subsequently provided the reducing environment for precipitation of uranium from groundwater. All three uranium associations show a close spatial distribution to the basal Dubawnt unconformity. The lithological and structural relationships of the Dubawnt Group rocks, types of mineralization and associated alteration assemblages are strikingly similar to the Beaverlodge district, Saskatchewan. (author)

Surficial uranium deposits: summary and conclusions

International Nuclear Information System (INIS)

Otton, J.K.

1984-01-01

Uranium occurs in a variety of surficial environments in calcretes, gypcretes, silcretes, dolocretes and in organic sediments. Groundwater moving on low gradients generates these formations and, under favourable circumstances, uranium deposits. A variety of geomorphic settings can be involved. Most surficial deposits are formed in desert, temperate wetland, tropical, or transitional environments. The largest deposits known are in sedimentary environments in arid lands. The deposits form largely by the interaction of ground or surface waters on the geomorphic surface in favourable geologic terrains and climates. The deposits are commonly in the condition of being formed or reconstituted, or being destroyed. Carnotite is common in desert deposits while in wetland deposits no uranium minerals may be seen. Radioactive disequilibrium is common, particularly in wetland deposits. Granites and related rocks are major source rocks and most large deposits are in regions with enriched uranium contents, i.e. significantly greater than 5 ppm uranium. Uranium dissolution and transport is usually under oxidizing conditions. Transport in desert conditions is usually as a bicarbonate. A variety of fixation mechanisms operate to extract the uranium and form the deposits. Physical barriers to groundwater flow may initiate ore deposition. Mining costs are likely to be low because of the near surface occurrence, but there may be processing difficulties as clay may be present and the saline or carbonate content may be high. (author)

Effect of heat treatment on the characteristics of tool steel deposited by the directed energy deposition process

Science.gov (United States)

Park, Jun Seok; Lee, Min-Gyu; Cho, Yong-Jae; Sung, Ji Hyun; Jeong, Myeong-Sik; Lee, Sang-Kon; Choi, Yong-Jin; Kim, Da Hye

2016-01-01

The directed energy deposition process has been mainly applied to re-work and the restoration of damaged steel. Differences in material properties between the base and the newly deposited materials are unavoidable, which may affect the mechanical properties and durability of the part. We investigated the effect of heat treatment on the characteristics of tool steel deposited by the DED process. We prepared general tool steel materials of H13 and D2 that were deposited onto heat-treated substrates of H13 and D2, respectively, using a direct metal tooling process. The hardness and microstructure of the deposited steel before and after heat treatment were investigated. The hardness of the deposited H13 steel was higher than that of wrought H13 steel substrate, while that of the deposited D2 was lower than that of wrought D2. The evolution of the microstructures by deposition and heat treatment varied depending on the materials. In particular, the microstructure of the deposited D2 steel after heat treatment consisted of fine carbides in tempered martensite and it is expected that the deposited D2 steel will have isotropic properties and high hardness after heat treatment.

Laser deposition of HTSC films

International Nuclear Information System (INIS)

Sobol', Eh.N.; Bagratashvili, V.N.; Zherikhin, A.N.; Sviridov, A.P.

1990-01-01

Studies of the high-temperature superconducting (HTSC) films fabrication by the laser deposition are reviewed. Physical and chemical processes taking place during laser deposition are considered, such as the target evaporation, the material transport from the target to the substrate, the film growth on the substrate, thermochemical reactions and mass transfer within the HTSC films and their stability. The experimental results on the laser deposition of different HTSC ceramics and their properties investigations are given. The major technological issues are discussed including the deposition schemes, the oxygen supply, the target compositions and structure, the substrates and interface layers selection, the deposition regimes and their impact on the HTSC films properties. 169 refs.; 6 figs.; 2 tabs

Atmospheric Deposition Modeling Results

Data.gov (United States)

U.S. Environmental Protection Agency — This asset provides data on model results for dry and total deposition of sulfur, nitrogen and base cation species. Components include deposition velocities, dry...

Adhesion Strength of Biomass Ash Deposits

DEFF Research Database (Denmark)

Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

2016-01-01

. Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...... deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, ash/deposit composition......, sintering duration, and steel type on the adhesion strength....

19 CFR 210.28 - Depositions.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Depositions. 210.28 Section 210.28 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.28 Depositions. (a) When depositions may be...

Global deposition of airborne dioxin.

Science.gov (United States)

Booth, Shawn; Hui, Joe; Alojado, Zoraida; Lam, Vicky; Cheung, William; Zeller, Dirk; Steyn, Douw; Pauly, Daniel

2013-10-15

We present a global dioxin model that simulates one year of atmospheric emissions, transport processes, and depositions to the earth's terrestrial and marine habitats. We map starting emission levels for each land area, and we also map the resulting deposits to terrestrial and marine environments. This model confirms that 'hot spots' of deposition are likely to be in northern Europe, eastern North America, and in parts of Asia with the highest marine dioxin depositions being the northeast and northwest Atlantic, western Pacific, northern Indian Ocean and the Mediterranean. It also reveals that approximately 40% of airborne dioxin emissions are deposited to marine environments and that many countries in Africa receive more dioxin than they produce, which results in these countries being disproportionately impacted. Since human exposure to dioxin is largely through diet, this work highlights food producing areas that receive higher atmospheric deposits of dioxin than others. Copyright © 2013 Elsevier Ltd. All rights reserved.

Depositional environment of the San Miguel lignite deposit in Atascosa and McMullen Counties, Texas

Energy Technology Data Exchange (ETDEWEB)

Gowan, S.W.

1985-01-01

An analysis of the environment of deposition of the San Miguel lignite deposit was carried out in order to understand newly discovered characteristics of the deposit. The environment of deposition of the overburden and underburden was evaluated through an interpretation of three continuous cores. Four coal cores and a highwall section were carefully described to determine the depositional environmental of the coal seams and partings. These studies were supplemented by the construction of seam and parting isopachs, and the analysis of the distribution of sulfur isotopes, sulfur, forms, and total sulfur within the coal. The sedimentary package is composed of a basal prograding barrier that beach, dune, and back-barrier sands. This unit correlates with a downdip sand that was also interpreted as a prograding barrier by other authors. The barrier is overlain by a series of slit and clay deposits of lagoonal, tidal flat, and tidal channel origin. These deposits are capped by restricted lagoon sediments composed of green, calcareous clays that occasionally contain shell layers. The restricted lagoon deposits formed when the barrier closed the lagoon off from the sea. Peat forming freshwater swamps eventually became established behind the barrier and on top of the restricted lagoon sediments. The parting isopachs reveal a reticulate morphology similar to the mangrove swamps located lateral to the modern Niger River Delta. The partings represent vegetated tidal flat deposits that formed during periodic invasions by the sea that killed the swamp and inundated the peat with sulfate rich water. The lignite interval is capped by open lagoon and tidal flat sediments.

Vertically aligned carbon nanotube growth by pulsed laser deposition and thermal chemical vapor deposition methods

International Nuclear Information System (INIS)

Sohn, Jung Inn; Nam, Chunghee; Lee, Seonghoon

2002-01-01

We have grown vertically aligned carbon nanotubes on the various substrates such as a planar p-type Si(1 0 0) wafer, porous Si wafer, SiO 2 , Si 3 N 4 , Al 2 O 3 , and Cr by thermal chemical vapor deposition (CVD) at 800 deg.C, using C 2 H 2 gas as a carbon source and Fe catalyst films deposited by a pulsed laser on the substrates. The Fe films were deposited for 5 min by pulsed laser deposition (PLD). The advantage of Fe deposition by PLD over other deposition methods lies in the superior adhesion of Fe to a Si substrate due to high kinetic energies of the generated Fe species. Scanning electron microscopy (SEM) images show that vertically well-aligned carbon nanotubes are grown on Fe nanoparticles formed from the thermal annealing of the Fe film deposited by PLD on the various substrates. Atomic force microscopy (AFM) images show that the Fe film annealed at 800 deg.C is broken to Fe nanoparticles of 10-50 nm in size. We show that the appropriate density of Fe nanoparticles formed from the thermal annealing of the film deposited by PLD is crucial in growing vertically aligned carbon nanotubes. Using a PLD and a lift-off method, we developed the selective growth of carbon nanotubes on a patterned Fe-coated Si substrate

Present condition of uranium exploration and the prospecting direction in southwest China

International Nuclear Information System (INIS)

Ni Shijun; Zhang Chengjiang; Xu Zhengqi; Chen Youliang

2012-01-01

Southwest China is one of the important areas where uranium is distributed. After exploration and research of 50 years, the metallogenic conditions for uranium deposits in Southwest China have been studied more deeply. It is found that uranium ore in Southwest China has more complete types, less deposits and more mineral occurrences, and the amount of uranium resources is disproportionate to the area of Southwest China. Researches of years show that Southwest China is characterized by thick crust. thick sedimentary cover, weak crust-mantle interaction, weak deep flu id activity in shallow strata, strong dynamic formation in shallow strata and obvious deep geologic process on block mar- gins. In this paper, the control of deep geologic process and evolution in uranium metallogenesis in Southwest China is studied by employing new theories and thoughts on the fundamental concept that deep geologic process and evolution has important control on super-large scale deposits. The study focuses on the crust-mantle structure and evolution with uranium metallogenesis, structural and magmatic activity and deep fluid activity with uranium metallogenesis, and ore-con- trolling role of penetrating faults on block edges and inside the blocks. To offer theoretic basis for large-scale uranium deposit prospecting in Southwest China, the key research on uranium deposit in Southwest China in future should be on the deep geologic evolution and uranium metallogenesis in Western Qinling Region, the uranium metallogenesis of iron oxide copper gold deposits on Kangdian axis, the uranium metallogenesis in Yunnan-Guizhou contiguous area, the hydrothermal uranium metallogenesis in Eastern Tibet and Western Sichuan, and the connection between sandstone type uranium deposit and magmatic activity. Meanwhile, the above regions are also the key ones for uranium deposit prospecting in Southwest China in a rather long period in future. (authors)

Understanding the spectrum of diesel injector deposits

Energy Technology Data Exchange (ETDEWEB)

Quigley, Robert; Barbour, Robert [Lubrizol Limited, Derby (United Kingdom); Arters, David; Bush, Jim [Lubrizol Corporation, Wickliffe, OH (United States)

2013-06-01

Understanding the origin of diesel fuel injector deposits used to be relatively simple; for the most part they were caused by the decomposition of fuel during the combustion process, were generally organic in nature and typically only affected the nozzle orifices. However, modem fuel injector designs appear to be both more severe in terms of generating conditions conducive to creating new and different types of deposits and more likely to have their operation affected by those deposits. Changes to fuel composition and type have in some cases increased the potential pool of reactive species or provided new potential deposit precursors. As a result, the universe of diesel injector deposits now range from the traditional organic to partially or fully inorganic in nature and from nozzle coking deposits to deposits which can seize the internal components of the injector; so called internal diesel injector deposits. Frequently, combinations of inorganic and organic deposits are found. While power loss is one well known issue associated with nozzle deposits, other field problems resulting from these new deposits include severe issues with drivability, emissions, fuel consumption and even engine failure. Conventional deposit control additive chemistries were developed to be effective against organic nozzle coking deposits. These conventional additives in many cases may prove ineffective against this wide range of deposit types. This paper discusses the range of deposits that have been found to adversely impact modem diesel fuel injectors and compares the performance of conventional and new, advanced deposit control additives against these various challenges to proper fuel injector functioning. (orig.)

A Micrometeorological Perspective on Deposition

DEFF Research Database (Denmark)

Jensen, Niels Otto

1981-01-01

An expression for the dry deposition velocity is given in terms of constant flux layer scaling. Numerical values of upper bounds on the deposition velocity is given for a typical situation. Some remarks are then offered on the relative merits of various ways in which the combined diffusion-deposition...

Chemical bath deposited and dip coating deposited CuS thin films - Structure, Raman spectroscopy and surface study

Science.gov (United States)

Tailor, Jiten P.; Khimani, Ankurkumar J.; Chaki, Sunil H.

2018-05-01

The crystal structure, Raman spectroscopy and surface microtopography study on as-deposited CuS thin films were carried out. Thin films deposited by two techniques of solution growth were studied. The thin films used in the present study were deposited by chemical bath deposition (CBD) and dip coating deposition techniques. The X-ray diffraction (XRD) analysis of both the as-deposited thin films showed that both the films possess covellite phase of CuS and hexagonal unit cell structure. The determined lattice parameters of both the films are in agreement with the standard JCPDS as well as reported data. The crystallite size determined by Scherrer's equation and Hall-Williamsons relation using XRD data for both the as-deposited thin films showed that the respective values were in agreement with each other. The ambient Raman spectroscopy of both the as-deposited thin films showed major emission peaks at 474 cm-1 and a minor emmision peaks at 265 cm-1. The observed Raman peaks matched with the covellite phase of CuS. The atomic force microscopy of both the as-deposited thin films surfaces showed dip coating thin film to be less rough compared to CBD deposited thin film. All the obtained results are presented and deliberated in details.

Calcium Pyrophosphate Deposition (CPPD)

Science.gov (United States)

... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

Aerosol Deposition in Health and Disease

Science.gov (United States)

2012-01-01

Abstract The success of inhalation therapy is not only dependent upon the pharmacology of the drugs being inhaled but also upon the site and extent of deposition in the respiratory tract. This article reviews the main mechanisms affecting the transport and deposition of inhaled aerosol in the human lung. Aerosol deposition in both the healthy and diseased lung is described mainly based on the results of human studies using nonimaging techniques. This is followed by a discussion of the effect of flow regime on aerosol deposition. Finally, the link between therapeutic effects of inhaled drugs and their deposition pattern is briefly addressed. Data show that total lung deposition is a poor predictor of clinical outcome, and that regional deposition needs to be assessed to predict therapeutic effectiveness. Indeed, spatial distribution of deposited particles and, as a consequence, drug efficiency is strongly affected by particle size. Large particles (>6 μm) tend to mainly deposit in the upper airway, limiting the amount of drugs that can be delivered to the lung. Small particles (<2 μm) deposit mainly in the alveolar region and are probably the most apt to act systemically, whereas the particle in the size range 2–6 μm are be best suited to treat the central and small airways. PMID:22686623

50 CFR 259.34 - Minimum and maximum deposits; maximum time to deposit.

Science.gov (United States)

2010-10-01

... B objective. A time longer than 10 years, either by original scheduling or by subsequent extension... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE AID TO FISHERIES CAPITAL CONSTRUCTION FUND...) Minimum annual deposit. The minimum annual (based on each party's taxable year) deposit required by the...

Electrostatic Deposition of Large-Surface Graphene

Directory of Open Access Journals (Sweden)

Charles Trudeau

2018-01-01

Full Text Available This work describes a method for electrostatic deposition of graphene over a large area using controlled electrostatic exfoliation from a Highly Ordered Pyrolytic Graphite (HOPG block. Deposition over 130 × 130 µm2 with 96% coverage is achieved, which contrasts with sporadic micro-scale depositions of graphene with little control from previous works on electrostatic deposition. The deposition results are studied by Raman micro-spectroscopy and hyperspectral analysis using large fields of view to allow for the characterization of the whole deposition area. Results confirm that laser pre-patterning of the HOPG block prior to cleaving generates anchor points favoring a more homogeneous and defect-free HOPG surface, yielding larger and more uniform graphene depositions. We also demonstrate that a second patterning of the HOPG block just before exfoliation can yield features with precisely controlled geometries.

Influence of deposition parameters on morphological properties of biomedical calcium phosphate coatings prepared using electrostatic spray deposition

International Nuclear Information System (INIS)

Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Schoonman, J.; Jansen, J.A.

2005-01-01

In order to deposit biomedical calcium phosphate (CaP) coatings with a defined surface morphology, the electrostatic spray deposition (ESD) technique was used since this technique offers the possibility to deposit ceramic coatings with a variety of surface morphologies. A scanning electron microscopical study was performed in order to investigate the influence of several deposition parameters on the final morphology of the deposited coatings. The chemical characteristics of the coatings were studied by means of X-ray diffraction and Fourier-transform infrared spectroscopy. Regarding the chemical coating properties, the results showed that the coatings can be described as crystalline carbonate apatite coatings, a crystal phase which is similar to the mineral phase of bone and teeth. The morphology of CaP coatings, deposited using the ESD technique, was strongly dependent on the deposition parameters. By changing the nozzle-to-substrate distance, the precursor liquid flow rate and the deposition temperature, coating morphologies were deposited, which varied from dense to highly porous, reticular morphologies. The formation of various morphologies was the result of an equilibrium between the relative rates of CaP solute precipitation/reaction, solvent evaporation and droplet spreading onto the substrate surface

42 CFR 422.388 - Deposits.

Science.gov (United States)

2010-10-01

... to CMS. (2) The deposit must at all times have a fair market value of an amount that is 120 percent... is made; (2) The fair market value exceeds the amount of the required deposit; or (3) The required... PROGRAM MEDICARE ADVANTAGE PROGRAM Provider-Sponsored Organizations § 422.388 Deposits. (a) Insolvency...

Micromorphology of modern tills in southwestern Spitsbergen – insights into depositional and post-depositional processes

Directory of Open Access Journals (Sweden)

Skolasińska Katarzyna

2016-12-01

Full Text Available Textural properties and microstructures are commonly used properties in the analysis of Pleistocene and older glacial deposits. However, contemporary glacial deposits are seldom studied, particularly in the context of post-depositional changes. This paper presents the results of a micromorphological study of recently deposited tills in the marginal zones of Hansbreen and Torellbreen, glaciers in southwestern Spitsbergen. The main objectives of this study were to compare modern tills deposited in subglacial and supraglacial conditions, as well as tills that were freshly released from ice with those laid down several decades ago. The investigated tills are primarily composed of large clasts of metamorphic rocks and represent coarse-grained, matrix-supported diamictons. The tills reveal several characteristic features for ductile (e.g. turbate structures and brittle (e.g. lineations, microshears deformations, which have been considered to be indicative of subglacial conditions. In supraglacial tills, the same structures are common as in the subglacial deposits, which points to the preservation of the primary features, though the sediment was transferred up to the glacier surface due to basal ice layer deformation and redeposited as slumps, or to formation of similar structures due to short-distance sediment re-deposition by mass flows. This study revealed that it might not be possible to distinguish subglacial and supraglacial tills on the basis of micromorphology if the latter are derived from a subglacial position. The only noted difference was the presence of iron oxide cementation zones and carbonate dissolution features in supraglacial tills. These features were found in tills that were deposited at least a few years ago and are interpreted to be induced by early post-depositional processes involving porewater/sediment interactions.

The geology of the surrounding metamorphic rock of Zaer granite (Morocco): contribution to the search for uranium

International Nuclear Information System (INIS)

Mathias, Laurent

1984-01-01

This research thesis reports a study which aimed at reconstituting the geological history of the Zaer region in Morocco with objectives of mining exploration and of assessment of its uranium metallogenic potential. The author examined the whole geological context by studying stratigraphy, sedimentology, tectonic, and petrography of rocks belonging to the concerned area. The main objective was to determine the origin of uranium between a granitic one and a sedimentary one. This meant a reconstitution of the geological history, and therefore the study of the metamorphized sedimentary surrounding rock, of the intrusive granite and of their different possible relationships. On a first part, the author analysed outcropping formations and tried to assign them with a stratigraphic position. He also tried to define the deposition modalities of these formations which could have conditioned sedimentary sites. In a second part, the author reports the study of geological structures and tectonic in order to try to recognise possible structures which could have promoted uranium deposition and trapping in the surrounding rock as well as in granite. The last part addresses the petrography of the different rocks met in the area, and mineralization, notably that of uranium [fr

Time Resolved Deposition Measurements in NSTX

International Nuclear Information System (INIS)

Skinner, C.H.; Kugel, H.; Roquemore, A.L.; Hogan, J.; Wampler, W.R.

2004-01-01

Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 (micro)g/cm 2 of deposition, however surprisingly, 15.9 (micro)g/cm 2 of material loss occurred at 7 discharges. The net deposited mass of 13.3 (micro)g/cm 2 matched the mass of 13.5 (micro)g/cm 2 measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition

Controllable deposition of gadolinium doped ceria electrolyte films by magnetic-field-assisted electrostatic spray deposition

International Nuclear Information System (INIS)

Ksapabutr, Bussarin; Chalermkiti, Tanapol; Wongkasemjit, Sujitra; Panapoy, Manop

2013-01-01

This paper describes a simple and low-temperature approach to fabrication of dense and crack-free gadolinium doped ceria (GDC) thin films with controllable deposition by a magnetic-field-assisted electrostatic spray deposition technique. The influences of external permanent magnets on the deposition of GDC films were investigated. The coating area deposited using two magnets with the same pole arrangement decreased in comparison with the case of no magnets, whereas the largest deposition area was obtained in the system of the opposite poles. Analysis of as-deposited films at 450 °C indicated the formation of uniform, smooth and dense thin films with a single-phase fluorite structure. The films produced in the system using same poles were thicker, smaller in crystallite size and smoother than those fabricated under other conditions. Additionally, the GDC film deposited using the same pole arrangement showed the maximum in electrical conductivity of about 2.5 × 10 −2 S/cm at a low operating temperature of 500 °C. - Highlights: • Magnetic-field-assisted electrostatic spray allows a controllable coating. • Dense, crack-free thin films were obtained at low process temperature of 450 °C. • Control of deposition, thickness and uniformity is easy to achieve simultaneously. • Films from the same pole were thicker, smaller in crystal size and smoother. • The maximum conductivity of doped ceria film was 2.5 × 10 −2 S/cm at 500 °C

Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

Directory of Open Access Journals (Sweden)

H. Guan

2010-05-01

Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km² spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

Market Discipline and Deposit Insurance

OpenAIRE

Peresetsky, Anatoly

2008-01-01

The paper examines Russian banks’ household deposit interest rates for the transition period of setting up the deposit insurance system. Monthly observations of Russian banks’ interest rates and balance sheets are used in a fixed effects panel data model. It is shown market discipline has been significantly diminished after switching to the deposit insurance.

Restoration of uranium solution mining deposits

International Nuclear Information System (INIS)

Devries, F.W.; Lawes, B.C.

1982-01-01

A process is provided for restoring an ore deposit after uranium solution mining using ammonium carbonate leaching solutions has ceased. The process involves flushing the deposit with an aqueous solution of a potassium salt during which potassium ions exchange with ammonium ions remaining in the deposit. The ammonium containing flushing solution is withdrawn from the deposit for disposal

Restoration of uranium solution mining deposits

Energy Technology Data Exchange (ETDEWEB)

Devries, F.W.; Lawes, B.C.

1982-01-19

A process is provided for restoring an ore deposit after uranium solution mining using ammonium carbonate leaching solutions has ceased. The process involves flushing the deposit with an aqueous solution of a potassium salt during which potassium ions exchange with ammonium ions remaining in the deposit. The ammonium containing flushing solution is withdrawn from the deposit for disposal.

Legal Deposit of Electronic Publications

Directory of Open Access Journals (Sweden)

Burcu Umut Zan

2009-06-01

Full Text Available The most important and basic role of the deposition studies, which are the greatest contributions to the knowledge sharing, is to gather the artistic and philosophical works of a country and provide them for the use of future researchers. However, since early deposition studies were limited with printed publications, they do not involve the electronic publication types appearing with the development of information technology. This stems from the fact that the electronic publications require procedures different from those of the printed publications in terms of deposition steps because of their structures. Today, in order to guarantee that all registered cultural products, which are mostly produced and used in the electronic environment could be fully collected, electronic publications should also be covered by and regulated under legal deposit. This study analyzes the deposition of electronic publications, within the framework of their storage and protection, being put in the use of the users as well as the common approaches to deposition practices in the world parallel to the developments in the information technology. The related situation in Turkey was also evaluated.

A radon progeny deposition model

International Nuclear Information System (INIS)

Rielage, Keith; Elliott, Steven R.; Hime, Andrew; Guiseppe, Vincent E.; Westerdale, S.

2010-01-01

The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of 210 Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

A Radon Progeny Deposition Model

International Nuclear Information System (INIS)

Guiseppe, V. E.; Elliott, S. R.; Hime, A.; Rielage, K.; Westerdale, S.

2011-01-01

The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of 210 Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

Deposition and Resuspension of Particles

DEFF Research Database (Denmark)

Lengweiler, P.; Nielsen, Peter V.; Moser, A.

A new experimental set-up to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airBorne dust concentration considerably. As a basis for developing methods to eliminate dust related problems in rooms......, there is a need for better understanding of the mechanism of dust deposition and resuspension....

Felsic magmatism and uranium deposits

International Nuclear Information System (INIS)

Cuney, M.

2014-01-01

Uranium strongly incompatible behaviour in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behaviour, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth which crystallized uraninite appeared at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: peralkaline, high-K metaluminous calc-alkaline, L-type peraluminous ones and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass in their volcanic equivalents represent the best U source. Peralkaline granites or syenites represent the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction at the present economic conditions and make them unfavourable U sources for other deposit types. By contrast, felsic peralkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals [U-thorite, allanite, Nb oxides] become metamict. The volcanic rocks of the same geochemistry may be also a

A remote coal deposit revisited

DEFF Research Database (Denmark)

Bojesen-Kofoed, Jørgen A.; Kalkreuth, Wolfgang; Petersen, Henrik I.

2012-01-01

discovery. The outcrops found in 2009 amount to approximately 8 m of sediment including a coal seam of 2 m thickness. More outcrops and additional coal deposits most certainly are to be found, pending further fieldwork. The deposits are Middle Jurassic, Callovian, in age and were deposited in a floodplain...... environment related to meandering river channels. Spores and pollen in the lower fluvial deposits reflect abundant vegetation of ferns along the river banks. In contrast, a sparse spore and pollen flora in the coals show a mixed vegetation of ferns and gymnosperms. Based on proximate and petrographic analyses...

Particle deposition in ventilation ducts

Energy Technology Data Exchange (ETDEWEB)

Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)

2002-09-01

Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 μm were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the

FDIC Summary of Deposits (SOD) Download File

Data.gov (United States)

Federal Deposit Insurance Corporation — The FDIC's Summary of Deposits (SOD) download file contains deposit data for branches and offices of all FDIC-insured institutions. The Federal Deposit Insurance...

Electronic properties of p-GaAs deposited on n-Si with pulsed-laser deposition

International Nuclear Information System (INIS)

Ullrich, B; Erlacher, A; Smith, H E; Mitchel, W C; Brown, G J

2008-01-01

By means of nanosecond laser pulses at 355, 532, and 1064 nm, p(Zn)-type GaAs was ablated and deposited on n-type Si. The samples showed rectification and Hall measurements established that the deposited material was p-type, but the active-doping concentration was six orders of magnitude below the target value. Because secondary-ion mass spectroscopy results indicated stoichiometric material transfer, we concluded that most of the Zn atoms do not act as acceptors because of the amorphous film texture. The work further showed indications that pulsed-laser deposition at 355 nm causes enhanced Si diffusion into the deposited film, compared to the ablations done at 532 and 1064 nm

Characterization of fluid inclusions and sulfur isotopes in the Iju porphyry copper deposit, North West of Shahr-e-Babak

Directory of Open Access Journals (Sweden)

Malihe Golestani

2017-07-01

chemical composition and under different temperature and pressure conditions (Rusk and Reed, 2008. The wide range in fluid inclusions data of the Iju deposit can be justified by physicochemical changes in the fluid as it is boiling and mixing with the surface fluids. Cooling, fluids mixing, boiling and fluid-rock reaction play important roles in the settling of chalcopyrite from the hydrothermal fluid and the dilution of saline ore-bearing fluids can cause the formation of copper ores from the ore-bearing fluid (Ulrich et al., 2002. Pyrite δ34S value ranges from -0.86 to +1.27‰ (average, +0.22‰ and the δ34SH2S value of the syngenetic fluid with pyrite ranges from -0.23 to -2.36‰ (average, -1.17‰. The limited and near zero range that is observed about δ34S value of the sulfur minerals indicates the controlling role of magmatic processes in the mineralization events (Chen et al., 2009. Acknowledgments This article is related to Project No. 27124.3 dated 2015, 2, 7 at the Ferdowsi University of Mashhad. We are thankful to and appreciate the Research and Development center of National Iranian Cu Industries (Shahr-e-Babak, Meiduk, especially S.M. Mousavi, for the financial support of this project and the necessary proceedings. References Chen, Y.J., Piranjno, F., Li, N., Guo, D.Sh. and Lai, Y., 2009. Isotope systematica and fluid inclusion studies of the Qiyugou breccia pipe- hosted gold deposit, Qinling Orogen, Henan province, China: Implication for ore genesis. Ore Geology Reviews, 35(2: 245-261. Dimitrijevic, M.D., 1973. Geology of Kerman region. Geological Survey of Iran, Tehran, Report No. Yu/52, 334 pp. Hassanzadeh, J., 1993. Metallogenic and tectonomagmatic events in the SE sector of the Cenozoic active continental margin of central Iran (Shahr e Babak area, Keman Province. Ph.D. thesis, University of California, Los Angeles, America, 204 pp. Rusk, B.G. and Reed, M.H., 2008. Fluid inclusion evidence for magmatic-hydrothermal fluid evolution in the porphyry

Comparison of stress in single and multiple layer depositions of plasma-deposited amorphous silicon dioxide

International Nuclear Information System (INIS)

Au, V; Charles, C; Boswell, R W

2006-01-01

The stress in a single-layer continuous deposition of amorphous silicon dioxide (SiO 2 ) film is compared with the stress within multiple-layer intermittent or 'stop-start' depositions. The films were deposited by helicon activated reactive evaporation (plasma assisted deposition with electron beam evaporation source) to a 1 μm total film thickness. The relationships for stress as a function of film thickness for single, two, four and eight layer depositions have been obtained by employing the substrate curvature technique on a post-deposition etch-back of the SiO 2 film. At film thicknesses of less than 300 nm, the stress-thickness relationships clearly show an increase in stress in the multiple-layer samples compared with the relationship for the single-layer film. By comparison, there is little variation in the film stress between the samples when it is measured at 1 μm film thickness. Localized variations in stress were not observed in the regions where the 'stop-start' depositions occurred. The experimental results are interpreted as a possible indication of the presence of unstable, strained Si-O-Si bonds in the amorphous SiO 2 film. It is proposed that the subsequent introduction of a 'stop-start' deposition process places additional strain on these bonds to affect the film structure. The experimental stress-thickness relationships were reproduced independently by assuming a linear relationship between the measured bow and film thickness. The constants of the linear model are interpreted as an indication of the density of the amorphous film structure

Uraniferous surficial deposits in Southern Africa

International Nuclear Information System (INIS)

Hambleton-Jones, B.B.; Levin, M.; Wagener, G.F.

1986-01-01

Surficial uranium deposits are located in the north-western Cape Province of South Africa, in the Namib Desert east of Walvis Bay in South West Africa/Namibia and in the Serule Block of Botswana. They have been classified into the valley-fill, lacustrine, and pedogenic types. Carnotite is the main uranium-bearing mineral in the larger surficial deposits, with other minerals such as soddyite and phosphuranylite occurring locally. Uraninite or urano-organic complexes occur in the reducing environments of the diatomaceous earth, peat-rich deposits. Economically, the valley-fill type is the most important, with the largest deposits occurring in South West Africa/Namibia. In South West Africa/Namibia the valley-fill surficial uranium deposits occur in the Tumas and Langer Heinrich formations of the Teriary to Recent Namib Group. The Tubas, Langer Heinrich, and Welwitchia deposits are discussed: in them, carnotite occurs in calcareous and gypsiferous fluvial gravels. The pedogenic deposit at Mile 72 occurs in weathered granite and overlying gypcrete and has little economic potential. The economic potential of the surficial deposits in the north-western Cape Province is very limited in comparison with their South West African/Namibian counterparts, but the most important deposits are the lacustrine type, in particular those containing peat and diatomaceous earth. The mechanisms for the precipitation and preservation of the uranium are discussed

Hideout in steam generator tube deposits

International Nuclear Information System (INIS)

Balakrishnan, P.V.; Franklin, K.J.; Turner, C.W.

1998-05-01

Hideout in deposits on steam generator tubes was studied using tubes coated with magnetite. Hideout from sodium chloride solutions at 279 degrees C was followed using an on-line high-temperature conductivity probe, as well as by chemical analysis of solution samples from the autoclave in which the studies were done. Significant hideout was observed only at a heat flux greater than 200 kW/m 2 , corresponding to a temperature drop greater than 2 degrees C across the deposits. The concentration factor resulting from the hideout increased highly non-linearly with the heat flux (varying as high as the fourth power of the heat flux). The decrease in the apparent concentration factor with increasing deposit thickness suggested that the pores in the deposit were occupied by a mixture of steam and water, which is consistent with the conclusion from the thermal conductivity measurements on deposits in a separate study. Analyses of the deposits after the hideout tests showed no evidence of any hidden-out solute species, probably due to the concentrations being very near the detection limits and to their escape from the deposit as the tests were being ended. This study showed that hideout in deposits may concentrate solutes in the steam generator bulk water by a factor as high as 2 x 10 3 . Corrosion was evident under the deposit in some tests, with some chromium enrichment on the surface of the tube. Chromium enrichment usually indicates an acidic environment, but the mobility required of chromium to become incorporated into the thick magnetite deposit may indicate corrosion under an alkaline environment. An alkaline environment could result from preferential accumulation of sodium in the solution in the deposit during the hideout process. (author)

Spatial atomic layer deposition: a route towards further industrialization of atomic layer deposition

NARCIS (Netherlands)

Poodt, P.; Cameron, D.C.; Dickey, E.; George, S.M.; Kuznetsov, Vladimir; Parsons, G.N.; Roozeboom, F.; Sundaram, G.; Vermeer, A.

2012-01-01

Spatial atomic layer deposition can be used as a high-throughput manufacturing technique in functional thin film deposition for applications such as flexible electronics. This; however, requires low-temperature processing and handling of flexible substrates. The authors investigate the process

The effect of fog on radionuclide deposition velocities

International Nuclear Information System (INIS)

Gibb, R.; Carson, P.; Thompson, W.

1997-01-01

Current nuclear power station release models do not evaluate deposition under foggy atmospheric conditions. Deposition velocities and scavenging coefficients of radioactive particles entrained in fog are presented for the Point Lepreau area of the Bay of Fundy coast. It is recommended to calculate deposition based on fog deposition velocities. The deposition velocities can be calculated from common meteorological data. The range of deposition velocities is approximately 1 - 100 cm/s. Fog deposition is surface roughness dependent with forests having larger deposition and deposition velocities than soil or grasses. (author)

Influence of the deposition geometry on the microstructure of sputter-deposited V-Al-C-N coatings

Energy Technology Data Exchange (ETDEWEB)

Darma, Susan; Krause, Baerbel; Doyle, Stephen; Mangold, Stefan; Baumbach, Tilo [ISS, Karlsruher Institut fuer Technologie (Germany); Ulrich, Sven; Stueber, Michael [IAM-AWP, Karlsruher Institut fuer Technologie (Germany)

2012-07-01

Multi-element hard coating materials such as V-Al-C-N are of great interest for many technological applications. Their mechanical properties depend on the composition and microstructure of the coating. In order to determine the optimum composition and deposition conditions of these complex materials, many samples are required. One powerful tool for reducing the number of experiments is based on the so-called combinatorial approach for thin film deposition: many different thin film samples can be realized simultaneously, exploiting the deposition gradient resulting from codeposition of several materials. We will present an X-ray diffraction study of the influence of the deposition geometry on the microstructure of V-Al-C-N coatings. The films were deposited by reactive RF magnetron sputtering from a segmented target composed of AlN and VC. Synchrotron radiation measurements where performed at the beamline PDIFF at ANKA. Significant texture changes were observed which can be attributed to the deposition geometry, as verified by calculations of the flux distribution. We conclude that codeposition can accelerate significantly the screening of new materials, under the condition that the desired property is not significantly influenced by the microstructural changes due to the deposition geometry.

Electroless atomic layer deposition

Science.gov (United States)

Robinson, David Bruce; Cappillino, Patrick J.; Sheridan, Leah B.; Stickney, John L.; Benson, David M.

2017-10-31

A method of electroless atomic layer deposition is described. The method electrolessly generates a layer of sacrificial material on a surface of a first material. The method adds doses of a solution of a second material to the substrate. The method performs a galvanic exchange reaction to oxidize away the layer of the sacrificial material and deposit a layer of the second material on the surface of the first material. The method can be repeated for a plurality of iterations in order to deposit a desired thickness of the second material on the surface of the first material.

Felsic magmatism and uranium deposits

International Nuclear Information System (INIS)

Cuney, Michel

2014-01-01

The strongly incompatible behaviour of uranium in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behavior, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth, which crystallized uraninite, dated at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: per-alkaline, high-K met-aluminous calc-alkaline, L-type peraluminous and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass of their volcanic equivalents represent the best U source. Per-alkaline granites or syenites are associated with the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction under the present economic conditions and make them unfavorable U sources for other deposit types. By contrast, felsic per-alkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals (U-thorite, allanite, Nb oxides) become metamict. The volcanic rocks of the same geochemistry may be

Vein-type uranium deposits

International Nuclear Information System (INIS)

Rich, R.A.; Holland, H.D.; Petersen, U.

1975-01-01

A critical review is presented of published data bearing on the mineralogy, paragenesis, geochemistry, and origin of veiw-type uranium deposits. Its aim is to serve as a starting point for new research and as a basis for the development of new exploration strategies. During the formation of both vein and sandstone types of deposits uranium seems to have been dissolved by and transported in rather oxidized solutions, and deposited where these solutions encountered reducing agents such as carbon, sulfides, ferrous minerals and hydrocarbons. Granitic rocks abnormally enriched in uranium have apparently been the most common source for uranium in vein-type deposits. Oxidizing solutions have been derived either from the surface or from depth. Surface solutions saturated with atmospheric oxygen have frequently passed through red bed or clean sandstone conduits on their way to and from uranium source rocks. Deep solutions of non-surface origin have apparently become sufficiently oxidizing by passage through and equilibration with red beds. The common association of clean sandstones or red beds with uranium-rich granites in the vicinity of vein-type uranium deposits is probably not fortuitous, and areas where these rock types are found together are considered particularly favorable targets for uranium exploration

Electrochemical deposition and characterization of zinc–nickel alloys deposited by direct and reverse current

Directory of Open Access Journals (Sweden)

JELENA B. BAJAT

2005-12-01

Full Text Available Zn–Ni alloys electrochemically deposited on steel under various deposition conditions were investigated. The alloys were deposited on a rotating disc electrode and on a steel panel from chloride solutions by direct and reverse current. The influence of reverse plating variables (cathodic and anodic current densities and their time duration on the composition, phase structure and corrosion properties were investigated. The chemical content and phase composition affect the anticorrosive properties of Zn–Ni alloys during exposure to a corrosive agent (3 % NaCl solution. It was shown that the Zn–Ni alloy electrodeposited by reverse current with a full period T = 1 s and r = 0.2 exhibits the best corrosion properties of all the investigated alloys deposited by reverse current.

Effects of deposition period on the chemical bath deposited Cu4SnS4 thin films

International Nuclear Information System (INIS)

Kassim, Anuar; Wee Tee, Tan; Soon Min, Ho.; Nagalingam, Saravanan

2010-01-01

Cu 4 SnS 4 thin films were prepared by simple chemical bath deposition technique. The influence of deposition period on the structural, morphological and optical properties of films was studied. The films were characterized using X-ray diffraction, atomic force microscopy and UV-Vis Spectrophotometer. X-ray diffraction patterns indicated that the films were polycrystalline with prominent peak attributed to (221) plane of orthorhombic crystal structure. The films prepared at 80 min showed significant increased in the intensity of all diffractions. According to AFM images, these films indicated that the surface of substrate was covered completely. The obtained films also produced higher absorption characteristics when compared to the films prepared at other deposition periods based on optical absorption studies. The band gap values of films deposited at different deposition periods were in the range of 1.6-2.1 eV. Deposition for 80 min was found to be the optimum condition to produce good quality thin films under the current conditions. (author).

The anthracite of Nazar-Aylok Deposit

International Nuclear Information System (INIS)

Pachadzhanov, D.N.; Valiev, Yu.Ya.

2013-01-01

Present article is devoted to anthracite of Nazar-Aylok Deposit. The ash content, composition of coals of Nazar-Aylok Deposit and thickness of deposit were considered. The coal samples were studied by means of neutron activation analysis.

Analysis on geological setting of uranium mineralization and prospecting strategy in Lujing area, Hunan province

International Nuclear Information System (INIS)

Huang Hongye; Huang Sidong; Cai Songfeng

2008-01-01

Lujing area is an important uranium metallogenic zone in China. Based on summarizing the geological background of Lujing uranium ore-field, it is analyzed that deep origin metallogenesis, deep-seated strike-slip faults, thermal metamorphic belt and granite-porphyry play important roles in uranium mineralizatiom. It is pointed out that the NNE to NE-trending Suichuan-Reshui left-handed strike-slip fault controls directly the sedimentary characteristics, tectonic framework and uranium metallogenesis. For the discovered deposits and occurrences, it needs to study in the view of deep origin metallogenesis and ore-control by deep-seated strike-slip fault, do more further research on their evolutionary features and coupling types. It also needs to explore new types, discover new favorable area, predict and optimize the break-through prospecting target so as to make scientific assesment on the uranium resources potentialities of the ore-field and its peripheral area. (authors)

Surface deposition from radioactive plumes

International Nuclear Information System (INIS)

Garland, J.A.

1980-01-01

Accidents involving nuclear plants may release radioactive particles and gases to the atmosphere. Dry deposition of particles has been investigated mainly in the laboratory and a general understanding of the transfer mechanisms has been established. However there is apparently a substantial discrepancy between the few field observations of dry deposition of particles and laboratory measurements, particularly for 0.1 - 1 μm particles for which laboratory work shows very small deposition rates. In addition there are few estimates of deposition rates for forest and some other kinds of terrain. The most important gas in the context of a nuclear accident is I-131 and the behaviour of this gas at grass surfaces has received much attention. However smaller quantities of other gases and vapours may be released and the surface absorption of these species may require further investigation. In addition there is little knowledge of the behaviour of gases over many types of surface. The rate of deposition of particles and gases is influenced by many parameters including wind speed and the temperature stratification of the lower atmosphere. Conditions which give poor atmospheric dispersion usually give lower deposition velocities. Transfer to man depends on the availability of deposited materials on crops and grass. A wide range of isotopes including iodine and several metallic fission products are lost with a half life for residence on grass ranging from a few days to a few tens days, depending on climatic conditions

Urban acid deposition in Greater Manchester

Energy Technology Data Exchange (ETDEWEB)

Lee, D.S.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E. (Manchester Polytechnic, Manchester (UK). Acid Rain Information Centre)

1989-08-01

Data are presented from a monitoring network of 18 bulk precipitation collectors and one wet-only collector in the urban area of Greater Manchester, in the north west of England. Weekly samples were analysed for all the major ions in precipitation along with gaseous nitrogen dioxide concentrations from diffusion tubes. Statistical analysis of the data shows significant spatial variation of non marine sulphate, nitrate, ammonium, acidity and calcium concentrations, and nitrogen dioxide concentrations. Calcium is thought to be responsible for the buffering of acidity and is of local origin. Wet deposition is the likely removal process for calcium in the atmosphere and probably by below cloud scavenging. Nitrate and ammonium concentrations and depositions show close spatial, temporal and statistical association. Examination of high simultaneous episodes of nitrate and ammonium deposition shows that these depositions cannot be explained in terms of trajectories and it is suggested that UK emissions of ammonia may be important. Statistical analysis of the relationships between nitrate and ammonium depositions, concentrations and precipitation amount suggest that ammonia from mesoscale sources reacts reversibly with nitric acid aerosol and is removed by below cloud scavenging. High episodes of the deposition of non marine sulphate are difficult to explain by trajectory analysis alone, perhaps suggesting local sources. In a comparison between wet deposition and bulk deposition, it was shown that only 15.2% of the non marine sulphur was dry deposited to the bulk precipitation collector. 63 refs., 86 figs., 31 tabs.

Deposition of acidifying compounds

International Nuclear Information System (INIS)

Fowler, D.; Cape, J.N.; Sutton, M.A.; Mourne, R.; Hargreaves, K.J.; Duyzer, J.H.; Gallagher, M.W.

1992-01-01

Inputs of acidifying compounds to terrestrial ecosystems include deposition of the gases NO 2 , NO, HNO 2 , HNO 3 , NH 3 and SO 2 and the ions NO 3- , NH 4+ , SO 4 2- and H + in precipitation, cloud droplets and particles. Recent research has identified particular ecosystems and regions in which terrestrial effects are closely linked with specific deposition processes. This review paper identifies areas in which important developments have occurred during the last five years and attempts to show which aspects of the subject are most important for policy makers. Amongst the conclusions drawn, the authors advise that current uncertainties in estimates of S and N inputs by dry deposition should be incorporated in critical load calculations, and that, in regions dominated by wet deposition, spatial resolution of total inputs should be improved to match the current scales of information on landscape sensitivity to acidic inputs. 44 refs., 9 figs

Carbonaceous deposits on naptha reforming catalysts

International Nuclear Information System (INIS)

Redwan, D.S.

1999-01-01

Carbonaceous deposits on naphtha reforming catalysts play a decisive role in limiting process performance. The deposits negatively after catalyst activity, selectivity and the production cycle of a semi regenerative reformer. The magnitude of negative effect of those deposits is directly proportional to their amounts and complexity. Investigations on used reforming catalysts samples reveal that the amount and type (complexity of the chemical nature) of carbonaceous deposits are directly proportional to the catalysts life on stream and the severity of operating conditions. In addition, the combustibility behavior of carbonaceous deposits on the catalyst samples taken from different reformers are found to be different. Optimal carbon removal, for in situ catalyst regeneration, requires the specific conditions be developed, based on the results of well designed and properly performed investigations of the amount and type of carbonaceous deposits. (author)

Influence of deposition time on the properties of chemical bath deposited manganese sulfide thin films

Directory of Open Access Journals (Sweden)

Anuar Kassim

2010-12-01

Full Text Available Manganese sulfide thin films were chemically deposited from an aqueous solution containing manganese sulfate, sodium thiosulfate and sodium tartrate. The influence of deposition time (2, 3, 6 and 8 days on the properties of thin films was investigated. The structure and surface morphology of the thin films were studied by X-ray diffraction and atomic force microscopy, respectively. In addition, in order to investigate the optical properties of the thin films, the UV-visible spectrophotometry was used. The XRD results indicated that the deposited MnS2 thin films exhibited a polycrystalline cubic structure. The number of MnS2 peaks on the XRD patterns initially increased from three to six peaks and then decreased to five peaks, as the deposition time was increased from 2 to 8 days. From the AFM measurements, the film thickness and surface roughness were found to be dependent on the deposition time.

Mathematical geology studies of deposit prospect types

International Nuclear Information System (INIS)

Liu Guangping

1998-08-01

Exact certainty prospect type of uranium deposit, not only can assure the quality of deposit prospects, but also increase economic benefits. Based on the standard of geological prospect of uranium deposit, the author introduces a method of Fuzzy Synthetical Comment for dividing prospect type of uranium deposit. The practical applications demonstrate that the regression accuracy, discriminated by Zadeh operator, of 15 known deposits is 100%

Matrix shaped pulsed laser deposition: New approach to large area and homogeneous deposition

Energy Technology Data Exchange (ETDEWEB)

Akkan, C.K.; May, A. [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany); Hammadeh, M. [Department for Obstetrics, Gynecology and Reproductive Medicine, IVF Laboratory, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Abdul-Khaliq, H. [Clinic for Pediatric Cardiology, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Aktas, O.C., E-mail: cenk.aktas@inm-gmbh.de [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany)

2014-05-01

Pulsed laser deposition (PLD) is one of the well-established physical vapor deposition methods used for synthesis of ultra-thin layers. Especially PLD is suitable for the preparation of thin films of complex alloys and ceramics where the conservation of the stoichiometry is critical. Beside several advantages of PLD, inhomogeneity in thickness limits use of PLD in some applications. There are several approaches such as rotation of the substrate or scanning of the laser beam over the target to achieve homogenous layers. On the other hand movement and transition create further complexity in process parameters. Here we present a new approach which we call Matrix Shaped PLD to control the thickness and homogeneity of deposited layers precisely. This new approach is based on shaping of the incoming laser beam by a microlens array and a Fourier lens. The beam is split into much smaller multi-beam array over the target and this leads to a homogenous plasma formation. The uniform intensity distribution over the target yields a very uniform deposit on the substrate. This approach is used to deposit carbide and oxide thin films for biomedical applications. As a case study coating of a stent which has a complex geometry is presented briefly.

Roughness evolution in Ga doped ZnO films deposited by pulsed laser deposition

International Nuclear Information System (INIS)

Liu Yunyan; Cheng Chuanfu; Yang Shanying; Song Hongsheng; Wei Gongxiang; Xue Chengshan; Wang Yongzai

2011-01-01

We analyze the morphology evolution of the Ga doped ZnO(GZO) films deposited on quartz substrates by a laser deposition system. The surface morphologies of the film samples grown with different times are measured by the atomic force microscope, and they are analyzed quantitatively by using the image data. In the initial stage of the growth time shorter than 8 min, our analysis shows that the GZO surface morphologies are influenced by such factors as the random fluctuations, the smoothening effects in the deposition, the lateral strain and the substrate. The interface width uw(t) and the lateral correlation length ξ(t) at first decrease with deposition time t. For the growth time larger than 8 min, w(t) and ξ(t) increase with time and it indicates the roughening of the surface and the surface morphology exhibits the fractal characteristics. By fitting data of the roughness w(t) versus deposition time t larger than 4 min to the power-law function, we obtain the growth exponent β is 0.3; and by the height-height correlation functions of the samples to that of the self-affine fractal model, we obtain the value of roughness exponent α about 0.84 for all samples with different growth time t.

The structural properties of CdS deposited by chemical bath deposition and pulsed direct current magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bass, K.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)

2015-05-01

Cadmium sulphide (CdS) thin films were deposited by two different processes, chemical bath deposition (CBD), and pulsed DC magnetron sputtering (PDCMS) on fluorine doped-tin oxide coated glass to assess the potential advantages of the pulsed DC magnetron sputtering process. The structural, optical and morphological properties of films obtained by CBD and PDCMS were investigated using X-ray photoelectron spectroscopy, X-ray diffraction, scanning and transmission electron microscopy, spectroscopic ellipsometry and UV-Vis spectrophotometry. The as-grown films were studied and comparisons were drawn between their morphology, uniformity, crystallinity, and the deposition rate of the process. The highest crystallinity is observed for sputtered CdS thin films. The absorption in the visible wavelength increased for PDCMS CdS thin films, due to the higher density of the films. The band gap measured for the as-grown CBD-CdS is 2.38 eV compared to 2.34 eV for PDCMS-CdS, confirming the higher density of the sputtered thin film. The higher deposition rate for PDCMS is a significant advantage of this technique which has potential use for high rate and low cost manufacturing. - Highlights: • Pulsed DC magnetron sputtering (PDCMS) of CdS films • Chemical bath deposition of CdS films • Comparison between CdS thin films deposited by chemical bath and PDCMS techniques • High deposition rate deposition for PDCMS deposition • Uniform, pinhole free CdS thin films.

The structural properties of CdS deposited by chemical bath deposition and pulsed direct current magnetron sputtering

International Nuclear Information System (INIS)

Lisco, F.; Kaminski, P.M.; Abbas, A.; Bass, K.; Bowers, J.W.; Claudio, G.; Losurdo, M.; Walls, J.M.

2015-01-01

Cadmium sulphide (CdS) thin films were deposited by two different processes, chemical bath deposition (CBD), and pulsed DC magnetron sputtering (PDCMS) on fluorine doped-tin oxide coated glass to assess the potential advantages of the pulsed DC magnetron sputtering process. The structural, optical and morphological properties of films obtained by CBD and PDCMS were investigated using X-ray photoelectron spectroscopy, X-ray diffraction, scanning and transmission electron microscopy, spectroscopic ellipsometry and UV-Vis spectrophotometry. The as-grown films were studied and comparisons were drawn between their morphology, uniformity, crystallinity, and the deposition rate of the process. The highest crystallinity is observed for sputtered CdS thin films. The absorption in the visible wavelength increased for PDCMS CdS thin films, due to the higher density of the films. The band gap measured for the as-grown CBD-CdS is 2.38 eV compared to 2.34 eV for PDCMS-CdS, confirming the higher density of the sputtered thin film. The higher deposition rate for PDCMS is a significant advantage of this technique which has potential use for high rate and low cost manufacturing. - Highlights: • Pulsed DC magnetron sputtering (PDCMS) of CdS films • Chemical bath deposition of CdS films • Comparison between CdS thin films deposited by chemical bath and PDCMS techniques • High deposition rate deposition for PDCMS deposition • Uniform, pinhole free CdS thin films

Influence of deposition rate on the properties of tin coatings deposited on tool steels using arc method

International Nuclear Information System (INIS)

Akhtar, P.; Abbas, M.

2007-01-01

Titanium nitride (TiN) widely used as hard coating material, was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapour deposition method. The study concentrated on cathodic arc physical vapour deposition (CAPVD), a technique used for the deposition of hard coatings for tooling applications, and which has many advantages. The main drawback of this technique, however, is the formation of macrodroplets (MD's) during deposition, resulting in films with rougher morphology. Various standard characterization techniques and equipment, such as electron microscopy, atomic force microscopy, hardness testing machine, scratch tester and pin-on-disc machine, were used to analyze and quantify the following properties and parameters, surface morphology, thickness, hardness, adhesion and coefficient of friction (COF) of the deposited coatings. Surface morphology revealed that the MD's produced during the etching stage, protruded through the thin film, resulting in film with deteriorated surface features. Both coating thickness and indentation loads influenced the hardness of the deposited coatings. The coatings deposited on HSS exhibit better adhesion compared to those on D2 tool steel. Standard deviation indicates that the coating deposited with thickness around 6.7 macro m showed the most stable trend of COF versus sliding distance. (author)

Ultraviolet optical properties of aluminum fluoride thin films deposited by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Hennessy, John, E-mail: john.j.hennessy@jpl.nasa.gov; Jewell, April D.; Balasubramanian, Kunjithapatham; Nikzad, Shouleh [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

2016-01-15

Aluminum fluoride (AlF{sub 3}) is a low refractive index material with promising optical applications for ultraviolet (UV) wavelengths. An atomic layer deposition process using trimethylaluminum and anhydrous hydrogen fluoride has been developed for the deposition of AlF{sub 3} at substrate temperatures between 100 and 200 °C. This low temperature process has resulted in thin films with UV-optical properties that have been characterized by ellipsometric and reflection/transmission measurements at wavelengths down to 200 nm. The optical loss for 93 nm thick films deposited at 100 °C was measured to be less than 0.2% from visible wavelengths down to 200 nm, and additional microstructural characterization demonstrates that the films are amorphous with moderate tensile stress of 42–105 MPa as deposited on silicon substrates. X-ray photoelectron spectroscopy analysis shows no signature of residual aluminum oxide components making these films good candidates for a variety of applications at even shorter UV wavelengths.

Post-deposition treatments of plasma-sprayed YBaCuO coatings deposited on nickel

Energy Technology Data Exchange (ETDEWEB)

Dube, D; Lambert, P; Arsenault, B; Champagne, B [National Research Council of Canada, Boucherville, PQ (Canada)

1990-12-15

As-sprayed YBaCuO coatings do not exhibit superconductivity because of the non-equilibrium solidification conditions of molten particles on the substrate and to the deposit's loss of oxygen. Therefore post-deposition treatments are required to restore the superconductivity. In this study, post-deposition treatments were carried out on thick YBaCuO coatings (200 {mu}m) deposited on cold nickel substrates to modify their microstructure, to restore the oxygen content and to improve their superconducting properties. These treatments consist in heating the coatings at various temperatures above 950deg C followed by controlled solidification cycles. The effect of these treatments on the microstructure of the coatings was assessed and the interaction between the coatings and the nickel substrate was also examined. Solidification cycles including a low cooling rate near the non-congruent melting temperature of YBa{sub 2}Cu{sub 3}O{sub x} and involving a temperature gradient were carried out to create a texture. (orig.).

Dry deposition fluxes and deposition velocities of trace metals in the Tokyo metropolitan area measured with a water surface sampler.

Science.gov (United States)

Sakata, Masahiro; Marumoto, Kohji

2004-04-01

Dry deposition fluxes and deposition velocities (=deposition flux/atmospheric concentration) for trace metals including Hg, Cd, Cu, Mn, Pb, and Zn in the Tokyo metropolitan area were measured using an improved water surface sampler. Mercury is deposited on the water surface in both gaseous (reactive gaseous mercury, RGM) and particulate (particulate mercury, Hg(p)) forms. The results based on 1 yr observations found that dry deposition plays a significant if not dominant role in trace metal deposition in this urban area, contributing fluxes ranging from 0.46 (Cd) to 3.0 (Zn) times those of concurrent wet deposition fluxes. The deposition velocities were found to be dependent on the deposition of coarse particles larger than approximately 5 microm in diameter on the basis of model calculations. Our analysis suggests that the 84.13% diameter is a more appropriate index for each deposited metal than the 50% diameter in the assumed undersize log-normal distribution, because larger particles are responsible for the flux. The deposition velocities for trace metals other than mercury increased exponentially with an increase in their 84.13% diameters. Using this regression equation, the deposition velocities for Hg(p) were estimated from its 84.13% diameter. The deposition fluxes for Hg(p) calculated from the estimated velocities tended to be close to the mercury fluxes measured with the water surface sampler during the study periods except during summer.

Vapor deposition of tantalum and tantalum compounds

International Nuclear Information System (INIS)

Trkula, M.

1996-01-01

Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

Litterfall mercury dry deposition in the eastern USA

International Nuclear Information System (INIS)

Risch, Martin R.; DeWild, John F.; Krabbenhoft, David P.; Kolka, Randall K.; Zhang, Leiming

2012-01-01

Mercury (Hg) in autumn litterfall from predominately deciduous forests was measured in 3 years of samples from 23 Mercury Deposition Network sites in 15 states across the eastern USA. Annual litterfall Hg dry deposition was significantly higher (median 12.3 micrograms per square meter (μg/m 2 ), range 3.5–23.4 μg/m 2 ) than annual Hg wet deposition (median 9.6 μg/m 2 , range 4.4–19.7 μg/m 2 ). The mean ratio of dry to wet Hg deposition was 1.3–1. The sum of dry and wet Hg deposition averaged 21 μg/m 2 per year and 55% was litterfall dry deposition. Methylmercury was a median 0.8% of Hg in litterfall and ranged from 0.6 to 1.5%. Annual litterfall Hg and wet Hg deposition rates differed significantly and were weakly correlated. Litterfall Hg dry deposition differed among forest-cover types. This study demonstrated how annual litterfall Hg dry deposition rates approximate the lower bound of annual Hg dry fluxes. - Highlights: ► Annual litterfall mercury dry deposition was significantly higher than wet deposition. ► The mean ratio of dry to wet mercury deposition was 1.3–1. ► The sum of dry and wet mercury deposition averaged 55% litterfall dry deposition. ► Litterfall mercury deposition was highest in the oak-hickory forest-cover type. ► Methylmercury was a median 0.8% of mercury in litterfall and ranged to 1.5%. - A multi-year study of Mercury Deposition Network sites found that annual mercury dry deposition from litterfall in predominately deciduous forests exceeded annual mercury wet deposition in the eastern USA.

Inhalation of nanoplatelets - Theoretical deposition simulations.

Science.gov (United States)

Sturm, Robert

2017-12-01

Primary objective of the contribution was the theoretical prediction of nanoplatelet deposition in the human respiratory tract. Modeling was founded on the hypothetical inhalation of graphene nanoplatelets (GNP) measuring 0.01 and 0.1μm in thickness and adopting a projected area diameter of 1-30μm. Particle uptake was assumed to take place with inhalation flow rates of 250, 500, 750, and 1000cm 3 s -1 , respectively. For an appropriate description of pulmonary particle behavior, transport of GNP in a stochastic lung structure and deposition formulae based on analytical and numerical studies were presupposed. The results obtained from the theoretical approach clearly demonstrate that GNP with a thickness of 0.01μm deposit in the respiratory tract by 20-50%, whereas GNP with a thickness of 0.1μm exhibit a deposition of 20-90%. Larger platelets deposit with higher probability than small ones. Increase of inhalation flow rate is accompanied by decreased deposition in the case of thin GNP, whilst thicker GNP are preferably accumulated in the extrathoracic region. Generation-specific deposition ranges from 0.05 to 7% (0.01μm) and from 0.05 to 9%, with maximum values being obtained in airway generation 20. In proximal airway generations (0-10), deposition is increased with inhalation flow rate, whereas in intermediate to distal generations a reverse effect may be observed. Health consequences of GNP deposition in different lung compartments are subjected to an intense debate. Copyright © 2017. Published by Elsevier GmbH.

Laser-induced chemical vapor deposition reactions

International Nuclear Information System (INIS)

Teslenko, V.V.

1990-01-01

The results of investigation of chemical reactions of deposition of different substances from the gas phase when using the energy of pulse quasicontinuous and continuous radiation of lasers in the wave length interval from 0.193 to 10.6 μm are generalized. Main attetion is paid to deposition of inorganic substances including nonmetals (C, Si, Ge and others), metals (Cu, Au, Zn, Cd, Al, Cr, Mo, W, Ni) and some simple compounds. Experimental data on the effect of laser radiation parameters and reagent nature (hydrides, halogenides, carbonyls, alkyl organometallic compounds and others) on the deposition rate and deposit composition are described in detail. Specific features of laser-chemical reactions of deposition and prospects of their application are considered

Deposition to forests in Europe: most important factors influencing dry deposition and models used for generalisation

International Nuclear Information System (INIS)

Erisman, Jan Willem; Draaijers, Geert

2003-01-01

The influence of forest characteristics on deposition can be modelled reasonably well; forest edge effects and dynamical processes are still uncertain. - Dry deposition of gases and particles to forests is influenced by factors influencing the turbulent transport, such as wind speed, tree height, canopy closure, LAI, etc. as well as by factors influencing surface condition, such as precipitation, relative humidity, global radiation, etc. In this paper, an overview of these factors is given and it is shown which are the most important determining temporal and spatial variation of dry deposition of sodium and sulphur. Furthermore, it is evaluated how well current deposition models are able to describe the temporal and spatial variation in dry deposition. It is concluded that the temporal variation is not modelled well enough, because of limited surface-wetness exchange parameterisations. The influence of forest characteristics are modelled reasonably well, provided enough data describing the forests and the spatial variation in concentration is available. For Europe these data are not available. The means to decrease the atmospheric deposition through forest management is discussed

Direct uptake by vegetation of deposited materials

International Nuclear Information System (INIS)

Eriksson, Aa.

1977-01-01

Interception and retention in pasture grass of nuclides in ionic form and of labelled particles (40-63, 63-100, 100-200 μ in size) were studied experimentally during 1968-70. The results obtained are compared with data from grazing experiments during 1970-72. The data showed that the relative amount of material intercepted by the vegetation decreased markedly in the following order: wet-deposited nuclides > wet-deposited particles > particles dry-deposited on grass wet rain > particles dry-deposited on grass superficially wet > particles dry-deposited on dry grass, and small particles > larger particles. At high relative humidity of the air much more of a deposition could be intercepted than at low relative humidity. The retention of intercepted material was influenced by type of material and by precipitation. Intense rains shortened the half residence time considerably. Dry-deposited materials intercepted in grass suffered marked losses by falloff during the first few days after deposition, which was followed by a phase with a longer half residence time. (author)

Sandstone-type uranium deposits

International Nuclear Information System (INIS)

Finch, W.I.; Davis, J.F.

1985-01-01

World-class sandstone-type uranium deposits are defined as epigenetic concentrations of uranium minerals occurring as uneven impregnations and minor massive replacements primarily in fluvial, lacustrine, and deltaic sandstone formations. The main purpose of this introductory paper is to define, classify, and introduce to the general geologic setting for sandstone-type uranium deposits

THE SECRETS OF MASSIVE SULFIDE DEPOSITS ON MID-OCEAN RIDGES AND KÜRE- MAĞARADORUK COPPER DEPOSIT

Directory of Open Access Journals (Sweden)

Yılmaz ALTUN

2015-07-01

Full Text Available Küre region is located in western part of the Pontide tectonic belt. The oldest rocks around Küre are Paleozoic metamorphic rocks constituting “Rhodope-Pontide” continent. Liassic-pre Liassic ophiolites and basaltic volcanics, which form Paleotethys Ocean Floor are situated on “Rhodope-Pontide” continent as Paleotethys Ocean Floor residuals. Massive sulfide deposits in Küre Region are closely associated with pre Liassic – Liassic basaltic volcanics and inter- calating black shale. These deposits are considered to have formed during hydrothermal mi- neralization processes when basaltic volcanism had stopped and defined as “Black Smoker” today. Massive sulfide bodies in Mağaradoruk copper deposits are lens shaped. Although ore lenses take place sometimes in basalts and black shales, they are generally located on basalts and are covered by black shales. In Küre region, fold structures are intensely observed, and Mağaradoruk deposit is located on western flank of an overturned anticline. Mağaradoruk deposit is formed by several small and a big ore body and by less developed, underlying stockwork disseminated ore. The big ore body is 600 m long, 250 m wide and nearly 40 m thick. As main ore minerals; pyrite and chalcopyrite are observed. In few amounts; marcasite, magnetite, hematite, sphalerite, covelline, neo-digenite, malachite, azurite, fahlers are seen. In fewer amounts; bravoite, lineiite (karolite, limonite, and in trace amounts; chromite, rutile anatase, chalcosine, cuprite, tenorite, pyrrhotite, valleriite, bornite, galenite, native copper and native gold are observed. Main gangue minerals are; quartz, siderite-ankerite calcite, dolomite and chlorite. Mağaradoruk massive sulfide deposit rocks resembles to Siirt Madenköy, Ergani massive sulfide deposits, to “Cyprus” type massive sulfide deposits and modern Cyprus type massive sulfide deposits in terms of mineral contents; and to Ergani Mihrapdağı, Papuke, Pakotai

47 CFR 32.4040 - Customers' deposits.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Customers' deposits. 32.4040 Section 32.4040... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.4040 Customers' deposits. (a) This account shall include the amount of cash deposited with the company by customers as security...

Water evaporation in silica colloidal deposits.

Science.gov (United States)

Peixinho, Jorge; Lefèvre, Grégory; Coudert, François-Xavier; Hurisse, Olivier

2013-10-15

The results of an experimental study on the evaporation and boiling of water confined in the pores of deposits made of mono-dispersed silica colloidal micro-spheres are reported. The deposits are studied using scanning electron microscopy, adsorption of nitrogen, and adsorption of water through attenuated total reflection-infrared spectroscopy. The evaporation is characterized using differential scanning calorimetry and thermal gravimetric analysis. Optical microscopy is used to observe the patterns on the deposits after evaporation. When heating at a constant rate and above boiling temperature, the release of water out of the deposits is a two step process. The first step is due to the evaporation and boiling of the surrounding and bulk water and the second is due to the desorption of water from the pores. Additional experiments on the evaporation of water from membranes having cylindrical pores and of heptane from silica deposits suggest that the second step is due to the morphology of the deposits. Copyright © 2013 Elsevier Inc. All rights reserved.

Bank deposits, notions and features of accounting

Directory of Open Access Journals (Sweden)

Georgeta MELNIC

2016-06-01

Full Text Available Bank deposits are the main method of raising capital and short-term available savings. The opening and using of the bank deposits is the main function of banks. In 2004 the Deposit Guarantee Fund was set up in the Republic of Moldova of Deposit Guarantee Fund and for the first time there was established a guaranteed bank minimum in case of bank insolvency which is currently 6,000 lei for the deposit of each natural person.

Chromium carbide thin films deposited by ultra-short pulse laser deposition

International Nuclear Information System (INIS)

Teghil, R.; Santagata, A.; De Bonis, A.; Galasso, A.; Villani, P.

2009-01-01

Pulsed laser deposition performed by a laser with a pulse duration of 250 fs has been used to deposit films from a Cr 3 C 2 target. Due to the different processes involved in the laser ablation when it is performed by an ultra-short pulse source instead of a conventional short pulse one, it has been possible to obtain in vacuum films containing only one type of carbide, Cr 3 C 2 , as shown by X-ray photoelectron spectroscopy. On the other hand, Cr 3 C 2 is not the only component of the films, since a large amount of amorphous carbon is also present. The films, deposited at room temperature, are amorphous and seem to be formed by the coalescence of a large number of particles with nanometric size. The film composition can be explained in terms of thermal evaporation from particles ejected from the target.

Controlling the resistivity gradient in chemical vapor deposition-deposited aluminum-doped zinc oxide

NARCIS (Netherlands)

Ponomarev, M. V.; Verheijen, M. A.; Keuning, W.; M. C. M. van de Sanden,; Creatore, M.

2012-01-01

Aluminum-doped ZnO (ZnO:Al) grown by chemical vapor deposition (CVD) generally exhibit a major drawback, i.e., a gradient in resistivity extending over a large range of film thickness. The present contribution addresses the plasma-enhanced CVD deposition of ZnO: Al layers by focusing on the control

Barren Miocene granitoids in the Central Andean metallogenic belt, Chile: Geochemistry and Nd-Hf and U-Pb isotope systematics

International Nuclear Information System (INIS)

Deckart, Katja; Godoy, Estanislao; Bertens, Alfredo; Jerez, Daniela; Saeed, Ayesha

2010-01-01

Four Middle-to-Late Miocene barren plutonic complexes that occur between the giant porphyry copper deposits of the central Chilean Andes were selected for U-Pb LA-ICPMS geochronology and Hf-isotope systematics on single zircon grains. Major and trace elements and Sr-Nd-Hf isotope whole rock geochemical studies were undertaken to compare with slightly younger or coeval barren and fertile intrusive rocks between 32 o and 34 o S. The studied granitoids yield resolvable crystallization ages of 11.3±0.1 Ma (Cerro Meson Alto massif), 10.3±0.2 Ma (La Gloria pluton), 14.9±0.2 Ma/14.9±0.1 Ma (Yerba Loca stock) and 11.2±0.1 Ma/14.7±0.1 Ma (San Francisco Batholith). Major and trace elements discard an adakitic signature as suggested for coeval porphyric intrusions at 32 o S, slightly younger mineralized porphyries at Rio Blanco-Los Bronces deposit and other Cenozoic adakites. Volcanic host rocks are less fractionated than the intrusive rock units. The same observation can be made for the unmineralized northern plutons compared to the southern ones. Initial Sr-Nd isotope data show insignificant variation (0.703761-0.704118 and 0.512758- 0.512882), plotting in the mantle array. Trace element enrichment can be explained by addition of subducted-slab fluids and/or terrigenous sediments to the mantle wedge prior to and/or slight crustal input during magma ascent. Zircon grains separated from these barren intrusives share a similar initial εHf-data variation for the younger age group (10-12 Ma; 7.04-9.54) and show a more scattered range for the older one (14-15 Ma; 8.50-15.34); both sets plot between the DM and CHUR evolution lines. There is evidence that magma evolution was slightly distinct through time from older to younger barren magmatism, compared to a few fertile porphyritic rocks from Rio Blanco-Los Bronces porphyry copper deposit. It is suggested that chronological inconsistencies within these complexes might be related to differential shortening across the NE

Dry deposition models for radionuclides dispersed in air: a new approach for deposition velocity evaluation schema

Science.gov (United States)

Giardina, M.; Buffa, P.; Cervone, A.; De Rosa, F.; Lombardo, C.; Casamirra, M.

2017-11-01

In the framework of a National Research Program funded by the Italian Minister of Economic Development, the Department of Energy, Information Engineering and Mathematical Models (DEIM) of Palermo University and ENEA Research Centre of Bologna, Italy are performing several research activities to study physical models and mathematical approaches aimed at investigating dry deposition mechanisms of radioactive pollutants. On the basis of such studies, a new approach to evaluate the dry deposition velocity for particles is proposed. Comparisons with some literature experimental data show that the proposed dry deposition scheme can capture the main phenomena involved in the dry deposition process successfully.

Atmospheric Deposition of Phosphorus to the Everglades: Concepts, Constraints, and Published Deposition Rates for Ecosystem Management

Directory of Open Access Journals (Sweden)

Garth W. Redfield

2002-01-01

Full Text Available This paper summarizes concepts underlying the atmospheric input of phosphorus (P to ecosystems, published rates of P deposition, measurement methods, and approaches to future monitoring and research. P conveyed through the atmosphere can be a significant nutrient source for some freshwater and marine ecosystems. Particle sources and sinks at the land-air interface produce variation in P deposition from the atmosphere across temporal and spatial scales. Natural plant canopies can affect deposition rates by changing the physical environment and surface area for particle deposition. Land-use patterns can alter P deposition rates by changing particle concentrations in the atmosphere. The vast majority of P in dry atmospheric deposition is conveyed by coarse (2.5 to 10 μm and giant (10 to 100 μm particles, and yet these size fractions represent a challenge for long-term atmospheric monitoring in the absence of accepted methods for routine sampling. Most information on P deposition is from bulk precipitation collectors and wet/dry bucket sampling, both with questionable precision and accuracy. Most published annual rates of P deposition are gross estimates derived from bulk precipitation sampling in locations around the globe and range from about 5 to well over 100 mg P m–2 year–1, although most inland ecosystems receive between 20 and 80 mg P m–2 year–1. Rates below 30 mg P m–2 year–1 are found in remote areas and near coastlines. Intermediate rates of 30 to 50 mg P m–2 year–1 are associated with forests or mixed land use, and rates of 50 to 100 mg P m–2 year–1 or more are often recorded from urban or agricultural settings. Comparison with other methods suggests that these bulk precipitation estimates provide crude boundaries around actual P deposition rates for various land uses. However, data screening cannot remove all positive bias caused by contamination of bucket or bulk collectors. As a consequence, continued sampling

A deposit model for carbonatite and peralkaline intrusion-related rare earth element deposits: Chapter J in Mineral deposit models for resource assessment

Science.gov (United States)

Verplanck, Philip L.; Van Gosen, Bradley S.; Seal, Robert R.; McCafferty, Anne E.

2014-01-01

Carbonatite and alkaline intrusive complexes, as well as their weathering products, are the primary sources of rare earth elements. A wide variety of other commodities have been exploited from carbonatites and alkaline igneous rocks including niobium, phosphate, titanium, vermiculite, barite, fluorite, copper, calcite, and zirconium. Other elements enriched in these deposits include manganese, strontium, tantalum, thorium, vanadium, and uranium. Carbonatite and peralkaline intrusion-related rare earth element deposits are presented together in this report because of the spatial, and potentially genetic, association between carbonatite and alkaline rocks. Although these rock types occur together at many locations, carbonatite and peralkaline intrusion-related rare earth element deposits are not generally found together.

Carbon deposition and hydrogen retention in tokamak

International Nuclear Information System (INIS)

Tanabe, Tetsuo

2006-01-01

The results of measurements on co-deposition of hydrogen isotopes and wall materials, hydrogen retention, redeposition of carbon and deposition of hydrogen on PMI of JT-60U are described. From above results, selection of plasma facing material and ability of carbon wall is discussed. Selection of plasma facing materials in fusion reactor, characteristics of carbon materials as the plasma facing materials, erosion, transport and deposition of carbon impurity, deposition of tritium in JET, results of PMI in JT-60, application of carbon materials to PFM of ITER, and future problems are stated. Tritium co-deposition in ITER, erosion and transport of carbon in tokamak, distribution of tritium deposition on graphite tile used as bumper limiter of TFTR, and measurement results of deposition of tritium on the Mark-IIA divertor tile and comparison between them are described. (S.Y.)

Magma ascent, fragmentation and depositional characteristics of "dry" maar volcanoes: Similarities with vent-facies kimberlite deposits

Science.gov (United States)

Berghuijs, Jaap F.; Mattsson, Hannes B.

2013-02-01

Several maar craters within the Lake Natron-Engaruka monogenetic volcanic field (LNE-MVF) of northern Tanzania show compelling evidence for magmatic fragmentation and dry deposition. This is in contradiction of the common belief that most maars are formed through the explosive interaction between ascending magma and ground- or surface water. We here present a detailed study on the eruptive and depositional characteristics of the Loolmurwak and Eledoi maar volcanoes, two of the largest craters in the LNE-MVF, focusing on high-resolution stratigraphy, sedimentology, grain size distribution, pyroclast textures and morphologies, bulk geochemistry and mineral chemistry. At both maars, ejected material has been emplaced by a combination of pyroclastic surges and fallout. Indicators of phreatomagmatic fragmentation and wet deposition, such as impact sags, accretionary lapilli, vesiculated tuffs and plastering against obstacles, are absent in the deposits. Juvenile material predominantly occurs as fluidal-shaped vesicular melt droplets and contains no glass shards produced by the breakage of bubble walls. The Eledoi deposits comprise a large amount of inversely graded beds and lenses, which result from grain flow in a dry depositional environment. Preferential deposition of fine material toward the northern side of its crater can be related to effective wind winnowing in a dry eruption plume. This large variety of observations testifies to the dominance of magmatic fragmentation as well as dry deposition at the Loolmurwak and Eledoi maars, which is in line with what has been found for other structures in the LNE-MVF but contrasts with current ideas on maar formation. We infer that a volatile-rich, olivine melilitic magma was formed by small amounts of partial melting at upper mantle depths. With minimum average ascent rates of 5.3 m s- 1 for Loolmurwak and 26.2 m s- 1 for Eledoi, this magma rapidly moved toward the surface and exsolved a substantial amount of volatiles

Regional aerosol deposition in human upper airways

International Nuclear Information System (INIS)

Swift, D.L.

1989-01-01

During the report period significant progress on the quantitative understanding of regional upper airway deposition of airborne particle has been realized. Replicate models of the human upper airways obtained from post-mortem casting of the nasal, oral, pharyngeal, laryngeal and upper tracheal regions and in vivo magnetic resonance imaging (MRI) of the same regions of adults and children have been employed to determine the overall and local deposition characteristics of aerosols in the ultrafine (1--100 μm diameter) and fine (0.8--12 μm diameter) region. Studies have been carried out for both nasal and oral breathing during inspiratory and expiratory flow at constant flow rates representative of rest and states of exercise. The results of these investigations indicate that particles in the size range of ''unattached'' radon progeny (1--3 nm) are deposited in both the nasal and oral passages with high efficiency (60--80%) for both inspiration and expiration, with the nasal deposition being somewhat greater (5--10%) than oral deposition. The effect of flow rate on upper airway deposition for both pathways is not great; data analysis indicates that the deposition for all flow rates from 4--50 liters/minute can be grouped by plotting deposition vs Q- 1/8 , where Q is flow rate, a far weaker dependency than observed for inertial deposition. Diffusional transport is the primary mechanism of deposition, and size dependence can be accounted for by plotting, deposition percent vs D n where D is particle diffusion coefficient and n ranges from 0.5--0.66. 2 refs

Climax-Type Porphyry Molybdenum Deposits

Science.gov (United States)

Ludington, Steve; Plumlee, Geoffrey S.

2009-01-01

Climax-type porphyry molybdenum deposits, as defined here, are extremely rare; thirteen deposits are known, all in western North America and ranging in age from Late Cretaceous to mainly Tertiary. They are consistently found in a postsubduction, extensional tectonic setting and are invariably associated with A-type granites that formed after peak activity of a magmatic cycle. The deposits consist of ore shells of quartz-molybdenite stockwork veins that lie above and surrounding the apices of cupola-like, highly evolved, calc-alkaline granite and subvolcanic rhyolite-porphyry bodies. These plutons are invariably enriched in fluorine (commonly >1 percent), rubidium (commonly >500 parts per million), and niobium-tantalum (Nb commonly >50 parts per million). The deposits are relatively high grade (typically 0.1-0.3 percent Mo) and may be very large (typically 100-1,000 million tons). Molybdenum, as MoS2, is the primary commodity in all known deposits. The effect on surface-water quality owing to natural influx of water or sediment from a Climax-type mineralized area can extend many kilometers downstream from the mineralized area. Waste piles composed of quartz-silica-pyrite altered rocks will likely produce acidic drainage waters. The potential exists for concentrations of fluorine or rare metals in surface water and groundwater to exceed recommended limits for human consumption near both mined and unmined Climax-type deposits.

Cu and Cu(Mn) films deposited layer-by-layer via surface-limited redox replacement and underpotential deposition

Energy Technology Data Exchange (ETDEWEB)

Fang, J.S., E-mail: jsfang@nfu.edu.tw [Department of Materials Science and Engineering, National Formosa University, Huwei 63201, Taiwan (China); Sun, S.L. [Department of Materials Science and Engineering, National Formosa University, Huwei 63201, Taiwan (China); Cheng, Y.L. [Department of Electrical Engineering, National Chi-Nan University, Nan-Tou 54561, Taiwan (China); Chen, G.S.; Chin, T.S. [Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan (China)

2016-02-28

Graphical abstract: - Abstract: The present paper reports Cu and Cu(Mn) films prepared layer-by-layer using an electrochemical atomic layer deposition (ECALD) method. The structure and properties of the films were investigated to elucidate their suitability as Cu interconnects for microelectronics. Previous studies have used primarily a vacuum-based atomic layer deposition to form a Cu metallized film. Herein, an entirely wet chemical process was used to fabricate a Cu film using the ECALD process by combining underpotential deposition (UPD) and surface-limited redox replacement (SLRR). The experimental results indicated that an inadequate UPD of Pb affected the subsequent SLRR of Cu and lead to the formation of PbSO{sub 4}. A mechanism is proposed to explain the results. Layer-by-layer deposition of Cu(Mn) films was successfully performed by alternating the deposition cycle-ratios of SLRR-Cu and UPD-Mn. The proposed self-limiting growth method offers a layer-by-layer wet chemistry-based deposition capability for fabricating Cu interconnects.

COPDIRC - calculation of particle deposition in reactor coolants

International Nuclear Information System (INIS)

Reeks, M.W.

1982-06-01

A description is given of a computer code COPDIRC intended for the calculation of the deposition of particulate onto smooth perfectly sticky surfaces in a gas cooled reactor coolant. The deposition is assumed to be limited by transport in the boundary layer adjacent to the depositing surface. This implies that the deposition velocity normalised with respect to the local friction velocity, is an almost universal function of the normalised particle relaxation time. Deposition is assumed similar to deposition in an equivalent smooth perfectly absorbing pipe. The deposition is calculated using 2 models. (author)

Radionuclide deposition control

International Nuclear Information System (INIS)

1980-01-01

A method is described for controlling the deposition, on to the surfaces of reactor components, of the radionuclides manganese-54, cobalt-58 and cobalt-60 from a liquid stream containing the radionuclides. The method consists of disposing a getter material (nickel) in the liquid stream, and a non-getter material (tantalum, tungsten or molybdenum) as a coating on the surfaces where deposition is not desired. The process is described with special reference to its use in the coolant circuit in sodium cooled fast breeder reactors. (U.K.)

Towards a genetic classification of uranium deposits

International Nuclear Information System (INIS)

Cuney, M.

2009-01-01

As the IAEA's uranium deposit classification is based on the deposit nature and morphology, some deposits which have been formed by very different genetic processes and located in very different geological environments, are grouped according to this classification. In order to build up a reliable genetic classification based on the mechanism at the origin of the formation of the deposit, the author presents the five main categories according to which uranium deposits can be classified: magmatic, hydrothermal, evapotranspiration, syn-sedimentary, and infiltration of meteoric water

Acidic deposition and global climate change

International Nuclear Information System (INIS)

Nikolaidis, N.P.; Ecsedy, C.; Olem, H.; Nikolaidis, V.S.

1990-01-01

A literature is presented which examines the research published on understanding ecosystem acidification and the effects of acidic deposition on freshwaters. Topics of discussion include the following: acidic deposition; regional assessments; atmospheric deposition and transport; aquatic effects; mathematical modeling; liming acidic waters; global climate change; atmospheric changes; climate feedbacks; and aquatic effects

Enhancement of deposition rate at cryogenic temperature in synchrotron radiation excited deposition of silicon film

International Nuclear Information System (INIS)

Nara, Yasuo; Sugita, Yoshihiro; Ito, Takashi; Kato, Hiroo; Tanaka, Ken-ichiro

1989-01-01

The authors have investigated the synchrotron radiation excited deposition of silicon films on the SiO 2 substrate by using SiH 4 /He mixture gas at BL-12C at Photon Factory. They used VUV light from the multilayer mirror with the center photon energy from 97 to 123eV, which effectively excites L-core electrons of silicon. Substrate temperature was widely varied from -178 degree C to 500 degree C. At -178 degree C, the deposition rate was as high as 400nm/200mAHr (normalized at the storage ring current at 200mA). As increasing the substrate temperature, the deposition rate was drastically decreased. The number of deposited silicon atoms is estimated to be 4 to 50% of incident photons, while the number of photo generated species in the gas phase within the mean free path from the surface is calculated as few as about 10 -3 of incident photons. These experimental results show that the deposition reaction is governed by the dissociation of surface adsorbates by the synchrotron radiation

Deposition of intranasal glucocorticoids--preliminary study.

Science.gov (United States)

Rapiejko, Piotr; Sosnowski, Tomasz R; Sova, Jarosław; Jurkiewicz, Dariusz

2015-01-01

Intranasal glucocorticoids are the treatment of choice in the therapy of rhinitis. The differences in efficiency of particular medications proven by therapeutic index may result from differences in composition of particular formulations as well as from diverse deposition in nasal cavities. Intranasal formulations of glucocorticoids differ in volume of a single dose in addition to variety in density, viscosity and dispenser nozzle structure. The aim of this report was to analyze the deposition of most often used intranasal glucocorticoids in the nasal cavity and assessment of the usefulness of a nose model from a 3D printer reflecting anatomical features of a concrete patient. Three newest and most often used in Poland intranasal glucocorticoids were chosen to analysis; mometasone furoate (MF), fluticasone propionate (FP) and fluticasone furoate (FF). Droplet size distribution obtained from the tested formulations was determined by use of a laser aerosol spectrometer Spraytec (Malvern Instruments, UK). The model of the nasal cavity was obtained using a 3D printer. The printout was based upon a tridimensional reconstruction of nasal cavity created on the basis of digital processing of computed tomography of paranasal sinuses. The deposition of examined medications was established by a method of visualization combined with image analysis using commercial substance which colored itself intensively under the influence of water being the dominant ingredient of all tested preparations. On the basis of obtained results regions of dominating deposition of droplets of intranasal medication on the wall and septum of the nasal cavity were compared. Droplet size of aerosol of tested intranasal medications typically lies within the range of 25-150 µm. All tested medications deposited mainly on the anterior part of inferior turbinate. FP preparation deposited also on the anterior part of the middle nasal turbinate, marginally embracing a fragment of the central part of this

Structural and Optical Properties of Chemical Bath Deposited Silver Oxide Thin Films: Role of Deposition Time

Directory of Open Access Journals (Sweden)

A. C. Nwanya

2013-01-01

Full Text Available Silver oxide thin films were deposited on glass substrates at a temperature of 50°C by chemical bath deposition technique under different deposition times using pure AgNO3 precursor and triethanolamine as the complexing agent. The chemical analysis based on EDX technique shows the presence of Ag and O at the appropriate energy levels. The morphological features obtained from SEM showed that the AgxO structures varied as the deposition time changes. The X-ray diffraction showed the peaks of Ag2O and AgO in the structure. The direct band gap and the refractive index increased as the deposition time increased and was in the range of 1.64–1.95 eV and 1.02–2.07, respectively. The values of the band gap and refractive index obtained indicate possible applications in photovoltaic and photothermal systems.

Formation, Sintering and Removal of Biomass Ash Deposits

DEFF Research Database (Denmark)

Laxminarayan, Yashasvi

conditions in laboratory-scale setups. Deposit formation was simulated in an Entrained Flow Reactor, to investigate the effect of operating conditions and ash chemistry on the rate of deposit formation. Experiments were performed using model biomass fly ash, prepared from mixtures of K2Si4O9, KCl, K2SO4, Ca....... Moreover, biomass ash deposits may cause severe corrosion of boiler surfaces. Therefore, reducing deposit formation and timely deposit removal are essential for optimal boiler operation. The formation, sintering and removal of boiler deposits has been investigated in this PhD project, by simulating boiler...... temperature increased the sticking probability of the fly ash particles/deposit surface, thereby increasing the rate of deposit formation. However, increasing flue gas velocity resulted in a decrease in the deposit formation rate, due to increased particle rebound. Furthermore, it was observed...

Remediation of spent block in Uvanas deposit

International Nuclear Information System (INIS)

Nurgaziev, M.A.; Iskakov, M.M.

2012-01-01

In 2007 by 'Kazatomprom' and 'Mining company' board decision, the branch of 'Mining company', 'Steppe ore management body' is reorganized in structure subdivision, the basic activity of which is organization and carrying out remediation works on spent blocks of PSV uranium deposit. In 2002 works are completed on OVOS for operating deposits Uvanas, Kanjugan, Northern Karamurun and Eastern Minkuduk. The results of present work were reported in IAEA conference. The working project 'Remediation of spent blocks of PSV uranium deposit PV-17 polygon of Steppe ore management body' approved in 2005 was developed for carrying out the remediation works. Works funding were carried out from liquidation fund of the current deposit established in accordance with the Republic of Kazakhstan law 'About interior and interior use'. Deposits remediation is the part of deposit operation life cycle which obliges to operate deposits with minimum expenditures for remediation.

The carbonaceous phyllite rock-hosted Pedra Verde copper mine, Borborema Province, Brazil: Stable isotope constraints, structural controls and metallogenic evolution

Science.gov (United States)

da Silva Nogueira de Matos, José Henrique; Saraiva dos Santos, Ticiano José; Virgínia Soares Monteiro, Lena

2017-12-01

The Pedra Verde Copper Mine is located in the Viçosa do Ceará municipality, State of Ceará, NE Brazil. The copper mineralization is hosted by the Pedra Verde Phyllite, which is a carbonaceous chlorite-calcite phyllite with subordinate biotite. It belongs to the Neoproterozoic Martinópole Group of the Médio Coreaú Domain, Borborema Province. The Pedra Verde deposit is stratabound and its ore zoning is conspicuous, according to the following sequence, from bottom to top: marcasite/pyrite, native silver, chalcopyrite, bornite, chalcocite, native copper and hematite. Barite and carbonaceous material are reported in ore zones. Zoning reflects the ore formation within a redox boundary developed due to the interaction between oxidized copper- and sulfate-bearing fluids and the reduced phyllite. Structural control on mineralization is evidenced by the association of the ore minerals with veins, hinge folds, shadow pressures, and mylonitic foliation. It was mainly exercised by a dextral transcurrent shear zone developed during the third deformational stage identified in the Médio Coreaú Domain between 590 Ma and 570 Ma. This points to the importance of epigenetic, post-metamorphic deformational events for ore formation. Oxygen isotopic composition (δ18OH2O = 8.94 to 11.28‰, at 250 to 300 °C) estimated for the hydrothermal fluids in equilibrium with calcite indicates metamorphic or evolved meteoric isotopic signatures. The δ13CPDB values (-2.60 to -9.25‰) obtained for hydrothermal calcite indicate mixing of carbon sources derived from marine carbonate rocks and carbonaceous material. The δ34SCDT values (14.88 to 36.91‰) of sulfides suggest evaporites as sulfate sources or a closed system in relation to SO42- availability to form H2S. Carbonaceous matter had a key role in thermochemical sulfate processes and sulfide precipitation. The Pedra Verde Copper Mine is considered the first stratabound meta-sedimentary rock-hosted copper deposit described in Brazil

Preservation of Urban Archaeological Deposits: monitoring and characterisation of archaeological deposits at Marks & Spencer, 44-45 Parliament Street, York

Directory of Open Access Journals (Sweden)

M. Davis

2002-03-01

Full Text Available The City of York Council has been pursuing a strict policy of in situ preservation of archaeological deposits since April 1990. Planning consent is normally granted in the historic core of York for a new development so long as less than 5% of the archaeological deposits that are preserved on a site are destroyed. During archaeological evaluation work carried out as part of the redevelopment and expansion proposals for Marks & Spencer plc on Parliament Street, deposit monitoring devices were installed to investigate and monitor both the character of the archaeological deposits present and also the burial environment surrounding them (of particular importance because the burial environment, in terms both of its characteristics and stability, is thought to play a vital role in the preservation in situ of a site's archaeological deposits. The monitoring programme was undertaken between June 1995 and April 1998. As a result the data from a total of 30 site visits have been collected and are presented in this report. This article discusses results of the deposit monitoring project and presents evidence of changes that appear to be taking place in the archaeological deposits. Although the lower deposits at Parliament Street are stable, the upper deposits show considerable seasonal variations. The concept of preservation of archaeological deposits in situ is now deeply embedded both in Codes of Professional Conduct (IFA Code of Conduct and in national policy guidance (PPG 16. However, this emphasis on preservation in situ has been criticised. Does conservation archaeology in general and the City of York policy in particular achieve the preservation of the remaining 95% of the archaeology? Or are these deposits condemned to unseen, unrecorded destruction, sealed below new buildings; indeed if this is the case, shouldn't these deposits be excavated now while they are still viable?

Metallogeny of The Sierra de Guanajuato Range, Central México

Science.gov (United States)

Pedro F., Z. D.

2004-12-01

The Sierra de Guanajuato Range (SGR), trending N315° at Central México, is an orographic feature extending over a distance of 80 km. SGR comprises three well defined lithostratigraphic units: (1) a cretaceous basement including an arc-derived terrane named Guanajuato Arc (GA) made of gabbro, diorite and basaltic pillowed lava, and volcano-sedimentary rocks belonging to Arperos fore-arc basin which are geochemically anomalous in Au (0.15 ppm), Ag (3 ppm), Cu (40 ppm), Pb (50 ppm) and Zn (15 ppm); (2) Early Tertiary intrusive rocks, e.g., Comanja Granite which is affected by the presence of tourmalinized (schörl) aplito-pegmatite dykes mineralized with rare earths elements, and (3) Eocene redbeds (1,500-2000 m) and Oligocene-Miocene volcanics cover. The metallogeny of the SGR shows a multiple origin in time and space: volcano-sedimentary, granitic and volcanic, being possible to define three metallogenic epochs: cretaceous, paleocene and oligocene. Cretaceous epoch includes: (a) volcanogenic massive sulphide deposits (VMS) of bimodal-siliclastic type belonging to León-Guanajuato district; wallrock of VMS is made of felsic-internediate volcanics and black argillite; at Los Gavilanes deposit paragenesis is next: chalcopyrite > sphalerite > galena, pyrite > pyrrhotite > marcasite; grade is as follows: Au: .02-.07 g/t; Ag: 157-18.5 g/t; Cu: 2.24-0.81%, Pb: 4.16-0.03%; Zn: 10.35-3.02 %; (b) lens-shaped stratiform bodies of massive pyrite (i. ex., San Ignacio prospect; ˜ 4,000 ton) of exhalative-sedimentary origin with chalcopyrite and sphalerite microveins. Paleocene epoch includes both quartz-cordierite-sanidine veins and replacement bodies of hydrothermal metamorphic filliation (W +Se-Bi, Pb, Zn, Cu), and pyrometasomatic bodies [Cu, Pb, Zn (Ag), W] which genetically are linked to Comanja Granite emplacement. The wallrock at El Maguey mine (35,000 ton; 0.6% WO3) is made of hornfel and the vein (1.8-3.2m width) has a banding structure made of : \\{quartz & K

In vitro tests for aerosol deposition. III: effect of inhaler insertion angle on aerosol deposition.

Science.gov (United States)

Delvadia, Renish R; Longest, P Worth; Hindle, Michael; Byron, Peter R

2013-06-01

Inhaler orientation with respect to a patient's mouth may be an important variable determining the efficiency of aerosol lung delivery. The effect of insertion angle on regional deposition was evaluated for a series of inhalers using concurrent in vitro and computational fluid dynamics (CFD) analysis. Geometrically realistic physical mouth-throat (MT) and upper tracheobronchial (TB) models were constructed to connect different inhalers at a series of insertion angles relative to the horizontal plane of the model. These models were used to assess albuterol sulfate deposition from the Novolizer(®) dry powder inhaler (DPI), Proventil(®) HFA pressurized metered dose inhaler (MDI), and Respimat(®) Soft Mist™ Inhaler (SMI) following the actuation of a single dose. Drug deposition from Novolizer DPI was studied for Salbulin(®) and an experimental "drug only" formulation. Albuterol sulfate was recovered and quantified from the device and the MT and TB regions. Significant differences in MT and total lung dose (TLD) of albuterol sulfate deposition were not observed for Salbulin Novolizer DPI and Respimat SMI inserted at different angles. In contrast, drug-only Novolizer DPI and Proventil HFA MDI showed a significant difference in MT and TLD deposition using different insertion angles. For drug-only Novolizer DPI and Proventil HFA MDI, the lowest and the highest MT depositions were observed at +10° and -20°, respectively; for Respimat SMI and Salbulin Novolizer DPI, these angles were -10° and +10°, and +20° and -20°, respectively. CFD simulations were in agreement with the experimental results and illustrated shifts in local particle deposition associated with changes in insertion angle. The effect of inhaler orientation at the inhaler-mouth interface on MT aerosol deposition appeared to be dependent on velocity, aerosol size, and formulation. These findings not only demonstrate the need for patient education on correct inhaler orientation, but provide important

Deposition of aerosol particles in bent pipe

International Nuclear Information System (INIS)

Matsui, Hiroshi; Ohhata, Tsutomu

1989-01-01

An equation to estimate deposition fraction of aerosol particles in a bent pipe is derived and the validity is verified experimentally. The equation is obtained by assuming that the resultant acceleration of the gravity and the centrifugal force induced in the bend acts on the aerosol particles, and is found to give a relatively accurate estimation of the deposition fraction if a certain correction factor is introduced to the equation. The deposition fraction has a minimum against Reynold number, and the deposition due to centrifugal force dominates at greater Reynolds number than that at the minimum deposition fraction. On the other hand, the smaller the radius of curvature of the bend is, the larger the deposition fraction due to the centrifugal force is. (author)

Reducing tube bundle deposition with alternative amines

International Nuclear Information System (INIS)

Turner, C.W.; Klimas, S.J.; Frattini, P.L.

1998-01-01

Particle deposition rates have been measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates an order of magnitude greater than those measured for magnetite, although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) ammonia (0.51) : dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat transfer mechanism from nucleate boiling to two-phase forced convection through a thin film. (author)

Reducing tube bundle deposition using alternative amines

International Nuclear Information System (INIS)

Turner, C.W.; Klimas, S.J.; Frattini, P.L.

1999-07-01

Particle deposition rates were measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled, using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates 10 times greater than those measured for magnetite although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) : ammonia (0.51) dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat-transfer mechanism from nucleate boiling to 2-phase forced-convection through a thin film. (author)

Selective deposition contact patterning using atomic layer deposition for the fabrication of crystalline silicon solar cells

International Nuclear Information System (INIS)

Cho, Young Joon; Shin, Woong-Chul; Chang, Hyo Sik

2014-01-01

Selective deposition contact (SDC) patterning was applied to fabricate the rear side passivation of crystalline silicon (Si) solar cells. By this method, using screen printing for contact patterning and atomic layer deposition for the passivation of Si solar cells with Al 2 O 3 , we produced local contacts without photolithography or any laser-based processes. Passivated emitter and rear-contact solar cells passivated with ozone-based Al 2 O 3 showed, for the SDC process, an up-to-0.7% absolute conversion-efficiency improvement. The results of this experiment indicate that the proposed method is feasible for conversion-efficiency improvement of industrial crystalline Si solar cells. - Highlights: • We propose a local contact formation process. • Local contact forms a screen print and an atomic layer deposited-Al 2 O 3 film. • Ozone-based Al 2 O 3 thin film was selectively deposited onto patterned silicon. • Selective deposition contact patterning method can increase cell-efficiency by 0.7%

Spray deposition using impulse atomization technique

International Nuclear Information System (INIS)

Ellendt, N.; Schmidt, R.; Knabe, J.; Henein, H.; Uhlenwinkel, V.

2004-01-01

A novel technique, impulse atomization, has been used for spray deposition. This single fluid atomization technique leads to different spray characteristics and impact conditions of the droplets compared to gas atomization technique which is the common technique used for spray deposition. Deposition experiments with a Cu-6Sn alloy were conducted to evaluate the appropriateness of impulse atomization to produce dense material. Based on these experiments, a model has been developed to simulate the thermal history and the local solidification rates of the deposited material. A numerical study shows how different cooling conditions affect the solidification rate of the material

Gigantic landslides versus glacial deposits: on origin of large hummock deposits in Alai Valley, Northern Pamir

Science.gov (United States)

Reznichenko, Natalya

2015-04-01

As glaciers are sensitive to local climate, their moraines position and ages are used to infer past climates and glacier dynamics. These chronologies are only valid if all dated moraines are formed as the result of climatically driven advance and subsequent retreat. Hence, any accurate palaeoenvironmental reconstruction requires thorough identification of the landform genesis by complex approach including geomorphological, sedimentological and structural landform investigation. Here are presented the implication of such approach for the reconstruction of the mega-hummocky deposits formation both of glacial and landslide origin in the glaciated Alai Valley of the Northern Pamir with further discussion on these and similar deposits validity for palaeoclimatic reconstructions. The Tibetan Plateau valleys are the largest glaciated regions beyond the ice sheets with high potential to provide the best geological record of glacial chronologies and, however, with higher probabilities of the numerous rock avalanche deposits including those that were initially considered of glacial origin (Hewitt, 1999). The Alai Valley is the largest intermountain depression in the upper reaches of the Amudarja River basin that has captured numerous unidentified extensive hummocky deposits descending from the Zaalai Range of Northern Pamir, covering area in more than 800 km2. Such vast hummocky deposits are usually could be formed either: 1) glacially by rapid glacial retreat due to the climate signal or triggered a-climatically glacial changes, such as glacial surge or landslide impact, or 2) during the landslide emplacement. Combination of sediment tests on agglomerates forming only in rock avalanche material (Reznichenko et al., 2012) and detailed geomorphological and sedimentological descriptions of these deposits allowed reconstructing the glacial deposition in the Koman and Lenin glacial catchments with identification of two gigantic rock avalanches and their relation to this glacial

Digitization of uranium deposit information in basin. A new strategy of ISL sandstone-type uranium deposits exploration

International Nuclear Information System (INIS)

Tan Chenglong

2006-01-01

The discovered ISL sandstone-type uranium deposits in the entire world are mostly blind deposits, many of them occur in bleak desert, gobi desert, and semi-hilly land area. Exploration methods for these deposits mainly depend on great and systematic drilling. There are many large-medium size Meso-Cenozoic sedimentary basins in northern China, and over twenty of them are thick overburden basins which are mostly the virgin land for ISL sandstone-type uranium deposit. Due to the comprehensive national power, geological background, uranium exploration ability, great and systematic drilling is not favorable for prospecting ISL sandstone-type uranium deposit in China. According to the exploration and prospecting experiences for mineral ore bodies at home and abroad, uranium information mapping based on geochemical survey of the basins is a new strategy for ISL sandstone-type uranium deposits. It is an economic, practical, fast and effective method, and has been manifested by the performing information digitization for oil and gas resources, gold mineral resources in China and the mapping of uranium information for whole Europe continent. (authors)

Oxide cathodes produced by plasma deposition

International Nuclear Information System (INIS)

Scheitrum, G.; Caryotakis, G.; Pi, T.; Umstattd, R.; Brown, I.; Montiero, O.

1997-01-01

These are two distinct applications for high-current-density, long-life thermionic cathodes. The first application is as a substitute for explosive emission cathodes used in high-power microwave (HPM) devices being developed for Air Force programs. The second application is in SLAC's X-band klystrons for the Next Linear Collider (NLC). SLAC, UCD, and LBL are developing a plasma deposition process that eliminates the problems with binders, carbonate reduction, peeling, and porosity. The emission layer is deposited using plasma deposition of metallic barium in vacuum with an oxygen background gas. An applied bias voltage drives the oxide plasma into the nickel surface. Since the oxide is deposited directly, it does not have problems with poisoning from a hydrocarbon binder. The density of the oxide layer is increased from the 40--50% for standard oxide cathodes to nearly 100% for plasma deposition

Acid Deposition Maps in Spain

International Nuclear Information System (INIS)

Artinano, B.; Cabal, H.; Garcia, C.

1998-01-01

Animal and monthly deposition velocity and total sulfur deposition maps have been performed for the peninsular Spain for 1992 by using the inferential method. To do this, updated databases with high space and time resolution, for land uses (CORINE) and meteorological information from analysis modelling for the same year, have been utilized. The final result are deposition maps in a 5x5 Km 2 grid which allow to assess the methodology used in Europe to obtain the maps of excedances over the critical loads of pollutants. (Author) 32 refs

Increasing aeolian dust deposition to snowpacks in the Rocky Mountains inferred from snowpack, wet deposition, and aerosol chemistry

Science.gov (United States)

Clow, David W.; Williams, Mark W.; Schuster, Paul F.

2016-01-01

Mountain snowpacks are a vital natural resource for ∼1.5 billion people in the northern Hemisphere, helping to meet human and ecological demand for water in excess of that provided by summer rain. Springtime warming and aeolian dust deposition accelerate snowmelt, increasing the risk of water shortages during late summer, when demand is greatest. While climate networks provide data that can be used to evaluate the effect of warming on snowpack resources, there are no established regional networks for monitoring aeolian dust deposition to snow. In this study, we test the hypothesis that chemistry of snow, wet deposition, and aerosols can be used as a surrogate for dust deposition to snow. We then analyze spatial patterns and temporal trends in inferred springtime dust deposition to snow across the Rocky Mountains, USA, for 1993–2014. Geochemical evidence, including strong correlations (r2 ≥ 0.94) between Ca2+, alkalinity, and dust concentrations in snow deposited during dust events, indicate that carbonate minerals in dust impart a strong chemical signature that can be used to track dust deposition to snow. Spatial patterns in chemistry of snow, wet deposition, and aerosols indicate that dust deposition increases from north to south in the Rocky Mountains, and temporal trends indicate that winter/spring dust deposition increased by 81% in the southern Rockies during 1993–2014. Using a multivariate modeling approach, we determined that increases in dust deposition and decreases in springtime snowfall combined to accelerate snowmelt timing in the southern Rockies by approximately 7–18 days between 1993 and 2014. Previous studies have shown that aeolian dust emissions may have doubled globally during the 20th century, possibly due to drought and land-use change. Climate projections for increased aridity in the southwestern U.S., northern Africa, and other mid-latitude regions of the northern Hemisphere suggest that aeolian dust emissions may continue to

Process and machinery description of equipment for deposition of canisters in medium-long deposition holes

International Nuclear Information System (INIS)

Kalbantner, P.

2001-08-01

In this report twelve methods are presented to deposit a canister with spent nuclear fuel in a horizontal hole, several canisters per hole (MLH). These methods are part of the KBS-3 system. They have been developed successively, after an analysis of weak points and strong points in previously described methods. In conformance with the guidelines for Project JADE, a choices of system has been considered during the development work. This is whether canister and bentonite buffer should be deposited 'in parts', i.e. at different occasions, but shortly after each other or 'in a package', i.e. together in a single package. The other choice in the guidelines for the JADE project, whether the canister should be placed in a radiation shield or not during transport in the secondary tunnels, was not relevant to MLR. The basic technical problem is depositing heavy objects, the canister and the buffer components, in an horizontal hole which is approximately 200 m deep. Two methods for depositing of the bentonite barrier and the canisters in separate processes have been studied. For depositing of the bentonite barrier and the canister 'in a package', four alternative techniques have been studied: a metallic sleeve around the package, a loading scoop that is rotated, a fork carriage and rails. The repeated transports in a hole, a consequence of depositing several canisters in the same hole, could lead to the rock being crushed. The mutual impact of machines, load and rock wall has therefore been particularly considered. In several methods, the use of a gangway has been proposed (steel plates or layer of ice). A failure mode and effect analysis has been performed for one of the twelve methods. When comparing with a method to deposit one canister per hole using the same technique, the need for equipment and resources is far larger for this MLH method if incidents should occur during depositing. The development work reported here has not yet yielded a definitive method for placing

The influence of spray properties on intranasal deposition.

Science.gov (United States)

Foo, Mow Yee; Cheng, Yung-Sung; Su, Wei-Chung; Donovan, Maureen D

2007-01-01

While numerous devices, formulations, and spray characteristics have been shown to influence nasal deposition efficiency, few studies have attempted to identify which of these interacting factors plays the greatest role in nasal spray deposition. The deposition patterns of solutions with a wide range of surface tensions and viscosities were measured using an MRI-derived nasal cavity replica. The resulting spray plumes had angles between 29 degrees and 80 degrees and contained droplet sizes (D(v50)) from 37-157 microm. Each formulation contained rhodamine 590 as a fluorescent marker for detection. Administration angles of 30 degrees , 40 degrees , or 50 degrees above horizontal were tested to investigate the role of user technique on nasal deposition. The amount of spray deposited within specific regions of the nasal cavity was determined by disassembling the replica and measuring the amount of rhodamine retained in each section. Most of the spray droplets were deposited onto the anterior region of the model, but sprays with small plume angles were capable of reaching the turbinate region with deposition efficiencies approaching 90%. Minimal dependence on droplet size, viscosity, or device was observed. Changes in inspiratory flow rate (0-60 L/min) had no significant effect on turbinate deposition efficiency. Both plume angle and administration angle were found to be important factors in determining deposition efficiency. For administration angles of 40 degrees or 50 degrees , maximal turbinate deposition efficiency (30-50%) occurred with plume angles of 55-65 degrees , whereas a 30 degrees administration angle gave an approximately 75% deposition efficiency for similar plume angles. Deposition efficiencies of approximately 90% could be achieved with plume angles deposition efficiency, while many other spray parameters, including particle size, have relatively minor influences on deposition within the nasal cavity.

SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

Science.gov (United States)

Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

2016-05-01

The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I-V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

Exploring the deposition of oxides on silicon for photovoltaic cells by pulsed laser deposition

NARCIS (Netherlands)

Doeswijk, L.M.; de Moor, Hugo H.C.; Rogalla, Horst; Blank, David H.A.

2002-01-01

Since most commercially available solar cells are still made from silicon, we are exploring the introduction of passivating qualities in oxides, with the potential to serve as an antireflection coating. Pulsed laser deposition (PLD) was used to deposit TiO2 and SrTiO3 coatings on silicon substrates.

The Pulsed Cylindrical Magnetron for Deposition

Science.gov (United States)

Korenev, Sergey

2012-10-01

The magnetron sputtering deposition of films and coatings broadly uses in microelectronics, material science, environmental applications and etc. The rate of target evaporation and time for deposition of films and coatings depends on magnetic field. These parameters link with efficiency of gas molecules ionization by electrons. The cylindrical magnetrons use for deposition of films and coatings on inside of pipes for different protective films and coatings in oil, chemical, environmental applications. The classical forming of magnetic field by permanent magnets or coils for big and long cylindrical magnetrons is complicated. The new concept of pulsed cylindrical magnetron for high rate deposition of films and coating for big and long pipes is presented in this paper. The proposed cylindrical magnetron has azimuthally pulsed high magnetic field, which allows forming the high ionized plasma and receiving high rate of evaporation material of target (central electrode). The structure of proposed pulsed cylindrical magnetron sputtering system is given. The main requirements to deposition system are presented. The preliminary data for forming of plasma and deposition of Ta films and coatings on the metal pipers are discussed. The comparison of classical and proposed cylindrical magnetrons is given. The analysis of potential applications is considered.

Vein type uranium deposits

International Nuclear Information System (INIS)

1986-01-01

Veins are tabular- or sheet-like masses of minerals occupying or following a fracture or a set of fractures in the enclosing rock. They have been formed later than the country rock and fractures, either by filling of the open spaces or by partial or complete replacement of the adjoining rock or most commonly by both of these processes combined. This volume begins with the occurrences and deposits known from old shield areas and the sedimentary belts surrounding them. They are followed by papers describing the European deposits mostly of Variscan age, and by similar deposits known from China being of Jurassic age. The volume is completed by two papers which do not fit exactly in the given scheme. A separate abstract was prepared for each of the 25 papers in this report

Liquefier Dynamics in Fused Deposition

DEFF Research Database (Denmark)

Bellini, Anna; Guceri, Selcuk; Bertoldi, Maurizio

2004-01-01

Layered manufacturing (LM) is an evolution of rapid prototyping (RP) technology whereby a part is built in layers. Fused deposition modeling (FDM) is a particular LM technique in which each section is fabricated through vector style deposition of building blocks, called roads, which...

Comparison of radiation detector performance for different metal contacts on CdZnTe deposited by electroless deposition method

Energy Technology Data Exchange (ETDEWEB)

Zheng, Q.; Dierre, F.; Crocco, J.; Bensalah, H.; Dieguez, E. [Crystal Growth Laboratory, Department of Materials Physics, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Ayoub, M. [Durham Scientific Crystals Laboratory, Netpark, Thomas Wright Way, Sedgefield, TS21, 3FD (United Kingdom); Corregidor, V.; Alves, E. [Unidade de Fisica e Aceleradores, LFI, ITN, E.N.10, 2686-953, Sacavem (Portugal); Fernandez-Ruiz, R. [Servicio Interdepartamental de Investigacion. Laboratorio de TXRF/Laue-XRD. Facultad de Ciencias, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Perez, J.M. [CIEMAT, Edificio 22, Avda Complutense 22, 28040 Madrid (Spain)

2011-11-15

A comparative study of four different metals gold (Au), platinum (Pt), ruthenium (Ru) and rhodium (Rh) deposited on CdZnTe(CZT) by the electroless deposition method has been carried out. Two of these materials, Ru and Rh, have been deposited for the first time by this method. In contrast to the Pt deposition, the deposition of Ru and Rh were not carried out under the optimal conditions. The metals deposited on the samples were identified by Total reflection X-ray Fluorescence (TXRF). Rutherford Backscattering Spectrometry (RBS) analyses show that Au forms the thickest layer ({proportional_to}160 nm) for the experimental conditions of this work. Current-voltage measurements show that Pt forms a more linear ohmic contact with the lowest leakage current. A {sup 57}Co gamma ray spectrum gave a better detector performance with a FWHM 11 keV at 122 keV. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Deposition of corrosion products in-core

International Nuclear Information System (INIS)

Burrill, K.A.

1994-11-01

Data on corrosion product deposits on fuel sheaths are presented for a variety of operating conditions and water chemistries: boiling and non-boiling water; surface heat flux; pH, dissolved hydrogen concentration. Corrosion product behaviour in-core may be interpreted in terms of the solubility of magnetite and how it changes with water chemistry and temperature. A hypothesis of the deposition and release mechanisms was proposed in the 1970s in which particles deposited onto the sheath and subsequently dissolved in the heated water while being irradiated. Some of the deposition data may be interpreted using a model of these mechanisms. (author). 5 refs., 6 tabs., 8 figs

Investigation of deposition characteristics and properties of high-rate deposited silicon nitride films prepared by atmospheric pressure plasma chemical vapor deposition

International Nuclear Information System (INIS)

Kakiuchi, H.; Nakahama, Y.; Ohmi, H.; Yasutake, K.; Yoshii, K.; Mori, Y.

2005-01-01

Silicon nitride (SiN x ) films have been prepared at extremely high deposition rates by the atmospheric pressure plasma chemical vapor deposition (AP-PCVD) technique on Si(001) wafers from gas mixtures containing He, H 2 , SiH 4 and N 2 or NH 3 . A 150 MHz very high frequency (VHF) power supply was used to generate high-density radicals in the atmospheric pressure plasma. Deposition rate, composition and morphology of the SiN x films prepared with various deposition parameters were studied by scanning electron microscopy and Auger electron spectroscopy. Fourier transformation infrared (FTIR) absorption spectroscopy was also used to characterize the structure and the chemical bonding configurations of the films. Furthermore, etching rate with buffered hydrofluoric acid (BHF) solution, refractive index and capacitance-voltage (C-V) characteristics were measured to evaluate the dielectric properties of the films. It was found that effective passivation of dangling bonds and elimination of excessive hydrogen atoms at the film-growing surface seemed to be the most important factor to form SiN x film with a dense Si-N network. The C-V curve of the optimized film showed good interface properties, although further improvement was necessary for use in the industrial metal-insulator-semiconductor (MIS) applications

Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

International Nuclear Information System (INIS)

Hernandez-Como, N.; Martinez-Landeros, V.; Mejia, I.; Aguirre-Tostado, F.S.; Nascimento, C.D.; Azevedo, G. de M; Krug, C.; Quevedo-Lopez, M.A.

2014-01-01

The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10 −1 to 10 4 Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 10 19 to 10 13 cm −3 and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm 2 /V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 10 19 to 10 13 cm −3 . • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied

Corrosion properties of aluminum based alloys deposited by ion beam assisted deposition

International Nuclear Information System (INIS)

Enders, B.; Krauss, S.; Wolf, G.K.

1994-01-01

The replacement of cadmium coatings by other protective measures is an important task because of the environmentally detrimental properties of cadmium. Therefore, aluminum and aluminum alloy coatings containing elements such as silicon or magnesium with more positive or negative positions in the galvanic series in relation to pure aluminum were deposited by ion beam assisted deposition onto glass and low carbon steel. Pure aluminum films were deposited onto low carbon steel in order to study the influence of the ion-to-atom arrival ratio and the angle of ion incidence on the corrosion properties. For examination of the pitting behavior as a function of the concentration of alloying element, quasipotentiostatic current-potential and potentiostatic current-time plots were measured in chlorine-containing acetate buffer. It is shown that these alloys can protect steel substrates under uniform and pitting corrosion conditions considerably better than pure aluminum coatings. ((orig.))

Hybrid inorganic–organic superlattice structures with atomic layer deposition/molecular layer deposition

Energy Technology Data Exchange (ETDEWEB)

Tynell, Tommi; Yamauchi, Hisao; Karppinen, Maarit, E-mail: maarit.karppinen@aalto.fi [Department of Chemistry, Aalto University, FI-00076 Aalto (Finland)

2014-01-15

A combination of the atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques is successfully employed to fabricate thin films incorporating superlattice structures that consist of single layers of organic molecules between thicker layers of ZnO. Diethyl zinc and water are used as precursors for the deposition of ZnO by ALD, while three different organic precursors are investigated for the MLD part: hydroquinone, 4-aminophenol and 4,4′-oxydianiline. The successful superlattice formation with all the organic precursors is verified through x-ray reflectivity studies. The effects of the interspersed organic layers/superlattice structure on the electrical and thermoelectric properties of ZnO are investigated through resistivity and Seebeck coefficient measurements at room temperature. The results suggest an increase in carrier concentration for small concentrations of organic layers, while higher concentrations seem to lead to rather large reductions in carrier concentration.

Structural characterization of MAPLE deposited lipase biofilm

Energy Technology Data Exchange (ETDEWEB)

Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Ausanio, Giovanni; Bloisi, Francesco [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Calabria, Raffaela [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Califano, Valeria, E-mail: v.califano@im.cnr.it [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Massoli, Patrizio [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Vicari, Luciano R.M. [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy)

2014-11-30

Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase.

Regional aerosol deposition in human upper airways

International Nuclear Information System (INIS)

Swift, D.L.

1991-01-01

During the current report experimental studies of upper respiratory deposition of radon progeny aerosols and stimulant aerosols were carried out in replicate casts of nasal and oral passages of adults and children. Additionally, preliminary studies of nasal passage deposition of unattached Po 218 particles was carried out in four human subjects. Data on nasal inspiratory deposition in replicate models of adults and infants from three collaborating laboratories were compared and a best-fit curve of deposition efficiency for both attached and unattached particles was obtained, showing excellent inter-laboratory agreement. This curve demonstrates that nasal inspiratory deposition of radon progeny is weakly dependent upon flow rate over physiologically realistic ranges of flow, does not show a significant age effect, and is relatively independent of nasal passage dimensions for a given age range. Improved replicate models of the human adult oral passage extending to the mid-trachea were constructed for medium and higher flow mouth breathing states; these models were used to assess the deposition of unattached Po 218 particles during oronasal breathing in the oral passage and demonstrated lower deposition efficiency than the nasal passage. Measurements of both Po 218 particle and attached fraction particle size deposition were performed in replicate nasal passage of a four week old infant. 5 refs., 1 fig

Ion vapor deposition and its application

International Nuclear Information System (INIS)

Bollinger, H.; Schulze, D.; Wilberg, R.

1981-01-01

Proceeding from the fundamentals of ion vapor deposition the characteristic properties of ion-plated coatings are briefly discussed. Examples are presented of successful applications of ion-plated coatings such as coatings with special electrical and dielectric properties, coatings for corrosion prevention, and coatings for improving the surface properties. It is concluded that ion vapor deposition is an advantageous procedure in addition to vapor deposition. (author)

Development of Budenovskoye Deposit in South Kazakhstan

International Nuclear Information System (INIS)

Matunov, A.; Niyetbayev, M.

2014-01-01

Budenovskoye deposit was discovered in 1979 in permeable alluvial deposits of the Upper Cretaceous and is the world largest sandstone type deposit. The prospecting and exploration works were started there in 1987 with inferred resources of the southern flank only estimated at about 200,000 tU. Key geology features of the deposit are: • The deposit is located in the maximum submerged part of the depression formed in the Upper Cretaceous period by channel facies; a very complex morphology of mineralisation in plan, large vertical area, multilayer structure, relatively high productivity of the deposits. • High-pressure nature of groundwaters with positive occurrence of piezometric level, very high water conductivity, permeability of horizons and their water abundance, lack of consistent confining layers, and location of the deposit in the artesian basin at the junction with hydrogeological massif of B Karatau Range. • Relatively low concentration of main syngenetic genesis reducing agents in ore-bearing rocks in combination with other factors causes the insufficiently contrastive reducing barrier and extraordinary stretched profile of epigenetic zonation with fuzzy boundaries between separate zones and subzones.

TULSA UNIVERSITY PARAFFIN DEPOSITION PROJECTS

Energy Technology Data Exchange (ETDEWEB)

Cem Sarica; Michael Volk

2004-06-01

As oil and gas production moves to deeper and colder water, subsea multiphase production systems become critical for economic feasibility. It will also become increasingly imperative to adequately identify the conditions for paraffin precipitation and predict paraffin deposition rates to optimize the design and operation of these multi-phase production systems. Although several oil companies have paraffin deposition predictive capabilities for single-phase oil flow, these predictive capabilities are not suitable for the multiphase flow conditions encountered in most flowlines and wellbores. For deepwater applications in the Gulf of Mexico, it is likely that multiphase production streams consisting of crude oil, produced water and gas will be transported in a single multiphase pipeline to minimize capital cost and complexity at the mudline. Existing single-phase (crude oil) paraffin deposition predictive tools are clearly inadequate to accurately design these pipelines, because they do not account for the second and third phases, namely, produced water and gas. The objective of this program is to utilize the current test facilities at The University of Tulsa, as well as member company expertise, to accomplish the following: enhance our understanding of paraffin deposition in single and two-phase (gas-oil) flows; conduct focused experiments to better understand various aspects of deposition physics; and, utilize knowledge gained from experimental modeling studies to enhance the computer programs developed in the previous JIP for predicting paraffin deposition in single and two-phase flow environments. These refined computer models will then be tested against field data from member company pipelines.

Dry deposition of gaseous oxidized mercury in Western Maryland.

Science.gov (United States)

Castro, Mark S; Moore, Chris; Sherwell, John; Brooks, Steve B

2012-02-15

The purpose of this study was to directly measure the dry deposition of gaseous oxidized mercury (GOM) in western Maryland. Annual estimates were made using passive ion-exchange surrogate surfaces and a resistance model. Surrogate surfaces were deployed for seventeen weekly sampling periods between September 2009 and October 2010. Dry deposition rates from surrogate surfaces ranged from 80 to 1512 pgm(-2)h(-1). GOM dry deposition rates were strongly correlated (r(2)=0.75) with the weekly average atmospheric GOM concentrations, which ranged from 2.3 to 34.1 pgm(-3). Dry deposition of GOM could be predicted from the ambient air concentrations of GOM using this equation: GOM dry deposition (pgm(-2)h(-1))=43.2 × GOM concentration-80.3. Dry deposition velocities computed using GOM concentrations and surrogate surface GOM dry deposition rates, ranged from 0.2 to 1.7 cms(-1). Modeled dry deposition rates were highly correlated (r(2)=0.80) with surrogate surface dry deposition rates. Using the overall weekly average surrogate surface dry deposition rate (369 ± 340 pg m(-2)h(-1)), we estimated an annual GOM dry deposition rate of 3.2 μg m(-2)year(-1). Using the resistance model, we estimated an annual GOM dry deposition rate of 3.5 μg m(-2)year(-1). Our annual GOM dry deposition rates were similar to the dry deposition (3.3 μg m(-2)h(-1)) of gaseous elemental mercury (GEM) at our site. In addition, annual GOM dry deposition was approximately 1/2 of the average annual wet deposition of total mercury (7.7 ± 1.9 μg m(-2)year(-1)) at our site. Total annual mercury deposition from dry deposition of GOM and GEM and wet deposition was approximately 14.4 μg m(-2)year(-1), which was similar to the average annual litterfall deposition (15 ± 2.1 μg m(-2)year(-1)) of mercury, which was also measured at our site. Copyright © 2012 Elsevier B.V. All rights reserved.

Progress in the Study of Coastal Storm Deposits

Science.gov (United States)

Xiong, Haixian; Huang, Guangqing; Fu, Shuqing; Qian, Peng

2018-05-01

Numerous studies have been carried out to identify storm deposits and decipher storm-induced sedimentary processes in coastal and shallow-marine areas. This study aims to provide an in-depth review on the study of coastal storm deposits from the following five aspects. 1) The formation of storm deposits is a function of hydrodynamic and sedimentary processes under the constraints of local geological and ecological factors. Many questions remain to demonstrate the genetic links between storm-related processes and a variety of resulting deposits such as overwash deposits, underwater deposits and hummocky cross-stratification (HCS). Future research into the formation of storm deposits should combine flume experiments, field observations and numerical simulations, and make full use of sediment source tracing methods. 2) Recently there has been rapid growth in the number of studies utilizing sediment provenance analysis to investigate the source of storm deposits. The development of source tracing techniques, such as mineral composition, magnetic susceptibility, microfossil and geochemical property, has allowed for better understanding of the depositional processes and environmental changes associated with coastal storms. 3) The role of extreme storms in the sedimentation of low-lying coastal wetlands with diverse ecosystem services has also drawn a great deal of attention. Many investigations have attempted to quantify widespread land loss, vertical marsh sediment accumulation and wetland elevation change induced by major hurricanes. 4) Paleostorm reconstructions based on storm sedimentary proxies have shown many advantages over the instrumental records and historic documents as they allow for the reconstruction of storm activities on millennial or longer time scales. Storm deposits having been used to establish proxies mainly include beach ridges and shelly cheniers, coral reefs, estuary-deltaic storm sequences and overwash deposits. Particularly over the past few

Metasomatic zoning at some stratiform rare metal deposits

International Nuclear Information System (INIS)

Altyntsev, Yu.V.; Bazhenov, M.I.; Bepeshov, G.V.; Komarnitskij, G.M.; Petrov, I.Ya.; Serykh, A.S.

1985-01-01

Metasomatic zoning of stratiform deposits of rare metals (Mo, Pb, As, V, Se, U, etc.) in intermontane depresions, deposited at the postorogenic stage of Paleozoic geosyncline region development, is considered. Geochemical and geophysical characteristics of metasomatic zoning in the case of sloping and steep rock deposition are given. It is established, that in rare metal deposits in variegated deposits of molassoid formation of Middle-Upper Paleozoic the external and internal zones of metasomatic alterations are distinctly separated. The external zone is presented by mineral association: quartz + -albile + -calcite + -epidote; the internal one - by hydromica + -chlorite + -analcite, laumontite + -hematite + -ankerite + -kaolinite. Geochemical zoning is manifested quite regularly at all the deposits and it is subjected to metasomatic zoning. Changes in physical properties of rocks reflect the metasomatic zoning. The character of metasomatic alterations of rocks, geochemical zoning of metasomatites at rare metal deposits in molassoid deposits and spatially contiguous deposits in volcanogenic complexes have common features. A supposition is made on polygenic ore formation in sedimentary rocks of the depressions

Temperature dependence of InN film deposition by an RF plasma-assisted reactive ion beam sputtering deposition technique

International Nuclear Information System (INIS)

Shinoda, Hiroyuki; Mutsukura, Nobuki

2005-01-01

Indium nitride (InN) films were deposited on Si(100) substrates using a radiofrequency (RF) plasma-assisted reactive ion beam sputtering deposition technique at various substrate temperatures. The X-ray diffraction patterns of the InN films suggest that the InN films deposited at substrate temperatures up to 370 deg C were cubic crystalline InN; and at 500 deg C, the InN film was hexagonal crystalline InN. In a scanning electron microscope image of the InN film surface, facets of cubic single-crystalline InN grains were clearly observed on the InN film deposited at 370 deg C. The inclusion of metallic indium appeared on the InN film deposited at 500 deg C

Dry deposition of particulate Cs-134 to several leafy vegetable species and comparison to deposition of gaseous radioiodine

International Nuclear Information System (INIS)

Tschiersch, J.; Shinonaga, T.; Heuberger, H.

2004-01-01

The height of the dry deposition of particulate radionuclides to leafy vegetable is quite uncertain because of the different habit, surface texture and leaf uptake of the different species. There is no comparative data on the deposition to various species, but leafy vegetables are taken as reference plants for the estimation of the height of contamination of vegetable foods after a nuclear accident. Therefore new chamber experiments were performed to determine under homogeneous and controlled conditions the dry deposition of particulate radio-caesium on mature leafy vegetable. The simultaneous exposition of endive, head lettuce, red oak leaf lettuce and spinach (spring leafy vegetable) rsp. curly kale, white cabbage and spinach (summer leafy vegetable) was arranged. The sample collective of each species was such large that for the expected variation of the results a statistically firm analysis was possible. For spring vegetable, there was no significant difference observed in deposition of 134 Cs between spinach and leaf lettuce, about twice the amount was deposited on both species as on endive and 3 times as on head lettuce. All summer vegetables showed differences in deposition for Caesium, the deposition to curly kale was highest, about twice that on spinach and 35 times (80 times) that on white cabbage. The normalized deposition velocity could be estimated, in average it was about 8 times lower for 134 Cs than for gaseous elemental 131 I. The influence of the particle size on the deposition velocity was small in the considered size range of 0.58-1.1μm (AMAD) of the monodisperse aerosol. Washing could reduce the contamination by about 45% for 134 Cs. (author)

Atomic layer deposition of copper thin film and feasibility of deposition on inner walls of waveguides

Science.gov (United States)

Yuqing, XIONG; Hengjiao, GAO; Ni, REN; Zhongwei, LIU

2018-03-01

Copper thin films were deposited by plasma-enhanced atomic layer deposition at low temperature, using copper(I)-N,N‧-di-sec-butylacetamidinate as a precursor and hydrogen as a reductive gas. The influence of temperature, plasma power, mode of plasma, and pulse time, on the deposition rate of copper thin film, the purity of the film and the step coverage were studied. The feasibility of copper film deposition on the inner wall of a carbon fibre reinforced plastic waveguide with high aspect ratio was also studied. The morphology and composition of the thin film were studied by atomic force microscopy and x-ray photoelectron spectroscopy, respectively. The square resistance of the thin film was also tested by a four-probe technique. On the basis of on-line diagnosis, a growth mechanism of copper thin film was put forward, and it was considered that surface functional group played an important role in the process of nucleation and in determining the properties of thin films. A high density of plasma and high free-radical content were helpful for the deposition of copper thin films.

A case of regression of atypical dense deposit disease without C3 deposition in a child.

Science.gov (United States)

Kim, Min Sun; Hwang, Pyoung Han; Kang, Mung Jae; Lee, Dae-Yeol

2010-07-01

Dense deposit disease (DDD) is a rare disorder characterized by the deposition of abnormal electron-dense material within the glomerular basement membrane of the kidneys. The diagnosis is made in most patients between 5 and 15 years of age, and within 10 years, approximately half of the affected patients progress to end-stage renal disease. We report a rare case of regressive DDD without C3 deposition after steroid therapy in an 11-year-old boy. The patient presented with edema, gross hematuria, and nephrotic-range proteinuria. Laboratory testing revealed a serum creatinine level of 1.17 mg/dL, albumin level of 2.3 g/dL, and serum C3 level of 125 mg/dL (range 90-180 mg/dL). The results of the renal biopsy were consistent with DDD without C3 deposition. After 6 weeks of steroid therapy, the nephrotic syndrome completely resolved. The follow-up renal biopsy showed a significant reduction in mesangial proliferation and disappearance of electron-dense deposits in the GBM.

Properties of indium tin oxide films deposited on unheated polymer substrates by ion beam assisted deposition

International Nuclear Information System (INIS)

Yu Zhinong; Li Yuqiong; Xia Fan; Zhao Zhiwei; Xue Wei

2009-01-01

The optical, electrical and mechanical properties of indium tin oxide (ITO) films prepared on polyethylene terephthalate (PET) substrates by ion beam assisted deposition at room temperature were investigated. The properties of ITO films can be improved by introducing a buffer layer of silicon dioxide (SiO 2 ) between the ITO film and the PET substrate. ITO films deposited on SiO 2 -coated PET have better crystallinity, lower electrical resistivity, and improved resistance stability under bending than those deposited on bare PET. The average transmittance and the resistivity of ITO films deposited on SiO 2 -coated PET are 85% and 0.90 x 10 -3 Ω cm, respectively, and when the films are bent, the resistance remains almost constant until a bending radius of 1 cm and it increases slowly under a given bending radius with an increase of the bending cycles. The improved resistance stability of ITO films deposited on SiO 2 -coated PET is mainly attributed to the perfect adhesion of ITO films induced by the SiO 2 buffer layer.

Ti-doped hydrogenated diamond like carbon coating deposited by hybrid physical vapor deposition and plasma enhanced chemical vapor deposition

Science.gov (United States)

Lee, Na Rae; Sle Jun, Yee; Moon, Kyoung Il; Sunyong Lee, Caroline

2017-03-01

Diamond-like carbon films containing titanium and hydrogen (Ti-doped DLC:H) were synthesized using a hybrid technique based on physical vapor deposition (PVD) and plasma enhanced chemical vapor deposition (PECVD). The film was deposited under a mixture of argon (Ar) and acetylene gas (C2H2). The amount of Ti in the Ti-doped DLC:H film was controlled by varying the DC power of the Ti sputtering target ranging from 0 to 240 W. The composition, microstructure, mechanical and chemical properties of Ti-doped DLC:H films with varying Ti concentrations, were investigated using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nano indentation, a ball-on-disk tribometer, a four-point probe system and dynamic anodic testing. As a result, the optimum composition of Ti in Ti-doped DLC:H film using our hybrid method was found to be a Ti content of 18 at. %, having superior electrical conductivity and high corrosion resistance, suitable for bipolar plates. Its hardness value was measured to be 25.6 GPa with a low friction factor.

The fluid mechanics of deposition - how it gets there and why lattice-bar supports are deposition resistant

International Nuclear Information System (INIS)

Schneider, B.; Aly, K.

2012-01-01

Much analysis, research and inspection has gone into the understanding of deposition within steam generators. All of that work notwithstanding, it still remains a mystery in many respects - particularly regarding the fluid mechanics of deposition. This presentation tracks corrosion product transport (CPT) ingress to an SG and the approximate distribution of the resultant deposition. It also investigates deposition of the small but highly problematic amount of CPT which ends up on the tube-supports (TSPs). CPT ingress during full-power operation of modern well-run steam generators (SGs) represents as reported elsewhere at this conference, a very small amount of material. Unfortunately operation has not always achieved such standards. Plants with a few decades operation may have significant deposition – a condition which may well be accompanied by severe tube and tube-support deposition and the consequent blockage of the TSPs. CPT ingress to a steam generator may, in very rough numbers, distribute as follows; i) removal by blow-down ~ 15% (i.e. - most of what comes in stays in the SG); ii) deposition to the SG tube surface ~ 50% (plated out thinly over the 1 to 2 acres of SG tube surface); iii) tube-sheet sludge pile ~ 25% (bad news for tube life, but easy to inspect and water-lance); iv) TSP deposition <~5% (a small but highly problematic amount of material). Deposition as it turns out is exacerbated by the fluid-mechanics at square-cornered contractions which may exist at the entrance to flow passages of some types of tube-supports. High local velocities will occur at such corners – resulting in a significant local static-pressure depression – which causes flash-evaporation – which can leave behind CPT materials particularly in areas of moderately high bulk quality. All of that results counter-intuitively, in the initiation of deposition right at the -corner of the tube support. This type of inlet-corner deposition was first seen about three decades ago at

Depositional characteristics of cretaceous cover in Xiangyangshan area of Heilongjiang province and analysis on prospect for sandstone hosted interlayer oxidation zone type uranium deposits

International Nuclear Information System (INIS)

Cai Yuqi; Li Shengxiang; Dong Wenming

2003-01-01

The depositional systems and characteristics of Cretaceous Cover depositional facies are discussed. In combination with logging curves in Xiangyangshan area, two depositional systems (namely, alluvial fan depositional system and alluvial plain depositional system) and five types of depositional facies are distinguished. Results of detailed research are given for each depositional facies in aspects of lithology, depositional structure, logging curve and grain size distribution pattern. Temporal and spatial distribution features of the depositional facies and the development features of interlayer oxidation zones of the second member of Quantou Formation are analyzed. Finally, conclusions on prospects for sandstone-hosted interlayer oxidation zone type uranium deposits in the study area are given in the aspect of depositional facies. (authors)

ROLE OF DEPOSIT POLICY FOR UKRAINIAN BANKING INSTITUTIONS

Directory of Open Access Journals (Sweden)

Nadezhda Bova

2015-11-01

Full Text Available The purpose of the paper is to define and demonstrate the role of deposit policy for banking institutions, summarize and highlight the problems and its solutions in deposit policy of Ukraine that provides economic downturn and recovery. Appropriate selection and implementation of the deposit policy objectives, its operational structure and tools determines the degree of development of financial inclusion, which generate developed financial market, ensures public confidence to the deposit services, and increases the level of savings that positively affects the banking system financial stability and economy in the country in whole. It is because of availability and security deposit services, commercial banks of Ukraine have the opportunity to increase its resource base due to savings of the population. Methodology. The paper is based on a synthesis of data to explore the bank deposit policy situation. The paper considers the scientific and theoretical approaches for the developing the deposit policy management. It contains the analysis of the dynamics and current situation and conditions of the resource potential of banking institutions in Ukraine. Results of the article shows direct dependency between savings, consumption and deposit policy, therefore every banking institution includes the mechanism of banking management of the development and implementation of deposit policy. Also, this management defines the deposit policy directions according to the conditions of bank resources mobilization and its applying in active operations. The obtained results confirm that the term “deposit policy” is too complex, but it is investigated in interaction with banking activity. It is explained how deposit policy influences banking system and has impact on economic growth in general. Practical implications. The research creates methodological approaches to the measurement of effectiveness of deposit policy. Also, it studies the existing ones. It provides

Study of nozzle deposit formation mechanism for direct injection gasoline engines; Chokufun gasoline engine yo nozzle no deposit seisei kaiseki

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, M; Saito, A [Toyota Central Research and Development Labs., Inc., Aichi (Japan); Matsushita, S [Toyota Motor Corp., Aichi (Japan); Shibata, H [Nippon Soken, Inc., Tokyo (Japan); Niwa, Y [Denso Corp., Aichi (Japan)

1997-10-01

Nozzles in fuel injectors for direct injection gasoline engines are exposed to high temperature combustion gases and soot. In such a rigorous environment, it is a fear that fuel flow rate changes in injectors by deposit formation on nozzles. Fundamental factors of nozzle deposit formation were investigated through injector bench tests and engine dynamometer tests. Deposit formation processes were observed by SEM through engine dynamometer tests. The investigation results reveal nozzle deposit formation mechanism and how to suppress the deposit. 4 refs., 8 figs., 3 tabs.

Biosensor Applications of MAPLE Deposited Lipase

Directory of Open Access Journals (Sweden)

Valeria Califano

2014-10-01

Full Text Available Matrix Assisted Pulsed Laser Evaporation (MAPLE is a thin film deposition technique derived from Pulsed Laser Deposition (PLD for deposition of delicate (polymers, complex biological molecules, etc. materials in undamaged form. The main difference of MAPLE technique with respect to PLD is the target: it is a frozen solution or suspension of the (guest molecules to be deposited in a volatile substance (matrix. Since laser beam energy is mainly absorbed by the matrix, damages to the delicate guest molecules are avoided, or at least reduced. Lipase, an enzyme catalyzing reactions borne by triglycerides, has been used in biosensors for detection of β-hydroxyacid esters and triglycerides in blood serum. Enzymes immobilization on a substrate is therefore required. In this paper we show that it is possible, using MAPLE technique, to deposit lipase on a substrate, as shown by AFM observation, preserving its conformational structure, as shown by FTIR analysis.

Tax evasion and Swiss bank deposits

DEFF Research Database (Denmark)

Johannesen, Niels

2014-01-01

quarters immediately before and after the tax was introduced. We also present evidence suggesting that the drop in Swiss bank deposits was driven by behavioral responses aiming to escape the tax - such as the transfer of funds to bank accounts in other offshore centers and the transfer of formal ownership......Bank deposits in offshore financial centers may be used to evade taxes on interest income. A recent EU reform limits the scope for this type of tax evasion by introducing a withholding tax on interest income earned by EU households in Switzerland and several other offshore centers. This paper...... estimates the impact of the withholding tax on Swiss bank deposits held by EU residents while using non-EU residents who were not subject to the tax as a comparison group. We present evidence that Swiss bank deposits owned by EU residents declined by 30–40% relative to other Swiss bank deposits in two...

Laser ablation and deposition of wide bandgap semiconductors: plasma and nanostructure of deposits diagnosis

Science.gov (United States)

Sanz, M.; López-Arias, M.; Rebollar, E.; de Nalda, R.; Castillejo, M.

2011-12-01

Nanostructured CdS and ZnS films on Si (100) substrates were obtained by nanosecond pulsed laser deposition at the wavelengths of 266 and 532 nm. The effect of laser irradiation wavelength on the surface structure and crystallinity of deposits was characterized, together with the composition, expansion dynamics and thermodynamic parameters of the ablation plume. Deposits were analyzed by environmental scanning electron microscopy, atomic force microscopy and X-ray diffraction, while in situ monitoring of the plume was carried out with spectral, temporal and spatial resolution by optical emission spectroscopy. The deposits consist of 25-50 nm nanoparticle assembled films but ablation in the visible results in larger aggregates (150 nm) over imposed on the film surface. The aggregate free films grown at 266 nm on heated substrates are thicker than those grown at room temperature and in the former case they reveal a crystalline structure congruent with that of the initial target material. The observed trends are discussed in reference to the light absorption step, the plasma composition and the nucleation processes occurring on the substrate.

49 CFR 386.46 - Depositions.

Science.gov (United States)

2010-10-01

..., INTERMODAL EQUIPMENT PROVIDER, BROKER, FREIGHT FORWARDER, AND HAZARDOUS MATERIALS PROCEEDINGS General Rules... to referral to the Office of Hearings, a party may petition the Assistant Administrator, in accordance with § 386.37, for leave to conduct a deposition based on good cause shown. (2) Depositions may be...

Thermal release of D2 from new Be-D co-deposits on previously baked co-deposits

Science.gov (United States)

Baldwin, M. J.; Doerner, R. P.

2015-12-01

Past experiments and modeling with the TMAP code in [1, 2] indicated that Be-D co-deposited layers are less (time-wise) efficiently desorbed of retained D in a fixed low-temperature bake, as the layer grows in thickness. In ITER, beryllium rich co-deposited layers will grow in thickness over the life of the machine. Although, compared with the analyses in [1, 2], ITER presents a slightly different bake efficiency problem because of instances of prior tritium recover/control baking. More relevant to ITER, is the thermal release from a new and saturated co-deposit layer in contact with a thickness of previously-baked, less-saturated, co-deposit. Experiments that examine the desorption of saturated co-deposited over-layers in contact with previously baked under-layers are reported and comparison is made to layers of the same combined thickness. Deposition temperatures of ∼323 K and ∼373 K are explored. It is found that an instance of prior bake leads to a subtle effect on the under-layer. The effect causes the thermal desorption of the new saturated over-layer to deviate from the prediction of the validated TMAP model in [2]. Instead of the D thermal release reflecting the combined thickness and levels of D saturation in the over and under layer, experiment differs in that, i) the desorption is a fractional superposition of desorption from the saturated over-layer, with ii) that of the combined over and under -layer thickness. The result is not easily modeled by TMAP without the incorporation of a thin BeO inter-layer which is confirmed experimentally on baked Be-D co-deposits using X-ray micro-analysis.

Thermal release of D_2 from new Be-D co-deposits on previously baked co-deposits

International Nuclear Information System (INIS)

Baldwin, M.J.; Doerner, R.P.

2015-01-01

Past experiments and modeling with the TMAP code in [1, 2] indicated that Be-D co-deposited layers are less (time-wise) efficiently desorbed of retained D in a fixed low-temperature bake, as the layer grows in thickness. In ITER, beryllium rich co-deposited layers will grow in thickness over the life of the machine. Although, compared with the analyses in [1, 2], ITER presents a slightly different bake efficiency problem because of instances of prior tritium recover/control baking. More relevant to ITER, is the thermal release from a new and saturated co-deposit layer in contact with a thickness of previously-baked, less-saturated, co-deposit. Experiments that examine the desorption of saturated co-deposited over-layers in contact with previously baked under-layers are reported and comparison is made to layers of the same combined thickness. Deposition temperatures of ∼323 K and ∼373 K are explored. It is found that an instance of prior bake leads to a subtle effect on the under-layer. The effect causes the thermal desorption of the new saturated over-layer to deviate from the prediction of the validated TMAP model in [2]. Instead of the D thermal release reflecting the combined thickness and levels of D saturation in the over and under layer, experiment differs in that, i) the desorption is a fractional superposition of desorption from the saturated over-layer, with ii) that of the combined over and under -layer thickness. The result is not easily modeled by TMAP without the incorporation of a thin BeO inter-layer which is confirmed experimentally on baked Be-D co-deposits using X-ray micro-analysis.

Hardness Enhancement of STS304 Deposited with Yttria Stabilized Zirconia by Aerosol Deposition Method

Energy Technology Data Exchange (ETDEWEB)

Lim, Il-Ho; Park, Chun-Kil; Kim, Hyung Sun; Jeong, Dea-Yong [Inha University, Incheon (Korea, Republic of); Lee, Yong-Seok [Sodoyeon Co., Yeoju (Korea, Republic of); Kong, Young-Min [University of Ulsan, Ulsan (Korea, Republic of); Kang, Kweon Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-03-15

To improve the surface hardness of the STS304, Yttria stabilized zirconia (YSZ) films with nano-sized grain were deposited by an aerosol-deposition (AD) method. Coating layers showed dense structure and had -5µm thickness. When 3 mol% YSZ powders with tetragonal phase were deposited on STS304 substrate, tetragonal structure was transformed to cubic structure due to the high impact energy during the AD process. At the same time, strong impact by YSZ particles allowed the austenite phase in STS304 to be transformed into martensite phase. Surface hardness measured with nano indentor showed that YSZ coated film had 11.5 GPa, which is larger value than 7 GPa of STS304.

Massive CO2 Ice Deposits Sequestered in the South Polar Layered Deposits of Mars

Science.gov (United States)

Phillips, Roger J.; Davis, Brian J.; Tanaka, Kenneth L.; Byrne, Shane; Mellon, Michael T.; Putzig, Nathaniel E.; Haberle, Robert M.; Kahre, Melinda A.; Campbell, Bruce A.; Carter, Lynn M.; Smith, Isaac B.; Holt, John W.; Smrekar, Suzanne E.; Nunes, Daniel C.; Plaut, Jeffrey J.; Egan, Anthony F.; Titus, Timothy N.; Seu, Roberto

2011-01-01

Shallow Radar soundings from the Mars Reconnaissance Orbiter reveal a buried deposit of carbon dioxide (CO2) ice within the south polar layered deposits of Mars with a volume of 9500 to 12,500 cubic kilometers, about 30 times that previously estimated for the south pole residual cap. The deposit occurs within a stratigraphic unit that is uniquely marked by collapse features and other evidence of interior CO2 volatile release. If released into the atmosphere at times of high obliquity, the CO2 reservoir would increase the atmospheric mass by up to 80%, leading to more frequent and intense dust storms and to more regions where liquid water could persist without boiling.

Preparation and characterization of thick metastable sputter deposits

International Nuclear Information System (INIS)

Allen, R.P.; Dahlgren, S.D.; Merz, M.D.

1975-01-01

High-rate dc supported-discharge sputtering techniques were developed and used to prepare 0.1 mm to 5.0 mm-thick deposits of a variety of metastable materials including amorphous alloys representing more than 15 different rare-earth-transition metal systems and a wide range of compositions and deposition conditions. The ability to prepare thick, homogeneous deposits has made it possible for the first time to investigate the structure, properties, and annealing behavior of these unique sputtered alloys using neutron diffraction, ultrasonic, and other experimental techniques that are difficult or impractical for thin films. More importantly, these characterization studies show that the structure and properties of the massive sputter deposits are independent of thickness and can be reproduced from deposit to deposit. Other advantages and applications of this metastable materials preparation technique include the possibility of varying structure and properties by control of the deposition parameters and the ability to deposit even reactive alloys with a very low impurity content

Estimating chemical composition of atmospheric deposition fluxes from mineral insoluble particles deposition collected in the western Mediterranean region

Directory of Open Access Journals (Sweden)

Y. Fu

2017-11-01

Full Text Available In order to measure the mass flux of atmospheric insoluble deposition and to constrain regional models of dust simulation, a network of automatic deposition collectors (CARAGA has been installed throughout the western Mediterranean Basin. Weekly samples of the insoluble fraction of total atmospheric deposition were collected concurrently on filters at five sites including four on western Mediterranean islands (Frioul and Corsica, France; Mallorca, Spain; and Lampedusa, Italy and one in the southern French Alps (Le Casset, and a weighing and ignition protocol was applied in order to quantify their mineral fraction. Atmospheric deposition is both a strong source of nutrients and metals for marine ecosystems in this area. However, there are few data on trace-metal deposition in the literature, since their deposition measurement is difficult to perform. In order to obtain more information from CARAGA atmospheric deposition samples, this study aimed to test their relevance in estimating elemental fluxes in addition to total mass fluxes. The elemental chemical analysis of ashed CARAGA filter samples was based on an acid digestion and an elemental analysis by inductively coupled plasma atomic emission spectroscopy (ICP-AES and mass spectrometry (MS in a clean room. The sampling and analytical protocols were tested to determine the elemental composition for mineral dust tracers (Al, Ca, K, Mg and Ti, nutrients (P and Fe and trace metals (Cd, Co, Cr, Cu, Mn, Ni, V and Zn from simulated wet deposition of dust analogues and traffic soot. The relative mass loss by dissolution in wet deposition was lower than 1 % for Al and Fe, and reached 13 % for P due to its larger solubility in water. For trace metals, this loss represented less than 3 % of the total mass concentration, except for Zn, Cu and Mn for which it could reach 10 %, especially in traffic soot. The chemical contamination during analysis was negligible for all the elements except for Cd

Dry deposition of radionuclides on leafy vegetables

International Nuclear Information System (INIS)

Heuberger, H.; Tschiersch, J.; Shinonaga, T.; Bunzl, K.; Pliml, A.; Dietl, F.; Keusch, M.

2004-01-01

The dry deposition of gaseous elemental radio-iodine and particulate radio-caesium on mature leafy vegetable was studied in chamber experiments. The simultaneous exposition of endive, head lettuce, red oak leaf lettuce and spinach (spring leafy vegetable) rsp. curly kale, white cabbage and spinach (summer leafy vegetable) was performed under homogeneous and controlled conditions. The sample collective of each species was such large that for the expected variation of the results a statistically firm analysis was possible. Significant differences were observed for the 131 I deposition on spring vegetable: the deposition on spinach was roughly 3times that on leaf lettuce, 4times that on endive and 9times that on head lettuce. For 134 Cs, there was no significant difference between spinach and leaf lettuce, about twice the amount was deposited on both species as on endive and 3times as on head lettuce. All summer vegetables showed differences in deposition. For lodine, the deposition on spinach was roughly 3times (6times) that on curly kale and 35times (100times) that on white cabbage in the 2 experiments. For caesium, the deposition to curly kale was highest, about twice that on spinach and 35times (80times) that on white cabbage. The deposition velocity could be estimated, in average it was about 8times higher for 131 I than for 134 Cs. The influence of the particle size on the deposition velocity was small in the considered size range. Washing could reduce the contamination by about 10% for 131 I and 45% for 134 Cs. (orig.)

Late Cretaceous porphyry copper mineralization in Sonora, Mexico: Implications for the evolution of the Southwest North America porphyry copper province

Science.gov (United States)

Barra, Fernando; Valencia, Victor A.

2014-10-01

Two porphyry Cu-Mo prospects in northern Sonora, Mexico (Fortuna del Cobre and Los Humos) located within the southwestern North American porphyry province have been dated in order to constrain the timing of crystallization and mineralization of these ore deposits. In Fortuna del Cobre, the pre-mineralization granodiorite porphyry yielded an U-Pb zircon age of 76.5 ± 2.3 Ma, whereas two samples from the ore-bearing quartz feldespathic porphyry were dated at 74.6 ± 1.3 and 75.0 ± 1.4 Ma. Four molybdenite samples from Los Humos porphyry Cu prospect yielded a weighted average Re-Os age of 73.5 ± 0.2 Ma, whereas two samples from the ore-bearing quartz monzonite porphyry gave U-Pb zircon ages of 74.4 ± 1.1 and 74.5 ± 1.3 Ma, showing a Late Cretaceous age for the emplacement of this ore deposit. The results indicate that Laramide porphyry Cu mineralization of Late Cretaceous age is not restricted to northern Arizona as previously thought and provide evidence for the definition of NS trending metallogenic belts that are parallel to the paleo-trench. Porphyry copper mineralization follows the inland migration trend of the magmatic arc as a result of the Farallon slab flattening during the Laramide orogeny.

Modelling of stomatal conductance and ozone deposition flux of Norway Spruce using deposition model

Czech Academy of Sciences Publication Activity Database

Zapletal, M.; Chroust, P.; Večeřa, Zbyněk; Mikuška, Pavel; Cudlín, Pavel; Urban, Otmar; Pokorný, Radek; Czerný, Radek; Janouš, Dalibor; Taufarová, Klára

2009-01-01

Roč. 12, 2-3 (2009), s. 75-81 ISSN 1335-339X R&D Projects: GA MŽP SP/1B7/189/07 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z40310501 Keywords : ozone concentration * ozone deposition * stomatal conductance * deposition velocity * resistance model * tropo-spheric ozone Subject RIV: DG - Athmosphere Sciences, Meteorology

Regional aerosol deposition in human upper airways

Energy Technology Data Exchange (ETDEWEB)

Swift, D.L.

1991-11-01

During the current report experimental studies of upper respiratory deposition of radon progeny aerosols and stimulant aerosols were carried out in replicate casts of nasal and oral passages of adults and children. Additionally, preliminary studies of nasal passage deposition of unattached Po{sup 218} particles was carried out in four human subjects. Data on nasal inspiratory deposition in replicate models of adults and infants from three collaborating laboratories were compared and a best-fit curve of deposition efficiency for both attached and unattached particles was obtained, showing excellent inter-laboratory agreement. This curve demonstrates that nasal inspiratory deposition of radon progeny is weakly dependent upon flow rate over physiologically realistic ranges of flow, does not show a significant age effect, and is relatively independent of nasal passage dimensions for a given age range. Improved replicate models of the human adult oral passage extending to the mid-trachea were constructed for medium and higher flow mouth breathing states; these models were used to assess the deposition of unattached Po{sup 218} particles during oronasal breathing in the oral passage and demonstrated lower deposition efficiency than the nasal passage. Measurements of both Po{sup 218} particle and attached fraction particle size deposition were performed in replicate nasal passage of a four week old infant. 5 refs., 1 fig.

Assessment of Global Mercury Deposition through Litterfall.

Science.gov (United States)

Wang, Xun; Bao, Zhengduo; Lin, Che-Jen; Yuan, Wei; Feng, Xinbin

2016-08-16

There is a large uncertainty in the estimate of global dry deposition of atmospheric mercury (Hg). Hg deposition through litterfall represents an important input to terrestrial forest ecosystems via cumulative uptake of atmospheric Hg (most Hg(0)) to foliage. In this study, we estimate the quantity of global Hg deposition through litterfall using statistical modeling (Monte Carlo simulation) of published data sets of litterfall biomass production, tree density, and Hg concentration in litter samples. On the basis of the model results, the global annual Hg deposition through litterfall is estimated to be 1180 ± 710 Mg yr(-1), more than two times greater than the estimate by GEOS-Chem. Spatial distribution of Hg deposition through litterfall suggests that deposition flux decreases spatially from tropical to temperate and boreal regions. Approximately 70% of global Hg(0) dry deposition occurs in the tropical and subtropical regions. A major source of uncertainty in this study is the heterogeneous geospatial distribution of available data. More observational data in regions (Southeast Asia, Africa, and South America) where few data sets exist will greatly improve the accuracy of the current estimate. Given that the quantity of global Hg deposition via litterfall is typically 2-6 times higher than Hg(0) evasion from forest floor, global forest ecosystems represent a strong Hg(0) sink.

Atmospheric deposition of heavy metals due to dry, wet and occult deposition at the altitude profile Achenkirch

International Nuclear Information System (INIS)

Stopper, S.

2001-12-01

The goal of this work was to determine the height dependence of the three types of deposition throughout a one year time period to be able to get information about their elevational and seasonal behavior. In the time period from October 1998 to November 1999 measurements of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn in aerosol, rain and cloud water were conducted in the Achenkirch-Valley in Tyrol, Austria. Afterwards the dry and occult deposition were modeled. The estimated annual inputs of metals at the two measurement sites Christlumkopf (1758 m a.s.l.) Mueeggerkoel (940 m a.s.l.) and the limits of the national law for protection of forest are shown. The measured depositions at both sites were far below the legal regulations. Due to the much higher occult deposition ratio at the top of the mountain the total annual input at the Christlumkopf was higher than at the Mueeggerkoel. This indicates the potential importance of occult deposition. (author)

Advance in research on aerosol deposition simulation methods

International Nuclear Information System (INIS)

Liu Keyang; Li Jingsong

2011-01-01

A comprehensive analysis of the health effects of inhaled toxic aerosols requires exact data on airway deposition. A knowledge of the effect of inhaled drugs is essential to the optimization of aerosol drug delivery. Sophisticated analytical deposition models can be used for the computation of total, regional and generation specific deposition efficiencies. The continuously enhancing computer seem to allow us to study the particle transport and deposition in more and more realistic airway geometries with the help of computational fluid dynamics (CFD) simulation method. In this article, the trends in aerosol deposition models and lung models, and the methods for achievement of deposition simulations are also reviewed. (authors)

Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Como, N. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Martinez-Landeros, V. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Mejia, I. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Aguirre-Tostado, F.S. [Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Nascimento, C.D.; Azevedo, G. de M; Krug, C. [Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91509-900 (Brazil); Quevedo-Lopez, M.A., E-mail: mquevedo@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States)

2014-01-01

The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10{sup −1} to 10{sup 4} Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 10{sup 19} to 10{sup 13} cm{sup −3} and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm{sup 2}/V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 10{sup 19} to 10{sup 13} cm{sup −3}. • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied.

Dry deposition of particles to ocean surfaces

NARCIS (Netherlands)

Larsen, S.E.; Edson, J.B.; Hummelshoj, P.; Jensen, N.O.; Leeuw, G. de; Mestayer, P.G.

1995-01-01

Dry deposition of atmospheric particles mainly depends on wind speed and particle diameter. The dry deposition velocity, Vd, is found to vary by a factor of 100-1,000 with diameter in a likely diameter range, adding uncertainty to deposition estimates, because the diameter distribution for many

European wet deposition maps based on measurements

NARCIS (Netherlands)

Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO

1995-01-01

To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

Annealing dependence of residual stress and optical properties of TiO2 thin film deposited by different deposition methods.

Science.gov (United States)

Chen, Hsi-Chao; Lee, Kuan-Shiang; Lee, Cheng-Chung

2008-05-01

Titanium oxide (TiO(2)) thin films were prepared by different deposition methods. The methods were E-gun evaporation with ion-assisted deposition (IAD), radio-frequency (RF) ion-beam sputtering, and direct current (DC) magnetron sputtering. Residual stress was released after annealing the films deposited by RF ion-beam or DC magnetron sputtering but not evaporation, and the extinction coefficient varied significantly. The surface roughness of the evaporated films exceeded that of both sputtered films. At the annealing temperature of 300 degrees C, anatase crystallization occurred in evaporated film but not in the RF ion-beam or DC magnetron-sputtered films. TiO(2) films deposited by sputtering were generally more stable during annealing than those deposited by evaporation.

Role of Mineral Deposits in Global Geochemical Cycles

Science.gov (United States)

Kesler, S.; Wilkinson, B.

2009-12-01

Mineral deposits represent the most extreme degree of natural concentration for most elements and their formation and destruction are important parts of global geochemical cycles. Quantitative estimates of the role that mineral deposits play in these geochemical cycles has been limited, however, by the lack of information on actual amounts of elements that are concentrated in these deposits, and their rates of formation and destruction at geologic time scales. Recent use of a “tectonic diffusion” model for porphyry copper deposits, the most important source of world copper, in conjunction with estimates of their copper content (Kesler and Wilkinson, 2008), allows an assessment of the role of copper deposits in Earth’s global copper cycles. These results indicate that ~4.5*10^8 Gg of Cu have been concentrated in porphyry copper deposits through Phanerozoic time, that deposits containing ~2.8*10^8 Gg of Cu have been removed by uplift and erosion over the same time period, and that deposits containing ~1.7*10^8 Gg remain in Earth’s crust. If styles of formation and destruction of other copper-bearing mineral deposits are similar, then all crustal deposits contain ~3*10^8 Gg of copper. This constitutes about 0.03% of the copper that resides in crustal rocks and provides a first-ever estimate of the rate at which natural geochemical cycles produce the extreme concentrations that constitute mineral deposits. Another ~8*10^8 Gg of copper have been destroyed during the uplift and erosion of mineral deposits over Phanerozoic time, a flux amounting to an annual contribution of about 1.5 Gg of copper to the near-surface environment. This amount is similar in magnitude to copper released by volcanic outgassing, but only ~2.5% of the 56 Gg of copper estimated to be released annually by weathering of average crustal rocks (Rauch and Graedel, 2007). The amount of copper removed from mineral deposits by mining, 1.1*10^4 Gg/year, is much larger than any natural