Ingham, E. S., Cook, N. J., Cliff, J., Ciobanu, C. L., & Huddleston, A. (2014). A combined chemical, isotopic and microstructural study of pyrite from roll-front uranium deposits, Lake Eyre Basin, South Australia. Geochimica et Cosmochimica Acta, 125, 440–465.
Abstract: The common sulfide mineral pyrite is abundant throughout sedimentary uranium systems at Pepegoona, Pepegoona West and Pannikan, Lake Eyre Basin, South Australia. Combined chemical, isotopic and microstructural analysis of pyrite indicates variation in fluid composition, sulfur source and precipitation conditions during a protracted mineralization event. The results show the significant role played by pyrite as a metal scavenger and monitor of fluid changes in low-temperature hydrothermal systems. In-situ micrometer-scale sulfur isotope analyses of pyrite demonstrated broad-scale isotopic heterogeneity (δ34S=−43.9 to +32.4‰VCDT), indicative of complex, multi-faceted pyrite evolution, and sulfur derived from more than a single source. Preserved textures support this assertion and indicate a genetic model involving more than one phase of pyrite formation. Authigenic pyrite underwent prolonged evolution and recrystallization, evidenced by a genetic relationship between archetypal framboidal aggregates and pyrite euhedra. Secondary hydrothermal pyrite commonly displays hyper-enrichment of several trace elements (Mn, Co, Ni, As, Se, Mo, Sb, W and Tl) in ore-bearing horizons. Hydrothermal fluids of magmatic and meteoric origins supplied metals to the system but the geochemical signature of pyrite suggests a dominantly granitic source and also the influence of mafic rock types. Irregular variation in δ34S, coupled with oscillatory trace element zonation in secondary pyrite, is interpreted in terms of continuous variations in fluid composition and cycles of diagenetic recrystallization. A late-stage oxidizing fluid may have mobilized selenium from pre-existing pyrite. Subsequent restoration of reduced conditions within the aquifer caused ongoing pyrite re-crystallization and precipitation of selenium as native selenium. These results provide the first qualitative constraints on the formation mechanisms of the uranium deposits at Beverley North. Insights into depositional conditions and sources of both sulfide and uranium mineralization and an improved understanding of pyrite geochemistry can also underpin an effective vector for uranium exploration at Beverley North and other sedimentary systems of the Lake Eyre Basin, as well as in comparable geological environments elsewhere.
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Hamutoko, J., Mapani, B., Ellmies, R., Bittner, A., & Külls, C. (2014). A fingerprinting method for the identification of uranium sources in alluvial aquifers: An example from the Khan and Swakop Rivers, Namibia. Physics and Chemistry of the Earth, Parts A/B/C, 72, 34–42.
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Tan, K., Li, C., Liu, J., Qu, H., Xia, L., Hu, Y., et al. (2014). A novel method using a complex surfactant for in-situ leaching of low permeable sandstone uranium deposits. Hydrometallurgy, 150, 99–106.
Abstract: Applications of a complex surfactant developed in-house to in-situ leaching of low permeable sandstone uranium deposits are described based on results from agitation leaching, column leaching, resin adsorption, and elution experiments using uranium containing solution from the in-situ leaching site. The results of agitation leaching experiments show that adding surfactant with different concentrations into leaching solution improves the leaching rate of uranium. The maximum leaching rate of uranium from agitation leaching reached 92.6% at an added surfactant concentration of 10mg/l. Result of column leaching experiment shows that adding surfactant with varying concentrations into leaching solutions increased the permeability coefficient of ore-bearing layer by 42.7–86.8%. The leaching rate of uranium from column leaching increased by 58.0% and reached 85.8%. The result of kinetic analysis shows that for the extraction of uranium controlled by diffusion without surfactant the apparent rate constant 0.0023/d changed to 0.0077/d for the extraction with surfactant controlled by both diffusion and surface chemical reactions. Results from resin adsorption and elution experiments show that there was no influence on resin adsorption and elution of uranium with an addition of 50mg/l surfactant to production solution from in-situ leaching. The adsorption curve, sorption capacity of resin, recycling of resin remained the same as without adding any surfactant. Introducing complex surfactant to leaching solution increased the peak concentration of uranium in eluents, reduced the residual uranium content in resin, and promoted the elution efficiency. The method of using a complex surfactant for in-situ leaching is useful for low permeable sandstone uranium deposits.
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Martínez-Santos, P., & Martínez-Alfaro, P. E. (2014). A priori mapping of historical water-supply galleries based on archive records and sparse material remains. An application to the Amaniel qanat (Madrid, Spain). Journal of Cultural Heritage, 15(6), 656–664.
Abstract: Engineering heritage refers to a broad variety of items of social, economic, aesthetic or historic relevance, including roads, dams, buildings and supply networks. Due to their utilitarian nature, their heritage value is often overlooked. This occurs even with those infrastructures that have played an essential role in underpinning the daily existence of entire civilizations. Underground water-supply networks provide an excellent example. Although there are exceptions, water networks tend to be functional in design, rather than monumental. Moreover, they present intricate linear layouts that often span several kilometres. This means they are costly to maintain once their operational life is over, and that they are prone to abandonment and destruction. Devising a priori protection strategies is important to preserve these valuable cultural assets. The following pages present a method to map linear structures based on archive records and sparse material remains. The method is illustrated through its application to the Amaniel qanat, a water-supply gallery built in Madrid, Spain, in the early 17th Century. An appraisal of the known remains was carried out first, leading to an inventory of galleries, shafts, shaft caps and deposits. This was followed by a thorough survey of over one thousand handwritten manuscripts, including physical descriptions of the aqueduct, budget accounts or water metering campaigns, among other documents. Known remains and written evidence were matched against original and auxiliary maps to reconstruct the itinerary of the aqueduct. This led to the identification of sectors where it is still possible to find remains in good condition. Thus, a priori mapping is advocated a valuable technique to locate and preserve these remains, as well as to devise non-invasive surveys and establish heritage protection zones.
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Shams, A. (2014). A rediscovered-new ‘Qanat’ system in the High Mountains of Sinai Peninsula, with Levantine reflections. Journal of Arid Environments, 110, 69–74.
Abstract: Since the Achaemenid Empire in 532–332 BCE, the ‘Qanat’ became the central irrigation system in the arid and semi-arid lands. Several terms are used for ‘Qanat’ in different regions, including the Karez, Qanat, Falaj type Daudi, Qanat Romani, Fuqara (Foggara), or Khettara as known in Central Asia, Persia, Southeast Arabia, Levant, North Africa, or Morocco respectively. Typically, the ground, spring or surface water (i.e. seasonal floods or river-fed) sources feed similar irrigation system. Based on thirteen years of extensive survey and analysis work (i.e. Sinai Peninsula Research 2000–2013 CE), this paper presents a rediscovered-new Qanat system in the High Mountains of Sinai Peninsula (i.e. UNESCO World Heritage Site ‘WHS’ no. 954) under chronological open question with Levantine reflections. In 1970s CE, the present Sinaitic site of Farsh Abu A’lwan or the anciently known Farsh Shamma’a was archaeologically surveyed without a direct reference to the Qanat system in-situ. Scientifically, it is an argumentative and unique Qanat system in terms of chronology, location (region), site (local-setting), water source, size and household utility. It is the only discovered ‘Qanat’ across the Sinai, connecting the Near East and North Africa.
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Joseph, J., & Külls, C. (2014). Calibration of 13C and 18O measurements in CO2 using Off-axis Integrated Cavity Output Spectrometer (ICOS). In EGU Geophysical Abstracts (659).
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Külls, C. (2014). Ecohydrological principles in economic models of water resources in drylands and desert restoration.
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Gaj, M., Beyer, M., Hamutoko, J., Uugulu, S., Wanke, H., Koeniger, P., et al. (2014). How do soil types affect stable isotope ratios of 2H and 18O under evaporation: A Fingerprint of the Niipele subbasin of the Cuvelai-Etosha basin, Namibia. In EGU Geophysical Abstracts (5890).
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Külls, C., Nunes, A., Köbel-Batista, M., Branquinho, C., Bianconi, N., & Costantini, E. (2014). Integrated use of soil physical and water isotope methods for ecohydrological characterization of desertified areas. In EGU Geophysical Abstracts (15430).
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Khoury, H. N., salameh, E. M., & Clark, I. D. (2014). Mineralogy and origin of surficial uranium deposits hosted in travertine and calcrete from central Jordan. Applied Geochemistry, 43, 49–65.
Abstract: Secondary uranium encrustations are hosted in thick travertine and calcrete deposits of Pleistocene–Recent age in central Jordan. The central Jordan varicolored marble and travertine are equivalent to the active metamorphic area in Maqarin, north Jordan. More than 100 samples were collected from the outcrops of the varicolored marble, travertine, calcrete, and the yellow uranium encrustations. The secondary yellow encrustations are mainly composed of uranyl vanadate complexes. Tyuyamunite Ca(UO2)2V25+O8·3(H2O)–strelkinite Na2(UO2)2V2O8·6(H2O) solid solution series are the major components and their composition reflects changes in the Ca/Na ratio in solution. Potentially, new vanadium free calcium uranate phases (restricted to the varicolored marble) were identified with CaO:UO3 ratios different from the known mineral vorlanite (CaU6+)O4. Carbon and oxygen isotope data from calcite in the varicolored marble are characterized by Rayleigh-type enrichment in light isotopes associated with release of 13C and 18O enriched CO2 by high temperature decarbonation during combustion of the bituminous marl. Stable isotope results from uranium hosted travertine and calcrete varieties exhibit a wide range in isotopic values, between decarbonated and normal sedimentary carbonate rocks. The depleted δ13C and δ18O values in the travertine are related to the kinetic reaction of atmospheric CO2 with hyperalkaline Ca(OH)2 water. The gradual enrichment of δ13C and δ18O values in the calcrete towards equilibrium with the surrounding environment is related to continuous evaporation during seasonal dry periods. Uranium mineralization in central Jordan resulted from the interplay of tectonic, climatic, hydrologic, and depositional events. The large distribution of surficial uranium occurrences hosted in travertine and calcrete deposits is related to the artesian ascending groundwater that formed extensive lakes along NNW–SSE trending depressions. Fresh groundwater moved upward through the highly fractured phosphate, bituminous marl and varicolored marble to form unusual highly alkaline water (hydroxide–sulfate type) enriched with sensitive redox elements among which were U and V.
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