GEOTHERMAL SURVEYS IN SEDIMENTARY ROCKS NEAR GRANTS AND LAGUNA, NEW MEXICO

Geophysics ◽  
1965 ◽  
Vol 30 (3) ◽  
pp. 396-402
Author(s):  
P. Edward Byerly
Keyword(s):  
New Mexico ◽  
Pore Water ◽  
Water Table ◽  
Sedimentary Rocks ◽  
Uranium Ore ◽  
Ore Body ◽  
Downward Migration ◽  
Ore Bodies ◽  
Oxygenated Water ◽  
Drill Holes

Data obtained from temperature surveys in drill holes over two uranium ore bodies are presented as maps of isotherms at depths of 100 ft or more. Temperature surveys in permeable ore bodies above the water table may reveal zones of downward migration of oxygenated water, or zones with a comparatively large retention of pore water. These zones may be associated with an increased amount of oxidation in an ore body which is not completely oxidized.

Oxygen, carbon and strontium isotope study of the carbonatitic dolomite host of the Bayan Obo Fe-Nb-REE deposit, Inner Mongolia, N China

1997 ◽  
Vol 61 (407) ◽  
pp. 531-541 ◽  
Author(s):  
M. J. Le Bas ◽  
B. Spiro ◽  
Yang Xueming
Keyword(s):  
Sedimentary Rocks ◽  
Coarse Grained ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Fine Grained ◽  
Dolomite Marble ◽  
Ore Body ◽  
Ore Bodies ◽  
Isotope Study ◽  
Bayan Obo

AbstractThe large Fe-Nb-REE deposit at Bayan Obo is hosted by a dolomite marble within the thrust complex of marbles, quartzites and slates that belongs to the Bayan Obo Formation of mid-Proterozoic age. The dolomite is either a dolomitized sedimentary limestone subsequently mineralized and tectonically thrust and folded, or a dolomite (or dolomitized) carbonatite intrusion with late-stage recrystallization and mineralization that has been subsequently tectonically deformed.O and C isotope data indicate that the sedimentary limestones and dolomites of the Bayan Obo Formation, which occur in the thrust stack together with quartzites and slates, have values of δO c. +20 per mil (SMOW) and δC c. zero. In contrast, the coarser grained facies of the large (0.5 × 10 km) dolomite marble which hosts the REE ore body has δO per mil values between +8 and +12 and δC values between −5 and −3, whereas the finer-grained recrystallized and REE-mineralized dolomite marble which occurs close to the ore bodies has δO between +12 to +16 and δC between −4 and zero. 87Sr/86Sr data confirm this distinction: >0.710 for the sedimentary rocks and <0.704 for the coarse- and fine-grained dolomite marbles.These data are taken to indicate that the large and coarse-grained dolomite was an igneous carbonatite (as borne out by its fenitic contact rocks and trace element geochemistry), and that the finer grained dolomite recrystallized under the influence of mineralizing solutions which entrained groundwater. The stratiform features in the coarse-grained dolomite that are evident in the field are interpreted as tectonic layering.

scholarly journals HERMIONE, EVOLUTION OF ATe-BEARING EPITHERMAL MINERALIZATION, ARGOLIS, HELLAS

2007 ◽  
Vol 40 (2) ◽  
pp. 996 ◽  
Author(s):  
S. Tombros ◽  
K. St. Seymour
Keyword(s):  
Sedimentary Rocks ◽  
Ore Deposits ◽  
Stage I ◽  
Stage Ii ◽  
Quartz Veins ◽  
Minor Contribution ◽  
Epithermal Mineralization ◽  
Ore Bodies ◽  
Calcite Veins ◽  
Sandstone Formation

The Cu-Te-bearing pyrite deposits of Hermione, Argolis are hosted in Miocenic ophiolites. The ophiolites are overlain by a shale-sandstone formation with intercalations of limestones and manganiferous sedimentary rocks. The ore deposits form irregular lenticular or stratiform ore bodies, and veins. These ore bodies are related to volcanic activity in an arc-related rift at the margins of a palaeocontinent. Late N- to NNE-trending, sinistral, milky quartz-pyrite-calcite veins cut the host ophiolites. Alteration haloes of quartz-calcite, albite-sericitechlorite, and chalcedony-epidote-clay minerals are developed in the lavas as concentric shells, or as envelops that parallel the quartz veins. The telluriumbearing mineralization is developed in two successive stages, characterized by the assemblages: pyrite-(pyrrhotite)-magnetite-chalcopyrite-sphalerite (Stage I) and galena-sphalerite-freibergite-marcasite-chalcocite (Stage II), followed by a supergene stage. The cobaltiferous pyrite-chalcopyrite geothermometer defined two ranges of last-equilibration temperatures: 220° to 250°Cfor Stage I, and 120° to 195°Cfor Stage II. The calculated δ18 Ο and SD compositions of the mineralizing fluids, at 200° and 250°C, reflect the dominance of a magmatic component. The calculated δ SH2S fluid values reveal a magmatic source for the sulphur, with minor contribution from submarine sediments, whereas tellurium is proposed to be derived from a mafic-ultramafic source.

scholarly journals Using Topographic Advantages in Formulating a Strategy to Access Ore Bodies at Ban Phuc Nikel Mine

2020 ◽  
Vol 174 ◽  
pp. 01013
Author(s):  
Hung Nguyen Phi ◽  
Thang Pham Duc
Keyword(s):  
Underground Mining ◽  
Mineral Deposit ◽  
Access Method ◽  
Near Surface ◽  
Ground Support ◽  
Mining Technique ◽  
Ore Body ◽  
Ore Bodies ◽  
Gain Access ◽  
Transport Potential

There are various types of underground mining that are categorized based on the kind of shafts used, the technique of extraction and the process used to get to a deposit. Development mining is composed of excavation almost entirely in (non-valuable) waste rock in order to gain access to the orebody. To start the mining, the first step is to make the path to go down. Development, the work of opening a mineral deposit for exploitation is performed. With it begins the actual mining of the deposit. Access to the deposit must be gained either by stripping the overburden, which is the soil and/or rock covering the deposit,to expose the near- surface ore for mining or by excavating openings from the surface to access more deeply buried deposits to prepare for underground mining. The type of underground mining technique used is typically based on the geology of the area, especially the amount of ground support needed to make mining safe. When using to exploit ore body by underground mining method, the textbook guide in universities of Vietnam had had 4 main strategies include: access by horizontal tunnel lines, access by incline shaft, vertical shaft and combination of above access method. In this study, we developed a solution outside of four above approaches, to take advantage of the topography, transport potential energy, and advantages when constructing sloped incline, backward from outside to inside.

Approaches to the study of hillslope development due to mass movement

1993 ◽  
Vol 17 (1) ◽  
pp. 32-49 ◽  
Author(s):  
S.M. Brooks ◽  
K.S. Richards ◽  
M.G. Anderson
Keyword(s):  
Internal Friction ◽  
Pore Water ◽  
Water Table ◽  
Soil Cover ◽  
Slip Surface ◽  
Mass Movement ◽  
Slope Angle ◽  
Geological Time ◽  
Stability Of Slopes ◽  
Pore Water Pressures

Slope-angle histograms have traditionally provided a data base for the evaluation of changing angles over geological time. Ideas relating to hillslope development due to mass movement have considered a lowering in regolith shear resistance due to weathering, producing slope-angle decline. Decreasing values for angles of internal friction, along with increasing pore water pressures, have been suggested to explain slope-angle decline through time. These ideas have considered simple changes in undifferentiated regolith. This article considers the role of progressive pedogenesis in determining the changing stability of slopes. For this it is necessary to evaluate the changes which occur within individual horizons to produce an increasingly differentiated soil cover. Angles of internal friction alter at different rates and in different ways depending on whether the horizon is losing or gaining weathered material through translocation. Furthermore, the increasing internal differentiation of the soil cover has complex effects on its hydrological response. Instead of the two scenarios previously envisaged, one involving the water table below the slip surface and the other involving the water table at the ground surface, slope stability needs to be evaluated in the light of continually changing negative or positive pore water pressures. Each storm produces a different response, and this response alters with soil development, complicating the assessment of failure timing and depth. The study of evolving soil profiles is of fundamental significance to a range of geomorphological processes, requiring closer evaluation in the future.

Research of Mining Method for Difficult-to-Mine Ore Bodies in Deep Mine

2014 ◽  
Vol 962-965 ◽  
pp. 1041-1046
Author(s):  
Qi Fa Ge ◽  
Xue Sen Sun ◽  
Wei Gen Zhu ◽  
Qing Gang Chen
Keyword(s):  
In Situ Stress ◽  
Mining Method ◽  
Deep Mining ◽  
Deep Mine ◽  
Ore Body ◽  
High In Situ Stress ◽  
Ore Bodies ◽  
Large Panel ◽  
Back Filling

There are many problems such as depth, high in-situ stress, high ground temperature and rockburst proneness etc. in deep mining. And it is an acknowledged and urgent mining technical puzzle about mining method of gently inclined and medium-thick ore bodies. For such an ore body in West wing of Dongguashan copper mine, if we use traditional mining method, it is hard to conquer such difficulties as high in-situ stress, large open area in roof, removal of mined ore by gravity etc. The theory of “large panel and lower sublevel height” will be easy to solve such problems. This paper use numerical technology to analyze and compare the technical and economical effectiveness for different selected mining method and its structure. The sublevel (at a height of 12 m) open stoping with back-filling by extraction in two steps is quite suitable for ensuring safety, increasing efficiency, productivity and reclaiming resource. The selected method is feasible and well worth spread.

The genesis of Proterozoic uranium deposits in Australia

1979 ◽  
Vol 291 (1381) ◽  
pp. 339-353 ◽  
Keyword(s):  
Precious Metals ◽  
Mineral Deposits ◽  
Uranium Deposits ◽  
The West ◽  
Acid Magma ◽  
Uranium Ore ◽  
Connate Water ◽  
Ore Bodies ◽  
Mineralizing Fluids ◽  
Proterozoic Age

The principal mineral deposits of Proterozoic age in Australia, not only of uranium but also of base and precious metals, are found within a north-trending belt central to the continent which stretches from Adelaide to Darwin. This belt represents the margin to the West Australian Archaean craton, and comprises orogenic and shelf domains that evolved throughout the Proterozoic; and it is suggested that the formation of the uranium deposits was an integral part of the evolution of the various geosynclines in the belt. The uranium ore bodies occupy structurally prepared features such as shears, faults and breccias, and are clearly introduced, but the source of the mineralizing fluids, and the precise mechanism of deposition, is, in some cases at least, in dispute. Mineralization per ascensum by connate water carrying metals desorbed from the sedimentary pile, or in association with acid magma which may itself be the product of anatexis, is favoured by the author.

The influence of currents induced in the host rock on electromagnetic response of a spheroid directly beneath a loop

Geophysics ◽  
1981 ◽  
Vol 46 (8) ◽  
pp. 1121-1136 ◽  
Author(s):  
Alexander A. Kaufman
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Asymptotic Expression ◽  
Surrounding Medium ◽  
Electromagnetic Response ◽  
Ore Body ◽  
Ore Bodies ◽  
Integral Equation Approach ◽  
Em Field ◽  
Special Case

A variety of time‐domain and frequency‐domain electromagnetic (EM) methods has come into use in minerals exploration for detection of conductive ore bodies. Because the responses of these various systems differ markedly from one another, the question arises as to which is the most effective for use in discovering a buried, conductive ore body. The question can be posed as follows: What type of exploration system provides the best signal‐to‐noise (S/N) ratio, when signal is defined as the anomalous EM field caused by the presence of a target body and noise is defined as EM responses from the surrounding medium? Analytic solution of the problem is tedious and has not yet been reported in the literature. I describe some results for a special case which reduces the complexity of the problem somewhat. The case treated is that of a conducting spheroid situated directly beneath a source loop. The EM responses caused by currents in the spheroid and in the surrounding medium were computed in both the frequency domain and time domain, using the integral equation approach, supplemented with evaluations of asymptotic expression for various field components. Results show that the transient method provides the best S/N ratio of the methods considered.

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