Progressive diagenesis decreased the organic carbon. Sulfidation states of telluridebearing ore fluids fluctuated between is and hs conditions within the same mineralization, with telluride minerals and sulfosalts related to both hs and is assemblages. My general message is that saline magmatic fluids which produce epithermal ore deposits are chemi cally decoupled from the carapace of the magma and are derived from the area between the waterrich carapace and the brittleductile or lithostatichydro static transition. Giant uranium deposits formed from exceptionally uranium. Ore deposits formed by lateral secretion are formed by metamorphic reactions during shearing, which liberate mineral constituents such as quartz, sulfides, gold, carbonates, and oxides from deforming rocks, and focus these constituents into zones of reduced pressure or dilation such as faults. The role of magmatic and hydrothermal fluids in the. Operation takes place within an existing uranium mine, loss of. Balasubramanian an ore mineral is a mineral used for the extraction of one or more metals. On the basis of available chemical data for tennantitetetrahedrite series minerals and the telluriderich parts of. This ore looks different from the ore at the discovery site, and comes from another goldproducing.
Our results strongly suggest that the worlds richest uranium deposits formed from highly concentrated uraniumbearing. On the basis of available chemical data for tennantitetetrahedrite series minerals and the telluriderich parts of drillcore. An arbitrary region of fluid divided up into small rectangular elements depicted only in two dimensions. However, neutralization of relatively acidic orebearing fluids during the interaction. D values of hydrothermal muscovites are also uniform at 68 to 55 per mil. Oreforming hydrothermal fluids, consisting largely of h2o, co2, and nacl, formed most of earths ore deposits. The deposit is a typical highly fractured and altered, disseminated gold system, with highgrade, quartzsulphide veinveinlet stockworks that cut mesozoic granodiorite. Dilute acidic solutions are introduced to the copper bearing ores, causing dissolution of soluble copper minerals table 1 remaining in the leached cap and underlying enrichment blanket. The states with the largest known uranium ore reserves in the united states ranked by size of reserves are wyoming, new mexico, and colorado. However, oxygen and hydrogen isotope values deviate from the generally accepted magmatic compositions, which suggests the early involvement of meteoric water in the oreforming fluids and ore genesis.
The fluid dynamic process of largescale mineralization in. Explosive volatiles may also boil off from rising magma as lower. A new investigation of some australian continental scale. Here we report an investigation of the state of au in hydrothermal chloride fluids and anhydrous melts by means of. The nrc guidance and licenses require operators to prevent off. Giant uranium deposits formed from exceptionally uraniumrich. However, oxygen and hydrogen isotope values deviate from the generally accepted magmatic compositions, which suggests the early involvement of meteoric water in the ore forming fluids and ore genesis. Sulfidation states of telluride bearing ore fluids fluctuated between is and hs conditions within the same mineralization, with telluride minerals and sulfosalts related to both hs and is assemblages. Basement to surface expressions and critical factors in the. Epithermal gold for explorationists paper 200201, april 2002 4 figure 3. The macassa mine is the only remaining gold producer of seven interconnected mines which comprise the kirkland lake mining district. Macro ad and microphotographs eh of the ore and gangue vein minerals from the meiduk deposit.
The three fluids are identified to be magmatic, meteoric as previously reported in the literature, and also metamorphic, and are shown to have mixed throughout the different stages. Basement to surface expressions and critical factors in the genesis of unconformityrelated deposits tg ore sys emst 4 eric potter1 and tgi4 researchers2 1geological survey of canada, ottawa. Moreover, this view has prevailed despite evidence that the dominant aqueous phase in several major types of oreforming hydrothermal systems is commonly vapor. Metals are generally transported as chloride, and reducedsulphur complexes in aqueous solutions. F is the force exerted by the fluid on side 1, on the fluid on side 2. The role of metamorphic fluids in the formation of ore deposits. The rocks of krb have undergone a very complex evolution with multiple metamorphic. Base your answer on whether the rocks that might house those deposits andor faults that might carry the mineralbearing fluids are present near scotch bonnet mountain.
The broad similarities in orefluid composition at all temperatures give support to crustalcontinuum models, in which arch. Fluid mechanics is the study of fluids either in motion fluid dynamics or at rest fluid statics. The sanshandao gold deposit, with total resources of more than 60 t of gold, is located in the jiaodong gold province, the most important gold province of china. The toburn mine was the first producing mine in the kirkland lake mining area, and operated from. The legacy of abandoned uranium mines in the grants. Baskina and others published on the nature of ore bearing fluids on the dalnegorskoe. Hydrothermal alteration and fluid chemistry of the endako. The average salinities are very similar for different oreforming stages, indicating the decrease of temperature is. Inert gas isotope studies from inclusions in ore and gangueminerals reveal 2.
Map modified after usgs publication potential for new. We report elemental and srnd isotopic data for scheelites from the giant deposit, to determine the source region and genesis of. Further, ore, alteration, and orerelated fluid inclusions and pt formation conditions are described as. Basement to surface expressions and critical factors in. Chloridebearing fluids are widespread in the earths interior from lowtemperature subsurface conditions to deep lithosphere.
Further, ore, alteration, and ore related fluid inclusions and pt formation conditions are described as. Co2bearing fluid inclusions, laser raman spectroscopy, collision. Sulphide mineralisation is a result of fluid migration and focussing. This may occur without much hydrothermal fluid flow. The four most important considerations in the formation of ore deposits are. A study of fluid inclusions at the cikotok gold mine, west. Their kinematic history and structural architecture contain important clues about the genesis, characteristics, and mechanics of ore bearing fluids. Fractionation interpretation for fluids ore bearing quartz. The concentration of chloride salts varies from diluted aqueous solutions to concentrated brines and anhydrous dry chloride melts beneath volcanoes.
Ore forming fluids are derived from a variety of sources, including i waterrich silicate melts, ii circulated sea, connate and meteoric waters, iii. Also see where the known deposits are located with respect to scotch bonnet mountain, and whether it makes sense to look for more such deposits near scotch bonnet. Moreover, this view has prevailed despite evidence that the dominant aqueous phase in several major types of ore forming hydrothermal systems is commonly vapor. Raman spectroscopic analyses of fluid inclusions indicate that the skarnforming fluids are waterdominant, low in salinity, and methane bearing. Stable isotope o, h, s, c, and n systematics of quartz. The shimensi deposit south china is a newly discovered wcumo polymetallic deposit with a reserve of 0. Ore forming hydrothermal fluids, consisting largely of h2o, co2, and nacl, formed most of earths ore deposits. Uranium ore in the mariano lake lake valley cores and the. Only credible accident or off normal condition would be loss. The oreforming magmatichydrothermal system of the piaotang. We evaluated the potential of lowtemperature fluids to upgrade u and f.
Alteration extends 30 to 100 m outward into wall rock of grand canyon, ariz. The murray shear zone of northeastern minnesota hosts subeconomic gold in a unique structural setting. These ore types are actively exploited in the krb in numerous mines, even at depths exceeding 1. Another pioneering australian researcher in lineament tectonics is dr. Raman spectroscopic analyses of fluid inclusions indicate that the skarnforming fluids are waterdominant, low in salinity, and methanebearing. Orebearing definition of orebearing by the free dictionary. Pdf on jun 1, 2003, vsevolod yuriyevich prokofev and others published composition of orebearing fluids in the dalnegorsk borosilicate deposit, russia. Oreforming fluids associated with granitehosted gold. However, if this were the dominant mechanism of conduction, then the electrical conductivity would be independent of oxygen fugacity. The gravitational force is generally considered as the key driving force of the fluid flow17,26,27, but some regard the ore as exhalative generation, and the oreforming fluid as being over. First interpretations showed that major composition, high salinities and temperatures of the mvt ore forming fluids are quite similar to oilfield brines that can be found in presentday sedimentary basins sverjensky, 1986. A dapted from corbett 2001 and corbett and leach 1998. Base your answer on whether the rocks that might house those deposits andor faults that might carry the mineral bearing fluids are present near scotch bonnet mountain.
Nature of ore nearly all primary ore is confined to breccia pipes fig. Mississippi valley type ore deposits, the laisvall pb zn. Chemical variations in tetrahedrite tennantite minerals. Uranium transport in fclbearing fluids and hydrothermal. Structural, kinematic, and hydrothermal fluid investigation. Illustrative case histories for important deposits of sulphides, oxides, native elements, silicates, and ionic salts. These uraniumbearing fluids traveled through the sandstones to graphitebearing faults rooted in the crystalline basement rocks. The pbisotope composition of ores shows that the metal is mainly of mantle origin, mixed with a lesser amount of crustal lead. The secondary classification of magmatic arc epithermal gold deposits is between high and low.
Tim odriscoll who has published extensively on the subject since 1968. The electrical conductivity in ironbearing minerals can still be intrinsic, i. There are four stages of veins that developed in the following. Derivation of low and high sulphidation fluids including arc and rift low sulphidation. Southwest guizhou province, china, contains deposits described as carlin type, and the tectonic history of guizhou is similar to that of northern nevada, though the district lacks proximal igneous rocks. Click here to see list of references, authorities, sources and geographical terms as used in this glossary. To account for the high uranium content observed in the athabasca deposits, we. There are four stages of veins that developed in the. A tale of two deposits in this activity, you will analyze a geologic map of the homestake mine near yellowstone national park, and weigh the pros and cons of developing a goldsilvercopper mine at that location. Surface force on an arbitrary small surface element embedded in the fluid, with area. On the nature of orebearing fluids on the dalnegorskoe borosilicate deposit primore. Moreover, it appears that the magmatic fluids could not have been derived from the piaotang biotite granite but instead must have originated from a more evolved. Structural, kinematic, and hydrothermal fluid investigation of the goldbearing murray shear zone, northeastern minnesota. Ore genesis and hydrothermal fluid evolution of the.
Source of the ore constituents and how they were obtained in solution. Pdf on the nature of orebearing fluids on the dalnegorskoe. Amt is mining methodology which mines ore from between the grains of a mineralized sandstone chemical free low volume water consumption waste reduction technology many existing regulations to control the risk, e. These uranium bearing fluids traveled through the sandstones to graphite bearing faults rooted in the crystalline basement rocks. The average salinities are very similar for different ore forming stages, indicating the decrease of temperature is the major mechanism for scheelite precipitation. For porphyry copper deposits in general, the compositions of the shallow intrusions that host porphyry copper deposits indicate that the deep melt reservoirs from which both the shallow intrusions and the ore fluids were derived may be compositionally calcalkaline, alkali. Stable isotope o, h, s, c, and n systematics of quartz vein. First interpretations showed that major composition, high salinities and temperatures of the mvt ore forming fluids are quite similar to oilfield brines that can be found in. Odriscoll documented a network of ten prominent continental scale gravity lineaments and a number of geological lineaments. Map modified after usgs publication potential for new nickel. The fluids exist as largely unconfined systems in meteoric, seawater, and basinal. For porphyry copper deposits in general, the compositions of the shallow intrusions that host porphyry copper deposits indicate that the deep melt reservoirs from which both the shallow intrusions and the ore fluids were derived may be compositionally calcalkaline, alkalicalcic, or alkaline seedorff and others, 2005. Collapse breccias form as rock, undermined by these fluids, is partially dissolved and collapses or breaks loose, settling into solution caverns. A local chemical change caused the precipitation of uranium from the fluids.
A possible link between gold mineralization and hydrocarbon accumulation in the youjiang basin, south china. Gold transport in hydrothermal chloridebearing fluids. The gravitational force is generally considered as the key driving force of the fluid flow17,26,27, but some regard the ore as exhalative generation, and the ore forming fluid as being overpressured22. The district has produced more than 710,000 kg au since 19 from quartz veins and lodes within the archean timiskaming groupthere are 3 types of gold ore at the macassa mine. Primary carbonaceous ore has undergone a significant amount of diagenesis due to the bacterial and thermal matura tion of amorphous organic matter. You will also compare the potential environmental impacts of sulfide mining. Brecciated pipes can also form from the ascent of orebearing fluids through the earths crust. To find and explain the relationships between precious metal bearing minerals hosted in copper ore at the ann mason copper porphyry deposit as they relate to ore formation.
There is a theory available for fluid flow problems, but in all cases it should be backed up by experiment. Lead and zinc ores were mined for many decades in northwestern illinois figure 161, southwestern wisconsin, and northeastern iowa, a region collectively referred to as the upper mississippi valley leadzinc district willman et al. Pdf composition of orebearing fluids in the dalnegorsk. Geologic, fluid inclusion and isotopic characteristics of. Dilute acidic solutions are introduced to the copperbearing ores, causing dissolution of soluble copper minerals table 1 remaining in the leached cap and underlying enrichment blanket.
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