The pbisotope composition of ores shows that the metal is mainly of mantle origin, mixed with a lesser amount of crustal lead. A dapted from corbett 2001 and corbett and leach 1998. Further, ore, alteration, and ore related fluid inclusions and pt formation conditions are described as. Pdf on jun 1, 2003, vsevolod yuriyevich prokofev and others published composition of orebearing fluids in the dalnegorsk borosilicate deposit, russia. Ore forming hydrothermal fluids, consisting largely of h2o, co2, and nacl, formed most of earths ore deposits. The nrc guidance and licenses require operators to prevent off. The electrical conductivity in ironbearing minerals can still be intrinsic, i. Sulphide mineralisation is a result of fluid migration and focussing. 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. 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. Baskina and others published on the nature of ore bearing fluids on the dalnegorskoe. The rocks of krb have undergone a very complex evolution with multiple metamorphic. Surface force on an arbitrary small surface element embedded in the fluid, with area. Chemical variations in tetrahedrite tennantite minerals.
Basement to surface expressions and critical factors in. Oreforming fluids are derived from a variety of sources, including i waterrich silicate melts, ii circulated sea, connate and meteoric waters, iii. The role of magmatic and hydrothermal fluids in the. Stable isotope o, h, s, c, and n systematics of quartz vein. Hydrothermal alteration and fluid chemistry of the endako. 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. The average salinities are very similar for different ore forming stages, indicating the decrease of temperature is the major mechanism for scheelite precipitation. This ore looks different from the ore at the discovery site, and comes from another goldproducing.
This may occur without much hydrothermal fluid flow. Macro ad and microphotographs eh of the ore and gangue vein minerals from the meiduk deposit. Alteration extends 30 to 100 m outward into wall rock of grand canyon, ariz. The deposit is a typical highly fractured and altered, disseminated gold system, with highgrade, quartzsulphide veinveinlet stockworks that cut mesozoic granodiorite. 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. On the basis of available chemical data for tennantitetetrahedrite series minerals and the telluriderich parts of drillcore. Derivation of low and high sulphidation fluids including arc and rift low sulphidation. However, if this were the dominant mechanism of conduction, then the electrical conductivity would be independent of oxygen fugacity. 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. 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.
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. Structural, kinematic, and hydrothermal fluid investigation of the goldbearing murray shear zone, northeastern minnesota. Explosive volatiles may also boil off from rising magma as lower. Giant uranium deposits formed from exceptionally uraniumrich. 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. The oreforming magmatichydrothermal system of the piaotang. Tim odriscoll who has published extensively on the subject since 1968. Gold transport in hydrothermal chloridebearing fluids. We report elemental and srnd isotopic data for scheelites from the giant deposit, to determine the source region and genesis of. Co2bearing fluid inclusions, laser raman spectroscopy, collision. The macassa mine is the only remaining gold producer of seven interconnected mines which comprise the kirkland lake mining district. 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. However, neutralization of relatively acidic orebearing fluids during the interaction.
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. Uranium transport in fclbearing fluids and hydrothermal. The four most important considerations in the formation of ore deposits are. We evaluated the potential of lowtemperature fluids to upgrade u and f.
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. 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. The legacy of abandoned uranium mines in the grants. The role of metamorphic fluids in the formation of ore deposits. 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. 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. On the nature of orebearing fluids on the dalnegorskoe borosilicate deposit primore. Collapse breccias form as rock, undermined by these fluids, is partially dissolved and collapses or breaks loose, settling into solution caverns. Here we report an investigation of the state of au in hydrothermal chloride fluids and anhydrous melts by means of. Metals are generally transported as chloride, and reducedsulphur complexes in aqueous solutions. Map modified after usgs publication potential for new.
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. Mississippi valley type ore deposits, the laisvall pb zn. F is the force exerted by the fluid on side 1, on the fluid on side 2. 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.
Geologic, fluid inclusion and isotopic characteristics of. Another pioneering australian researcher in lineament tectonics is dr. 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. Oreforming hydrothermal fluids, consisting largely of h2o, co2, and nacl, formed most of earths ore deposits. Epithermal gold for explorationists paper 200201, april 2002 4 figure 3. Basement to surface expressions and critical factors in the. Illustrative case histories for important deposits of sulphides, oxides, native elements, silicates, and ionic salts. Primary carbonaceous ore has undergone a significant amount of diagenesis due to the bacterial and thermal matura tion of amorphous organic matter. Oreforming fluids associated with granitehosted gold. Fluid mechanics is the study of fluids either in motion fluid dynamics or at rest fluid statics. 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.
These uranium bearing fluids traveled through the sandstones to graphite bearing faults rooted in the crystalline basement rocks. 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. D values of hydrothermal muscovites are also uniform at 68 to 55 per mil. A study of fluid inclusions at the cikotok gold mine, west. Inert gas isotope studies from inclusions in ore and gangueminerals reveal 2. On the basis of available chemical data for tennantitetetrahedrite series minerals and the telluriderich parts of. The fluids exist as largely unconfined systems in meteoric, seawater, and basinal. Pdf on the nature of orebearing fluids on the dalnegorskoe. Uranium ore in the mariano lake lake valley cores and the.
Ore was transported in tunnels to the shaft and cages that lifted the ore to surface. 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. 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. Our results strongly suggest that the worlds richest uranium deposits formed from highly concentrated uraniumbearing.
The secondary classification of magmatic arc epithermal gold deposits is. The murray shear zone of northeastern minnesota hosts subeconomic gold in a unique structural setting. Ore genesis and hydrothermal fluid evolution of the. The shimensi deposit south china is a newly discovered wcumo polymetallic deposit with a reserve of 0. Moreover, this view has prevailed despite evidence that the dominant aqueous phase in several major types of oreforming hydrothermal systems is commonly vapor.
Geologic, fluid inclusion and isotopic characteristics of the. A local chemical change caused the precipitation of uranium from the fluids. Balasubramanian an ore mineral is a mineral used for the extraction of one or more metals. Orebearing definition of orebearing by the free dictionary. 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. A new investigation of some australian continental scale. 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. Map modified after usgs publication potential for new nickel.
Pdf composition of orebearing fluids in the dalnegorsk. 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. The secondary classification of magmatic arc epithermal gold deposits is between high and low. Progressive diagenesis decreased the organic carbon. An arbitrary region of fluid divided up into small rectangular elements depicted only in two dimensions. Moreover, this view has prevailed despite evidence that the dominant aqueous phase in several major types of ore forming hydrothermal systems is commonly vapor.
There is a theory available for fluid flow problems, but in all cases it should be backed up by experiment. The toburn mine was the first producing mine in the kirkland lake mining area, and operated from. 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. Click here to see list of references, authorities, sources and geographical terms as used in this glossary. Further, ore, alteration, and orerelated fluid inclusions and pt formation conditions are described as. These ore types are actively exploited in the krb in numerous mines, even at depths exceeding 1. You will also compare the potential environmental impacts of sulfide mining. Raman spectroscopic analyses of fluid inclusions indicate that the skarnforming fluids are waterdominant, low in salinity, and methane bearing.
There are four stages of veins that developed in the. 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. Only credible accident or off normal condition would be loss. The fluid dynamic process of largescale mineralization in. There are four stages of veins that developed in the following.
Source of the ore constituents and how they were obtained in solution. Stable isotope o, h, s, c, and n systematics of quartz. The states with the largest known uranium ore reserves in the united states ranked by size of reserves are wyoming, new mexico, and colorado. A possible link between gold mineralization and hydrocarbon accumulation in the youjiang basin, south china.
Structural, kinematic, and hydrothermal fluid investigation. Giant uranium deposits formed from exceptionally uranium. 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 broad similarities in orefluid composition at all temperatures give support to crustalcontinuum models, in which arch.
Raman spectroscopic analyses of fluid inclusions indicate that the skarnforming fluids are waterdominant, low in salinity, and methanebearing. The average salinities are very similar for different oreforming stages, indicating the decrease of temperature is. Operation takes place within an existing uranium mine, loss of. The aqueous part of orebearing fluids usually comes from 1 surface water including. These uraniumbearing fluids traveled through the sandstones to graphitebearing faults rooted in the crystalline basement rocks. Their kinematic history and structural architecture contain important clues about the genesis, characteristics, and mechanics of ore bearing fluids. Click sync in the bottom of the screen once you added your ebook and click done after the synchronization is complete.
Chloridebearing fluids are widespread in the earths interior from lowtemperature subsurface conditions to deep lithosphere. Odriscoll documented a network of ten prominent continental scale gravity lineaments and a number of geological lineaments. To account for the high uranium content observed in the athabasca deposits, we. Ore forming fluids are derived from a variety of sources, including i waterrich silicate melts, ii circulated sea, connate and meteoric waters, iii. Brecciated pipes can also form from the ascent of orebearing fluids through the earths crust.
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