Kimberlites and Lamproites: Primary Sources of Diamond
... On the basis of this evidence, it is now believed that some diamonds are derived by the disaggregation of such source rocks. Thus, the recognition of purple subcalcic chrome pyrope xenocrysts, known colloquially as GI0 garnets, in kimberlites Is commonly regarded as a key indicator for the presence ...
... On the basis of this evidence, it is now believed that some diamonds are derived by the disaggregation of such source rocks. Thus, the recognition of purple subcalcic chrome pyrope xenocrysts, known colloquially as GI0 garnets, in kimberlites Is commonly regarded as a key indicator for the presence ...
Chapter 21: Metamorphism
... s1 > s2 = s3 foliation and no lineation s1 = s2 > s3 lineation and no foliation s1 > s2 > s3 both foliation and lineation Figure 21-3. Flattening of a ductile homogeneous sphere (a) containing randomly oriented flat disks or flakes. In (b), the matrix flows with progressive flattening, a ...
... s1 > s2 = s3 foliation and no lineation s1 = s2 > s3 lineation and no foliation s1 > s2 > s3 both foliation and lineation Figure 21-3. Flattening of a ductile homogeneous sphere (a) containing randomly oriented flat disks or flakes. In (b), the matrix flows with progressive flattening, a ...
*αí *ß>* * æn*ôn* m* m m m m m m m m m m m m m m m
... stockwork veining and the exsolution of volatiles and fluids. Pressure draw-down caused by cooling of the intrusion and parent melt facilitates the downward percolation of meteoric w aters to porphyry depths, and results in overprinting retrograde alteration. Porphyry copper mineralization is interp ...
... stockwork veining and the exsolution of volatiles and fluids. Pressure draw-down caused by cooling of the intrusion and parent melt facilitates the downward percolation of meteoric w aters to porphyry depths, and results in overprinting retrograde alteration. Porphyry copper mineralization is interp ...
majalah perdana
... holes into outer and inner propylitic zones, porphyry style veins, and core potassic zones. Additional alteration study was done by PIMA work on 102 samples taken from 6 holes of Cross Section TRK01. Clay minerals, illite, and montmorillonite are the main minerals identified in the vein samples. KAl ...
... holes into outer and inner propylitic zones, porphyry style veins, and core potassic zones. Additional alteration study was done by PIMA work on 102 samples taken from 6 holes of Cross Section TRK01. Clay minerals, illite, and montmorillonite are the main minerals identified in the vein samples. KAl ...
Tungsten profile - British Geological Survey
... scheelite is more abundant than wolframite. Lower temperature scheelite-bearing quartz veins commonly carry minor amounts of gold and sulphides. Tungsten may be recovered as a co-product of gold mining. The mineralisation occurs in greenstone belts in the deposits of Archaean age19 e.g. Hollinger (O ...
... scheelite is more abundant than wolframite. Lower temperature scheelite-bearing quartz veins commonly carry minor amounts of gold and sulphides. Tungsten may be recovered as a co-product of gold mining. The mineralisation occurs in greenstone belts in the deposits of Archaean age19 e.g. Hollinger (O ...
Tungsten profile - British Geological Survey
... scheelite is more abundant than wolframite. Lower temperature scheelite-bearing quartz veins commonly carry minor amounts of gold and sulphides. Tungsten may be recovered as a co-product of gold mining. The mineralisation occurs in greenstone belts in the deposits of Archaean age19 e.g. Hollinger (O ...
... scheelite is more abundant than wolframite. Lower temperature scheelite-bearing quartz veins commonly carry minor amounts of gold and sulphides. Tungsten may be recovered as a co-product of gold mining. The mineralisation occurs in greenstone belts in the deposits of Archaean age19 e.g. Hollinger (O ...
Ga 31
... aluminum production owing to their high silica content; consequently, recovery of gallium from these deposits is unlikely. Some domestic zinc ores have the potential to be significant sources of gallium. The United States meets its current and expected future needs for gallium through imports of pri ...
... aluminum production owing to their high silica content; consequently, recovery of gallium from these deposits is unlikely. Some domestic zinc ores have the potential to be significant sources of gallium. The United States meets its current and expected future needs for gallium through imports of pri ...
Economic geology research, volume 1 1999-2000
... Granberg, Viterliden, Gråberget, Sarvasåive, Sadenåive, Vaikijaur, Iekelvare, and Sjisjka. Most deposits share common characteristics, such as being hosted by intermediate to felsic intrusive rocks. They are all also Cu±Au±Fe oxide dominated deposits with a similar ore mineralogy and they generally ...
... Granberg, Viterliden, Gråberget, Sarvasåive, Sadenåive, Vaikijaur, Iekelvare, and Sjisjka. Most deposits share common characteristics, such as being hosted by intermediate to felsic intrusive rocks. They are all also Cu±Au±Fe oxide dominated deposits with a similar ore mineralogy and they generally ...
Chapter 21: Metamorphism
... • Occurs in areas that have not experienced significant deformation or orogeny • Restricted to large, relatively undisturbed sedimentary piles away from active plate margins – The Gulf of Mexico ...
... • Occurs in areas that have not experienced significant deformation or orogeny • Restricted to large, relatively undisturbed sedimentary piles away from active plate margins – The Gulf of Mexico ...
Introduction to Metamorphism
... • Occurs in areas that have not experienced significant deformation or orogeny • Restricted to large, relatively undisturbed sedimentary piles away from active plate margins – The Gulf of Mexico ...
... • Occurs in areas that have not experienced significant deformation or orogeny • Restricted to large, relatively undisturbed sedimentary piles away from active plate margins – The Gulf of Mexico ...
Sublayer and Offset Dikes of the Sudbury Igneous
... to cut rocks of the SIC or younger rocks. (2) Footwall Breccia; this is a breccia composed of shattered and crushed country rocks that forms a layer, 10 to 50 m thick between the SIC and the footwall gneisses and monzonites along much of the North Range of the Sudbury structure. It extends up to a f ...
... to cut rocks of the SIC or younger rocks. (2) Footwall Breccia; this is a breccia composed of shattered and crushed country rocks that forms a layer, 10 to 50 m thick between the SIC and the footwall gneisses and monzonites along much of the North Range of the Sudbury structure. It extends up to a f ...
CPC-2014 - TU Freiberg
... Although nearly all marine stage boundaries of the Carboniferous and Permian are ratified or close to ratification, nearly nothing is known about the correlation of the system and stage boundaries into the vast continental deposits on the CP Earth. However, the Late Carboniferous and Permian was a t ...
... Although nearly all marine stage boundaries of the Carboniferous and Permian are ratified or close to ratification, nearly nothing is known about the correlation of the system and stage boundaries into the vast continental deposits on the CP Earth. However, the Late Carboniferous and Permian was a t ...
geology of the storkollen blankenberg area, kragerø, norway
... isotope determination of the lead) from pegmatites near Arendal gave about 1050 million years; the zircon age from pegmatite near Tvede strand (also in the Bamle formation) gave 720 million years. The cores of the largest gabbro bodies, however, escaped meta morphism and still retain their origina ...
... isotope determination of the lead) from pegmatites near Arendal gave about 1050 million years; the zircon age from pegmatite near Tvede strand (also in the Bamle formation) gave 720 million years. The cores of the largest gabbro bodies, however, escaped meta morphism and still retain their origina ...
The Use of Magnetic Susceptibility of Rocks in Geological
... sublattices are roughly balanced and therefore the magnetism of these materials is relatively weak. The paramagnetic and diamagnetic susceptibilities are field-independent, while the ferromagnetic susceptibility is field-dependent (Fig. 1b). Due to the last effect, the susceptibilities measured in d ...
... sublattices are roughly balanced and therefore the magnetism of these materials is relatively weak. The paramagnetic and diamagnetic susceptibilities are field-independent, while the ferromagnetic susceptibility is field-dependent (Fig. 1b). Due to the last effect, the susceptibilities measured in d ...
PRESIDENTIAL ADDRESS Patterns of mineral
... both that many mineral groups are represented and that some minerals like geikielite and baddeleyite, normally considered exotics, are surprisingly common at least in certain types of metamorphic rocks. Although the occurrence and importance of trace minerals in metamorphic rocks is widely appreciat ...
... both that many mineral groups are represented and that some minerals like geikielite and baddeleyite, normally considered exotics, are surprisingly common at least in certain types of metamorphic rocks. Although the occurrence and importance of trace minerals in metamorphic rocks is widely appreciat ...
Mineralogy Petrology
... 1. Definition of a mineral A mineral is a naturally-occurring, homogeneous solid with a definite, but generally not fixed, chemical composition and an ordered atomic arrangement. It is usually formed by inorganic processes. Let's look at the five parts of this definition: 1.) "Naturally occurring" m ...
... 1. Definition of a mineral A mineral is a naturally-occurring, homogeneous solid with a definite, but generally not fixed, chemical composition and an ordered atomic arrangement. It is usually formed by inorganic processes. Let's look at the five parts of this definition: 1.) "Naturally occurring" m ...
Geological framework and mineralization of Papua New Guinea
... There are very few publications that summarize the geology of Papua New Guinea, despite the presence of several very large or giant deposits, and the tremendous prospectivity of the country. Most publications consist of journal papers that deal with specific aspects of the geology or very small are ...
... There are very few publications that summarize the geology of Papua New Guinea, despite the presence of several very large or giant deposits, and the tremendous prospectivity of the country. Most publications consist of journal papers that deal with specific aspects of the geology or very small are ...
Setting Based Classification
... Contact Metamorphism Polymetamorphic rocks are common, usually representing an orogenic event followed by a contact one • Spotted phyllite (or slate) • Overprint may be due to: – Lag time between the creation of the magma at depth during T maximum, and its migration to the lower grade rocks above ...
... Contact Metamorphism Polymetamorphic rocks are common, usually representing an orogenic event followed by a contact one • Spotted phyllite (or slate) • Overprint may be due to: – Lag time between the creation of the magma at depth during T maximum, and its migration to the lower grade rocks above ...
petrology of the sthathbogie batholith: a cordierite-bearing
... chen'ricalfeatures of the type-B garnets are summarized in Tables 3 and 5. The more leucocratic porphyritic microgranites, especially near the edges of the batholith, contain patches of tourmaline intergrown with the groundmass phases. This feature is most common in variants with a relatively coarse ...
... chen'ricalfeatures of the type-B garnets are summarized in Tables 3 and 5. The more leucocratic porphyritic microgranites, especially near the edges of the batholith, contain patches of tourmaline intergrown with the groundmass phases. This feature is most common in variants with a relatively coarse ...
Memoir 36: Geology of Organ Mountains and southern San Andres
... Dunham wrote Geology of the Organ Mountains, yet his account of the geology of the range is as timely today as it was in 1935 and his writing style is as much a pleasure to read now as then. His description of the ore deposits and his petrographic work with the igneous and metamorphic rocks are not ...
... Dunham wrote Geology of the Organ Mountains, yet his account of the geology of the range is as timely today as it was in 1935 and his writing style is as much a pleasure to read now as then. His description of the ore deposits and his petrographic work with the igneous and metamorphic rocks are not ...
Mineral profile - British Geological Survey
... laterites. Cobalt dispersed in silicates and sulphides within the host rock is remobilised and deposited in weathered layers as hydroxides and oxides near the surface and as silicates at deeper levels. These deposits are generally about 20 metres thick and mid-Tertiary25 to recent in age. They are p ...
... laterites. Cobalt dispersed in silicates and sulphides within the host rock is remobilised and deposited in weathered layers as hydroxides and oxides near the surface and as silicates at deeper levels. These deposits are generally about 20 metres thick and mid-Tertiary25 to recent in age. They are p ...
Late Pliocene to Holocene platform evolution in northern Belize, and
... view of upper Quaternary platform and foreplatform evolution in Belize, they encompassed only part of the extensive Belize platform and only that of Late Quaternary age. Whether their conclusions are applicable to the northern shelf area as well is uncertain, however, especially considering known al ...
... view of upper Quaternary platform and foreplatform evolution in Belize, they encompassed only part of the extensive Belize platform and only that of Late Quaternary age. Whether their conclusions are applicable to the northern shelf area as well is uncertain, however, especially considering known al ...
Metamorphic Intro
... s1 > s2 = s3 foliation and no lineation s1 = s2 > s3 lineation and no foliation s1 > s2 > s3 both foliation and lineation Flattening of a ductile homogeneous sphere (a) containing randomly oriented flat disks or flakes. In (b), the matrix flows with progressive flattening, and the flakes ...
... s1 > s2 = s3 foliation and no lineation s1 = s2 > s3 lineation and no foliation s1 > s2 > s3 both foliation and lineation Flattening of a ductile homogeneous sphere (a) containing randomly oriented flat disks or flakes. In (b), the matrix flows with progressive flattening, and the flakes ...
Provenance of zircon of the lowermost sedimentary cover, Estonia
... the mineralogies of weathering profiles (Kuuspalu et al. 1971, Puura et al. 1983), and the lithologies of Vendian and Cambrian deposits (Mens & Pirrus 1986) have been studied. The results of these investigations are used as background information for the present project. Subsurface geological mappin ...
... the mineralogies of weathering profiles (Kuuspalu et al. 1971, Puura et al. 1983), and the lithologies of Vendian and Cambrian deposits (Mens & Pirrus 1986) have been studied. The results of these investigations are used as background information for the present project. Subsurface geological mappin ...
Ore genesis
The various theories of ore genesis explain how the various types of mineral deposits form within the Earth's crust. Ore genesis theories are dependent on the mineral or commodity.Ore genesis theories generally involve three components: source, transport or conduit, and trap. This also applies to the petroleum industry, which was first to use this methodology. Source is required because metal must come from somewhere, and be liberated by some process Transport is required first to move the metal-bearing fluids or solid minerals into the right position, and refers to the act of physically moving the metal, as well as chemical or physical phenomenon which encourage movement Trapping is required to concentrate the metal via some physical, chemical or geological mechanism into a concentration which forms mineable oreThe biggest deposits are formed when the source is large, the transport mechanism is efficient, and the trap is active and ready at the right time.