Author: David Richard Lentz
Publisher:
ISBN:
Category : Pegmatites
Languages : en
Pages :
Book Description
Fluorite-apatite-calcite veins, have inclusions and selvages of coarse-grained biotite, K-feldspar, Ca amphibole, Ca pyroxene, and titanite with occasional magnetite, sulphides, and rate-element minerals.
Petrogenesis of U-, Th-, Mo-, and Ree-bearing Pegmatites, Skarns, and Veins in the Central Metasedimentary Belt of the Grenville Province Ontario and Quebec
Author: David Richard Lentz
Publisher:
ISBN:
Category : Pegmatites
Languages : en
Pages :
Book Description
Fluorite-apatite-calcite veins, have inclusions and selvages of coarse-grained biotite, K-feldspar, Ca amphibole, Ca pyroxene, and titanite with occasional magnetite, sulphides, and rate-element minerals.
Publisher:
ISBN:
Category : Pegmatites
Languages : en
Pages :
Book Description
Fluorite-apatite-calcite veins, have inclusions and selvages of coarse-grained biotite, K-feldspar, Ca amphibole, Ca pyroxene, and titanite with occasional magnetite, sulphides, and rate-element minerals.
Petrogenesis of Uranium-, Thorium-, Molybdenum-, and Rare Earth Element-bearing Pegmatites, Skarns, and Veins in the Central Metasedimentary Belt of the Grenville Province, Ontario and Quebec
Author: David Richard Lentz
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Field examination of late-tectonic, U-, Th-, Mo-, and REE-bearing pegmatites, skarns, and veins in the southwestern Grenville Province indicates that they are spatially and temporally related. These observations lead to a renewal of the hypothesis that the deposits were related to intrusion of the pegmatites and formation of the skarns. The granitic pegmatites are related either to chemical fractionation of late-tectonic granitic plutons or mid-crustal anatectic melts with emplacement at the present structural level. This interpretation is based primarily on their discordant nature, late tectonic age, and moderately-evolved chemical composition. At the time of pegmatite emplacement the host rocks remained above 500$\sp\circ$C. Endoskarns (within pegmatite) are dominated by calc-silicate minerals (Ca pyroxene, scapolite, andradite, and titanite) and have a similar origin to the hybridized pegmatites involving metasomatic reaction of the pegmatite and skarn by either diffusion or infiltration of chemical components into the pegmatite. The exoskarns are dominantly primary with a mineralogical zonation which may be characterized as proximal to distal with relation to the pegmatite. The absence of calcite within the proximal skarn is explained in that the pegmatite-derived fluids were undersaturated in calcite resulting in dissolution. Calcite veins represent distal primary skarn. Secondary tremolite-phlogopite-sulphide replacement veins occur within the primary skarn. Fluorite-apatite-calcite veins, have inclusions and selvages of coarse-grained biotite, K-feldspar, Ca amphibole, Ca pyroxene, and titanite with occasional magnetite, sulphides, and rate-element minerals. Common minerals within the pegmatites, skarns, and veins facilitated a chemical comparison of these minerals. The colour of ferromagnesian phases, particularly Ca pyroxene and biotite/phlogopite was used in the field to describe the relative iron contents of these phases. In general, iron was highest in the minerals associated with the pegmatites, and proximal skarn; more magnesium rich in the skarns not directly associated with a pegmatite. Major- and trace-element distribution coefficients (K$\sb{\rm D})$ for coexisting phases in veins and skarns are indistinguishable, although only a few elements (Fe, Mg, Mn, and Zn) have regular distributions. In a more detailed study of the Hunt Mo skarn, four zones have been identified in the exoskarn which is, in part, consistent with observations from many other skarns in the region. The proximal zone 1 assemblage is narrow, coarse-grained (1 metre), and dominantly composed of Fe-rich Ca pyroxene, scapolite (or microcline or albite), titanite, pyrite, and molybdenite (rare quartz). The dominant skarn type, zone 2, is fine- to coarse-grained and consists of Fe-bearing Ca pyroxene, phlogopite/biotite, titanite, pyrite, and pyrrhotite, with irregular phlogopite (possibly secondary) veinlets throughout. Apatite is an accessory phase within zone 2 skarns. The third zone is composed of Ca pyroxene; phlogopite, and tremolite, and occasionally calcite and pyrite which are fine to medium grained. The fourth zone represents small veins hosted in graphite-bearing phlogopite-diopside-dolomite-calcite marble, and is dominated by fine- to medium-grained tremolite, phlogopite, calcite, pyrite $(\pm$ graphite). (Abstract shortened by UMI.).
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Field examination of late-tectonic, U-, Th-, Mo-, and REE-bearing pegmatites, skarns, and veins in the southwestern Grenville Province indicates that they are spatially and temporally related. These observations lead to a renewal of the hypothesis that the deposits were related to intrusion of the pegmatites and formation of the skarns. The granitic pegmatites are related either to chemical fractionation of late-tectonic granitic plutons or mid-crustal anatectic melts with emplacement at the present structural level. This interpretation is based primarily on their discordant nature, late tectonic age, and moderately-evolved chemical composition. At the time of pegmatite emplacement the host rocks remained above 500$\sp\circ$C. Endoskarns (within pegmatite) are dominated by calc-silicate minerals (Ca pyroxene, scapolite, andradite, and titanite) and have a similar origin to the hybridized pegmatites involving metasomatic reaction of the pegmatite and skarn by either diffusion or infiltration of chemical components into the pegmatite. The exoskarns are dominantly primary with a mineralogical zonation which may be characterized as proximal to distal with relation to the pegmatite. The absence of calcite within the proximal skarn is explained in that the pegmatite-derived fluids were undersaturated in calcite resulting in dissolution. Calcite veins represent distal primary skarn. Secondary tremolite-phlogopite-sulphide replacement veins occur within the primary skarn. Fluorite-apatite-calcite veins, have inclusions and selvages of coarse-grained biotite, K-feldspar, Ca amphibole, Ca pyroxene, and titanite with occasional magnetite, sulphides, and rate-element minerals. Common minerals within the pegmatites, skarns, and veins facilitated a chemical comparison of these minerals. The colour of ferromagnesian phases, particularly Ca pyroxene and biotite/phlogopite was used in the field to describe the relative iron contents of these phases. In general, iron was highest in the minerals associated with the pegmatites, and proximal skarn; more magnesium rich in the skarns not directly associated with a pegmatite. Major- and trace-element distribution coefficients (K$\sb{\rm D})$ for coexisting phases in veins and skarns are indistinguishable, although only a few elements (Fe, Mg, Mn, and Zn) have regular distributions. In a more detailed study of the Hunt Mo skarn, four zones have been identified in the exoskarn which is, in part, consistent with observations from many other skarns in the region. The proximal zone 1 assemblage is narrow, coarse-grained (1 metre), and dominantly composed of Fe-rich Ca pyroxene, scapolite (or microcline or albite), titanite, pyrite, and molybdenite (rare quartz). The dominant skarn type, zone 2, is fine- to coarse-grained and consists of Fe-bearing Ca pyroxene, phlogopite/biotite, titanite, pyrite, and pyrrhotite, with irregular phlogopite (possibly secondary) veinlets throughout. Apatite is an accessory phase within zone 2 skarns. The third zone is composed of Ca pyroxene; phlogopite, and tremolite, and occasionally calcite and pyrite which are fine to medium grained. The fourth zone represents small veins hosted in graphite-bearing phlogopite-diopside-dolomite-calcite marble, and is dominated by fine- to medium-grained tremolite, phlogopite, calcite, pyrite $(\pm$ graphite). (Abstract shortened by UMI.).
U-, Mo-, and REE-bearing Pegmatites, Skarns and Veins in the Central Metasedimentary Belt, Grenville Province, Ontario
Author: David R. Lentz
Publisher: Sudbury, Ont. : Geological Association of Canada, Toronto '91 Organizing Committee
ISBN:
Category : Geology
Languages : en
Pages : 80
Book Description
Publisher: Sudbury, Ont. : Geological Association of Canada, Toronto '91 Organizing Committee
ISBN:
Category : Geology
Languages : en
Pages : 80
Book Description
Fenite, Carbonatite and Other Alkalic Rocks in the Bancroft-Haliburton-Muskoka Regions
Author: S. B. Lumbers
Publisher:
ISBN:
Category : Alkalic igneous rocks
Languages : en
Pages : 22
Book Description
Publisher:
ISBN:
Category : Alkalic igneous rocks
Languages : en
Pages : 22
Book Description
Canadian Journal of Earth Sciences
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 554
Book Description
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 554
Book Description
CIM Bulletin
Author: Canadian Institute of Mining and Metallurgy
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 440
Book Description
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 440
Book Description
Geology of Ontario
Author: Ontario. Ministry of Northern Development and Mines
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 834
Book Description
This volume describes the Grenville Province and the Proterozoic history of central and southern Ontario; the Paleozoic, Mesozoic, and Quaternary geology of Ontario; the metallogeny of metallic mineral deposits in Superior and Grenville Provinces and of the northern Great Lakes Region; Tectonic evolution; and regional geochemical mapping generally and in Superior Province.
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 834
Book Description
This volume describes the Grenville Province and the Proterozoic history of central and southern Ontario; the Paleozoic, Mesozoic, and Quaternary geology of Ontario; the metallogeny of metallic mineral deposits in Superior and Grenville Provinces and of the northern Great Lakes Region; Tectonic evolution; and regional geochemical mapping generally and in Superior Province.
Metamorphic Crystallization
Author: Ralph Kretz
Publisher:
ISBN:
Category : Nature
Languages : en
Pages : 524
Book Description
Metamorphic Crystallization investigates the upper regions of the crystalline Earth, where countless solid-state chemical changes have taken place during the long history of the planet. The exploration proceeds in five stages. Firstly, a brief reminder of the importance of field, microscopic, and experimental phase-equilibrium results in metamorphic studies is given, followed by a review of classical thermodynamics as applied to minerals. Different kinds of mineral equilibria are defined, and representative natural and experimental examples of each kind are examined. The kinetics of reactions involving crystals (reaction rate, diffusion, nucleation, crystal growth), referring to certain experiments that have provided information on these microprocesses, are reviewed. Finally, the granular microstructure of natural samples (crystal shape, size, spatial distribution) together with chemical data are examined, and an interpretation of these observations in terms of mineral kinetics is pursued. This exploration intends to leave the reader more appreciative of changes which occur within the Earth, and more interested in the application of thermodynamics and kinetics in the study of these changes.
Publisher:
ISBN:
Category : Nature
Languages : en
Pages : 524
Book Description
Metamorphic Crystallization investigates the upper regions of the crystalline Earth, where countless solid-state chemical changes have taken place during the long history of the planet. The exploration proceeds in five stages. Firstly, a brief reminder of the importance of field, microscopic, and experimental phase-equilibrium results in metamorphic studies is given, followed by a review of classical thermodynamics as applied to minerals. Different kinds of mineral equilibria are defined, and representative natural and experimental examples of each kind are examined. The kinetics of reactions involving crystals (reaction rate, diffusion, nucleation, crystal growth), referring to certain experiments that have provided information on these microprocesses, are reviewed. Finally, the granular microstructure of natural samples (crystal shape, size, spatial distribution) together with chemical data are examined, and an interpretation of these observations in terms of mineral kinetics is pursued. This exploration intends to leave the reader more appreciative of changes which occur within the Earth, and more interested in the application of thermodynamics and kinetics in the study of these changes.
Field Trip Guidebook
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 74
Book Description
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 74
Book Description
CIM Bulletin
Author: Canadian Institute of Mining, Metallurgy and Petroleum
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages :
Book Description