Preliminary Geologic Map of the Redondo Peak
... pumice fall deposit occurs between the Otowi and Tshirege members on the west side of Peralta Canyon. This general area also contains two outcrops of Older Gravels overlying the Tshirege Member. The famous resurgent dome of Valles Caldera (Smith and Bailey, 1968) occurs on the northern margin of the ...
... pumice fall deposit occurs between the Otowi and Tshirege members on the west side of Peralta Canyon. This general area also contains two outcrops of Older Gravels overlying the Tshirege Member. The famous resurgent dome of Valles Caldera (Smith and Bailey, 1968) occurs on the northern margin of the ...
AN EARLY PERMIAN SUBTROPICAL CARBONATE SYSTEM:
... the predominant fossils throughout the extent of these two units, with local occurrences of large fusulinids and colonial corals. This mixed photozoan-heterozoan assemblage is similar to the sediments of modern-day subtropical settings. Although the Raanes and Great Bear Cape have warm-water rocks b ...
... the predominant fossils throughout the extent of these two units, with local occurrences of large fusulinids and colonial corals. This mixed photozoan-heterozoan assemblage is similar to the sediments of modern-day subtropical settings. Although the Raanes and Great Bear Cape have warm-water rocks b ...
Chapter 07 - Duplin County Schools
... • Erosion is the removal and transport of weathered material from one location to another. ...
... • Erosion is the removal and transport of weathered material from one location to another. ...
2. - Teacher Friendly Guides
... detailed sequence of rocks for the history that has gone on under our feet. What is not possible from only one location is making sense of why this particular sequence of events took place when and where it did, particularly relative to sequences in other places around it. The distribution of rocks ...
... detailed sequence of rocks for the history that has gone on under our feet. What is not possible from only one location is making sense of why this particular sequence of events took place when and where it did, particularly relative to sequences in other places around it. The distribution of rocks ...
labradorite 1 - Geological Association of Canada
... The mineral labradorite is one of the most beautiful and popular of the semiprecious stones and is often used in jewellery and ornaments. It is found in abundance near the community of Nain and elsewhere in Labrador, and on the island of Newfoundland. Labradorite is usually dark grey, but in the rig ...
... The mineral labradorite is one of the most beautiful and popular of the semiprecious stones and is often used in jewellery and ornaments. It is found in abundance near the community of Nain and elsewhere in Labrador, and on the island of Newfoundland. Labradorite is usually dark grey, but in the rig ...
Gifford Bay Trail. - Jersey Geology Trail
... Subsequently, the volcanic rocks were uplifted and eroded to produce the Rozel Conglomerate to the east and the lamprophyre dykes were intruded. These occur with two different strikes, N-S here but NW-SE further west of Plémont where there is a minor swarm. This intrusive phase is later than the mai ...
... Subsequently, the volcanic rocks were uplifted and eroded to produce the Rozel Conglomerate to the east and the lamprophyre dykes were intruded. These occur with two different strikes, N-S here but NW-SE further west of Plémont where there is a minor swarm. This intrusive phase is later than the mai ...
Granitoids in Poland, AM Monograph No
... differentiated into several varieties which differ in colour, structure, main mineral contents and chemical composition. The colour of the rocks depends on the dark mineral content and on the way of their arrangement in the rock. The rock seems to be lighter and more coarse-grained where dark minera ...
... differentiated into several varieties which differ in colour, structure, main mineral contents and chemical composition. The colour of the rocks depends on the dark mineral content and on the way of their arrangement in the rock. The rock seems to be lighter and more coarse-grained where dark minera ...
Radiometric dating results 5
... transected by several branches of the Karesuando-Arjeplog deformation zone but in domains between these branches the rocks may show only minor signs of deformation, such as at the sample locality. The metadiorite is dark grey, medium-grained and isotropic. In some outcrops it is altered and contains ...
... transected by several branches of the Karesuando-Arjeplog deformation zone but in domains between these branches the rocks may show only minor signs of deformation, such as at the sample locality. The metadiorite is dark grey, medium-grained and isotropic. In some outcrops it is altered and contains ...
Cabo de La Vela (“La Vela” Cape) and Surroundings
... serpentinized ultramafic rocks, gabbros, and andesitic dykes and forms low hills, sometimes covered by Cenozoic sediments and separated by extensive plains formed on other Cretaceous rock massifs, which apparently present some similarities (Ingeominas 2002). The Etpana and Jarara Formations are assoc ...
... serpentinized ultramafic rocks, gabbros, and andesitic dykes and forms low hills, sometimes covered by Cenozoic sediments and separated by extensive plains formed on other Cretaceous rock massifs, which apparently present some similarities (Ingeominas 2002). The Etpana and Jarara Formations are assoc ...
Geologic Structures and Deformation
... • down-arched series of strata with all beds dipping in towards center through 360 degrees • rocks become progressively older away from center on an eroded surface If circular, no single fold axis—if elongated in shape there can be a fold axis assigned ...
... • down-arched series of strata with all beds dipping in towards center through 360 degrees • rocks become progressively older away from center on an eroded surface If circular, no single fold axis—if elongated in shape there can be a fold axis assigned ...
Climax Quadrangle Geologic Map, Lake and Park Counties, Colorado
... bedrock) to >5 ft as a discontinuous cover, are mapped as a “fractional” map unit, shown by a map unit abbreviation that lists the Quaternary deposit in the numerator and the underlying deposit in the denominator (e.g., Qpt/Tp). Areas where Quaternary deposits nowhere exceed 5 ft thick and includ ...
... bedrock) to >5 ft as a discontinuous cover, are mapped as a “fractional” map unit, shown by a map unit abbreviation that lists the Quaternary deposit in the numerator and the underlying deposit in the denominator (e.g., Qpt/Tp). Areas where Quaternary deposits nowhere exceed 5 ft thick and includ ...
Geodynamic Significance of the Kontum Massif in
... reported by Hutchison [1989] are estimates) and include K-Ar ages of 241–244 Ma from synkinematic biotites in a cordierite-sillimanite-biotite gneiss (Tran Ngoc Nam 1998), a 240-Ma 40Ar/39Ar age for a charnockite (Maluski and Lepvrier 1998; Maluski et al. 1999a), and U-Pb SHRIMP ages around 250 Ma f ...
... reported by Hutchison [1989] are estimates) and include K-Ar ages of 241–244 Ma from synkinematic biotites in a cordierite-sillimanite-biotite gneiss (Tran Ngoc Nam 1998), a 240-Ma 40Ar/39Ar age for a charnockite (Maluski and Lepvrier 1998; Maluski et al. 1999a), and U-Pb SHRIMP ages around 250 Ma f ...
Nitrogen-isotope record of fluid-rock interactions in the
... the cooling intrusive body. Such transport is consistent with the predictions of recent theoretical models of late-stage hydrothermal evolution in cooling intrusive systems. ...
... the cooling intrusive body. Such transport is consistent with the predictions of recent theoretical models of late-stage hydrothermal evolution in cooling intrusive systems. ...
Magmatic Evolution of the Eocene Volcanic Rocks of the Bijgerd
... eruptions from one or more sources. Hydrated volcanic fragments in hyaloclastic rocks, and the presence of a sequence of shallow and intermediate-depth marine microfossils, suggest that the Middle Eocene units were erupted in a marine basin. The bimodal volcanism of the Late Eocene is distinguished ...
... eruptions from one or more sources. Hydrated volcanic fragments in hyaloclastic rocks, and the presence of a sequence of shallow and intermediate-depth marine microfossils, suggest that the Middle Eocene units were erupted in a marine basin. The bimodal volcanism of the Late Eocene is distinguished ...
Geochemistry and petrogenesis of extrusive rocks, dykes and high
... gabbro (FMG) and vari-textured gabbro (VTG). The aphyric, FMG occurs as irregular bodies intruded by regular, 10 to 40 cm-wide, and irregular, 0.5 to 15 cm wide, mafic dykes. Some of the dykes are rooted in irregular gabbro bodies. This close, rooted association of dykes and irregular magma bodies ...
... gabbro (FMG) and vari-textured gabbro (VTG). The aphyric, FMG occurs as irregular bodies intruded by regular, 10 to 40 cm-wide, and irregular, 0.5 to 15 cm wide, mafic dykes. Some of the dykes are rooted in irregular gabbro bodies. This close, rooted association of dykes and irregular magma bodies ...
LODE-GOLD DEPOSITS
... listed in the bibliography on page 16 and in lists of references found after the description of mineralized areas. Acknowledgment is made of these sources of info:rmation. The present writer accepts responsibility for many of the generalizations ma.de, particularly on the geology in areas not covere ...
... listed in the bibliography on page 16 and in lists of references found after the description of mineralized areas. Acknowledgment is made of these sources of info:rmation. The present writer accepts responsibility for many of the generalizations ma.de, particularly on the geology in areas not covere ...
Rare earth elements in Québec, Canada: Main deposit
... neighbours in the solar system, because of the greater stability of their atomic nuclei (Oddo-Harkins effect); and 2) the predominance of light REE (LREE: La to Eu) compared to heavy REE (HREE: Gd to Lu) in the Earth’s crust, since LREE are more incompatible than HREE (Walters et al., 2011). The REE ...
... neighbours in the solar system, because of the greater stability of their atomic nuclei (Oddo-Harkins effect); and 2) the predominance of light REE (LREE: La to Eu) compared to heavy REE (HREE: Gd to Lu) in the Earth’s crust, since LREE are more incompatible than HREE (Walters et al., 2011). The REE ...
Chapter 9 Proterozoic
... – Archean: little or no free oxygen – the amount present – at the beginning of the Proterozoic was probably no more than 1% of that present now – Stromatolites—not common until: ...
... – Archean: little or no free oxygen – the amount present – at the beginning of the Proterozoic was probably no more than 1% of that present now – Stromatolites—not common until: ...
Red-bed copper deposits of the Quebec Appalachians
... feldspar and other magmatic silicates are replaced by hematite (Figs. 15a, b). The chlorite has Fe/(Fe+Mg) ratios varying from 0.29 to 0.36, a range within that of the chlorite investigated by Cathelineau & Nieva (1985). Application of their chlorite geothermometer suggests temperatures between 155 ...
... feldspar and other magmatic silicates are replaced by hematite (Figs. 15a, b). The chlorite has Fe/(Fe+Mg) ratios varying from 0.29 to 0.36, a range within that of the chlorite investigated by Cathelineau & Nieva (1985). Application of their chlorite geothermometer suggests temperatures between 155 ...
Selleck, B., McLelland, J. and Hamilton, M. (2004)
... dissolved silica, and apparently alumina, since the large clusters of sillimanite crystals appear to have grown within the veins via precipitation from fluid and thus represent at least local mobilization of alumina. Coherent quartz-sillimanite veins are often found within granite that contains isol ...
... dissolved silica, and apparently alumina, since the large clusters of sillimanite crystals appear to have grown within the veins via precipitation from fluid and thus represent at least local mobilization of alumina. Coherent quartz-sillimanite veins are often found within granite that contains isol ...
SYMPOSIUM ON LAYERED INTRUSIONS
... from crystals, will sweep over the floor; the top crystals of the pile will have an opportunity to grow, and an ad cumulate or, in extreme cases, a rock with harrisitic texture, will result. On the other hand, it may be that during circulation the heat loss and the effect of increasing hydrostatic p ...
... from crystals, will sweep over the floor; the top crystals of the pile will have an opportunity to grow, and an ad cumulate or, in extreme cases, a rock with harrisitic texture, will result. On the other hand, it may be that during circulation the heat loss and the effect of increasing hydrostatic p ...
Radiogenic heat production of Archaean to Permian geological
... Karelian craton at ca. 1.9 Ga (Krill et al. 1985; Braathen & Davidsen 2000). The rocks were mostly metamorphosed under low to medium conditions (sub-greenschist to amphibolite-facies) (Siedlecka et al. 1985) during this event. Unfortunately, no heat-production data are available for the Karasjok–Kau ...
... Karelian craton at ca. 1.9 Ga (Krill et al. 1985; Braathen & Davidsen 2000). The rocks were mostly metamorphosed under low to medium conditions (sub-greenschist to amphibolite-facies) (Siedlecka et al. 1985) during this event. Unfortunately, no heat-production data are available for the Karasjok–Kau ...
geologic map (scale 1 :250000) of the penokean orogen, central
... is to the Penokean orogen as the Alleghanian orogeny is to the Appalachian orogen (Seacor and others, 1986). It has been recognized for years that there are pronounced increases in stratigraphic and structural complexity, and also of metamorphic grade, from northnorthwest to south-southeast across t ...
... is to the Penokean orogen as the Alleghanian orogeny is to the Appalachian orogen (Seacor and others, 1986). It has been recognized for years that there are pronounced increases in stratigraphic and structural complexity, and also of metamorphic grade, from northnorthwest to south-southeast across t ...
Research Article
... and D3 are commonly observed, while the occurrence of the D2 structure is limited. In all the rocks, D1 structure is characterized by a distinct foliation (Sl-foliation) parallel to lithologic boundaries. In some metapelites, there are many kinds of asymmetric deformation structures: intrafolial fol ...
... and D3 are commonly observed, while the occurrence of the D2 structure is limited. In all the rocks, D1 structure is characterized by a distinct foliation (Sl-foliation) parallel to lithologic boundaries. In some metapelites, there are many kinds of asymmetric deformation structures: intrafolial fol ...
Water-rock interaction observed in the brittle-plastic transition zone
... Oxidation state may be changed since FeO increases whereas total Fe content does not change. As for cataclastic part, CaO, Na2 O and K2 O seem to be changed probably due to alteration of feldspar. Mineral assemblages in the reference sample and deformed granodiorites are quartz - plagioclase - potas ...
... Oxidation state may be changed since FeO increases whereas total Fe content does not change. As for cataclastic part, CaO, Na2 O and K2 O seem to be changed probably due to alteration of feldspar. Mineral assemblages in the reference sample and deformed granodiorites are quartz - plagioclase - potas ...
Clastic rock
Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus, chunks and smaller grains of rock broken off other rocks by physical weathering. Geologists use the term clastic with reference to sedimentary rocks as well as to particles in sediment transport whether in suspension or as bed load, and in sediment deposits.