Mineralogic and Oxygen Isotopic Studies of Open
... al., 1993), in part owing to the presence of potentially exploitable Cu-Ni sulfide mineralization. The purpose of this study is to document geochemical and mineralogical variations in the lesser studied South Kawishiwi intrusion (Fig. 2), and to use the data to constrain possible open system magmati ...
... al., 1993), in part owing to the presence of potentially exploitable Cu-Ni sulfide mineralization. The purpose of this study is to document geochemical and mineralogical variations in the lesser studied South Kawishiwi intrusion (Fig. 2), and to use the data to constrain possible open system magmati ...
Trace element composition and degree of partial melting of pelitic
... The Aoyama area were previously divided into two regional metamorphic zones and one contact metamorphic zone of postregional metamorphic origin, utilizing mineral assemblages in pelitic lithology (Kawakami, 2001a). The regional metamorphic zones in the order of ascending metamorphic grade are (i) si ...
... The Aoyama area were previously divided into two regional metamorphic zones and one contact metamorphic zone of postregional metamorphic origin, utilizing mineral assemblages in pelitic lithology (Kawakami, 2001a). The regional metamorphic zones in the order of ascending metamorphic grade are (i) si ...
Stress and Strain - Academic Home Page
... penetrative structures in a rock. Not all foliations and lineations are fabrics… Gneissosity and cross-bedding are examples of rock fabric Glacial striations are not fabrics because they are surface features, and do not penetrate the rock ...
... penetrative structures in a rock. Not all foliations and lineations are fabrics… Gneissosity and cross-bedding are examples of rock fabric Glacial striations are not fabrics because they are surface features, and do not penetrate the rock ...
Review of Greenland Avtivities 2001 - Kimberlites and other
... concentrations of the trace elements Ba, Cr, Ni, Nb, Sr, P, Ti and light REE. In view of the particular mineralogy and chemistry of the alkaline rocks, their presence within the gneiss-dominated Archaean basement should be readily detectable in the stream sediment geochemical survey. However, becaus ...
... concentrations of the trace elements Ba, Cr, Ni, Nb, Sr, P, Ti and light REE. In view of the particular mineralogy and chemistry of the alkaline rocks, their presence within the gneiss-dominated Archaean basement should be readily detectable in the stream sediment geochemical survey. However, becaus ...
19. petrology of siliceous rocks recovered
... Figure 4. Photomicrographs of radiolarian mudstone and chert, (a) and (c) are of Eocene radiolarian porcelanite from Sample 291-4-4, 12-17 cm (b) and (d) are of a Mesozoic radiolarian chert from the Franciscan Formation near Sausalito, Marin County, California. Scale bars represent 500µ. (a) Poorly ...
... Figure 4. Photomicrographs of radiolarian mudstone and chert, (a) and (c) are of Eocene radiolarian porcelanite from Sample 291-4-4, 12-17 cm (b) and (d) are of a Mesozoic radiolarian chert from the Franciscan Formation near Sausalito, Marin County, California. Scale bars represent 500µ. (a) Poorly ...
Heavy minerals (HM)
... Left – etch pits and mammillated surface ; right – etch pits and faceted surface etch pits can be randomly distributed or preferentially distributed ...
... Left – etch pits and mammillated surface ; right – etch pits and faceted surface etch pits can be randomly distributed or preferentially distributed ...
Modeling the thermal evolution of fault
... models: implications for the solidi®cation of granitoid plutons AARON S. YOSHINOBU*, DAVID A. OKAYA and SCOTT R. PATERSON Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089-0740, U.S.A. (Received 1 July 1997; accepted in revised form 20 April 1998) AbstractÐA two- ...
... models: implications for the solidi®cation of granitoid plutons AARON S. YOSHINOBU*, DAVID A. OKAYA and SCOTT R. PATERSON Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089-0740, U.S.A. (Received 1 July 1997; accepted in revised form 20 April 1998) AbstractÐA two- ...
The Cerros del Rio volcanic field
... The Cerros del Rio hawaiite flows span the entire history of the field. The early hawaiite formed extensive flat-topped areas, but later hawaiite formed long, narrow finger-like flows. The rock is generally gray in hand specimen, with an aphanitic groundmass and olivine phenocrysts. In thin section, ...
... The Cerros del Rio hawaiite flows span the entire history of the field. The early hawaiite formed extensive flat-topped areas, but later hawaiite formed long, narrow finger-like flows. The rock is generally gray in hand specimen, with an aphanitic groundmass and olivine phenocrysts. In thin section, ...
Abyssal peridotites, very slow spreading ridges and
... however, representing layer 3 and possible palaeo-magma chambers are rare. This suggests a highly segmented crustal structure, with anomalously thin crust near fracture zones that may consist of only a thin veneer of pillow basalt erupted over mantle peridotite. The dredged peridotites underwent hig ...
... however, representing layer 3 and possible palaeo-magma chambers are rare. This suggests a highly segmented crustal structure, with anomalously thin crust near fracture zones that may consist of only a thin veneer of pillow basalt erupted over mantle peridotite. The dredged peridotites underwent hig ...
VEIN URANIUM - Publications du gouvernement du Canada
... crossfaults, such as the Larum, South Radiore, and George Lake faults (Fig. 13.1-4). Stratigraphically the orebodies occur near the Tazin-Martin unconformity. The rocks in the footwall of the St. Louis Fault represent units of the Tazin domain and may form part of a subduction zone assemblage; the f ...
... crossfaults, such as the Larum, South Radiore, and George Lake faults (Fig. 13.1-4). Stratigraphically the orebodies occur near the Tazin-Martin unconformity. The rocks in the footwall of the St. Louis Fault represent units of the Tazin domain and may form part of a subduction zone assemblage; the f ...
Introduction to Metamorphism
... Contact Metamorphism – Most easily recognized where a pluton is introduced into shallow rocks in a static environment – The rocks near the pluton are often high-grade rocks with an isotropic fabric: hornfelses (or granofelses) in which relict textures and structures are common – Polymetamorphic roc ...
... Contact Metamorphism – Most easily recognized where a pluton is introduced into shallow rocks in a static environment – The rocks near the pluton are often high-grade rocks with an isotropic fabric: hornfelses (or granofelses) in which relict textures and structures are common – Polymetamorphic roc ...
Chapter 21: Metamorphism
... Contact Metamorphism – Most easily recognized where a pluton is introduced into shallow rocks in a static environment – The rocks near the pluton are often high-grade rocks with an isotropic fabric: hornfelses (or granofelses) in which relict textures and structures are common – Polymetamorphic roc ...
... Contact Metamorphism – Most easily recognized where a pluton is introduced into shallow rocks in a static environment – The rocks near the pluton are often high-grade rocks with an isotropic fabric: hornfelses (or granofelses) in which relict textures and structures are common – Polymetamorphic roc ...
Rare-earth elements minerals in carbonatites of the Kola
... rock‐forming concentrations. In a recent review of compositional and mineralogical data for Kola carbonatites (including Khibina, Kovdor, Vuoriyarvi and Turiy Mys) (Zaitsev et al., 2014) established a threshold for the content of REE at 2,000–3,000 ppm, above which REE‐minerals are ...
... rock‐forming concentrations. In a recent review of compositional and mineralogical data for Kola carbonatites (including Khibina, Kovdor, Vuoriyarvi and Turiy Mys) (Zaitsev et al., 2014) established a threshold for the content of REE at 2,000–3,000 ppm, above which REE‐minerals are ...
Pdf, 13.7 Mb - Ministry of Energy and Mines and Responsible for
... the Tanbreez project in the southern part known as Kringlerne (Fig. 1). The first detailed mapping and petrological studies of the complex were published by Ussing (1912), who also defined the term ‘agpaitic’ for rocks where the molar ratio (Na+K)/ Al is greater than or equal to 1.2. Since then, the ...
... the Tanbreez project in the southern part known as Kringlerne (Fig. 1). The first detailed mapping and petrological studies of the complex were published by Ussing (1912), who also defined the term ‘agpaitic’ for rocks where the molar ratio (Na+K)/ Al is greater than or equal to 1.2. Since then, the ...
860 hard minerals
... Gem hunters uncovered more than 480 diamonds at Crater of Diamonds in 2006. Most were small, about the size of a match head. But some, like Gatliff’s discovery, were bigger — and more valuable. Gems, such as diamonds, rubies, and emeralds, are all types of crystals. They vary in color because they a ...
... Gem hunters uncovered more than 480 diamonds at Crater of Diamonds in 2006. Most were small, about the size of a match head. But some, like Gatliff’s discovery, were bigger — and more valuable. Gems, such as diamonds, rubies, and emeralds, are all types of crystals. They vary in color because they a ...
NORTH--MA€HÄKOS-l4EIIKA- • AREA - Library
... in the east side of the area. More than half the area has a rather monotonous topography underlain by volcanic rocks of relatively recent age. This distribution of rock types reduces the chance of the discovery of minerals such as mica, kyanite, vermiculite and garnet, which from time to time have p ...
... in the east side of the area. More than half the area has a rather monotonous topography underlain by volcanic rocks of relatively recent age. This distribution of rock types reduces the chance of the discovery of minerals such as mica, kyanite, vermiculite and garnet, which from time to time have p ...
Insights from the Strange Lake Pluton
... Two characteristics of peralkaline igneous rocks that are poorly understood are the extreme enrichment in HFSE, notably Zr, Nb, Y and REE, and the occurrence of fluid inclusions dominated by methane and higher hydrocarbons. Although much of the HFSE enrichment can be explained by magmatic processes, ...
... Two characteristics of peralkaline igneous rocks that are poorly understood are the extreme enrichment in HFSE, notably Zr, Nb, Y and REE, and the occurrence of fluid inclusions dominated by methane and higher hydrocarbons. Although much of the HFSE enrichment can be explained by magmatic processes, ...
PowerPoint - Cal State LA - Instructional Web Server
... E.g., corals and algae common in carbonate rocks, and mostly found tropical to subtropical latitudes or from about 30o N and S latitudes Most carbonate sediments generated in photic zone Unlike sandstones, most carbonate grains formed in environment in which they are deposited Detrital grains in san ...
... E.g., corals and algae common in carbonate rocks, and mostly found tropical to subtropical latitudes or from about 30o N and S latitudes Most carbonate sediments generated in photic zone Unlike sandstones, most carbonate grains formed in environment in which they are deposited Detrital grains in san ...
A Martian analog in Kansas: Comparing Martian strata with Permian
... structures (Kargel, 2004). In addition, hematite concretions in the Jurassic Navajo Sandstone of Utah have been compared favorably to the ‘‘blueberry’’ concretions on Mars (Chan et al., 2004). The middle Permian Nippewalla Group is a stronger terrestrial analog, because it has striking similarities ...
... structures (Kargel, 2004). In addition, hematite concretions in the Jurassic Navajo Sandstone of Utah have been compared favorably to the ‘‘blueberry’’ concretions on Mars (Chan et al., 2004). The middle Permian Nippewalla Group is a stronger terrestrial analog, because it has striking similarities ...
Characteristics and Petrogenesis of Alaskan-Type Ultramafic
... Chichagof Island (Himmelberg and others, 1987), and the residual mantle harzburgite exposed in the Atlin quadrangle southeast of Skagway (Himmelberg and others, 1986a). Serpentinites near Point Marsden and north of Greens Creek on northern Admiralty Island, and in the Coast Mountains south of the Ta ...
... Chichagof Island (Himmelberg and others, 1987), and the residual mantle harzburgite exposed in the Atlin quadrangle southeast of Skagway (Himmelberg and others, 1986a). Serpentinites near Point Marsden and north of Greens Creek on northern Admiralty Island, and in the Coast Mountains south of the Ta ...
Read 27th May, 1929.
... Africa. It is constituted of ancient gne.issoid and granitic rocks, schists, quartzites, crystalline limestones and other more or less highly metamorphosed sediments. The task of unravelling the stratigraphical succession of its sedimentary components presents great difficulties, for not only have t ...
... Africa. It is constituted of ancient gne.issoid and granitic rocks, schists, quartzites, crystalline limestones and other more or less highly metamorphosed sediments. The task of unravelling the stratigraphical succession of its sedimentary components presents great difficulties, for not only have t ...
Crystal Fractionation and the Evolution of Intra
... exceptionally high K2O contents, but because of high K2O/Na2O ratios. They are also termed ‘tholeiitic’ (despite the presence of many alkalic members within the suites) because of the tholeiitic nature of the associated least-evolved mafic units. Figure 3a shows the variation of alkalis with silica ...
... exceptionally high K2O contents, but because of high K2O/Na2O ratios. They are also termed ‘tholeiitic’ (despite the presence of many alkalic members within the suites) because of the tholeiitic nature of the associated least-evolved mafic units. Figure 3a shows the variation of alkalis with silica ...
Geology of the Granby Fault, an Eocene Extensional Fault in
... The syenite of the Coryell suite is mainly exposed as a pluton more than 2 km wide in the hanging-wall of the Granby Fault at the northern end of the map area. There, it occurs as a pink, coarse-grained, K-feldspar + biotite ± amphibole- phyric syenite, that may grade into a massive K-feldspar megac ...
... The syenite of the Coryell suite is mainly exposed as a pluton more than 2 km wide in the hanging-wall of the Granby Fault at the northern end of the map area. There, it occurs as a pink, coarse-grained, K-feldspar + biotite ± amphibole- phyric syenite, that may grade into a massive K-feldspar megac ...
geology of the granby fault, an eocene extensional fault in southeast
... The syenite of the Coryell suite is mainly exposed as a pluton more than 2 km wide in the hanging-wall of the Granby Fault at the northern end of the map area. There, it occurs as a pink, coarse-grained, K-feldspar + biotite ± amphibole- phyric syenite, that may grade into a massive K-feldspar megac ...
... The syenite of the Coryell suite is mainly exposed as a pluton more than 2 km wide in the hanging-wall of the Granby Fault at the northern end of the map area. There, it occurs as a pink, coarse-grained, K-feldspar + biotite ± amphibole- phyric syenite, that may grade into a massive K-feldspar megac ...
Igneous rock
Igneous rock (derived from the Latin word ignis meaning fire) is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. Igneous rock may form with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. This magma can be derived from partial melts of pre-existing rocks in either a planet's mantle or crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Over 700 types of igneous rocks have been described, most of them having formed beneath the surface of Earth's crust.