Structure and emplac.. - Department of Earth Sciences
... nested, non-concentric intrusive centers that are successively younger to the south. The northern and central centers show the same evolutionary sequence of (1) intrusion of concentric gabbroic cone sheets, (2) intrusion of massive core gabbros, and (3) development of subvertical, ductile ring fault ...
... nested, non-concentric intrusive centers that are successively younger to the south. The northern and central centers show the same evolutionary sequence of (1) intrusion of concentric gabbroic cone sheets, (2) intrusion of massive core gabbros, and (3) development of subvertical, ductile ring fault ...
Perspectives on the origin of plagiogranite in ophiolites from oxygen
... insights into a myriad of processes in modern and ancient settings, their petrogenesis has been the subject of much debate. Most early interpretations of oceanic plagiogranite regarded them as the products of fractional crystallization of basaltic magma at low pressures (e.g., Aldiss, 1981; discussi ...
... insights into a myriad of processes in modern and ancient settings, their petrogenesis has been the subject of much debate. Most early interpretations of oceanic plagiogranite regarded them as the products of fractional crystallization of basaltic magma at low pressures (e.g., Aldiss, 1981; discussi ...
the form of the fongen-hyllingen gabbro complex, trondheim region
... the olivine-bearing to the pyroxene gabbros. Abrupt cryptic layering is shown for example by olivine, which only occurs in the deeper parts of the body and is absent in the dioritic and felsic differentiates. Systematic petrographic studies of material from the northern part of the complex are curre ...
... the olivine-bearing to the pyroxene gabbros. Abrupt cryptic layering is shown for example by olivine, which only occurs in the deeper parts of the body and is absent in the dioritic and felsic differentiates. Systematic petrographic studies of material from the northern part of the complex are curre ...
Sample pages 1 PDF
... may be the first person to see new excavations, he or she should be able to identify approximately any rock exposed, for this identification might lead to the early recognition of a problem. This identification need not be as accurate as a geologist should give, but should be not too far from the tr ...
... may be the first person to see new excavations, he or she should be able to identify approximately any rock exposed, for this identification might lead to the early recognition of a problem. This identification need not be as accurate as a geologist should give, but should be not too far from the tr ...
NORSK GEOLOGISK TIDSSKRIFT 45 DISTRIBUTION PATTERNS
... of increasing enrichment in the lighter REE they are: Basaltic group A. This was first recognized by FREY and HASKIN (1964) under the name 'oceanic basalts', but this is not a good name to designate the group, since it does not include the basalt of Kilauea (Hawaii). Four rocks show this REE distrib ...
... of increasing enrichment in the lighter REE they are: Basaltic group A. This was first recognized by FREY and HASKIN (1964) under the name 'oceanic basalts', but this is not a good name to designate the group, since it does not include the basalt of Kilauea (Hawaii). Four rocks show this REE distrib ...
geochemical study of the çaşurtepe formation
... green, cm to m thick amphibolites, alternated with white, cream coloured quartz- feldspatic bands. The contact between the two is sharp and irregular in places. Further up, the unit is composed of thick gneisses, alternating with thin bands of amphibolites: At the uppermost levels the unit is cut by ...
... green, cm to m thick amphibolites, alternated with white, cream coloured quartz- feldspatic bands. The contact between the two is sharp and irregular in places. Further up, the unit is composed of thick gneisses, alternating with thin bands of amphibolites: At the uppermost levels the unit is cut by ...
Description of sandstones in the Ulaanbaatar
... arenite. They are clast supported and poorly-sorted, with dominantly angular to very angular grains mainly composed of quartz, potassium feldspar, plagioclase and rock fragments of rhyolite and tuff. The modal framework grain analysis shows that sandy detritus was derived from “continental crust” wh ...
... arenite. They are clast supported and poorly-sorted, with dominantly angular to very angular grains mainly composed of quartz, potassium feldspar, plagioclase and rock fragments of rhyolite and tuff. The modal framework grain analysis shows that sandy detritus was derived from “continental crust” wh ...
Geochemistry of Jurassic Oceanic Crust beneath
... possibly a Jurassic carbonate platform. Layer 2 (pillows and dikes or sills) is ~2 km thick, whereas crustal layer 3 (intrusives, primarily gabbros) has a thickness of ~2·5 km. The 15 my subaerial volcanic history of Gran Canaria (Schmincke, 1982; Hoernle & Schmincke, 1993a, 1993b) can be divided in ...
... possibly a Jurassic carbonate platform. Layer 2 (pillows and dikes or sills) is ~2 km thick, whereas crustal layer 3 (intrusives, primarily gabbros) has a thickness of ~2·5 km. The 15 my subaerial volcanic history of Gran Canaria (Schmincke, 1982; Hoernle & Schmincke, 1993a, 1993b) can be divided in ...
What`s the Story with Sand?
... manganese-containing elements and causes the formation of iron oxides which are the red pigments in Georgia’s red clay. (This process is commonly known as “rusting.”) Another chemical reaction – hydrolysis - causes weathering of silicate minerals to form clays. Biological weathering can be caused b ...
... manganese-containing elements and causes the formation of iron oxides which are the red pigments in Georgia’s red clay. (This process is commonly known as “rusting.”) Another chemical reaction – hydrolysis - causes weathering of silicate minerals to form clays. Biological weathering can be caused b ...
Minerals and Their Prop. Guide
... 83. An element is a chemically pure substance made of just one kind of atom. 84. Some minerals, such as sulfur seen here, are made of just one kind of element. 85. But most minerals, such as azurite, are made of two or more elements. 86. While there are 90 elements that naturally occur in the Earth’ ...
... 83. An element is a chemically pure substance made of just one kind of atom. 84. Some minerals, such as sulfur seen here, are made of just one kind of element. 85. But most minerals, such as azurite, are made of two or more elements. 86. While there are 90 elements that naturally occur in the Earth’ ...
Petrography of Lithified Cave Sediments
... Coarse, angular, fragmental deposits are common in caves. They do not all, however, have the same origin, and the term “breccia” is frequently misused in relation to cave deposits. Coarse-grained cave deposits in general, including: - diamictites, produced by slumping or rapid flood processes; congl ...
... Coarse, angular, fragmental deposits are common in caves. They do not all, however, have the same origin, and the term “breccia” is frequently misused in relation to cave deposits. Coarse-grained cave deposits in general, including: - diamictites, produced by slumping or rapid flood processes; congl ...
File
... The longer it takes for the magma to cool, the more time mineral crystals have to grow. Back to Jeopardy Board ...
... The longer it takes for the magma to cool, the more time mineral crystals have to grow. Back to Jeopardy Board ...
Robinson-7873.pm - Mineralogical Society of America
... The Aztec Wash pluton can be divided into two distinct, major zones (Figs. 1 and 2): a lower heterogeneous zone (H zone) and an upper “homogeneous” granite (G zone) (Falkner et al. 1995). The H zone, which comprises 60–80% of the exposure, includes sheets of fine-grained mafic rock; coarser mafic cu ...
... The Aztec Wash pluton can be divided into two distinct, major zones (Figs. 1 and 2): a lower heterogeneous zone (H zone) and an upper “homogeneous” granite (G zone) (Falkner et al. 1995). The H zone, which comprises 60–80% of the exposure, includes sheets of fine-grained mafic rock; coarser mafic cu ...
Minerals and Trace Minerals - Mineral Resources International (UK)
... anions) are inherently metallic. This does not, however, mean that they are either toxic or non-toxic. For example, magnesium is a metallic element, which is an essential nutrient that serves several vital functions in the body; 2. Metallic elements can be found in solid metal or metallic form such ...
... anions) are inherently metallic. This does not, however, mean that they are either toxic or non-toxic. For example, magnesium is a metallic element, which is an essential nutrient that serves several vital functions in the body; 2. Metallic elements can be found in solid metal or metallic form such ...
10090-13688-1
... The area of interest is underlain by mid-Devonian rocks of the Guysborough Group (Cormier et al. 1995; Dunning et al. 2002) and is structurally bounded on all sides, which has led to the setting being interpreted to represent a positive flower structure related to dextral movement along the terrane ...
... The area of interest is underlain by mid-Devonian rocks of the Guysborough Group (Cormier et al. 1995; Dunning et al. 2002) and is structurally bounded on all sides, which has led to the setting being interpreted to represent a positive flower structure related to dextral movement along the terrane ...
UNITED STATES DEPARTMENT OF THE INTERIOR CECIL D
... and carbonaceous metasedimentary rocks, and a variety of carbonate rocks. Lithologic units within the metamorphic terrane trend generally north-northeast and dip moderately toward the southeast. Thrust faults locally juxtapose lithologic units in the metamorphic terrane, and normal faults displace b ...
... and carbonaceous metasedimentary rocks, and a variety of carbonate rocks. Lithologic units within the metamorphic terrane trend generally north-northeast and dip moderately toward the southeast. Thrust faults locally juxtapose lithologic units in the metamorphic terrane, and normal faults displace b ...
Geology of the eastern part of the Meråker area
... grains. Some quartz grains show stram shadows when seen under crossed nicols. Most quartz grains contain inclusions, which were not studied in detail. Feldspar. Detrital grains of feldspar are mostly plagioclase. The grains have the subangular shapes which are the result of little mechanical abrasio ...
... grains. Some quartz grains show stram shadows when seen under crossed nicols. Most quartz grains contain inclusions, which were not studied in detail. Feldspar. Detrital grains of feldspar are mostly plagioclase. The grains have the subangular shapes which are the result of little mechanical abrasio ...
Early Tertiary-Age Kamiah Volcanics, North
... width to length ratios ranging from 1:3 to 1:lO. The grains are moderately to strongly alined in forty-one of the forty-eight specimens examined. In a few specimens, two directions of alinement are present, with most of the grains alined in one direction, and narrow zones of grains with a different ...
... width to length ratios ranging from 1:3 to 1:lO. The grains are moderately to strongly alined in forty-one of the forty-eight specimens examined. In a few specimens, two directions of alinement are present, with most of the grains alined in one direction, and narrow zones of grains with a different ...
Chapter Summary
... Elements, in different combinations, make up all the substances on earth. Eight of these elements make up over 98% of the earth's outer layer, a crust. The three most abundant elements are oxygen (46.5%), silicon (27.8%), and aluminum (8.1%), and so about 75% of the Earth´s crust is made up of these ...
... Elements, in different combinations, make up all the substances on earth. Eight of these elements make up over 98% of the earth's outer layer, a crust. The three most abundant elements are oxygen (46.5%), silicon (27.8%), and aluminum (8.1%), and so about 75% of the Earth´s crust is made up of these ...
What is a mineral?
... The answer is A. Minerals are crystalline solids. Only a solid can be a mineral, but not all solids are minerals. ...
... The answer is A. Minerals are crystalline solids. Only a solid can be a mineral, but not all solids are minerals. ...
Genesis of platinum-group minerals in the Las Aguilas mafic
... (dunites, harzburgites, lherzolites) are partly altered to serpentine and secondary magnetite. Textural observations of dunite and pyroxenite reveal that fresh to partially serpentinised olivine, orthopyroxene and chromian spinel formed cumulates with interstitial sulphides. For these rocks, orthopy ...
... (dunites, harzburgites, lherzolites) are partly altered to serpentine and secondary magnetite. Textural observations of dunite and pyroxenite reveal that fresh to partially serpentinised olivine, orthopyroxene and chromian spinel formed cumulates with interstitial sulphides. For these rocks, orthopy ...
Tinos, Cyclades
... ancient ocean crust preserved in ophiolites have provided important insight into the processes of hydrothermal seawater^rock interaction occurring at oceanic spreading centers [1^4]. Typically, it is found that gabbros have N18 O values lower than that of unaltered MORB (5.7 þ 0.2x) [5,6] as a resul ...
... ancient ocean crust preserved in ophiolites have provided important insight into the processes of hydrothermal seawater^rock interaction occurring at oceanic spreading centers [1^4]. Typically, it is found that gabbros have N18 O values lower than that of unaltered MORB (5.7 þ 0.2x) [5,6] as a resul ...
PORPHYRY Cu+/-Mo+/-Au
... DEPOSIT FORM: Large zones of hydrothermally altered rock contain quartz veins and stockworks, sulphide-bearing veinlets; fractures and lesser disseminations in areas up to 10 km2 in size, commonly coincident wholly or in part with hydrothermal or intrusion breccias and dike swarms. Deposit boundarie ...
... DEPOSIT FORM: Large zones of hydrothermally altered rock contain quartz veins and stockworks, sulphide-bearing veinlets; fractures and lesser disseminations in areas up to 10 km2 in size, commonly coincident wholly or in part with hydrothermal or intrusion breccias and dike swarms. Deposit boundarie ...
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.