The generation of high Sr/Y plutons following Late Jurassic arc–arc
... controversy exists regarding mechanisms of their generation, the tectonic settings in which they form, and their relationship to contractional deformation through time. In the Blue Mountains province (NE Oregon), a suite of Late Jurassic (148–145 Ma), high Sr/Y plutons intrude Middle Jurassic (162–1 ...
... controversy exists regarding mechanisms of their generation, the tectonic settings in which they form, and their relationship to contractional deformation through time. In the Blue Mountains province (NE Oregon), a suite of Late Jurassic (148–145 Ma), high Sr/Y plutons intrude Middle Jurassic (162–1 ...
FLUORINE AND CHLORINE IN BIOTITE FROM THE SARNWOSAR
... volcaniclastic and pyroclastic rocks. As a result several million tons of iron ores formed within carbonate rocks in the Sangan area. The Sarnowsar granitic rocks are mainly granite to granodiorite, metaluminous, I type and high calc-alkaline. Fluorine contents in the biotite range from 0.37 to 4.4 ...
... volcaniclastic and pyroclastic rocks. As a result several million tons of iron ores formed within carbonate rocks in the Sangan area. The Sarnowsar granitic rocks are mainly granite to granodiorite, metaluminous, I type and high calc-alkaline. Fluorine contents in the biotite range from 0.37 to 4.4 ...
Zarasvandi et al..fm
... Eocene volcanic activity consisted of andesitic lavas, trachyandesite, and pyroclastic rocks in the first stage, and two pulses that include dacitic domes and pyroclastic rocks in the late stage. Andesitic rocks with propylitic alteration occur in the western and southwestern parts of the study area ...
... Eocene volcanic activity consisted of andesitic lavas, trachyandesite, and pyroclastic rocks in the first stage, and two pulses that include dacitic domes and pyroclastic rocks in the late stage. Andesitic rocks with propylitic alteration occur in the western and southwestern parts of the study area ...
IQUAME - Guidelines for the Review
... Sedimentary material in which at least 50 percent of the primary and/or recrystallized constituents are composed of one (or more) of the carbonate minerals calcite, aragonite and dolomite, in particles of intrabasinal origin. Sedimentary material that consists of at least 50 percent material produce ...
... Sedimentary material in which at least 50 percent of the primary and/or recrystallized constituents are composed of one (or more) of the carbonate minerals calcite, aragonite and dolomite, in particles of intrabasinal origin. Sedimentary material that consists of at least 50 percent material produce ...
Peer-reviewed Article PDF
... The chemical and mineralogical composition of clastic sedimentary rocks is controlled by various factors such as source rock composition, chemical and physical weathering and sedimantition processes such as mechanical sorting decomposition and diagenesis [1-4]. It is on this basic, therefore, that t ...
... The chemical and mineralogical composition of clastic sedimentary rocks is controlled by various factors such as source rock composition, chemical and physical weathering and sedimantition processes such as mechanical sorting decomposition and diagenesis [1-4]. It is on this basic, therefore, that t ...
How to Identify Rocks and Minerals
... RHYOLITE (rock) ...................................................................................................... 72 ...
... RHYOLITE (rock) ...................................................................................................... 72 ...
How to Identify Rocks and Minerals
... RHYOLITE (rock) ...................................................................................................... 72 ...
... RHYOLITE (rock) ...................................................................................................... 72 ...
Chapter 11
... All rocks are formed at certain temperatures and pressures on or more commonly, beneath the earth’s surface, and these rocks are the most stable at the conditions under which they form. Therefore, changing the temperature and/or pressure conditions may lead to a different rock, one that changed in o ...
... All rocks are formed at certain temperatures and pressures on or more commonly, beneath the earth’s surface, and these rocks are the most stable at the conditions under which they form. Therefore, changing the temperature and/or pressure conditions may lead to a different rock, one that changed in o ...
Crustal contamination of mafic magmas: evidence from a
... sion indicates a considerable extension of the continental crust (Tarney and Weaver, 1987). Studies of rift-related mafic dike swarms are essential for understanding generation of such extensive mafic magmatism, and they may be used to identify mantle plumes (Ernst and Buchan, 1997, 2001). There is ...
... sion indicates a considerable extension of the continental crust (Tarney and Weaver, 1987). Studies of rift-related mafic dike swarms are essential for understanding generation of such extensive mafic magmatism, and they may be used to identify mantle plumes (Ernst and Buchan, 1997, 2001). There is ...
CALCITE – AMPHIBOLE – CLINOPYROXENE ROCK FROM THE AFRIKANDA
... clearly necessary for a critical assessment of the various genetic models proposed in the earlier studies. In the present work, we characterize the occurrence, interrelationships and compositional variation of silicate minerals from CAPR, and discuss implications of these mineralogical observations ...
... clearly necessary for a critical assessment of the various genetic models proposed in the earlier studies. In the present work, we characterize the occurrence, interrelationships and compositional variation of silicate minerals from CAPR, and discuss implications of these mineralogical observations ...
chapter – iv
... Cheranmahadevi fault trends in N-S direction and the Achankovil fault trends towards NW-SE direction (Figure 4.1). The Kanyakumari – Tenkasi Belt (ktsb) is running roughly NW-SE direction to the south of the Tiruchirapalli-Madurai-Palayamkottai block (TMP). The Achankovil lineament (AK) marks the no ...
... Cheranmahadevi fault trends in N-S direction and the Achankovil fault trends towards NW-SE direction (Figure 4.1). The Kanyakumari – Tenkasi Belt (ktsb) is running roughly NW-SE direction to the south of the Tiruchirapalli-Madurai-Palayamkottai block (TMP). The Achankovil lineament (AK) marks the no ...
the Scanned PDF - Mineralogical Society of America
... probable sedimentary origin; (2) these orbicules in themselves are not schistose;(3) a secondary schistosity in the schist around these orbicules is noticeable; (4) many orbicules have cores of schist or recrystallized schist; (5) replacement intergrowths and relics are common in the orbicules; (6) ...
... probable sedimentary origin; (2) these orbicules in themselves are not schistose;(3) a secondary schistosity in the schist around these orbicules is noticeable; (4) many orbicules have cores of schist or recrystallized schist; (5) replacement intergrowths and relics are common in the orbicules; (6) ...
Lecture notes on Metamorphic Petrology
... 2- Barrovian Zonal Scheme (MP metamorphism) The classical zones of metamorphism in the Scottish Highlands and many other parts of the world include six distinct mineral assemblages that occur in the metapelites. ...
... 2- Barrovian Zonal Scheme (MP metamorphism) The classical zones of metamorphism in the Scottish Highlands and many other parts of the world include six distinct mineral assemblages that occur in the metapelites. ...
Kyanite and Staurolite Detrital Grains: Chemistry and
... (Received 31/5/2006 , Accepted 20/9/2006) ABSTRACT The present work describes the mineralogy and optical properties of the detrital kyanite and staurolite occurring in the recent deposits of Tigris River and its tributaries in northern Iraq using thin section microscopy and scanning electron microsc ...
... (Received 31/5/2006 , Accepted 20/9/2006) ABSTRACT The present work describes the mineralogy and optical properties of the detrital kyanite and staurolite occurring in the recent deposits of Tigris River and its tributaries in northern Iraq using thin section microscopy and scanning electron microsc ...
Chapter 5 Intrusive Igneous Rocks
... Quartz veins are ubquitous in the northern part of the district where they are commonly seen intruding granitic rocks， rhyolite dykes， and volcanic rocks. The quartz veins vary from stringers a few millimetres wide to dykes up to 30 m wide. Ruxton (1958) divided the quartz veins into two types: 1) h ...
... Quartz veins are ubquitous in the northern part of the district where they are commonly seen intruding granitic rocks， rhyolite dykes， and volcanic rocks. The quartz veins vary from stringers a few millimetres wide to dykes up to 30 m wide. Ruxton (1958) divided the quartz veins into two types: 1) h ...
LECTURE 13 - Introduction to Volcanic Rocks 1
... – Polygenetic • volcano resulting from many eruptions, separated by relatively long periods and often involving different magmas. • Complex “plumbing systems” with intricate complicated conduit systems used many times during different eruptive phases. • Example – Hawaii ...
... – Polygenetic • volcano resulting from many eruptions, separated by relatively long periods and often involving different magmas. • Complex “plumbing systems” with intricate complicated conduit systems used many times during different eruptive phases. • Example – Hawaii ...
sedimentary rock texture - Beck-Shop
... can also occur, particularly in the basal part (see Figure 5.37 and Section 5.3.4). In some rudites, such as those deposited by debris flows, large clasts occur towards the top of the bed; these were carried there by the upward buoyancy of the flow. The shape and roundness of pebbles can be describe ...
... can also occur, particularly in the basal part (see Figure 5.37 and Section 5.3.4). In some rudites, such as those deposited by debris flows, large clasts occur towards the top of the bed; these were carried there by the upward buoyancy of the flow. The shape and roundness of pebbles can be describe ...
Distribution of potassium feldspar polymorphs
... retain orthoclase when enclosed as xenoliths in microcline-bearing rocks, or when cut by minor bodies of microcline-bearing rocks. The K-feldspar variation may reflect increasing water content or the peralkaline or peraluminous character of the fractionating magmas. These factors affect the feldspar ...
... retain orthoclase when enclosed as xenoliths in microcline-bearing rocks, or when cut by minor bodies of microcline-bearing rocks. The K-feldspar variation may reflect increasing water content or the peralkaline or peraluminous character of the fractionating magmas. These factors affect the feldspar ...
Lecture notes on Metamorphic Petrology
... ii) Calc-silicate rocks: carbonate is subordinate (carbonate <50%) and may be composed of Ca-Mg-Fe-Al silicate minerals, such as diopside, grossular, Ca-amphiboles, vesuvianite, epidote, ...
... ii) Calc-silicate rocks: carbonate is subordinate (carbonate <50%) and may be composed of Ca-Mg-Fe-Al silicate minerals, such as diopside, grossular, Ca-amphiboles, vesuvianite, epidote, ...
The Square Peak volcanic series, norhtern Quitman Mountains
... The Peace hornblende tuff is trachytic and grades laterally from a lithic crystal tuff to a crystal tuff. The unit has a maximum thickness of about 220 m and is characterized by the great variability in the lithic fragment and crystal content and in the degree of welding. The basal part of the unit ...
... The Peace hornblende tuff is trachytic and grades laterally from a lithic crystal tuff to a crystal tuff. The unit has a maximum thickness of about 220 m and is characterized by the great variability in the lithic fragment and crystal content and in the degree of welding. The basal part of the unit ...
Geological Interpretive Signs
... soil profile. Although they are very weathered, it is still possible to see the original sedimentary bedding from when this rock was originally deposited, around 750 million years ago. At the boundary between these two soils a concentration of calcrete can be observed, which reflects water pooling i ...
... soil profile. Although they are very weathered, it is still possible to see the original sedimentary bedding from when this rock was originally deposited, around 750 million years ago. At the boundary between these two soils a concentration of calcrete can be observed, which reflects water pooling i ...
esper signius larsen, jr. - National Academy of Sciences
... one of the greatest of field geologists and laboratory petrologists. The volcanics of the San Juan Region of southwestern Colorado, the igneous rocks of the Highwood Mountains of Montana, and the batholithic rocks of southern California were the major objects of his studies. However, not only did he ...
... one of the greatest of field geologists and laboratory petrologists. The volcanics of the San Juan Region of southwestern Colorado, the igneous rocks of the Highwood Mountains of Montana, and the batholithic rocks of southern California were the major objects of his studies. However, not only did he ...
alteration of wall rocks by co2-rich water ascending in fault zones
... fluids of mantle origin. Ascending CO2 dissolves in groundwater of the fractured sedimentary rocks of the Variscan basement. Alteration reactions have been derived from petrological analyses of wall rocks, fluid chemistry, and thermodynamic modelling. The principle reaction is the alteration of chlo ...
... fluids of mantle origin. Ascending CO2 dissolves in groundwater of the fractured sedimentary rocks of the Variscan basement. Alteration reactions have been derived from petrological analyses of wall rocks, fluid chemistry, and thermodynamic modelling. The principle reaction is the alteration of chlo ...
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.