petrogenesis of the oligocene east tintic volcanic field, utah
... high K2O, Rb, and Al2O3/CaO ratios and modest SiO2 enrichment of these rocks appear to result from extensive, high-pressure fractional crystallization of clinopyroxene (without plagioclase). Two-pyroxene shoshonite-trachyte series magma was likely produced by mixing between mafic and silicic clinopy ...
... high K2O, Rb, and Al2O3/CaO ratios and modest SiO2 enrichment of these rocks appear to result from extensive, high-pressure fractional crystallization of clinopyroxene (without plagioclase). Two-pyroxene shoshonite-trachyte series magma was likely produced by mixing between mafic and silicic clinopy ...
A PETROGRAPHIC COMPARISON OF A TERTIARY ALKALINE
... clayJike sediments to biotite-hornfels, and of sandstone into quartzite. Mechanical de{ormation or disturbance of the country-rock-except formation of volcanic breccia-is usually minor; the ernplacement of the whole complex has a distinctly atectonic character. The sedimentary roof is entirely remov ...
... clayJike sediments to biotite-hornfels, and of sandstone into quartzite. Mechanical de{ormation or disturbance of the country-rock-except formation of volcanic breccia-is usually minor; the ernplacement of the whole complex has a distinctly atectonic character. The sedimentary roof is entirely remov ...
Ch 9 Metamorphic Rocks
... 1) I can explain what defines a metamorphic rock as well as why they are valuable. 2) I can describe the three types of metamorphism: regional and contact metamorphism and metamorphism with chemically active fluids 3) I can explain the different types of foliated and nonfoliated metamorphic rocks, h ...
... 1) I can explain what defines a metamorphic rock as well as why they are valuable. 2) I can describe the three types of metamorphism: regional and contact metamorphism and metamorphism with chemically active fluids 3) I can explain the different types of foliated and nonfoliated metamorphic rocks, h ...
the geology of the warsak area~ peshawar, west pakistan
... a series of metasediments of the greenschist facies (slates, phyllites, mica schists, garnet schists, hornblende schists, calcareous schists and marbles), which have been divided into a Lower, Middle and Upper Series. On the eastern side the metasediments disappear under the alluvium of the Peshawar ...
... a series of metasediments of the greenschist facies (slates, phyllites, mica schists, garnet schists, hornblende schists, calcareous schists and marbles), which have been divided into a Lower, Middle and Upper Series. On the eastern side the metasediments disappear under the alluvium of the Peshawar ...
Gemstones (New Zealand nature series)
... Stones of "gem quality" are free of flaws, they have good colour and transparency (where applicable) and are large enough to be cut and worn effectively. But even in the world's major gem fields the number of top-quality stones is limited, and poor stones are most often found. Gemstones are members ...
... Stones of "gem quality" are free of flaws, they have good colour and transparency (where applicable) and are large enough to be cut and worn effectively. But even in the world's major gem fields the number of top-quality stones is limited, and poor stones are most often found. Gemstones are members ...
Mineralogy and phase relations in the blueschist facies
... chlorite + phengite * lawsonite, with sporadic occurrence of aragoniteand epidote. The common assemblage in basic schistsat Black Butte is quartz + albite + epidote + chlorite + pumpellyite * crossite + sphene.Actinolite is uncommon and does not coexist with epidote or crossite. Aragonite, stilpnome ...
... chlorite + phengite * lawsonite, with sporadic occurrence of aragoniteand epidote. The common assemblage in basic schistsat Black Butte is quartz + albite + epidote + chlorite + pumpellyite * crossite + sphene.Actinolite is uncommon and does not coexist with epidote or crossite. Aragonite, stilpnome ...
Timing and magma evolution of the Chelopech volcanic complex
... phenocrysts consist of plagioclase, zoned amphibole, minor biotite, titanite and rare corroded quartz crystals, whereas the microlites consist of plagioclase and amphibole only. The accessory minerals are apatite, zircon, and Ti-magnetite. Lilov and Chipchakova (1999) obtained an age of 65–67 Ma for ...
... phenocrysts consist of plagioclase, zoned amphibole, minor biotite, titanite and rare corroded quartz crystals, whereas the microlites consist of plagioclase and amphibole only. The accessory minerals are apatite, zircon, and Ti-magnetite. Lilov and Chipchakova (1999) obtained an age of 65–67 Ma for ...
MINERAL ISOGRADS IN SOUTHEASTERN PENNSYLVANIA Hucn
... Igneous Rocks The pre-Glenarm rocks (Baltimore and Pickering gneisses)contain igneous intrusions ranging from ultrabasic (peridotite) through basic (gabbro) and calcic (anorthosite) to granite. Much of this igneous material is restricted to the pre-Glenarm complex but certain igneous rocks occur wit ...
... Igneous Rocks The pre-Glenarm rocks (Baltimore and Pickering gneisses)contain igneous intrusions ranging from ultrabasic (peridotite) through basic (gabbro) and calcic (anorthosite) to granite. Much of this igneous material is restricted to the pre-Glenarm complex but certain igneous rocks occur wit ...
47 In nature there is a wide variety of sedimentary rocks and each
... that makes up the rocks. All sedimentary rocks are composed of the products of “weathering”, the process that causes the physical and/or chemical breakdown of a pre-existing rock (termed a source rock). These “products” include detrital grains (chemically stable grains) and material in solution. Det ...
... that makes up the rocks. All sedimentary rocks are composed of the products of “weathering”, the process that causes the physical and/or chemical breakdown of a pre-existing rock (termed a source rock). These “products” include detrital grains (chemically stable grains) and material in solution. Det ...
ch04 - earthjay science
... There are more than 3000 minerals on the Earth, but only a few are common and make up most of the rocks. ...
... There are more than 3000 minerals on the Earth, but only a few are common and make up most of the rocks. ...
petrology and Structure of the Southern Wet Mountains, Colorado
... porphyry, hostouite, ami quart/, latile porPty/yThe age of the dikes is uncertain, as no dikes extend into the sedimentary rocks Iroin the Precambrian complex. The dikes are not metamorphosed, and generally their strikes are straight and do not follow gneissoid or schistose structures, which suggest ...
... porphyry, hostouite, ami quart/, latile porPty/yThe age of the dikes is uncertain, as no dikes extend into the sedimentary rocks Iroin the Precambrian complex. The dikes are not metamorphosed, and generally their strikes are straight and do not follow gneissoid or schistose structures, which suggest ...
Shallow-Level Migmatization of Gabbros in a
... with perfectly preserved igneous textures. They are all relatively enriched in Al, Na, P, Sr, Ba, Nb, Y and the rare earth elements compared with the unaffected country rock beyond the aureole. Migmatization under such low-pressure conditions was possible because of the unusual tectonic and magmatic ...
... with perfectly preserved igneous textures. They are all relatively enriched in Al, Na, P, Sr, Ba, Nb, Y and the rare earth elements compared with the unaffected country rock beyond the aureole. Migmatization under such low-pressure conditions was possible because of the unusual tectonic and magmatic ...
6 Metamorphic Rocks
... In this chapter, phase diagrams are used as graphical summaries of the stability fields of minerals. Phase diagrams tell us much about the origin of metamorphic rocks, which have all recrystallized because of changes in their physical or chemical environment. But how do we know that kyanite is not s ...
... In this chapter, phase diagrams are used as graphical summaries of the stability fields of minerals. Phase diagrams tell us much about the origin of metamorphic rocks, which have all recrystallized because of changes in their physical or chemical environment. But how do we know that kyanite is not s ...
Sedimentary Rock
... Clastic Sedimentary Rock c. Breccia is a clastic sedimentary rock composed of angular, or rocks with sharp corners, that are compacted or cemented together. d. Sandstone is made mainly of sand-sized quartz grains that have been cemented together, but have large enough pores between the grains that ...
... Clastic Sedimentary Rock c. Breccia is a clastic sedimentary rock composed of angular, or rocks with sharp corners, that are compacted or cemented together. d. Sandstone is made mainly of sand-sized quartz grains that have been cemented together, but have large enough pores between the grains that ...
Shields and Precambrian fossils
... • Sponges are probably the most primitive multicellular organisms around today • Consist of a largely undifferentiated mass of gelatinous cells supported by a variably rigid structure (your modern bath-sponge is the skeleton of a modern sponge animal) ...
... • Sponges are probably the most primitive multicellular organisms around today • Consist of a largely undifferentiated mass of gelatinous cells supported by a variably rigid structure (your modern bath-sponge is the skeleton of a modern sponge animal) ...
"Rock around Uptown Waterloo" tour script
... the rocks are grey or whitish. If you look closely at the grey rocks, you will see that most have fossils in them. The grey rocks are limestone. Limestone is a sedimentary rock formed in a warm shallow sea. It is formed by the accumulation of shells and corals which hardened and turned into rock ove ...
... the rocks are grey or whitish. If you look closely at the grey rocks, you will see that most have fossils in them. The grey rocks are limestone. Limestone is a sedimentary rock formed in a warm shallow sea. It is formed by the accumulation of shells and corals which hardened and turned into rock ove ...
Experimental_laboratory_files/2004_The source of Granites
... alternative way is to assume that I-type granites typically with low 87Sr86/Sr initial ratios are generated from a crustal source that has this particular composition. Comparison with Archaean crust array (Fig. 1a) suggests that tonalites of the lower crust (e.g. Weaver & Tarney 1981) are good candi ...
... alternative way is to assume that I-type granites typically with low 87Sr86/Sr initial ratios are generated from a crustal source that has this particular composition. Comparison with Archaean crust array (Fig. 1a) suggests that tonalites of the lower crust (e.g. Weaver & Tarney 1981) are good candi ...
GEOLOGY OF THE EASTERN PART OF THE CHIMALA SHEET (246)
... the regional fabric orientation. Some of the less well-layered Fe-quartzites might have an exhalative, rather than a clastic origin. Two-mica paragneiss/schist: These rocks are rather poorly exposed in the SE part of the area, where they tend to crop out in the topographic lows between ridges of mor ...
... the regional fabric orientation. Some of the less well-layered Fe-quartzites might have an exhalative, rather than a clastic origin. Two-mica paragneiss/schist: These rocks are rather poorly exposed in the SE part of the area, where they tend to crop out in the topographic lows between ridges of mor ...
Generalized Models of Porphyry Copper Deposits: Anatomy
... Cross section showing spatial relationships between porphyry-Cu stocks, an underlying pluton, overlying comagmatic volcanic rocks, and the lithocap. The precursor pluton is composite, multiphase, whereas the parental pluton is shown as a single body in which the concentric dotted-lines mark its prog ...
... Cross section showing spatial relationships between porphyry-Cu stocks, an underlying pluton, overlying comagmatic volcanic rocks, and the lithocap. The precursor pluton is composite, multiphase, whereas the parental pluton is shown as a single body in which the concentric dotted-lines mark its prog ...
QUARTZ XENOCRYSTS IN OLIVINE BASALT FROM THE
... over much of the surface of an individual. Always, however, the color grades ofi marginally into the normal colorlessor nearly colorlessclinopyroxene. In the contact zone where quartz grains of granitic inclusions lie at the adjacent contact or within the zone, the olivine has reacted directly to fo ...
... over much of the surface of an individual. Always, however, the color grades ofi marginally into the normal colorlessor nearly colorlessclinopyroxene. In the contact zone where quartz grains of granitic inclusions lie at the adjacent contact or within the zone, the olivine has reacted directly to fo ...
Preliminary study on geology, mineral potential and characteristics
... Located in Afar Regional State, northeastern Ethiopia, Dallol area represents the second lowest water uncovered oceanic crust on Earth with a depth of ~120 m below sea level ( reference missing Fig.1). The region is also known for its huge natural resources such as rock salt, potash and manganese de ...
... Located in Afar Regional State, northeastern Ethiopia, Dallol area represents the second lowest water uncovered oceanic crust on Earth with a depth of ~120 m below sea level ( reference missing Fig.1). The region is also known for its huge natural resources such as rock salt, potash and manganese de ...
A2 Course Study Guide
... augite, while in rhyolites they are more commonly feldspar. Sometimes, however, so much crystallisation takes place that olivine crystals sink downwards through the melt, accumulating at lower levels to form rocks crammed with olivine. These lavas, of course, have compositions very different from th ...
... augite, while in rhyolites they are more commonly feldspar. Sometimes, however, so much crystallisation takes place that olivine crystals sink downwards through the melt, accumulating at lower levels to form rocks crammed with olivine. These lavas, of course, have compositions very different from th ...
Pdf - Text of NPTEL IIT Video Lectures
... some crystals which are quiet large in comparison with general crystal size. So, these are all rock crystals in this case, these are crystals and the larger crystals are known as phenocrysts. Now, if you recall from what we discussed in the previous class, previous lesson; the size of mineral really ...
... some crystals which are quiet large in comparison with general crystal size. So, these are all rock crystals in this case, these are crystals and the larger crystals are known as phenocrysts. Now, if you recall from what we discussed in the previous class, previous lesson; the size of mineral really ...
Journal of Maps
... Structural-geological mapping of metamorphic basements is an important task to reconstruct the tectono-metamophic evolution and the relationships between deformation, localization of metamorphic transformations, protolith chemistry, textures and mineral compositions. Modern mapping of metamorphic ba ...
... Structural-geological mapping of metamorphic basements is an important task to reconstruct the tectono-metamophic evolution and the relationships between deformation, localization of metamorphic transformations, protolith chemistry, textures and mineral compositions. Modern mapping of metamorphic ba ...
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.