An Investigation of the carbonatites of the Kaapvaal Craton and their
... This work is presented in five chapters. The first chapter (this chapter) is an introduction, which presents some basic background of carbonatites. Chapter 2: Carbonatite formation reviews models of carbonatite formation in order to provide insight into carbonatite formation. A petrogenetic model is ...
... This work is presented in five chapters. The first chapter (this chapter) is an introduction, which presents some basic background of carbonatites. Chapter 2: Carbonatite formation reviews models of carbonatite formation in order to provide insight into carbonatite formation. A petrogenetic model is ...
GeoEssex Fact Sheet No. 2
... cemented together by iron-stained sand whereas puddingstone is a much harder rock whereby the sand between the pebbles has been completely turned to a solid mass of silica (quartz) with no visible sand remaining. Puddingstone must be one of the most instantly recognisable rocks; when cut and polish ...
... cemented together by iron-stained sand whereas puddingstone is a much harder rock whereby the sand between the pebbles has been completely turned to a solid mass of silica (quartz) with no visible sand remaining. Puddingstone must be one of the most instantly recognisable rocks; when cut and polish ...
Gondwana Park draft2corr
... Khumib, Huab and Tafelkop Basalts. The Tafelberg Basalts are by far the most abundant basalt type in the main Etendeka lava field. They are interbedded with the Khumib Basalts north of Terrace Bay and become progressively rarer further north. The Huab Basalts are a very fine-grained variety. The Taf ...
... Khumib, Huab and Tafelkop Basalts. The Tafelberg Basalts are by far the most abundant basalt type in the main Etendeka lava field. They are interbedded with the Khumib Basalts north of Terrace Bay and become progressively rarer further north. The Huab Basalts are a very fine-grained variety. The Taf ...
Noertemann et al_mineralogy_Navachab
... The only magmatic remnant discovered was twinned plagioclase. Most biotite in the metalamprophyre may also be magmatic. Texturally, amphibole, carbonate and sphene are of metamorphic origin, and ilmenite, Ti-rich clinopyroxene, amphibole, feldspar and analcime were replaced during metamorphism and m ...
... The only magmatic remnant discovered was twinned plagioclase. Most biotite in the metalamprophyre may also be magmatic. Texturally, amphibole, carbonate and sphene are of metamorphic origin, and ilmenite, Ti-rich clinopyroxene, amphibole, feldspar and analcime were replaced during metamorphism and m ...
Tectonic Setting and Regional Geology of the KSZ
... Lithologies in the KSZ are unique to the Keraf area and they were formed by the tectonic events of the KSZ. E-W geo-traverses in the Keraf area have revealed that the Keraf Petrotectonic Assemblage comprises: high- to medium grade gneiss, siliciclastic and carbonate-rich low-grade metasediments whic ...
... Lithologies in the KSZ are unique to the Keraf area and they were formed by the tectonic events of the KSZ. E-W geo-traverses in the Keraf area have revealed that the Keraf Petrotectonic Assemblage comprises: high- to medium grade gneiss, siliciclastic and carbonate-rich low-grade metasediments whic ...
−−Loose to very well consolidated gravel, sand,
... related to modern stream courses. They are distinguished from younger alluvial fans and fluvial deposits by higher topographic position, greater degree of dissection, and stronger profile development. They are less permeable than younger deposits, and locally contain fresh− water mollusks and extinc ...
... related to modern stream courses. They are distinguished from younger alluvial fans and fluvial deposits by higher topographic position, greater degree of dissection, and stronger profile development. They are less permeable than younger deposits, and locally contain fresh− water mollusks and extinc ...
Fluorite (2013) - Department of Natural Resources
... to quality and specification. These grades are based on fluthese textures. Its measured density varies from 3.0 to 3.6 orite (CaF2) content and the amount of impurities (e.g., o g/cm3 and it has a melting point of 1403 C. The phenomecalcite, quartz, sulphur, arsenic, and lead). There are three non o ...
... to quality and specification. These grades are based on fluthese textures. Its measured density varies from 3.0 to 3.6 orite (CaF2) content and the amount of impurities (e.g., o g/cm3 and it has a melting point of 1403 C. The phenomecalcite, quartz, sulphur, arsenic, and lead). There are three non o ...
Occurrence of mylonite zones and pseudotachylyte veins around the
... crostructures along the Shimono-sawa route is top-to-theeast. The fault rock distribution along the examined route is schematically shown in Fig. 3. Mylonite zones are clustered in the columnar section (Fig. 3). There are three clusters of ca. 20 to 100 m in thickness (shear zone A, B, and C). Outcr ...
... crostructures along the Shimono-sawa route is top-to-theeast. The fault rock distribution along the examined route is schematically shown in Fig. 3. Mylonite zones are clustered in the columnar section (Fig. 3). There are three clusters of ca. 20 to 100 m in thickness (shear zone A, B, and C). Outcr ...
THE GEOLOGY AND GEOCHEMISTRY OF BERYLLIUM IN
... and others (1959), and only general statements need be given here. De tailed geochemical studies on certain types of deposits are discussed under the respective deposits. Beryllium is a ra re element in the upper part of the lithosphere (approximately 5 parts per million), and all current knowledge ...
... and others (1959), and only general statements need be given here. De tailed geochemical studies on certain types of deposits are discussed under the respective deposits. Beryllium is a ra re element in the upper part of the lithosphere (approximately 5 parts per million), and all current knowledge ...
Fluid flow and Al transport during quartz
... rocks in the Saxa Vord Pelites of Unst in the Shetland Islands (Scotland) were investigated to constrain the geochemical alteration associated with metamorphic fluid infiltration during the Caledonian Orogeny (~490-390 Ma). In particular, hypotheses concerning the mobility of Al, an element once tho ...
... rocks in the Saxa Vord Pelites of Unst in the Shetland Islands (Scotland) were investigated to constrain the geochemical alteration associated with metamorphic fluid infiltration during the Caledonian Orogeny (~490-390 Ma). In particular, hypotheses concerning the mobility of Al, an element once tho ...
Geological Setting
... Gondwanaland, initiated in the Early Cretaceous (130 Ma) (Moore, 1999). Uplift in the Pliocene and Plio-Pleistocene (4-2 Ma) occurred on the western margin of the continent, with flexuring along a southwest-northeast axis forming depressions in the Bushveld, Bushmanland, Karoo-Lesotho and Botswana. ...
... Gondwanaland, initiated in the Early Cretaceous (130 Ma) (Moore, 1999). Uplift in the Pliocene and Plio-Pleistocene (4-2 Ma) occurred on the western margin of the continent, with flexuring along a southwest-northeast axis forming depressions in the Bushveld, Bushmanland, Karoo-Lesotho and Botswana. ...
Sabzevar Ophiolite, NE Iran - The University of Texas at Dallas
... south and east and the Binalud mountains (Turan block) to the north, and that this small oceanic arc basin existed from at least mid-Cretaceous times. Intraoceanic subduction began before the Albian (100–113 Ma) and was responsible for generating Sabzevar SSZ-related magmas, ultimately forming a mag ...
... south and east and the Binalud mountains (Turan block) to the north, and that this small oceanic arc basin existed from at least mid-Cretaceous times. Intraoceanic subduction began before the Albian (100–113 Ma) and was responsible for generating Sabzevar SSZ-related magmas, ultimately forming a mag ...
REE-Y, Ti, and P Remobilization in Magmatic Rocks by
... al., 2009). Indeed, these experiments show that for chloriderich fluids such as those responsible for the formation of porphyry copper deposits (Seedorff et al., 2005), chloride complexes may control the transport of REE, as is also indicated by thermodynamic modelling (e.g., Douville et al., 1999). ...
... al., 2009). Indeed, these experiments show that for chloriderich fluids such as those responsible for the formation of porphyry copper deposits (Seedorff et al., 2005), chloride complexes may control the transport of REE, as is also indicated by thermodynamic modelling (e.g., Douville et al., 1999). ...
Petrotectonics of ultrahigh-pressure crustal and upper
... arc on the crust of the stable, hanging-wall plate, but consumption of a small intervening ocean basin prior to collision does not generate a substantial arc. Most mountain chains are a reflection of their specific geography and unique plate-tectonic history; each orogen tends to exhibit major struc ...
... arc on the crust of the stable, hanging-wall plate, but consumption of a small intervening ocean basin prior to collision does not generate a substantial arc. Most mountain chains are a reflection of their specific geography and unique plate-tectonic history; each orogen tends to exhibit major struc ...
The geological singularities of a world
... to an exceptional ore deposit. In the Almaden town surroundings special geological events occurred that gave rise to some deposits of a scarce metal that are surely unique at crustal levels. The Hg deposit of Almaden is located in a Hercynian WNW-ESE bearing syncline where a very complete Palaeozoic ...
... to an exceptional ore deposit. In the Almaden town surroundings special geological events occurred that gave rise to some deposits of a scarce metal that are surely unique at crustal levels. The Hg deposit of Almaden is located in a Hercynian WNW-ESE bearing syncline where a very complete Palaeozoic ...
Precambrian and Tertiary Geology of Las Tablas
... of new phases by statistical fluctuations of concentration, and grain growth by accretion of atoms to surfaces of nuclei. Kyanite is present in all the vitreous quartzite, and is associated with both metamorphic facies. It occurs along bedding planes, in hema tite-rich laminae, and in quartzose vein ...
... of new phases by statistical fluctuations of concentration, and grain growth by accretion of atoms to surfaces of nuclei. Kyanite is present in all the vitreous quartzite, and is associated with both metamorphic facies. It occurs along bedding planes, in hema tite-rich laminae, and in quartzose vein ...
engineer engineering geology
... Mr. D Naresh Kumar and Mr.G Siva Vignan, Vignan, Assistant Professor Mr. D Naresh Kumar and Mr.G Siva Vignan, Vignan, Assistant Professor ...
... Mr. D Naresh Kumar and Mr.G Siva Vignan, Vignan, Assistant Professor Mr. D Naresh Kumar and Mr.G Siva Vignan, Vignan, Assistant Professor ...
Fractionation and Liquid Immiscibility in an Anorthositic
... by Shaw (1972) and Bottinga & Weill (1970) to provide estimates of rates of settling or floating. At 1000 °C for spherical pillows with a 10 cm radius, the most iron-rich diorite would settle through granite at a rate of about 0-04 cm/sec (or 2-5 cm/minute). The field relations also strongly suggest ...
... by Shaw (1972) and Bottinga & Weill (1970) to provide estimates of rates of settling or floating. At 1000 °C for spherical pillows with a 10 cm radius, the most iron-rich diorite would settle through granite at a rate of about 0-04 cm/sec (or 2-5 cm/minute). The field relations also strongly suggest ...
Sept-Oct2011GemHunter - Wyoming Prospectors Association
... greenish gray quartz with amethyst is as much as 12 inches long and may cement the breccia. After being mined, much of the amethyst is apparently heat-treated to produce yellow and orange-brown citrine under a trade name of ‘Rio Grande topaz’. At the Grogo do Choch deposit, amethyst is associated wi ...
... greenish gray quartz with amethyst is as much as 12 inches long and may cement the breccia. After being mined, much of the amethyst is apparently heat-treated to produce yellow and orange-brown citrine under a trade name of ‘Rio Grande topaz’. At the Grogo do Choch deposit, amethyst is associated wi ...
Regionally Important Geodiversity Sites
... which has provided the field evidence for understanding the rocks of the Cambrian, Ordovician, Silurian and Carboniferous Periods in geological time. This long geological history is recognisable in the landscape of Pembrokeshire but is most easily read in its complex rocky coastline. This has result ...
... which has provided the field evidence for understanding the rocks of the Cambrian, Ordovician, Silurian and Carboniferous Periods in geological time. This long geological history is recognisable in the landscape of Pembrokeshire but is most easily read in its complex rocky coastline. This has result ...
OPAQUE OXIDES IN SOME ROCKS OF THE BASEMENT
... chalcopyrite, and pyrrhotite are present in a hornblende-augite-hypersthene-olivinegabbro from Matapau. The magnetite crystals are occasionally micrographically intergrown with both olivine and augite, but are free of ex-solution intergrowths with other iron oxides. The chalcopyrite in parts replace ...
... chalcopyrite, and pyrrhotite are present in a hornblende-augite-hypersthene-olivinegabbro from Matapau. The magnetite crystals are occasionally micrographically intergrown with both olivine and augite, but are free of ex-solution intergrowths with other iron oxides. The chalcopyrite in parts replace ...
New geologic, fluid inclusion and stable isotope studies on
... performed at the Instituto de Geociências, University of Campinas, Brazil, on six doubly polished plates of quartz. Microthermometry measurements of inclusion fluids were performed on a LINKAM THMSG600 stage attached to a conventional petrographic microscope. The stage was calibrated using synthetic ...
... performed at the Instituto de Geociências, University of Campinas, Brazil, on six doubly polished plates of quartz. Microthermometry measurements of inclusion fluids were performed on a LINKAM THMSG600 stage attached to a conventional petrographic microscope. The stage was calibrated using synthetic ...
the Minerals and Rocks
... of the text, will prove more valuable to the collector than pages of explanation. The description of certain minerals includes handy tips on collecting, handling, cleaning, preserving, or displaying them-information not readily available elsewhere. The descriptions also cover the chemical compositio ...
... of the text, will prove more valuable to the collector than pages of explanation. The description of certain minerals includes handy tips on collecting, handling, cleaning, preserving, or displaying them-information not readily available elsewhere. The descriptions also cover the chemical compositio ...
Occurrence of mylonite zones and pseudotachylyte veins around the base... the upper crust: An example from the southern Hidaka metamorphic
... crostructures along the Shimono-sawa route is top-to-theeast. The fault rock distribution along the examined route is schematically shown in Fig. 3. Mylonite zones are clustered in the columnar section (Fig. 3). There are three clusters of ca. 20 to 100 m in thickness (shear zone A, B, and C). Outcr ...
... crostructures along the Shimono-sawa route is top-to-theeast. The fault rock distribution along the examined route is schematically shown in Fig. 3. Mylonite zones are clustered in the columnar section (Fig. 3). There are three clusters of ca. 20 to 100 m in thickness (shear zone A, B, and C). Outcr ...
UNCONFORMITY-ASSOCIATED URANIUM
... Unconformity-associated uranium deposits typically consist of uranium concentrations at the base of a Proterozoic sandstone sequence where i t unconformably overlies preMiddle Proterozoic metamorphic basement rocks, which commonly include graphtic pelitic units. The deposits are associated with faul ...
... Unconformity-associated uranium deposits typically consist of uranium concentrations at the base of a Proterozoic sandstone sequence where i t unconformably overlies preMiddle Proterozoic metamorphic basement rocks, which commonly include graphtic pelitic units. The deposits are associated with faul ...
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.