the Geologic Map, Buena Vista East Quadrangle, Open
... metamorphic and intrusive igneous rocks. Granodiorite and quartz diorite of Boulder Creek age are part of an irregular batholith that is exposed over a large area of central Colorado (Tweto, 1987). The granodiorite, which is locally gneissic, has been dated at 1672±5 Ma (Bickford and others, 1989) i ...
... metamorphic and intrusive igneous rocks. Granodiorite and quartz diorite of Boulder Creek age are part of an irregular batholith that is exposed over a large area of central Colorado (Tweto, 1987). The granodiorite, which is locally gneissic, has been dated at 1672±5 Ma (Bickford and others, 1989) i ...
Analcime phenocrysts in igneous rocks: Primary or secondary
... are due to alteration of glass rather than alteration of analcime. Although the Crowsnest locality is noteworthy for its large fresh analcime crystals, such pristine analcime is actually rare within the formation. Most of the analcime is altered in some fashion. It might be stressedhere that the alt ...
... are due to alteration of glass rather than alteration of analcime. Although the Crowsnest locality is noteworthy for its large fresh analcime crystals, such pristine analcime is actually rare within the formation. Most of the analcime is altered in some fashion. It might be stressedhere that the alt ...
composition and provenance of clastic material in the vendian
... poorly cored and the drillcores are not longer available. Therefore, in the present paper the original and traditional name of this formation has been maintained in accordance with the standard scheme of the Cambrian in the East European Craton (Mens et al., 1990). The total lack of fossils in the ¯ ...
... poorly cored and the drillcores are not longer available. Therefore, in the present paper the original and traditional name of this formation has been maintained in accordance with the standard scheme of the Cambrian in the East European Craton (Mens et al., 1990). The total lack of fossils in the ¯ ...
NEOPROTEROZOIC OPHIOLITES IN THE ARABIAN SHIELD
... 1979), and are interpreted as pelagic sediments at the top of the ophiolite succession. The complex is steeply dipping, and the exposures are effectively a cross-section through the ophiolite. The gross distribution of rock types suggests an ophiolite succession younging from south to north but the ...
... 1979), and are interpreted as pelagic sediments at the top of the ophiolite succession. The complex is steeply dipping, and the exposures are effectively a cross-section through the ophiolite. The gross distribution of rock types suggests an ophiolite succession younging from south to north but the ...
Clay mineral evolution - Brown University Planetary Geosciences
... environment of Earth, Mars, and the parent bodies of carbonaceous chondrite meteorites. They also represent perhaps the most important class of minerals with which mankind interacts on a daily basis. Therefore, understanding the evolution of clay minerals as products of physical, chemical, and biolo ...
... environment of Earth, Mars, and the parent bodies of carbonaceous chondrite meteorites. They also represent perhaps the most important class of minerals with which mankind interacts on a daily basis. Therefore, understanding the evolution of clay minerals as products of physical, chemical, and biolo ...
ore deposit types and their primary expressions
... Additional and essential requirements include energy (generally thermal, gravitational or deformational) to power the transport mechanism and a suitable crustal structure to focus ore-forming components and accommodate their deposition. Metals are largely derived from the mantle or crust by partial ...
... Additional and essential requirements include energy (generally thermal, gravitational or deformational) to power the transport mechanism and a suitable crustal structure to focus ore-forming components and accommodate their deposition. Metals are largely derived from the mantle or crust by partial ...
Gold mineralization and associated alteration zones of the Biely vrch
... The deposit is located in the central zone of the Neogene Javorie stratovolcano, and shares many properties typical for Au-porphyry deposits. Parental intrusion of diorite to andesite porphyry and its andesitic volcanic host rocks are affected by extensive alteration, dominated by intermediate argil ...
... The deposit is located in the central zone of the Neogene Javorie stratovolcano, and shares many properties typical for Au-porphyry deposits. Parental intrusion of diorite to andesite porphyry and its andesitic volcanic host rocks are affected by extensive alteration, dominated by intermediate argil ...
- Mineral Resources Tasmania
... Cambrian structural history of Tasmania … … … … … … … … … … … … … … … … … … … … … 3-D geological model showing extent of outcropping and concealed allochthonous Early Cambrian ultramafic-mafic complexes in mainland Tasmania … … … … … … … … … … … … 3-D geological model showing distribution of the mai ...
... Cambrian structural history of Tasmania … … … … … … … … … … … … … … … … … … … … … 3-D geological model showing extent of outcropping and concealed allochthonous Early Cambrian ultramafic-mafic complexes in mainland Tasmania … … … … … … … … … … … … 3-D geological model showing distribution of the mai ...
Zircon - Elements Magazine
... amounts of temperature- or process-sensitive trace elements, including the rare earth elements (REE, or lanthanides), yttrium (Y) and titanium (Ti), zircon can also provide compelling chemical evidence for the mineral–melt–fluid processes operating during crust formation and maturation, hydrothermal ...
... amounts of temperature- or process-sensitive trace elements, including the rare earth elements (REE, or lanthanides), yttrium (Y) and titanium (Ti), zircon can also provide compelling chemical evidence for the mineral–melt–fluid processes operating during crust formation and maturation, hydrothermal ...
Mineral-Resource Assessment of Luna County, New Mexico
... Luna County, in southwestern New Mexico (Fig. 1) is not well known for its mineral potential, but more than $16 million worth of metals and nonmetals have been produced from the county from 1876 to 2000. Much of this production has come from 11 types of metallic deposits and six types of industrial ...
... Luna County, in southwestern New Mexico (Fig. 1) is not well known for its mineral potential, but more than $16 million worth of metals and nonmetals have been produced from the county from 1876 to 2000. Much of this production has come from 11 types of metallic deposits and six types of industrial ...
Supporting Information S6: Effects of the
... Here we outline the principal petrographic and mineralogical features of igneous rocks sampled ...
... Here we outline the principal petrographic and mineralogical features of igneous rocks sampled ...
geology of Tasmania - Mineral Resources Tasmania
... (R. F. Berry, University of Tasmania, personal communication) identified an early 1300 Ma metamorphic event, allowing the possibility that part of the Franklin MC is a Mesoproterozoic basement to Tasmania. ...
... (R. F. Berry, University of Tasmania, personal communication) identified an early 1300 Ma metamorphic event, allowing the possibility that part of the Franklin MC is a Mesoproterozoic basement to Tasmania. ...
U–Th–Pb geochronologic constraints on the structural evolution of the
... 3. Previous timing constraints for deformation 3.1. Southwest-verging structures: D1 and D2 In regions adjacent to the northern Selkirk Mountains, Murphy et al. (1995) constrained the age of southwestverging F1 and F2 folds to be ca. 185–174 Ma. The older age limit is based, in part, on the 187–185 ...
... 3. Previous timing constraints for deformation 3.1. Southwest-verging structures: D1 and D2 In regions adjacent to the northern Selkirk Mountains, Murphy et al. (1995) constrained the age of southwestverging F1 and F2 folds to be ca. 185–174 Ma. The older age limit is based, in part, on the 187–185 ...
Uranium - Geological Survey
... outer rock shell surrounding the dome. The gneiss is migmatised along the planes of gneissosity and also intruded by large amounts of late to post-kinematic uraniferous alaskite. In the Khan Formation, clinopyroxene and hornblende are the main dark minerals present, whereas biotite is predominant in ...
... outer rock shell surrounding the dome. The gneiss is migmatised along the planes of gneissosity and also intruded by large amounts of late to post-kinematic uraniferous alaskite. In the Khan Formation, clinopyroxene and hornblende are the main dark minerals present, whereas biotite is predominant in ...
The Regolith Glossary
... their usage. Most scientific disciplines have classifications which make use of words in very specific ways. This glossary has included the more common of these, particularly words for landforms and soils. An example is the word ‘hill’, which is completely well understood by all English speakers, bu ...
... their usage. Most scientific disciplines have classifications which make use of words in very specific ways. This glossary has included the more common of these, particularly words for landforms and soils. An example is the word ‘hill’, which is completely well understood by all English speakers, bu ...
EFFECTS OF ORGANIC LIGANDS ON GRANITE DISSOLUTION IN
... 1997; Zhang and Bloom, 1999; Welch and others, 2002; Brantley, 2004), very few analogous data are available for bulk rocks. Moreover, these studies on monomineralic specimens emphasized mobility of major, rather than minor and trace elements. In previous work (Neaman and others, 2005a, 2005b), we in ...
... 1997; Zhang and Bloom, 1999; Welch and others, 2002; Brantley, 2004), very few analogous data are available for bulk rocks. Moreover, these studies on monomineralic specimens emphasized mobility of major, rather than minor and trace elements. In previous work (Neaman and others, 2005a, 2005b), we in ...
Tourmaline-rich pseudomorphs in sillimanite zone metapelites
... Textural features combined with mineral chemistry preserved in metamorphic rocks provide insights into metamorphic reaction mechanisms as well as open vs. closed system processes. Prograde tourmaline-rich muscovite pseudomorphs after staurolite develop in sillimanite zone metapelites adjacent to per ...
... Textural features combined with mineral chemistry preserved in metamorphic rocks provide insights into metamorphic reaction mechanisms as well as open vs. closed system processes. Prograde tourmaline-rich muscovite pseudomorphs after staurolite develop in sillimanite zone metapelites adjacent to per ...
ZEOLITES IN FISSURES OF CRYSTALLINE BASEMENT ROCKS
... that were originally formed during Alpine greenschist metamorphism. Whereas albitization of plagioclase in higher grade rocks releases the necessary components for zeolite formation, a process that is accompanied by a distinct porosity increase. Zeolite fissures occur in the zone where fluid inclusi ...
... that were originally formed during Alpine greenschist metamorphism. Whereas albitization of plagioclase in higher grade rocks releases the necessary components for zeolite formation, a process that is accompanied by a distinct porosity increase. Zeolite fissures occur in the zone where fluid inclusi ...
GEOLOGY OF THE RAINBOW MOUNTAIN
... The upper Paleozoic strata have been divided into two lithologic successions. The older is named the Tetelna Complex, and it ranges in age from middle Pennsylvanian to early Permian. The Tetelna Complex is overlain by the younger Mankomen Group, which is early to middle Permian and possibly late Per ...
... The upper Paleozoic strata have been divided into two lithologic successions. The older is named the Tetelna Complex, and it ranges in age from middle Pennsylvanian to early Permian. The Tetelna Complex is overlain by the younger Mankomen Group, which is early to middle Permian and possibly late Per ...
Aggregate terminology - Applied Petrography Group
... Chlorides, in concrete mixes – usually sodium chloride, occurs naturally in marine and some coastal sources of aggregates and also occur at significant levels in some inland sedimentary deposits. Chlorides have little significance on the properties of plain concrete but they introduce corrosion ris ...
... Chlorides, in concrete mixes – usually sodium chloride, occurs naturally in marine and some coastal sources of aggregates and also occur at significant levels in some inland sedimentary deposits. Chlorides have little significance on the properties of plain concrete but they introduce corrosion ris ...
Geology Level II - Marais des Cygnes District
... right or wrong, great or disgusting, fun or boring. There is very little middle ground. The role of the leader is most crucial at this stage, as these children look to the adult for approval and follow rules primarily out of respect for the adult. Individual evaluation by adults is preferable to gro ...
... right or wrong, great or disgusting, fun or boring. There is very little middle ground. The role of the leader is most crucial at this stage, as these children look to the adult for approval and follow rules primarily out of respect for the adult. Individual evaluation by adults is preferable to gro ...
Mineral Grain–Complete
... Further, this paper is primarily concerned with natural, solid grains that have formed at or near the surface of Earth. It is not that other substances or environments are uncommon or uninteresting, but for the practical reasons of length and coherence of topic. The surface and near surface processe ...
... Further, this paper is primarily concerned with natural, solid grains that have formed at or near the surface of Earth. It is not that other substances or environments are uncommon or uninteresting, but for the practical reasons of length and coherence of topic. The surface and near surface processe ...
The Malaysian - Thai Working Group
... part of the Transect area. The arenaceous facies consists of yellowish grey, light grey, thin- to medium-bedded, fine- to medium-grained metasandstone and metagreywacke interbedded with minor metasiltstone. The Gerik formation (Pgk) is distributed in the southwestern part of the Transect area. It co ...
... part of the Transect area. The arenaceous facies consists of yellowish grey, light grey, thin- to medium-bedded, fine- to medium-grained metasandstone and metagreywacke interbedded with minor metasiltstone. The Gerik formation (Pgk) is distributed in the southwestern part of the Transect area. It co ...
surficial geologic map of the dent quadrangle, clearwater county
... the hydrogeologic regime, and the occurrence of basalt overlying clay-rich weathered basement rocks. The largest landslides occur where canyoncutting has exposed landslide-prone sediments to steep topography. Slope failures have occurred where the fine-grained sedimentary interbeds and weathered bas ...
... the hydrogeologic regime, and the occurrence of basalt overlying clay-rich weathered basement rocks. The largest landslides occur where canyoncutting has exposed landslide-prone sediments to steep topography. Slope failures have occurred where the fine-grained sedimentary interbeds and weathered bas ...
A Review of the Geochemical Processes
... numerous chelate and other organic complexes of thorium, all of which render the element relatively soluble (and mobile) under certain natural conditions. Thorium and uranium are chemically similar due to the similarities in ionic size and bond character of these elements. This explains why they ten ...
... numerous chelate and other organic complexes of thorium, all of which render the element relatively soluble (and mobile) under certain natural conditions. Thorium and uranium are chemically similar due to the similarities in ionic size and bond character of these elements. This explains why they ten ...
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.