Geology and paragenesis of the Boseto copper deposits, Kalahari
... Hydrothermal Alteration Associated with Mineralization ................................................. 55 ...
... Hydrothermal Alteration Associated with Mineralization ................................................. 55 ...
Workshop Report - Consortium for Ocean Leadership
... processes of mantle melting, melt aggregation and transport have undergone large advances with the integration of mantle geochemistry and rock physics. There was considerable discussion of the origin and consequences of focused viscous deformation along mantle shear zones, with application to meltin ...
... processes of mantle melting, melt aggregation and transport have undergone large advances with the integration of mantle geochemistry and rock physics. There was considerable discussion of the origin and consequences of focused viscous deformation along mantle shear zones, with application to meltin ...
ü STRUCTURAL LANDFORMS
... many of which, for reasons of space, have not been utilised. Only one request for illustrative material was directly refused, and, whether the prints supplied were used or not, I wish to thank those who went to so much trouble on my behalf. I am grateful to the many organisations and individuals who ...
... many of which, for reasons of space, have not been utilised. Only one request for illustrative material was directly refused, and, whether the prints supplied were used or not, I wish to thank those who went to so much trouble on my behalf. I am grateful to the many organisations and individuals who ...
163f71 • BUREAU OF MINERAL RESOURCES GEOLOGY AND
... lithic tuff in the Alligator Creek area suggests that metamorphic effects may not be due solely to the numerous intrusions. The tuffs are generally hard and massive with no recognisable bedding, but a small proportion arc fine, ashy, and well bedded. Pebbly and sandy tuff occurs, but is not common. ...
... lithic tuff in the Alligator Creek area suggests that metamorphic effects may not be due solely to the numerous intrusions. The tuffs are generally hard and massive with no recognisable bedding, but a small proportion arc fine, ashy, and well bedded. Pebbly and sandy tuff occurs, but is not common. ...
Rock-physics modeling of a dispersed
... quartz. However, throughout this portion, the total porosity comes entirely from the wet clay. So here, as the clay volume increases, quartz is being replaced by wet clay. As wet clay has higher neutron porosity but in general lower density and Pvelocity than quartz grains, when clay volume increase ...
... quartz. However, throughout this portion, the total porosity comes entirely from the wet clay. So here, as the clay volume increases, quartz is being replaced by wet clay. As wet clay has higher neutron porosity but in general lower density and Pvelocity than quartz grains, when clay volume increase ...
Physical Properties of Reservoir Rocks
... are sedimentary in origin. Sedimentary rocks that contain oil and gas are generally divided into two categories: clastic sedimentary rocks and carbonate sedimentary rocks. The former chiefly includes conglomerate, sandstone, and mudstone, while the latter usually refers to limestone and dolomite. Sa ...
... are sedimentary in origin. Sedimentary rocks that contain oil and gas are generally divided into two categories: clastic sedimentary rocks and carbonate sedimentary rocks. The former chiefly includes conglomerate, sandstone, and mudstone, while the latter usually refers to limestone and dolomite. Sa ...
Garnet in the Earth`s Mantle
... grossular–almandine mixtures with wide variations in the grossular content (Jacob 2004). Arguably, the most important feature of eclogites is that their bulk compositions often closely resemble the compositions of basalts. The amount of eclogite in the mantle, its origins, and the part it plays in p ...
... grossular–almandine mixtures with wide variations in the grossular content (Jacob 2004). Arguably, the most important feature of eclogites is that their bulk compositions often closely resemble the compositions of basalts. The amount of eclogite in the mantle, its origins, and the part it plays in p ...
1571751 b895 - Göteborgs universitet
... The region is dominated by submarine, felsic metavolcanic rocks with subaerial and submarine intervals, lavas and intermediate to basic volcanic rocks. The metavolcanic rocks were divided by Oen et al. (1982) into three groups, the lower-, medium- and upper leptite groups (Table 1). An age of 1.9 to ...
... The region is dominated by submarine, felsic metavolcanic rocks with subaerial and submarine intervals, lavas and intermediate to basic volcanic rocks. The metavolcanic rocks were divided by Oen et al. (1982) into three groups, the lower-, medium- and upper leptite groups (Table 1). An age of 1.9 to ...
The relationship between mineral composition
... history of the deposit. It will be seen that temporal relationships exist between the various Pb–Cu–Te phases, whose crystallization order would have been determined by closed-system evolution of the fluid composition. The rarer Te minerals often grew by themselves on quartz matrix, without contacti ...
... history of the deposit. It will be seen that temporal relationships exist between the various Pb–Cu–Te phases, whose crystallization order would have been determined by closed-system evolution of the fluid composition. The rarer Te minerals often grew by themselves on quartz matrix, without contacti ...
Diatomite - NSW Resources and Energy
... Diatomite deposits in New South Wales were all formed in lacustrine environments, are mostly associated with Tertiary volcanic rocks and are in the age range of 11 Ma to 21 Ma (Holmes et al. 1989). Most deposits occur at or near the base of a volcanic sequence within what were topographic lows and a ...
... Diatomite deposits in New South Wales were all formed in lacustrine environments, are mostly associated with Tertiary volcanic rocks and are in the age range of 11 Ma to 21 Ma (Holmes et al. 1989). Most deposits occur at or near the base of a volcanic sequence within what were topographic lows and a ...
Geologic map of the Hood River Quadrangle, Washington and Oregon
... cross-cutting feeder dikes are exposed. At the head of the slide, a well preserved intact cinder cone and undisturbed flows demonstrate large block sliding. Broken, hummocky exposures of platy flows east of the cinder cone, lldown slide", represents the greatest volume and areal extent of the flows. ...
... cross-cutting feeder dikes are exposed. At the head of the slide, a well preserved intact cinder cone and undisturbed flows demonstrate large block sliding. Broken, hummocky exposures of platy flows east of the cinder cone, lldown slide", represents the greatest volume and areal extent of the flows. ...
New Chemical Weathering Indices for Estimating
... Düzgören-Aydın et al. (2002) and Düzgören-Aydın & Aydın (2003) explained that geochemical signatures of weathering should be used to establish a framework for the interpretation of the heterogeneity level and the prediction of the variability in engineering properties of rocks. Before proceeding wit ...
... Düzgören-Aydın et al. (2002) and Düzgören-Aydın & Aydın (2003) explained that geochemical signatures of weathering should be used to establish a framework for the interpretation of the heterogeneity level and the prediction of the variability in engineering properties of rocks. Before proceeding wit ...
faults and joints
... Joints normally are barren cracks or empty fissures but some may contain coatings. Narrow veins with infilling minerals, commonly quartz or calcite, are also extension fractures treated as joints. ...
... Joints normally are barren cracks or empty fissures but some may contain coatings. Narrow veins with infilling minerals, commonly quartz or calcite, are also extension fractures treated as joints. ...
976 Frenchman Map Units
... Basaltic flow rocks and associated cinders that crop out in the central east part of the Frenchman Mountain Quadrangle have been correlated with the 11.5- to 8.5-Ma volcanics of Callville Mesa (Anderson and others, 1972; Feuerbach and others, 1991) on the basis of stratigraphic position. The basalts ...
... Basaltic flow rocks and associated cinders that crop out in the central east part of the Frenchman Mountain Quadrangle have been correlated with the 11.5- to 8.5-Ma volcanics of Callville Mesa (Anderson and others, 1972; Feuerbach and others, 1991) on the basis of stratigraphic position. The basalts ...
Pre-Cougar Point Tuff Volcanic Rocks Near the Idaho
... Basin. The Bieroth volcanics are ferrolatitic to rhyodacitic in composition and contain abundant phenotrysts, including hornblende and biotite. The Bieroth volcanics are part of the Eocene province of calcalkaline volcanism that extends southward, and generally becomes younger, from the Challis volc ...
... Basin. The Bieroth volcanics are ferrolatitic to rhyodacitic in composition and contain abundant phenotrysts, including hornblende and biotite. The Bieroth volcanics are part of the Eocene province of calcalkaline volcanism that extends southward, and generally becomes younger, from the Challis volc ...
tertiary igneous rocks and laramide structure and stratigraphy
... mostly related to the last episode. During these magmatic episodes regional stresses changed from compressional to extensional. This transition influenced both the character and extent of magmatic activity in south-central Colorado and northern New Mexico. The Spanish Peaks region is dominated by nu ...
... mostly related to the last episode. During these magmatic episodes regional stresses changed from compressional to extensional. This transition influenced both the character and extent of magmatic activity in south-central Colorado and northern New Mexico. The Spanish Peaks region is dominated by nu ...
Volatile Cycling of H2O, CO2, F, and Cl in the HIMU Mantle: A New
... and White, 1982; Zindler and Hart, 1986; Hauri and Hart, 1993; Kelley et al., 2005; Hanyu et al., 2011, 2014]. Alternatively, the high U/Pb inferred for the HIMU mantle source may be a result of U incorporation into oceanic crust during submarine alteration [Hart and Staudigel, 1982; Hofmann and Whi ...
... and White, 1982; Zindler and Hart, 1986; Hauri and Hart, 1993; Kelley et al., 2005; Hanyu et al., 2011, 2014]. Alternatively, the high U/Pb inferred for the HIMU mantle source may be a result of U incorporation into oceanic crust during submarine alteration [Hart and Staudigel, 1982; Hofmann and Whi ...
Bushnell, Kent, 1967, Geology of the Rowland Quadrangle, Elko County, Nevada: Nevada Bureau of Mines and Geology Bulletin 67, 44 p.
... and quartzitic formations of the eastern facies: Tennessee Mountain Formation ( G O ) , Prospect Mountain(?) Quartzite, and some unnamed formations. An overlap assemblage of conglomerates and limestones, the Sunflower Formation and its tentatively correlative Diamond A Formation, of Upper Pennsylvan ...
... and quartzitic formations of the eastern facies: Tennessee Mountain Formation ( G O ) , Prospect Mountain(?) Quartzite, and some unnamed formations. An overlap assemblage of conglomerates and limestones, the Sunflower Formation and its tentatively correlative Diamond A Formation, of Upper Pennsylvan ...
Mogollon Rim Volcanism and Geochronology
... and 6 feet of basaltic cinders in the same way as in the Mogollon Rim . In the latter place, the two basic ash deposits are about 100 feet thick. The ratio in unit thickness of 100 to 6 at Government Pass is again roughly equivalent to the ratio of 1500 to 75 for the Mogollon Rim section. This propo ...
... and 6 feet of basaltic cinders in the same way as in the Mogollon Rim . In the latter place, the two basic ash deposits are about 100 feet thick. The ratio in unit thickness of 100 to 6 at Government Pass is again roughly equivalent to the ratio of 1500 to 75 for the Mogollon Rim section. This propo ...
O A
... The dolostones in the studied area are grey massive rocks. The crystal size of Um Gheig Formation dolostones ranges from 15 to 300 µm which indicate early to late diagenetic dolomite. The non–planar boundaries are generally irregular to curved and embedded in micrite dolostones matrix (Plate I: A an ...
... The dolostones in the studied area are grey massive rocks. The crystal size of Um Gheig Formation dolostones ranges from 15 to 300 µm which indicate early to late diagenetic dolomite. The non–planar boundaries are generally irregular to curved and embedded in micrite dolostones matrix (Plate I: A an ...
11. Lithologic-Mineralogic Studies of the Sedimentary Deposits from
... peripheries and within the debris. The hydroxides are mainly present as cement in the interstices between fragments. However, they do appear as a cohesive mass (Sections 4-1, 5-1, 5-2). There are also fragments of palagonitized hyaloclastite, fresh green basalt glass, and pyroxenes. Tabular crystals ...
... peripheries and within the debris. The hydroxides are mainly present as cement in the interstices between fragments. However, they do appear as a cohesive mass (Sections 4-1, 5-1, 5-2). There are also fragments of palagonitized hyaloclastite, fresh green basalt glass, and pyroxenes. Tabular crystals ...
Provided for non-commercial research and educational use only
... exerting enough pressure to cause brittle fracture. Plant roots likewise are able to expand within fractures and microfractures. Anisotropic response to heating and cooling (in rocks or individual crystals) causes thermal shock over extreme events or rock fabric fatigue over long periods (see Chapte ...
... exerting enough pressure to cause brittle fracture. Plant roots likewise are able to expand within fractures and microfractures. Anisotropic response to heating and cooling (in rocks or individual crystals) causes thermal shock over extreme events or rock fabric fatigue over long periods (see Chapte ...
AREA IN
... ably, there is no other area in the Trondheim region, at any rate not in the southern and central part, which display so low-grade meta morphism. The occurrence of several fossil horizons through a greater part of the series of strata in the area is evidently conditioned by this Iow-grade metamorph ...
... ably, there is no other area in the Trondheim region, at any rate not in the southern and central part, which display so low-grade meta morphism. The occurrence of several fossil horizons through a greater part of the series of strata in the area is evidently conditioned by this Iow-grade metamorph ...
Linear Vent Area of the Soldier Meadow Tuff, an Ash-Flow
... 1941) that ash flows related to calderas have erupted either from central vents or, more commonly, from concentric or radial fissures . These fissures may be caused by doming above a rising or swelling magma body (Smith and Ba iley, 1968, p. 637). Because of subsequent caldera collapse, as well as l ...
... 1941) that ash flows related to calderas have erupted either from central vents or, more commonly, from concentric or radial fissures . These fissures may be caused by doming above a rising or swelling magma body (Smith and Ba iley, 1968, p. 637). Because of subsequent caldera collapse, as well as l ...
Lower Continental Crust. - UCSB Earth Science
... OF CONTINENTAL CRUST Earth’s continental crust is widely believed to be andesitic to dacitic, with 57 to 66 wt% SiO2 (e.g., Rudnick & Gao 2003, 2014), distinct from mafic oceanic crust, with 48 to 52 wt% SiO2 , and from upper mantle residual peridotites, with <46 wt% SiO2 . Compared with oceanic crus ...
... OF CONTINENTAL CRUST Earth’s continental crust is widely believed to be andesitic to dacitic, with 57 to 66 wt% SiO2 (e.g., Rudnick & Gao 2003, 2014), distinct from mafic oceanic crust, with 48 to 52 wt% SiO2 , and from upper mantle residual peridotites, with <46 wt% SiO2 . Compared with oceanic crus ...
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.