Introduction and project objectives
... in type and composition belong to this suite which is found both north and south of the Hout River Shear Zone. Most of the phases of the GHGS have emplacement ages of around 2900Ma and seem to have been generated by dehydration melting of amphibolites and biotite gneiss protoliths (Robb et al., ...
... in type and composition belong to this suite which is found both north and south of the Hout River Shear Zone. Most of the phases of the GHGS have emplacement ages of around 2900Ma and seem to have been generated by dehydration melting of amphibolites and biotite gneiss protoliths (Robb et al., ...
Falls Lake geology_from_CGS1994 guidebook
... pebbles up to a few centimeters across, of granite and pegmatite. Evidence that some small fragments of ultramafic and mafic rock originated as sedimentary clasts is equivocal, although the possibility has been suggested on the basis of their round to angular shapes and embayed margins (Figure 3 of ...
... pebbles up to a few centimeters across, of granite and pegmatite. Evidence that some small fragments of ultramafic and mafic rock originated as sedimentary clasts is equivocal, although the possibility has been suggested on the basis of their round to angular shapes and embayed margins (Figure 3 of ...
Earth Revealed - Metamorphic Rocks
... 1. What is not associated with the metamorphism of igneous and sedimentary rocks? (a) change in appearance (b) recrystallization of minerals (c) new mineral composition (d) melting under high temperature and pressure 2. Which rock would not be considered a protolith of slate, gneiss, marble, or amph ...
... 1. What is not associated with the metamorphism of igneous and sedimentary rocks? (a) change in appearance (b) recrystallization of minerals (c) new mineral composition (d) melting under high temperature and pressure 2. Which rock would not be considered a protolith of slate, gneiss, marble, or amph ...
PDF
... The term 'Pan-African' was coined by W Q Kennedy in 1964 on the basis of an assessment of available Rb-Sr and K-Ar ages in Africa. The Pan-African was interpreted as a tectono-thermal event, some 500 Ma ago, during which a number of mobile belts formed, surrounding older cratons. The concept was the ...
... The term 'Pan-African' was coined by W Q Kennedy in 1964 on the basis of an assessment of available Rb-Sr and K-Ar ages in Africa. The Pan-African was interpreted as a tectono-thermal event, some 500 Ma ago, during which a number of mobile belts formed, surrounding older cratons. The concept was the ...
On the origin and tectonic significance of the intra-plate
... keeping the general correlation for the 1000 Ma mobile belts, are designed to accommodate other smaller cratonic fragments such as Oaxaquia of southern Mexico, or the Grenvillian age basement inliers of the northern Andes in South America. Fig. 2, adapted from Cordani and Teixeira (2007), brings th ...
... keeping the general correlation for the 1000 Ma mobile belts, are designed to accommodate other smaller cratonic fragments such as Oaxaquia of southern Mexico, or the Grenvillian age basement inliers of the northern Andes in South America. Fig. 2, adapted from Cordani and Teixeira (2007), brings th ...
Evolution of the Precambrian Rocks of Yellowstone
... 2. The Junction Butte migmatites formed by in situ partial melting whereas injection migmatites occur on Garnet Hill 3. The Junction Butte gneiss are consistent with the Mesoarchean gneiss of the eastern Beartooth Mtns. Both gneisses belong to the tonalitetrondjemite-granodiorite (TTG) suite that is ...
... 2. The Junction Butte migmatites formed by in situ partial melting whereas injection migmatites occur on Garnet Hill 3. The Junction Butte gneiss are consistent with the Mesoarchean gneiss of the eastern Beartooth Mtns. Both gneisses belong to the tonalitetrondjemite-granodiorite (TTG) suite that is ...
Twentieth lecture - 23 October, 2013
... Very active - initially molten, then skinned over with a thin surface layer, continually broken by volcanic activity. ...
... Very active - initially molten, then skinned over with a thin surface layer, continually broken by volcanic activity. ...
The Fossil Record and Evolution
... Environments of Deposition Sedimentary rocks may be: Extrabasinal in origin Sediments formed from the weathering of pre-existing rocks outside the basin, and transported to the environment of deposition Intrabasinal in origin Sediments form inside the basin; includes chemical precipitates, most carb ...
... Environments of Deposition Sedimentary rocks may be: Extrabasinal in origin Sediments formed from the weathering of pre-existing rocks outside the basin, and transported to the environment of deposition Intrabasinal in origin Sediments form inside the basin; includes chemical precipitates, most carb ...
Recommendation of a Strategy - University of South Alabama
... Steep reverse faults Greater regional dip than the major thrusts that occur between them. ...
... Steep reverse faults Greater regional dip than the major thrusts that occur between them. ...
Seismic structure of the crust and uppermost mantle of the Capricorn
... of the longer of the two transects in this study. On the basis of recent geological mapping and a re-evaluation of geological data at all scales, this craton has been divided into several terranes and domains (Cassidy et al., 2006a). In the area traversed in this study, these include the Narryer Ter ...
... of the longer of the two transects in this study. On the basis of recent geological mapping and a re-evaluation of geological data at all scales, this craton has been divided into several terranes and domains (Cassidy et al., 2006a). In the area traversed in this study, these include the Narryer Ter ...
2015-defense
... orientations with an average value of 37.5 ± 20.6° . • The mean splitting time is 1.09± 0.34s. • Sudden change of fast orientations at the boundary of Kalahari Craton. ...
... orientations with an average value of 37.5 ± 20.6° . • The mean splitting time is 1.09± 0.34s. • Sudden change of fast orientations at the boundary of Kalahari Craton. ...
GY 112 Lecture Notes
... plate tectonics like we have today (e.g., spreading and subduction). There was rifting and the result was probably great flooding by lava, but this is not the same thing as “continental drift”. Geologists believe that the oldest rocks to form on the Earth (after initial formation that is) were “ocea ...
... plate tectonics like we have today (e.g., spreading and subduction). There was rifting and the result was probably great flooding by lava, but this is not the same thing as “continental drift”. Geologists believe that the oldest rocks to form on the Earth (after initial formation that is) were “ocea ...
Ore Deposits of Mafic Igneous Rocks
... - Natural concentration of ore minerals that formed during one or more geological events - May comprise of one or more orebodies - Mixture of valuable and gangue minerals - Of which at least one valuable mineral is of sufficient concentration, quantity and value - To be profitable mined, milled and ...
... - Natural concentration of ore minerals that formed during one or more geological events - May comprise of one or more orebodies - Mixture of valuable and gangue minerals - Of which at least one valuable mineral is of sufficient concentration, quantity and value - To be profitable mined, milled and ...
Geología Norteamerica
... the Proto-Pacific oceanic basin and the growth of the Paleozoic oceanic lithosphere against the newly generated passive margin of the western North America. By Permian times, the sea floor spreading produced a huge ocean and the Proto-Pacific was only a part of it. The name of the huge ocean that su ...
... the Proto-Pacific oceanic basin and the growth of the Paleozoic oceanic lithosphere against the newly generated passive margin of the western North America. By Permian times, the sea floor spreading produced a huge ocean and the Proto-Pacific was only a part of it. The name of the huge ocean that su ...
PreparationForMidTerm
... what different types of sediments accumulate in greenstone belts and at the edge of much wider continents? what is the origin of Earth's early atmosphere and oceans? How did they differ from the present ones? we also pointed out that continents are "sialic" (or more granitic) than the oceanic crust ...
... what different types of sediments accumulate in greenstone belts and at the edge of much wider continents? what is the origin of Earth's early atmosphere and oceans? How did they differ from the present ones? we also pointed out that continents are "sialic" (or more granitic) than the oceanic crust ...
Cordilleran foreland vs hinterland deformation: Thermal controls of
... and hinterland deformation. In the foreland the deep crust and upper mantle have remained largely undeformed during late Mesozoic to early Tertiary tectonics. Shortening occurred primarily in overlying sedimentary thrust sheets, mediated by high pore fluid pressures, i.e., thinned skin tectonics. In ...
... and hinterland deformation. In the foreland the deep crust and upper mantle have remained largely undeformed during late Mesozoic to early Tertiary tectonics. Shortening occurred primarily in overlying sedimentary thrust sheets, mediated by high pore fluid pressures, i.e., thinned skin tectonics. In ...
The metamorphic evolution of the Mozambique Belt in Central
... path, dominated by decompression during final stages of exhumation. The IBC segment of the Eastern Granulites forms a ‘beta’-shaped retrograde path accompanied by strike-slip tectonics at granulite facies metamorphic conditions. We interpret this highly dynamic initial cooling stage at a particular ...
... path, dominated by decompression during final stages of exhumation. The IBC segment of the Eastern Granulites forms a ‘beta’-shaped retrograde path accompanied by strike-slip tectonics at granulite facies metamorphic conditions. We interpret this highly dynamic initial cooling stage at a particular ...
No Slide Title
... craton margins, consisting of uplifted, folded, metamorphosed marine and terrestrial deposits - often accompanied by intrusive and extrusive igneous rocks (i.e. distinctive suites of rocks). These mountain chains were subject to erosion and became sediment sources for later deposits - shales + greyw ...
... craton margins, consisting of uplifted, folded, metamorphosed marine and terrestrial deposits - often accompanied by intrusive and extrusive igneous rocks (i.e. distinctive suites of rocks). These mountain chains were subject to erosion and became sediment sources for later deposits - shales + greyw ...
Early Paleozoic Geology 1.
... craton margins, consisting of uplifted, folded, metamorphosed marine and terrestrial deposits - often accompanied by intrusive and extrusive igneous rocks (i.e. distinctive suites of rocks). These mountain chains were subject to erosion and became sediment sources for later deposits - shales + greyw ...
... craton margins, consisting of uplifted, folded, metamorphosed marine and terrestrial deposits - often accompanied by intrusive and extrusive igneous rocks (i.e. distinctive suites of rocks). These mountain chains were subject to erosion and became sediment sources for later deposits - shales + greyw ...
No Slide Title
... – a southern equatorial position during the Cambrian – to north temperate latitudes – by the end of the Silurian Period ...
... – a southern equatorial position during the Cambrian – to north temperate latitudes – by the end of the Silurian Period ...
geochronology of proterozoic basement inliers from the colombian
... to ovoid, with dimensions between 50 and 150 µm. Their internal structure on CL images is characterized by very clear core-border patterns. Most cores show oscillatory zoning typical of magmatic zircons, while borders are usually diffuse and homogenous, typical of metamorphic overgrowth. Such typolo ...
... to ovoid, with dimensions between 50 and 150 µm. Their internal structure on CL images is characterized by very clear core-border patterns. Most cores show oscillatory zoning typical of magmatic zircons, while borders are usually diffuse and homogenous, typical of metamorphic overgrowth. Such typolo ...
Metamorphic conditions of the omphacite
... to the Creative Commons CC-BY 4.0 License requiring that the original work has been properly cited. ...
... to the Creative Commons CC-BY 4.0 License requiring that the original work has been properly cited. ...
The Precambrian of Central and Southern Saskatchewan
... nature of recrystallized microstructures suggest possible amphibolite facies metamorphic conditions. The unit could represent an Early Proterozoic shelf sequence, comparable with either the Snowy Pass Supergroup of the Medicine Bow Mountains in southeast Wyoming or parts of the Wollaston Group. The ...
... nature of recrystallized microstructures suggest possible amphibolite facies metamorphic conditions. The unit could represent an Early Proterozoic shelf sequence, comparable with either the Snowy Pass Supergroup of the Medicine Bow Mountains in southeast Wyoming or parts of the Wollaston Group. The ...
Sa˜o Luıs Craton and Gurupi Belt
... þ3.5 (Klein & Moura 2001; Klein et al. 2005a). A similar metavolcano-sedimentary sequence that occurs in the basement sequence of the Gurupi Belt (Fig. 3) has zircon Pb–Pb ages of 2148–2160 Ma (Klein & Moura 2001) and it is possible that the supracrustal sequence of the São Luı́s Craton also contin ...
... þ3.5 (Klein & Moura 2001; Klein et al. 2005a). A similar metavolcano-sedimentary sequence that occurs in the basement sequence of the Gurupi Belt (Fig. 3) has zircon Pb–Pb ages of 2148–2160 Ma (Klein & Moura 2001) and it is possible that the supracrustal sequence of the São Luı́s Craton also contin ...
Yilgarn Craton
The Yilgarn Craton is a large craton that constitutes the bulk of the Western Australian land mass. It is bounded by a mixture of sedimentary basins and Proterozoic fold and thrust belts. Zircon grains in the Jack Hills, Narryer Terrane have been dated at ~4.27 Ga, with one detrital zircon dated as old as 4.4 Ga.