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... Khida terrane are Cryogenian arc assemblages and late Cryogenian to Ediacaran granites, in terms of their crystallization ages, but their negative initial eNd, Paleoproterozoic Nd model ages, and evolved Sr and O isotopic signatures (Whitehouse et al., 2001; Stoeser and Frost, 2006) imply the presen ...
... Khida terrane are Cryogenian arc assemblages and late Cryogenian to Ediacaran granites, in terms of their crystallization ages, but their negative initial eNd, Paleoproterozoic Nd model ages, and evolved Sr and O isotopic signatures (Whitehouse et al., 2001; Stoeser and Frost, 2006) imply the presen ...
Igneous Rocks - AC Reynolds High
... that cool slowly beneath Earth’s surface are called intrusive igneous rocks. Granite is the most common intrusive igneous rock. Initially, scientists did not believe that granite was igneous in origin because it was coarse grained and thus unlike the fine-grained surface rocks that formed from lava. ...
... that cool slowly beneath Earth’s surface are called intrusive igneous rocks. Granite is the most common intrusive igneous rock. Initially, scientists did not believe that granite was igneous in origin because it was coarse grained and thus unlike the fine-grained surface rocks that formed from lava. ...
NWGS BC Coast Range
... General Geology of the Coast Mountains Terminology and General Description The “Coast Belt” is one of the five morphogeological belts of the Canadian segment of the North American Cordillera, and includes both the physiographic Coast Mountains and Cascade Ranges (Fig. 2A: Wheeler and McFeely, 1991; M ...
... General Geology of the Coast Mountains Terminology and General Description The “Coast Belt” is one of the five morphogeological belts of the Canadian segment of the North American Cordillera, and includes both the physiographic Coast Mountains and Cascade Ranges (Fig. 2A: Wheeler and McFeely, 1991; M ...
the kroksfjordur central volcano in north
... (Fig. 3), and which may show "folding" features. The groundmass consists in the main of closely packed, parallel-lying plagioclase tablets set in a matrix of devitrified glass. The groundmass further contains equidimensional grains of pyroxene and ore. The phenocryst generation consists of a weakly ...
... (Fig. 3), and which may show "folding" features. The groundmass consists in the main of closely packed, parallel-lying plagioclase tablets set in a matrix of devitrified glass. The groundmass further contains equidimensional grains of pyroxene and ore. The phenocryst generation consists of a weakly ...
The Geology How old are the rocks?
... of Warley Wise Grit at the bottom of the gorge where the river is narrowest. This restriction contrasts with the wide basin immediately downstream known as the Sales Wheel which has been cut in the softer Sabden Shales. The rocks are youngest to the west and they get older upstream. The rocks in thi ...
... of Warley Wise Grit at the bottom of the gorge where the river is narrowest. This restriction contrasts with the wide basin immediately downstream known as the Sales Wheel which has been cut in the softer Sabden Shales. The rocks are youngest to the west and they get older upstream. The rocks in thi ...
anorogenic granitoids of the early precambrian magmatism of the
... linear predominatly diagonal faults. One of the major structures, controlling emplacement of the massif, is a long northeastern mantle-rooted lineament, whose existence has been established by geophysical data (Sollogub 1986; Fig. 1). The northern edge of the massif is limited by latitudinal the Ovr ...
... linear predominatly diagonal faults. One of the major structures, controlling emplacement of the massif, is a long northeastern mantle-rooted lineament, whose existence has been established by geophysical data (Sollogub 1986; Fig. 1). The northern edge of the massif is limited by latitudinal the Ovr ...
Regional vs Contact Metamorphism
... Metamorphism literally means to “change form.” These changes take thousands to millions of years to complete. During this period of change minerals within the rocks flow in solid state and can change on the atomic scale. Metamorphism most often occurs during one of two geologic events; 1) mounta ...
... Metamorphism literally means to “change form.” These changes take thousands to millions of years to complete. During this period of change minerals within the rocks flow in solid state and can change on the atomic scale. Metamorphism most often occurs during one of two geologic events; 1) mounta ...
Electromagnetic imaging of magma across the Narmada Son lineament, central India
... field, using the induction coil magnetometers. Data were analyzed using a single site analysis procedure. The analysis was done using the robust processing technique (Jones and Jödicke, 1984) for obtaining the auto and cross power spectra required for computing the frequency variation of the appare ...
... field, using the induction coil magnetometers. Data were analyzed using a single site analysis procedure. The analysis was done using the robust processing technique (Jones and Jödicke, 1984) for obtaining the auto and cross power spectra required for computing the frequency variation of the appare ...
Coire Uaigneich
... envelopes to the granites of both the Western Red Hills and the Eastern Red Hills centres may be verified at a number of localities (for example, on the north side of Glamaig, north-east of Mheall a' Mhaoil; on the south and west of Beinn na Caillich, west ofKilchrist). The emplacement of the Skye g ...
... envelopes to the granites of both the Western Red Hills and the Eastern Red Hills centres may be verified at a number of localities (for example, on the north side of Glamaig, north-east of Mheall a' Mhaoil; on the south and west of Beinn na Caillich, west ofKilchrist). The emplacement of the Skye g ...
Structure and evolution of the continental margin off Norway and the
... >25 km to <10 km (Figure 3; profile 1). The sedimentary succession is the thickest along the western part of the basin; 15–16 km, decreasing to 12–13 km landwards. The deep Møre Basin comprises sub-basins separated by intrabasinal highs formed during Late Jurassic-Early Cretaceous rifting. Most of t ...
... >25 km to <10 km (Figure 3; profile 1). The sedimentary succession is the thickest along the western part of the basin; 15–16 km, decreasing to 12–13 km landwards. The deep Møre Basin comprises sub-basins separated by intrabasinal highs formed during Late Jurassic-Early Cretaceous rifting. Most of t ...
Introduction - Beck-Shop
... into the mantle (Mann & Taira, 2004). Although crustal growth by this mechanism appears minimal on modern Earth, it is interesting to speculate whether superplume events were more important earlier in Earth history, and this is one question that will only be answered by full characterization of Eart ...
... into the mantle (Mann & Taira, 2004). Although crustal growth by this mechanism appears minimal on modern Earth, it is interesting to speculate whether superplume events were more important earlier in Earth history, and this is one question that will only be answered by full characterization of Eart ...
Mantle Exhumation in an Early Paleozoic Passive Margin, Northern
... mantle during rifting of continental lithosphere at least 25 km thick subjected continental margin metasediments to conditions above the fluid-absent metapelite solidus. The contrasting strength of upper mantle and crustal lithologies during extension may explain the structural juxtaposition and bou ...
... mantle during rifting of continental lithosphere at least 25 km thick subjected continental margin metasediments to conditions above the fluid-absent metapelite solidus. The contrasting strength of upper mantle and crustal lithologies during extension may explain the structural juxtaposition and bou ...
Tectonic Evolution and Dynamics of Deepwater Area of Pearl River
... Deepwater basins have increasingly become the most important field of Chinese hydrocarbon exploration in recent years. There are widespread deepwater basins distributed on the northern South China Sea (SCS) (Wu et al., 2009; Zhang et al., 2007). The ...
... Deepwater basins have increasingly become the most important field of Chinese hydrocarbon exploration in recent years. There are widespread deepwater basins distributed on the northern South China Sea (SCS) (Wu et al., 2009; Zhang et al., 2007). The ...
The western margin of Mexico is ideally - Earth Science
... Alisitos arc terrane of the Baja California Peninsula represent major components of this margin (Fig. 1). These terranes are significant because they constitute about a third of Mexico (Fig. 1), a portion of the continent that was tectonically assembled in relatively recent geologic time (largely la ...
... Alisitos arc terrane of the Baja California Peninsula represent major components of this margin (Fig. 1). These terranes are significant because they constitute about a third of Mexico (Fig. 1), a portion of the continent that was tectonically assembled in relatively recent geologic time (largely la ...
The Chemistry of Rocks in the Wissahickon Valley
... formed mudstones, coarser sediments formed sandstone, and volcanic ash dissolved in the early seas and gave rise to carbonate based rocks. Towards the end of the eon (around 570-500 mya), the Iapetus ocean formed to the east of Laurentia and the North American craton. It is interesting to note that ...
... formed mudstones, coarser sediments formed sandstone, and volcanic ash dissolved in the early seas and gave rise to carbonate based rocks. Towards the end of the eon (around 570-500 mya), the Iapetus ocean formed to the east of Laurentia and the North American craton. It is interesting to note that ...
macpherson_hall_1999 Tectonic controls on arc magmatism
... being subducted towards the north (Vroon et al, 1993). The second zone of convergence occurs where lithosphere of the Pacific Ocean is subducted towards the west. A subduction zone extends from Japan, through the Izu Bonin and Mariana trenches to the Ayu Trough. Magmatism has occurred in this arc ...
... being subducted towards the north (Vroon et al, 1993). The second zone of convergence occurs where lithosphere of the Pacific Ocean is subducted towards the west. A subduction zone extends from Japan, through the Izu Bonin and Mariana trenches to the Ayu Trough. Magmatism has occurred in this arc ...
Studies on quartz as the tracer of fluid migration
... • Double-sided-polished thin sections of the sandstones, and quartz crystals themselves, were prepared for fluid inclusion studies using two preparation techniques (Jarmołowicz-Szulc 2001a,b). • The microscopic studies performed in the Petrological Department of the Polish Geological Institute in Wa ...
... • Double-sided-polished thin sections of the sandstones, and quartz crystals themselves, were prepared for fluid inclusion studies using two preparation techniques (Jarmołowicz-Szulc 2001a,b). • The microscopic studies performed in the Petrological Department of the Polish Geological Institute in Wa ...
Preliminary Investigation of the Thermotectonic History of the Central
... This paper reports results of 1:20 000 scale bedrock mapping in two areas in the central Rottenstone Domain of northern Saskatchewan. In the Hickson Lake area, on the eastern edge of the Rottenstone Domain, two distinct packages of metamorphosed supracrustal rocks were recognized on the east side of ...
... This paper reports results of 1:20 000 scale bedrock mapping in two areas in the central Rottenstone Domain of northern Saskatchewan. In the Hickson Lake area, on the eastern edge of the Rottenstone Domain, two distinct packages of metamorphosed supracrustal rocks were recognized on the east side of ...
Geology of the Gorny Altai subduction–accretion complex, southern
... The former, also called Pacific-type (Matsuda and Uyeda, 1971) or Miyashiro-type (Maruyama, 1997), sis characterized by the formation of subduction–accretion complexes involving high-P/T metamorphic (HP) rocks, and extensive calc-alkaline magmatism that usually results in a voluminous increase of con ...
... The former, also called Pacific-type (Matsuda and Uyeda, 1971) or Miyashiro-type (Maruyama, 1997), sis characterized by the formation of subduction–accretion complexes involving high-P/T metamorphic (HP) rocks, and extensive calc-alkaline magmatism that usually results in a voluminous increase of con ...
SUPERFAULTS AND PSEUDOTACHYLYTES
... of faults that produced melted rock. First, we examined an ancient shearing process in continental crustal rocks in central Colorado. Second, we examined a subduction zone setting at Kodiak Island, Alaska. Both locations document, in outcrop and in thin-section, evidence that melted rock was generat ...
... of faults that produced melted rock. First, we examined an ancient shearing process in continental crustal rocks in central Colorado. Second, we examined a subduction zone setting at Kodiak Island, Alaska. Both locations document, in outcrop and in thin-section, evidence that melted rock was generat ...
Plate boundaries, rifts and transforms in Iceland
... magmatism of the hotspot leads to a wider and more complicated plate boundary deformation zone than is observed along normal oceanic plate boundaries. Furthermore, the relative movement of the boundary with respect to the roots of the hotspot leads to unstable boundaries and rift jumps, when crustal ...
... magmatism of the hotspot leads to a wider and more complicated plate boundary deformation zone than is observed along normal oceanic plate boundaries. Furthermore, the relative movement of the boundary with respect to the roots of the hotspot leads to unstable boundaries and rift jumps, when crustal ...
Continental geotherm and the evolution of rifted margins
... produces the thick sequences of igneous rocks found at volcanic rifted margins (White and McKenzie, 1989; Bown and White, 1995; Hopper et al., 2003). Lowering the Tp of the sublithospheric mantle to below 1300 8C similarly leads to a decrease in the amount of melt generated at effectively infinite s ...
... produces the thick sequences of igneous rocks found at volcanic rifted margins (White and McKenzie, 1989; Bown and White, 1995; Hopper et al., 2003). Lowering the Tp of the sublithospheric mantle to below 1300 8C similarly leads to a decrease in the amount of melt generated at effectively infinite s ...
3.4 Metamorphic Rocks
... Foliated Metamorphic Rocks When rocks undergo contact metamorphism, they become more compact and thus more dense. A common example is the metamorphic rock slate. Slate forms when shale is subjected to temperatures and pressures only slightly greater than those at which the shale formed. The pressure ...
... Foliated Metamorphic Rocks When rocks undergo contact metamorphism, they become more compact and thus more dense. A common example is the metamorphic rock slate. Slate forms when shale is subjected to temperatures and pressures only slightly greater than those at which the shale formed. The pressure ...
Late Precambrian Stratigraphy and Structure of the North
... expected to occur in the deep substratum of the Southern Barents Shelf while equivalents of the pericratonic deposits of the Varanger-Kildin Zone may possibly be hidden beneath the Palaeozoic strata of the Russian Platform, assuming that the SW-NE margin-to-basin facies distribution constitutes a re ...
... expected to occur in the deep substratum of the Southern Barents Shelf while equivalents of the pericratonic deposits of the Varanger-Kildin Zone may possibly be hidden beneath the Palaeozoic strata of the Russian Platform, assuming that the SW-NE margin-to-basin facies distribution constitutes a re ...
Northern Flin Flon Belt compilation, Manitoba (parts of NTS 63K12, 13)
... MORB-type volcanic rocks and, during subsequent deformation, was associated with approximately 3 km of sinistral displacement in the NFFB, inferred as a result of oblique-slip movement along the fault (Figures GS-7-2 and -3). The Northeast Arm shear zone is a crustal-scale feature (David and Syme, 1 ...
... MORB-type volcanic rocks and, during subsequent deformation, was associated with approximately 3 km of sinistral displacement in the NFFB, inferred as a result of oblique-slip movement along the fault (Figures GS-7-2 and -3). The Northeast Arm shear zone is a crustal-scale feature (David and Syme, 1 ...
Great Lakes tectonic zone
The Great Lakes tectonic zone is bounded by South Dakota at its tip and heads northeast to south of Duluth, Minnesota, then heads east through northern Wisconsin, Marquette, Michigan, and then trends more northeasterly to skim the northern-most shores of lakes Michigan and Huron before ending in the Sudbury, Ontario, Canada, area.During the Late Archean Era the Algoman orogeny added landmass to the Superior province by volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Lake Huron region near Sudbury, Ontario, Canada.This crustal boundary is the Great Lakes tectonic zone. It is 1,400 km (870 mi) long, and separates the older Archean gneissic terrane to the south from younger Late Archean greenstone-granite terrane to the north.The zone is characterized by active compression during the Algoman orogeny (about 2,700 million years ago), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation during Phanerozoic time (the past 500 million years).Collision began along the Great Lakes tectonic zone (GLTZ) with the Algoman mountain-building event and continued for tens of millions of years. During the formation of the GLTZ, the gneissic Minnesota River Valley subprovince was thrust up onto the Superior province's edge as it consumed the Superior province's oceanic crust. Fragmentation of the Kenorland supercontinent began 2,450 million years ago and was completed by 2,100 million years ago. The Wyoming province is the continental landmass that is hypothesized to have rifted away from the southern Superior province portion of Kenorland, before moving rapidly west and docking with the Laurentia supercontinent 1,850 to 1,715 million years ago. Sedimentation from the GLTZ-rifting environment continued into the Penokean orogeny, which is the next major tectonic event in the Great Lakes region. Several earthquakes have been documented in Minnesota, Michigan's Upper Peninsula and Sudbury in the last 120 years along the GLTZ.