a comparison of the krušné hory-erzgebirge
... granites probably represent the postmagmatically altered apical contact parts of the YIC granites and may well be arranged in NW trending ridges in the Eastern pluton and a bow-shaped lineament in the Western pluton (Štemprok, 1986). If we apply this type of interpretation to the Cornubian batholith ...
... granites probably represent the postmagmatically altered apical contact parts of the YIC granites and may well be arranged in NW trending ridges in the Eastern pluton and a bow-shaped lineament in the Western pluton (Štemprok, 1986). If we apply this type of interpretation to the Cornubian batholith ...
mineralogy - West Virginia University
... liquid, fall to bottom of magma chamber • Called fractional crystallization • The last liquid to crystallize will contain more volatiles and incompatible elements (K, Rb, Li, Be, B, and REEs) • Pegmatites form from these residual liquids, large crystals because H2O acts as a flux ...
... liquid, fall to bottom of magma chamber • Called fractional crystallization • The last liquid to crystallize will contain more volatiles and incompatible elements (K, Rb, Li, Be, B, and REEs) • Pegmatites form from these residual liquids, large crystals because H2O acts as a flux ...
PDF
... rocks may be the result of the remelting of pre-existing continental crust, in which case the crust is referred to as “reworked,” “rejuvenated” or “remelted.” Juvenile versus reworked crust can also be distinguished by whether isotopic compositions are relatively homogeneous and mantle-like (in the ...
... rocks may be the result of the remelting of pre-existing continental crust, in which case the crust is referred to as “reworked,” “rejuvenated” or “remelted.” Juvenile versus reworked crust can also be distinguished by whether isotopic compositions are relatively homogeneous and mantle-like (in the ...
The Architecture, Chemistry, and Evolution of Continental Magmatic
... subduction magmatism where the upper plate is continental and/or accreted transitional lithosphere. The active-type example is the Andean arc of South America. Well-studied deeply exhumed analogs to the Andean volcanic arc occur as composite batholiths along western North America. The South and Nort ...
... subduction magmatism where the upper plate is continental and/or accreted transitional lithosphere. The active-type example is the Andean arc of South America. Well-studied deeply exhumed analogs to the Andean volcanic arc occur as composite batholiths along western North America. The South and Nort ...
Chapter 4 Rocks
... c. squeezing loose sediment between layers which are more dense and solid d. rock that forms quickly from magma erupting from a volcano ____ 20. Which factors allow rocks to bend or fold without melting? a. gravity and pressure c. pressure and temperature b. composition and gravity d. temperature an ...
... c. squeezing loose sediment between layers which are more dense and solid d. rock that forms quickly from magma erupting from a volcano ____ 20. Which factors allow rocks to bend or fold without melting? a. gravity and pressure c. pressure and temperature b. composition and gravity d. temperature an ...
Indentation of a continent with a built
... when magmas rising from the subducting oceanic plate arc weld the accreted prism of sediments into continental crust in either island or cordilleran arcs (Mitchel and Garson, 1976). Open-ocean subduction may be punctuated by the docking of small terrains with large continents. However, large persist ...
... when magmas rising from the subducting oceanic plate arc weld the accreted prism of sediments into continental crust in either island or cordilleran arcs (Mitchel and Garson, 1976). Open-ocean subduction may be punctuated by the docking of small terrains with large continents. However, large persist ...
Upper mantle beneath Southeast Asia from S velocity tomography
... [1] We present a three-dimensional, S velocity model of the SE Asian-western Pacific upper mantle with 400-km lateral resolution. Using the novel Automated Multimode Inversion technique, we processed 4038 vertical-component seismograms and extracted 22,708 linear equations with uncorrelated uncertai ...
... [1] We present a three-dimensional, S velocity model of the SE Asian-western Pacific upper mantle with 400-km lateral resolution. Using the novel Automated Multimode Inversion technique, we processed 4038 vertical-component seismograms and extracted 22,708 linear equations with uncorrelated uncertai ...
Ar– Ar ages of intrusions in East Greenland: Rift-to
... Igneous Province. The alkaline intrusions mainly crop out in tectonic and magmatic lineaments orthogonal to the rifted margin and occur up to 100 km inland. The area south of the Kangerlussuaq Fjord includes at least four tectonic lineaments and the intrusions are confined to three time windows at 5 ...
... Igneous Province. The alkaline intrusions mainly crop out in tectonic and magmatic lineaments orthogonal to the rifted margin and occur up to 100 km inland. The area south of the Kangerlussuaq Fjord includes at least four tectonic lineaments and the intrusions are confined to three time windows at 5 ...
Hot and cold granites? Implications of zircon
... metaluminous or marginally peraluminous; they are slightly less felsic (59–72 wt% SiO2) than intrusions with inheritance. Nine metaluminous to weakly peraluminous and three strongly peraluminous (muscovite 6 garnet bearing; Miller, 1985) intrusions with 62–75 wt% SiO2 have very small amounts of prem ...
... metaluminous or marginally peraluminous; they are slightly less felsic (59–72 wt% SiO2) than intrusions with inheritance. Nine metaluminous to weakly peraluminous and three strongly peraluminous (muscovite 6 garnet bearing; Miller, 1985) intrusions with 62–75 wt% SiO2 have very small amounts of prem ...
- Wiley Online Library
... the overriding plate (retro-plate) experienced more localized deformation. In their experiments the crustal suture migrated continuously toward the retro-side of the box (i.e., in the direction of subduction),producing an orogen composed largely of crust derived from the subducting plate (proplate). ...
... the overriding plate (retro-plate) experienced more localized deformation. In their experiments the crustal suture migrated continuously toward the retro-side of the box (i.e., in the direction of subduction),producing an orogen composed largely of crust derived from the subducting plate (proplate). ...
MAJOR-ELEMENT CHEMISTRY OF PLUTONIC ROCK SUITES
... 1971): (1) at ocean--ocean plate boundaries where oceanic lithosphere is subducted beneath oceanic lithosphere; (2) at ocean--continent plate boundaries where oceanic lithosphere is subducted beneath continental lithosphere; and (3) at continent--continent collision boundaries. In the last case, sub ...
... 1971): (1) at ocean--ocean plate boundaries where oceanic lithosphere is subducted beneath oceanic lithosphere; (2) at ocean--continent plate boundaries where oceanic lithosphere is subducted beneath continental lithosphere; and (3) at continent--continent collision boundaries. In the last case, sub ...
Lithospheric evolution of the Andean fold–thrust belt, Bolivia, and
... Andean plateau between 188 and 208 S from Late Cretaceous to present. By integrating geophysical results of upper mantle structure, crustal thickness, and composition with recently published structural, stratigraphic, and thermochronologic data, we emphasize the importance of both the crust and uppe ...
... Andean plateau between 188 and 208 S from Late Cretaceous to present. By integrating geophysical results of upper mantle structure, crustal thickness, and composition with recently published structural, stratigraphic, and thermochronologic data, we emphasize the importance of both the crust and uppe ...
34 - School of Ocean and Earth Science and Technology
... These weathering-resistant grains are in ~3.6 Ga quartzrich gneisses (originally sandstones). Before being incorporated into quartz sands at ~3.6 Ga, they had already been through at least one pass of the rock cycle of rock formation-metamorphism-weathering-erosion-deposition. Small outcrops of ro ...
... These weathering-resistant grains are in ~3.6 Ga quartzrich gneisses (originally sandstones). Before being incorporated into quartz sands at ~3.6 Ga, they had already been through at least one pass of the rock cycle of rock formation-metamorphism-weathering-erosion-deposition. Small outcrops of ro ...
An Investigation of the carbonatites of the Kaapvaal Craton and their
... Carbonatites are exotic rocks which usually occur in discrete intrusions. Considering the association of carbonatites with rifting environments, this dissertation proposes that: carbonatites occur in extensional tectonic settings and therefore carbonatite occurrence can be used to constrain an exten ...
... Carbonatites are exotic rocks which usually occur in discrete intrusions. Considering the association of carbonatites with rifting environments, this dissertation proposes that: carbonatites occur in extensional tectonic settings and therefore carbonatite occurrence can be used to constrain an exten ...
Lithosphere
... pilot hole drilled in 2002 went through a 1 km thick Cenozoic sedimentary section overlying Salinian granite, consistent with the geologic model. In 2004 and 2005, phases 1 and 2 of the main SAFOD hole were drilled, and at 1920 m measured depth (mmd—the distance measured along the borehole), the bor ...
... pilot hole drilled in 2002 went through a 1 km thick Cenozoic sedimentary section overlying Salinian granite, consistent with the geologic model. In 2004 and 2005, phases 1 and 2 of the main SAFOD hole were drilled, and at 1920 m measured depth (mmd—the distance measured along the borehole), the bor ...
appendix 2 - Rockmass.net
... 2.2 Composition and structure of faults Faults and fracture zones can vary in composition from mostly brecciated or crushed material with relatively small amounts of clay to highly weathered or hydrothermally altered, highly plastic, swelling clay gouge. The composition of these pieces can be simila ...
... 2.2 Composition and structure of faults Faults and fracture zones can vary in composition from mostly brecciated or crushed material with relatively small amounts of clay to highly weathered or hydrothermally altered, highly plastic, swelling clay gouge. The composition of these pieces can be simila ...
Post-Paleozoic activity
... not been reported from the Alleghanides, although marine faunas are reported (Thibaudeau, 1987) from coal-bearing beds of the Pictou Group in Nova Scotia, indicating that during the late Paleozoic some basins in the northern Appalachians stood near sea level. By Late Triassic time, streams in the so ...
... not been reported from the Alleghanides, although marine faunas are reported (Thibaudeau, 1987) from coal-bearing beds of the Pictou Group in Nova Scotia, indicating that during the late Paleozoic some basins in the northern Appalachians stood near sea level. By Late Triassic time, streams in the so ...
A Tectonic Model for Evolution of the Cascade Range
... slab of oceanic plate undergoing subduction, rotated during early Eocene from a southern point near the Klamath Mountains. The block rafted against the continent by middle Eocene but continued to rotate until middle Miocene. In model 2 , after being rafted against the continent in middle Eocene as a ...
... slab of oceanic plate undergoing subduction, rotated during early Eocene from a southern point near the Klamath Mountains. The block rafted against the continent by middle Eocene but continued to rotate until middle Miocene. In model 2 , after being rafted against the continent in middle Eocene as a ...
Rifting, Seafloor Spreading, and Extensional Tectonics
... margins. Because these rifts cut into the continent at a high angle, they are called aulacogens. They may be relicts of unsuccessful rifting events that occurred prior to the successful rifting that generated the margins of North America at the beginning of the Phanerozoic. Late Proterozoic successf ...
... margins. Because these rifts cut into the continent at a high angle, they are called aulacogens. They may be relicts of unsuccessful rifting events that occurred prior to the successful rifting that generated the margins of North America at the beginning of the Phanerozoic. Late Proterozoic successf ...
Global tectonic significance of the Solomon
... shown are accreted oceanic rocks in ancient orogenic belts, or ‘‘classic ophiolites’’, as compiled by Exxon Tectonic Map of the World (1985) and Coffin and Eldholm (2001). Numbered areas 1 – 5 within Precambrian cratons are selected localities of proposed Archean oceanic plateaus taken from the lite ...
... shown are accreted oceanic rocks in ancient orogenic belts, or ‘‘classic ophiolites’’, as compiled by Exxon Tectonic Map of the World (1985) and Coffin and Eldholm (2001). Numbered areas 1 – 5 within Precambrian cratons are selected localities of proposed Archean oceanic plateaus taken from the lite ...
Nature and origin of Lofdal Carbonatite associated REE Deposit
... mineralisation. In addition, HREE enrichment in Lofdal carbonatites seems to be associated with late stage hydrothermal processes (Swinden, 2012), in contrast to other carbonatite deposits e.g. Mountain Pass, which is of magmatic origin. (Walters, 2011) At Lofdal, two specific areas, area 2 and area ...
... mineralisation. In addition, HREE enrichment in Lofdal carbonatites seems to be associated with late stage hydrothermal processes (Swinden, 2012), in contrast to other carbonatite deposits e.g. Mountain Pass, which is of magmatic origin. (Walters, 2011) At Lofdal, two specific areas, area 2 and area ...
54. Regional Geology of the Goban Spur Continental Margin
... All available geophysical data have been integrated with the Leg 80 drilling results to produce a regional geological synthesis of the Goban Spur passive continental margin. The thin sediment sequence overlying basement is divided into three seismostratigraphic sequences. The lowest of these, sequen ...
... All available geophysical data have been integrated with the Leg 80 drilling results to produce a regional geological synthesis of the Goban Spur passive continental margin. The thin sediment sequence overlying basement is divided into three seismostratigraphic sequences. The lowest of these, sequen ...
13 Oxygen Isotopes in Zircon - University of Wisconsin
... independently determined by Eiler et al. (1997). These to 5‰ in δ O (Bindeman and Valley (2000a, data show that Hf substitution measurably affects data 2001, 2003). correction (from Peck et al. 2001). A relatively new and very promising approach to zircon separation is the Electric Pulse Disintegrat ...
... independently determined by Eiler et al. (1997). These to 5‰ in δ O (Bindeman and Valley (2000a, data show that Hf substitution measurably affects data 2001, 2003). correction (from Peck et al. 2001). A relatively new and very promising approach to zircon separation is the Electric Pulse Disintegrat ...
Fast and slow spreading ridges - Archimer
... quenched lava roofs (about 15 cm thick), generally collapsed and lying on the basaltic seafloor, and by pillars which record the different lava levels of the lakes. These features are indicative of tectonic activity and magma supply in a way ...
... quenched lava roofs (about 15 cm thick), generally collapsed and lying on the basaltic seafloor, and by pillars which record the different lava levels of the lakes. These features are indicative of tectonic activity and magma supply in a way ...
2.1.1 Introduction
... recorded at seismograph stations around the world, can be used to determine the nature of the faulting associated with the earthquake, to infer the orientation of the fault plane and to gain information on the state of stress of the lithosphere. The result of such an analysis is referred to as a foc ...
... recorded at seismograph stations around the world, can be used to determine the nature of the faulting associated with the earthquake, to infer the orientation of the fault plane and to gain information on the state of stress of the lithosphere. The result of such an analysis is referred to as a foc ...
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.