active geological processes controlling seismisity in northeast russia
... Seismic belts of northeast Russia are spatually confined to the boundaries of lithospheric plates (North American, Eurasian, Okhotomorsk and Chinese) where specifical parageneses of seismogenic structures are formed. The boundary between the Eurasian and Chinese (Amurian) plates in marked by the Bai ...
... Seismic belts of northeast Russia are spatually confined to the boundaries of lithospheric plates (North American, Eurasian, Okhotomorsk and Chinese) where specifical parageneses of seismogenic structures are formed. The boundary between the Eurasian and Chinese (Amurian) plates in marked by the Bai ...
A Geochemical Classification for Feldspathic Igneous Rocks
... using five geochemical variables: the FeO/(FeO þMgO) ratio or Fe-index, the modified alkali^lime index, the aluminum-saturation index, the alkalinity index, and the feldspathoid silica-saturation index.The Fe-index distinguishes between melts that have undergone extensive iron enrichment during diff ...
... using five geochemical variables: the FeO/(FeO þMgO) ratio or Fe-index, the modified alkali^lime index, the aluminum-saturation index, the alkalinity index, and the feldspathoid silica-saturation index.The Fe-index distinguishes between melts that have undergone extensive iron enrichment during diff ...
Historical Geology Tectonics
... continents collide one of them can not be subducted (too thick and buoyant), therefore the plates are welded together forming a SUTURE ZONE and producing a large mountain chain, containing sedimentary, igneous and metamorphic rock. ...
... continents collide one of them can not be subducted (too thick and buoyant), therefore the plates are welded together forming a SUTURE ZONE and producing a large mountain chain, containing sedimentary, igneous and metamorphic rock. ...
Forced fords and thrust belt machanics
... ramps- "they just go along for the ride, and some of the beds happen to fined themselves in awkward places and are required to stretch or bend" 2-main types of forced folds: fault-bend folds fault-propagation folds ...
... ramps- "they just go along for the ride, and some of the beds happen to fined themselves in awkward places and are required to stretch or bend" 2-main types of forced folds: fault-bend folds fault-propagation folds ...
27 Mineralogy and geochemistry of recent detrital sediments from
... evolved (felsic) material in the source rocks [47]. The alkaline oxides (Na2O and K2O) have relatively high contents, those in Na2O vary from 0.03 to 2.4 wt.% and those in K 2O from 0.85 to 2 wt.%. Besides, the contents in Na2O of the alluvial materials of the first alluvial profile are quite higher ...
... evolved (felsic) material in the source rocks [47]. The alkaline oxides (Na2O and K2O) have relatively high contents, those in Na2O vary from 0.03 to 2.4 wt.% and those in K 2O from 0.85 to 2 wt.%. Besides, the contents in Na2O of the alluvial materials of the first alluvial profile are quite higher ...
Evolution of lithosphere during oceanic plate reconfiguration along
... University of Tennessee, Knoxville, TN, USA New geochemical and petrological data are reported for mantle xenoliths dredged from the Ferrel Seamount ~150 km off the west coast of Baja California, Mexico. The Ferrel Seamount is located on Miocene oceanic crust (Chon 5, 10 – 13 Ma), atop a segment of ...
... University of Tennessee, Knoxville, TN, USA New geochemical and petrological data are reported for mantle xenoliths dredged from the Ferrel Seamount ~150 km off the west coast of Baja California, Mexico. The Ferrel Seamount is located on Miocene oceanic crust (Chon 5, 10 – 13 Ma), atop a segment of ...
Recent Rapid Uplift of Today`s Mountains
... volcanism, and erosion that sculpt mountains. In their book they repeatedly relate how geological features they and other fellow geomorphologists observe in the field fail to match the explanations of their theorist colleagues. Yet in the end they offer no suggestion as to how the disparity between ...
... volcanism, and erosion that sculpt mountains. In their book they repeatedly relate how geological features they and other fellow geomorphologists observe in the field fail to match the explanations of their theorist colleagues. Yet in the end they offer no suggestion as to how the disparity between ...
The Hindu Kush Seismic Zone as a Paradigm
... whereby a narrow zone of ∼100-km-thick crust was exhumed vertically upward by horizontal contraction between two rigid blocks and subsequent erosion. Although nowhere on Earth today is the crust thicker than ∼75 km, heating during thermal equilibration of such a thick root would destroy any UHP rock ...
... whereby a narrow zone of ∼100-km-thick crust was exhumed vertically upward by horizontal contraction between two rigid blocks and subsequent erosion. Although nowhere on Earth today is the crust thicker than ∼75 km, heating during thermal equilibration of such a thick root would destroy any UHP rock ...
1:500K Tectonic units of Western Australia
... A user can view the attribute table of a theme as described in the data dictionary listing at the beginning of this document and see the item names along with the data type and description. When a user views the attribute table, the user will see the item names described in the data dictionary, and ...
... A user can view the attribute table of a theme as described in the data dictionary listing at the beginning of this document and see the item names along with the data type and description. When a user views the attribute table, the user will see the item names described in the data dictionary, and ...
PDF
... shear zone. The rocks include island-arc and extensionalbasin deposits, ocean-basin to continental-slope deposits, and subduction-related intrusive rocks characteristic of the types formed at the margins of crustal blocks. The Ariab series (in the Ariab Belt; Fig. 1) (Aye et al., 1985; Bakheit, 1991 ...
... shear zone. The rocks include island-arc and extensionalbasin deposits, ocean-basin to continental-slope deposits, and subduction-related intrusive rocks characteristic of the types formed at the margins of crustal blocks. The Ariab series (in the Ariab Belt; Fig. 1) (Aye et al., 1985; Bakheit, 1991 ...
Re^Os evidence for replacement of ancient mantle
... Ma followed by rifting during the period of 2300^ 2400 Ma with subsequent collision at 1800^2000 Ma representing the ¢nal cratonization event. To the south of the North China Craton lies the Qinling^Dabie^Sulu high- to ultrahigh-pressure metamorphic belt, which extends east^west for ca. 2000 km and ...
... Ma followed by rifting during the period of 2300^ 2400 Ma with subsequent collision at 1800^2000 Ma representing the ¢nal cratonization event. To the south of the North China Craton lies the Qinling^Dabie^Sulu high- to ultrahigh-pressure metamorphic belt, which extends east^west for ca. 2000 km and ...
1 Ocean-Continent Convergent Plate Boundaries
... If the magma at a continental arc is felsic, it may be too viscous (thick) to rise through the crust. The magma will cool slowly to form granite or granodiorite. These large bodies of intrusive igneous rocks are called batholiths, ...
... If the magma at a continental arc is felsic, it may be too viscous (thick) to rise through the crust. The magma will cool slowly to form granite or granodiorite. These large bodies of intrusive igneous rocks are called batholiths, ...
Igneous rocks
... there is not enough time for large crystals to form. – Extrusive igneous rocks have no visible mineral grains. – When magma cools slowly beneath Earth’s surface, there is sufficient time for large crystals to form. – Intrusive igneous rocks may have crystals larger ...
... there is not enough time for large crystals to form. – Extrusive igneous rocks have no visible mineral grains. – When magma cools slowly beneath Earth’s surface, there is sufficient time for large crystals to form. – Intrusive igneous rocks may have crystals larger ...
The origin and evolution of the Earth`s continental crust
... massive intracrustal melting to produce granites, transfers heat-producing elements to the upper crust and generally 'stabilises ' the crust. It was non-synchronous over the globe and extended over several hundred million years. Many geological events correlate with a major change at the Archaean-Pr ...
... massive intracrustal melting to produce granites, transfers heat-producing elements to the upper crust and generally 'stabilises ' the crust. It was non-synchronous over the globe and extended over several hundred million years. Many geological events correlate with a major change at the Archaean-Pr ...
Presnall, D. C. and C. E. Helsley (1982) Diapirism of depleted peridotite - a model for the origin of hot spots, Phys. Earth Planet. Int., 29, 148-160.
... It is suggested that depleted diapirs exist with varying amounts of depletion, diameters, upward velocities and source volumes. Such variations could explain the occurrence of hot spots with widely varying lifetimes and rates of lava production. For highly depleted diapirs with very low Fe/Mg, the d ...
... It is suggested that depleted diapirs exist with varying amounts of depletion, diameters, upward velocities and source volumes. Such variations could explain the occurrence of hot spots with widely varying lifetimes and rates of lava production. For highly depleted diapirs with very low Fe/Mg, the d ...
Evolution of the Indian Continental Lithosphere: Insights from
... to ~450 km that has evolved over time as a relatively strong segment of the mantle between earth’s crust and the underlying asthenospheric (weak) mantle. This sub-crustal lithospheric mantle (SCLM), also referred to as the tectosphere (Jordon, 1995) and “mantle lid” is thicker below the Continents t ...
... to ~450 km that has evolved over time as a relatively strong segment of the mantle between earth’s crust and the underlying asthenospheric (weak) mantle. This sub-crustal lithospheric mantle (SCLM), also referred to as the tectosphere (Jordon, 1995) and “mantle lid” is thicker below the Continents t ...
nemei lake area - Publications Centre
... The earliest published description of rocks in the area is that of Mclnnes (1913) who in 1910 travelled along the Churchill River and briefly described the gneisses in the northern part of the maparea. The Pelican Narrows quadrangle (63-M), which includes the present area, was reconnoitred in 1929 a ...
... The earliest published description of rocks in the area is that of Mclnnes (1913) who in 1910 travelled along the Churchill River and briefly described the gneisses in the northern part of the maparea. The Pelican Narrows quadrangle (63-M), which includes the present area, was reconnoitred in 1929 a ...
Metamorphism and Metamorphic Rocks
... from preexisting rocks igneous, sedimentary, and other metamorphic rocks that have been altered by the agents of metamorphism. • Metamorphism means to “change form” • The transition of one rock into another by temperatures and/or pressures unlike those in which it formed • Changes in mineralogy and ...
... from preexisting rocks igneous, sedimentary, and other metamorphic rocks that have been altered by the agents of metamorphism. • Metamorphism means to “change form” • The transition of one rock into another by temperatures and/or pressures unlike those in which it formed • Changes in mineralogy and ...
Review sheet – Chapter 3 Understand that the Earth is density
... are more dense (heavier) than the layers above (lightest, least dense elements on surface) Know that density is measured as mass over (divided by) volume Know that the core contains materials with the greatest density, while the crust contains the least dense materials (elements) Know that the Earth ...
... are more dense (heavier) than the layers above (lightest, least dense elements on surface) Know that density is measured as mass over (divided by) volume Know that the core contains materials with the greatest density, while the crust contains the least dense materials (elements) Know that the Earth ...
The Development of Highly Strained Rocks in the Pelican Window
... extensive uniformity and relatively fine grain size, the intimate association with the pe1itic rocks, the presence of discontinuous calc-silicate layers and pods as well as magnetite, and an apparent crude stratigraphic symmetry of t he units around the Sahli Granite (which is mirrored farther north ...
... extensive uniformity and relatively fine grain size, the intimate association with the pe1itic rocks, the presence of discontinuous calc-silicate layers and pods as well as magnetite, and an apparent crude stratigraphic symmetry of t he units around the Sahli Granite (which is mirrored farther north ...
Ocean-Continent Convergent Plate Boundaries - PAMS
... subduction zone, where the Juan de Fuca Plate is sinking into the mantle. The Juan de Fuca Plate is being created at a spreading center, the Juan de Fuca Ridge. Let’s see the results of subduction of the Juan de Fuca Plate. ...
... subduction zone, where the Juan de Fuca Plate is sinking into the mantle. The Juan de Fuca Plate is being created at a spreading center, the Juan de Fuca Ridge. Let’s see the results of subduction of the Juan de Fuca Plate. ...
millenderdale
... Farm. The gabbro has been pervasively hornfelsed and in places is altered to a dark, granulartextured mafic rock consisting essentially of plagioclase, pyroxene and amphibole; the dykes were probably doleritic originally but have been almost entirely altered to a similar lithology. The Millenderdale ...
... Farm. The gabbro has been pervasively hornfelsed and in places is altered to a dark, granulartextured mafic rock consisting essentially of plagioclase, pyroxene and amphibole; the dykes were probably doleritic originally but have been almost entirely altered to a similar lithology. The Millenderdale ...
IM_chapter7 Metamorphic Rocks
... a particular range of temperatures and pressures. Each facies is named after its most characteristic rock or mineral. ...
... a particular range of temperatures and pressures. Each facies is named after its most characteristic rock or mineral. ...
Deep crustal structure along the Niigata-Kobe Tectonic Zone, Japan:
... the uppermost mantle in region C is caused by the existence of fluids derived from the Pacific slab, which is related to the volcanism in the back-arc side (Hasegawa and Nakajima, 2004). The low-velocity zone in the upper crust appears to reflect the Niigata sedimentary basin, which was formed as a ...
... the uppermost mantle in region C is caused by the existence of fluids derived from the Pacific slab, which is related to the volcanism in the back-arc side (Hasegawa and Nakajima, 2004). The low-velocity zone in the upper crust appears to reflect the Niigata sedimentary basin, which was formed as a ...
SGES 1302 Lecture3
... Since the average density of surface material is only around 3000 kg/m3, we must conclude that denser materials exist within Earth's core. Further evidence for the high density core comes from the study of seismology. In its earliest stages, about 4.5 billion years ago, melting would have caused den ...
... Since the average density of surface material is only around 3000 kg/m3, we must conclude that denser materials exist within Earth's core. Further evidence for the high density core comes from the study of seismology. In its earliest stages, about 4.5 billion years ago, melting would have caused den ...
Baltic Shield
The Baltic Shield (sometimes referred to as the Fennoscandian Shield) is located in Fennoscandia (Norway, Sweden and Finland), northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton. It is composed mostly of Archean and Proterozoic gneisses and greenstones which have undergone numerous deformations through tectonic activity (see Geology of Fennoscandia map [1]). The Baltic Shield contains the oldest rocks of the European continent. The lithospheric thickness is about 200-300 km. During the Pleistocene epoch, great continental ice sheets scoured and depressed the shield's surface, leaving a thin covering of glacial material and innumerable lakes and streams. The Baltic Shield is still rebounding today following the melting of the thick glaciers during the Quaternary Period.