Structure and evolution of the continental margin off Norway and the
... related to the development of a core complex in the middle to lower crust in the Lofoten Islands region, which has been exhumed along detachments during large-scale extension (e.g., Mjelde et al., 1993; Steltenpohl et al., 2004; Tsikalas et al., 2005b). The continental crust on the Lofoten-Vesteråle ...
... related to the development of a core complex in the middle to lower crust in the Lofoten Islands region, which has been exhumed along detachments during large-scale extension (e.g., Mjelde et al., 1993; Steltenpohl et al., 2004; Tsikalas et al., 2005b). The continental crust on the Lofoten-Vesteråle ...
Introduction to the Silurian
... The aim of stratigraphy is to study rock successions preserved from the past and to bring them to life as sequences of events through geological time. By correlating events such as sea-level changes, climatic variations and crustal deformation against the standard geological timescale, stratigraphic ...
... The aim of stratigraphy is to study rock successions preserved from the past and to bring them to life as sequences of events through geological time. By correlating events such as sea-level changes, climatic variations and crustal deformation against the standard geological timescale, stratigraphic ...
Ophiolite concept and its evolution
... concept was confusing because “it obscured critical relationships of its [ophiolite] various members to the tectonic cycle” (p. 393). Linking serpentinites and alpine-type peridotites to orogeny and mountain building episodes, Hess (1955) argued that serpentinites and rocks of Steinmann’s trinity ar ...
... concept was confusing because “it obscured critical relationships of its [ophiolite] various members to the tectonic cycle” (p. 393). Linking serpentinites and alpine-type peridotites to orogeny and mountain building episodes, Hess (1955) argued that serpentinites and rocks of Steinmann’s trinity ar ...
pdf version - Berkeley Seismological Lab
... present tectonic deformation which likely have a series of fault zones. Almost all earthquakes of magnitude >8 and 80–90% of earthquakes of M > 7 occur along these boundaries (Zhang et al. 2003). Groundwater levels rose in the Chuandian block, north and east of the South China block, and on the junc ...
... present tectonic deformation which likely have a series of fault zones. Almost all earthquakes of magnitude >8 and 80–90% of earthquakes of M > 7 occur along these boundaries (Zhang et al. 2003). Groundwater levels rose in the Chuandian block, north and east of the South China block, and on the junc ...
Crustal growth at active continental margins: Numerical
... is pushed toward an either fixed or moving continental plate (1500 km) reproducing a collision zone. The rectangular grid with 2041 201 nodes is non-uniform, resulting in a high resolution (1 km 1 km) area in the center of the model covering 1500 km horizontally, while the rest of the model remai ...
... is pushed toward an either fixed or moving continental plate (1500 km) reproducing a collision zone. The rectangular grid with 2041 201 nodes is non-uniform, resulting in a high resolution (1 km 1 km) area in the center of the model covering 1500 km horizontally, while the rest of the model remai ...
Mesozoic tectonics of the Maria fold and thrust belt and McCoy basin
... and McCoy Basin tectonic provinces of southeastern California. We also present new geologic mapping, structural analysis from macroscopic to microscopic scale, U-Pb zircon ages and Ar-Ar hornblende and biotite ages from key areas in the Maria Fold and Thrust Belt and McCoy Basin to resolve kinematic ...
... and McCoy Basin tectonic provinces of southeastern California. We also present new geologic mapping, structural analysis from macroscopic to microscopic scale, U-Pb zircon ages and Ar-Ar hornblende and biotite ages from key areas in the Maria Fold and Thrust Belt and McCoy Basin to resolve kinematic ...
- Mineralogical Society of America
... we conceptualize it, the conversion of low-permeability bedrock to regolith generally begins due to the transport of meteoric water into protolith through the large-scale fractures that are present as a result of regional tectonic factors or exhumation (Wyrick and Borchers 1981; Molnar et al. 2007). ...
... we conceptualize it, the conversion of low-permeability bedrock to regolith generally begins due to the transport of meteoric water into protolith through the large-scale fractures that are present as a result of regional tectonic factors or exhumation (Wyrick and Borchers 1981; Molnar et al. 2007). ...
Geomorphology of lunar grabens requires igneous dikes at depth
... source depths and required magma overpressures. Dike-forming magmas are likely mantle derived, originating from depths greater than 20 km, with dike widths exceeding 100–500 m. Such dike geometric properties are only plausible if a mechanically weak lunar lithosphere was under extension at the time ...
... source depths and required magma overpressures. Dike-forming magmas are likely mantle derived, originating from depths greater than 20 km, with dike widths exceeding 100–500 m. Such dike geometric properties are only plausible if a mechanically weak lunar lithosphere was under extension at the time ...
Chapter 6 and 7 Joints
... Joint: is a fracture without displacement. The important of the joints not only their important in controlling landscape morphology, but also because they affect rock strength and permeability. As well as they reflect the history of stress and strain in a region. ...
... Joint: is a fracture without displacement. The important of the joints not only their important in controlling landscape morphology, but also because they affect rock strength and permeability. As well as they reflect the history of stress and strain in a region. ...
Petrogenesis of the Eocene and Mio–Pliocene alkaline basaltic
... Chile spreading Ridge (SCR) beneath the South American plate began 14–15 Ma ago when a segment of the ridge collided with the Chile Trench near Tierra del Fuego (~558S, Cande and Leslie, 1986), generating a triple junction (the Chile Triple Junction, CTJ). Since then, the resulting northward migrati ...
... Chile spreading Ridge (SCR) beneath the South American plate began 14–15 Ma ago when a segment of the ridge collided with the Chile Trench near Tierra del Fuego (~558S, Cande and Leslie, 1986), generating a triple junction (the Chile Triple Junction, CTJ). Since then, the resulting northward migrati ...
Article - The Oceanography Society
... seamounts offer major passageways for fluid circulation that promotes geochemical exchange between seawater and the volcanic oceanic crust, and seamounts likely host significant microbial communities. Water circulation may be promoted by hydrothermal siphons in conjunction with the underlying oceani ...
... seamounts offer major passageways for fluid circulation that promotes geochemical exchange between seawater and the volcanic oceanic crust, and seamounts likely host significant microbial communities. Water circulation may be promoted by hydrothermal siphons in conjunction with the underlying oceani ...
Evolution of the continental crust
... crust is generated, and the amounts of residual crustal material recycled back into the mantle. The degree of differentiation can be estimated from the compositions of model new crust and the upper continental crust19. Calculations reveal that the upper crust reflects ,14% partial melting, or the an ...
... crust is generated, and the amounts of residual crustal material recycled back into the mantle. The degree of differentiation can be estimated from the compositions of model new crust and the upper continental crust19. Calculations reveal that the upper crust reflects ,14% partial melting, or the an ...
How Old is the Earth - The Fleming Consulting Group
... 17th-century Irish cleric, for example, calculated that creation occurred in ...
... 17th-century Irish cleric, for example, calculated that creation occurred in ...
Re^Os evidence for replacement of ancient mantle
... (3800^3000 Ma) granitic gneisses and supracrustal rocks, including ultrama¢c to felsic volcanic rocks and metasediments [17,18]. The Western Block is characterized by late Archean to Paleoproterozoic metasedimentary belts that unconformably overlie Archean basement [17,21,22], which consists of gran ...
... (3800^3000 Ma) granitic gneisses and supracrustal rocks, including ultrama¢c to felsic volcanic rocks and metasediments [17,18]. The Western Block is characterized by late Archean to Paleoproterozoic metasedimentary belts that unconformably overlie Archean basement [17,21,22], which consists of gran ...
Late Cretaceous–early Cenozoic tectonic evolution of
... prior to the 75 Ma or younger initiation of slip on the Nacimiento fault. Hence, formation of the schists was at least in part a separate phenomenon from the juxtaposition of the Salinian and Nacimiento blocks. On the other hand, both events appear to have been occurring simultaneously sometime betw ...
... prior to the 75 Ma or younger initiation of slip on the Nacimiento fault. Hence, formation of the schists was at least in part a separate phenomenon from the juxtaposition of the Salinian and Nacimiento blocks. On the other hand, both events appear to have been occurring simultaneously sometime betw ...
Ridge subduction and porphyry copper
... related to adakite or adakitic rocks, distributed linearly with a roughly east-west trend. More normal calc-alkaline rocks flank both sides of the adakite belt. There are also A-type granites whose distribution roughly overlaps with the adakites, but they are ca. 10 million years younger, having for ...
... related to adakite or adakitic rocks, distributed linearly with a roughly east-west trend. More normal calc-alkaline rocks flank both sides of the adakite belt. There are also A-type granites whose distribution roughly overlaps with the adakites, but they are ca. 10 million years younger, having for ...
Extensional and transtensional continental arc basins: case studies
... to Miocene arc volcanism in the Great Basin: the arc migrated southwestward, accompanied by extension resulting from slab steepening/rollback during ongoing subduction (Dickinson, 2006; Cousens et al., 2008; Busby and Putirka, 2009). This extension was superimposed across a high, broad plain produce ...
... to Miocene arc volcanism in the Great Basin: the arc migrated southwestward, accompanied by extension resulting from slab steepening/rollback during ongoing subduction (Dickinson, 2006; Cousens et al., 2008; Busby and Putirka, 2009). This extension was superimposed across a high, broad plain produce ...
TROPICS Continent-Building in Costa Rica
... Any model for the formation and evolution of continents should explain their distinctive lithospheric structure and chemical composition. Ultimately, continental crust is derived from processing rocks formed by melting the upper mantle, although unlike the mid-ocean ridge environment, multiple stage ...
... Any model for the formation and evolution of continents should explain their distinctive lithospheric structure and chemical composition. Ultimately, continental crust is derived from processing rocks formed by melting the upper mantle, although unlike the mid-ocean ridge environment, multiple stage ...
The Use of Magnetic Susceptibility of Rocks in Geological
... The paramagnetic and diamagnetic susceptibilities are field-independent, while the ferromagnetic susceptibility is field-dependent (Fig. 1b). Due to the last effect, the susceptibilities measured in different fields are incomparable and the use of a standard field would be advantageous in comparativ ...
... The paramagnetic and diamagnetic susceptibilities are field-independent, while the ferromagnetic susceptibility is field-dependent (Fig. 1b). Due to the last effect, the susceptibilities measured in different fields are incomparable and the use of a standard field would be advantageous in comparativ ...
Sedimentary record of the tectonic growth of a collisional continental
... sandstone. The overall stratigraphy of the Nutzotin Mountains sequence represents a general upward-shallowing and upward-coarsening package that represents a general transition from distal mud-rich submarine-fan strata to more proximal sand-rich submarine-fan strata that are in turn overlain by mari ...
... sandstone. The overall stratigraphy of the Nutzotin Mountains sequence represents a general upward-shallowing and upward-coarsening package that represents a general transition from distal mud-rich submarine-fan strata to more proximal sand-rich submarine-fan strata that are in turn overlain by mari ...
Strength of the lithosphere and strain localisation in the Baikal rift
... doi:10.1016/j.epsl.2008.03.012 ...
... doi:10.1016/j.epsl.2008.03.012 ...
Durham Research Online
... Figure 4. All model results and the calculated scaling law (dotted line) in a slab viscosity (s) vs. lower crust viscosity (l) plot. Dots represent the break-off mode (filled dots for the intermediate behaviour, outlined also by the grey banded area) and squares represent the delamination mode. and ...
... Figure 4. All model results and the calculated scaling law (dotted line) in a slab viscosity (s) vs. lower crust viscosity (l) plot. Dots represent the break-off mode (filled dots for the intermediate behaviour, outlined also by the grey banded area) and squares represent the delamination mode. and ...
EAST AFRICAN RIFT SYSTEM
... generated from melts at depths of about or greater than 35 km. More saturated basalts (transitional between alkaline and tholeiitic) followed in the rifts generated at shallower depth. A final stage with full scale separation of the continental blocks and tholeiitic magmatism forming new oceanic cru ...
... generated from melts at depths of about or greater than 35 km. More saturated basalts (transitional between alkaline and tholeiitic) followed in the rifts generated at shallower depth. A final stage with full scale separation of the continental blocks and tholeiitic magmatism forming new oceanic cru ...
las pailas geothermal area rincon de la vieja volcano, costa rica
... The area is characterised by fumarolic activity and hot springs, and severe clay alteration on the surface (smectite and kaolinite). The water is bicarbonate rich and to a lesser proportion acid, sulphate water. Las Pailas (low pans for cooking or boiling things) has a surface alteration area of app ...
... The area is characterised by fumarolic activity and hot springs, and severe clay alteration on the surface (smectite and kaolinite). The water is bicarbonate rich and to a lesser proportion acid, sulphate water. Las Pailas (low pans for cooking or boiling things) has a surface alteration area of app ...
From Source to Sinks in Auriferous Magmatic
... Porphyry-type systems are spatially and genetically associated with porphyritic intrusions. The stocks are of calcalkaline to alkaline composition and oxidized. The stocks are characterized by hydrous phenocryst phases, such as amphibole and biotite, whose stability requires at least 4 wt% H 2O in ...
... Porphyry-type systems are spatially and genetically associated with porphyritic intrusions. The stocks are of calcalkaline to alkaline composition and oxidized. The stocks are characterized by hydrous phenocryst phases, such as amphibole and biotite, whose stability requires at least 4 wt% H 2O in ...
Algoman orogeny
The Algoman orogeny, known as the Kenoran orogeny in Canada, was an episode of mountain-building (orogeny) during the Late Archean Eon that involved repeated episodes of continental collisions, compressions and subductions. The Superior province and the Minnesota River Valley terrane collided about 2,700 to 2,500 million years ago. The collision folded the Earth's crust and produced enough heat and pressure to metamorphose the rock. Blocks were added to the Superior province along a 1,200 km (750 mi) boundary that stretches from present-day eastern South Dakota into the Lake Huron area. The Algoman orogeny brought the Archaen Eon to a close, about 2,500 million years ago; it lasted less than 100 million years and marks a major change in the development of the earth’s crust.The Canadian shield contains belts of metavolcanic and metasedimentary rocks formed by the action of metamorphism on volcanic and sedimentary rock. The areas between individual belts consist of granites or granitic gneisses that form fault zones. These two types of belts can be seen in the Wabigoon, Quetico and Wawa subprovinces; the Wabigoon and Wawa are of volcanic origin and the Quetico is of sedimentary origin. These three subprovinces lie linearly in southwestern- to northeastern-oriented belts about 140 km (90 mi) wide on the southern portion of the Superior Province.The Slave province and portions of the Nain province were also affected. Between about 2,000 and 1,700 million years ago these combined with the Sask and Wyoming cratons to form the first supercontinent, the Kenorland supercontinent.