Oxygen 18oxygen 16 and DH studies of plutonic granitic and
... between the North American plate and terrane I, which was accretedduring the Late Jurassic,and the Coast Plutonic Belt between terrane I and terrane II, which was accreted during the Cretaceous. Note in this model that the suggestedaccretion period is the main period of plutonism. However, for these ...
... between the North American plate and terrane I, which was accretedduring the Late Jurassic,and the Coast Plutonic Belt between terrane I and terrane II, which was accreted during the Cretaceous. Note in this model that the suggestedaccretion period is the main period of plutonism. However, for these ...
alleghanian plutonism in the eastern blue ridge
... (Hatcher 1987; Figure 1). Magmatism was widespread in the southern Appalachians during the assembly of Pangaea but was mostly focused in the Piedmont and in Carolinia (Charlotte and Carolina terranes; Figure 2). There are four Alleghanian plutons located in the EBR which formed pre- to syn-tectonica ...
... (Hatcher 1987; Figure 1). Magmatism was widespread in the southern Appalachians during the assembly of Pangaea but was mostly focused in the Piedmont and in Carolinia (Charlotte and Carolina terranes; Figure 2). There are four Alleghanian plutons located in the EBR which formed pre- to syn-tectonica ...
high-sulphidation, epithermal-style
... The late Neoproterozoic Avalonian succession of the Burin Peninsula is host to one of the largest (and least-explored) metamorphosed auriferous epithermal systems in Canada. Extensive zones of advanced argillic alteration, containing the high-sulphidation alteration assemblage pyrophyllite–alunite–q ...
... The late Neoproterozoic Avalonian succession of the Burin Peninsula is host to one of the largest (and least-explored) metamorphosed auriferous epithermal systems in Canada. Extensive zones of advanced argillic alteration, containing the high-sulphidation alteration assemblage pyrophyllite–alunite–q ...
Hafnium isotope evidence for slab melt contributions in the Central
... A survey of global arc lavas shows that calc-alkaline lavas with low Lu/Hf ratios, reflecting melting in the presence of residual garnet and preferential mobilization of Hf over Lu from the subducted slab, are generally associated with hot slab conditions. These include arcs where young (b 30 Ma old) ...
... A survey of global arc lavas shows that calc-alkaline lavas with low Lu/Hf ratios, reflecting melting in the presence of residual garnet and preferential mobilization of Hf over Lu from the subducted slab, are generally associated with hot slab conditions. These include arcs where young (b 30 Ma old) ...
Magma Genesis and Mantle Dynamics at the Harrat Ash
... Voluminous Cenozoic alkali basaltic volcanism occurs in western Arabia, extending from Yemen over a distance of 2500 km to southeastern Turkey (Fig. 1a). These volcanic fields, the so-called Harrats, cover an area of ~200 000 km2, with an average thickness of about 100 m (Coleman et al., 1983; Nasir ...
... Voluminous Cenozoic alkali basaltic volcanism occurs in western Arabia, extending from Yemen over a distance of 2500 km to southeastern Turkey (Fig. 1a). These volcanic fields, the so-called Harrats, cover an area of ~200 000 km2, with an average thickness of about 100 m (Coleman et al., 1983; Nasir ...
Slayt 1
... In order re-examine the calculated reservoir temperatures, an enthalpy versus SiO2 mixing model was used with respect to (Figure 6)4. In the process, the used enthalpy values reflect surface temperatures and have been gathered from (5). In this diagram, the mixing line cuts through quartz solubility ...
... In order re-examine the calculated reservoir temperatures, an enthalpy versus SiO2 mixing model was used with respect to (Figure 6)4. In the process, the used enthalpy values reflect surface temperatures and have been gathered from (5). In this diagram, the mixing line cuts through quartz solubility ...
The Relevance of Brittle Fault Zones in Tunnel Construction
... which are part of the Lower Inn Valley Fault Zone. During construction of the Brixlegg-East and Vomp-East reconBrittle fault zones have great influence on underground naissance tunnels, different types of brittlely deformed construction projects, especially in the case of deep lying rocks were encou ...
... which are part of the Lower Inn Valley Fault Zone. During construction of the Brixlegg-East and Vomp-East reconBrittle fault zones have great influence on underground naissance tunnels, different types of brittlely deformed construction projects, especially in the case of deep lying rocks were encou ...
6. The main mineralization types of the Arabian Shield
... The entire Arabian Shield is, except for some gneissic structures, only slightly metamorphosed and constitutes one of the best preserved and exposed Neoproterozoic assemblages resulting from the accretion of several volcanic-arcs. It is overlain to the east, north and south by a thick Phanerozoic se ...
... The entire Arabian Shield is, except for some gneissic structures, only slightly metamorphosed and constitutes one of the best preserved and exposed Neoproterozoic assemblages resulting from the accretion of several volcanic-arcs. It is overlain to the east, north and south by a thick Phanerozoic se ...
Low-Temperature Geothermal System in Sedimentary Basin and
... relief, to provide both a source of sediment and a relatively low place for the deposition of that sediment. It should be mentioned that the term “sedimentary basin” is usually not applied to relatively thin and very extensive deposits of sandstone, limestone, and shale from epicontinental seas on t ...
... relief, to provide both a source of sediment and a relatively low place for the deposition of that sediment. It should be mentioned that the term “sedimentary basin” is usually not applied to relatively thin and very extensive deposits of sandstone, limestone, and shale from epicontinental seas on t ...
Elevated 87Sr/86Sr Ratios From Mafic Intrusions in the Atlanta Lobe
... American continents are some of the most obvious examples of recent genesis and reworking of continental crust, and their origins are of fundamental geologic importance. The volumetric dominance of monzogranites, granodiorites, and tonalites in these batholiths was recognized very early. However, it ...
... American continents are some of the most obvious examples of recent genesis and reworking of continental crust, and their origins are of fundamental geologic importance. The volumetric dominance of monzogranites, granodiorites, and tonalites in these batholiths was recognized very early. However, it ...
OVERVIEW Tectonics of the Himalaya and southern Tibet from two
... carapace in the form of clasts within the Kailas conglomerate has been expanded upon greatly by subsequent researchers (Ryerson et al., 1995; Murphy et al., 1997b; Miller et al., 1999; Yin et al., 1999). However, most of these studies have focused on postcollisional geologic problems, and relatively ...
... carapace in the form of clasts within the Kailas conglomerate has been expanded upon greatly by subsequent researchers (Ryerson et al., 1995; Murphy et al., 1997b; Miller et al., 1999; Yin et al., 1999). However, most of these studies have focused on postcollisional geologic problems, and relatively ...
Geology of the Kimberley Region, Western Australia: The East
... gave rise to ultrabasic differentiates (Alice Downs Ultrabasics). A second period of folding affected the rocks over most of the region, but it was more intense and was accompanied by high-grade metamorphism along a narrow belt extending diagonally across the map area, called the Halls Creek Mobile ...
... gave rise to ultrabasic differentiates (Alice Downs Ultrabasics). A second period of folding affected the rocks over most of the region, but it was more intense and was accompanied by high-grade metamorphism along a narrow belt extending diagonally across the map area, called the Halls Creek Mobile ...
STRUCTURAL GEOLOGY
... and the limbs dip towards each other and converse condition antiform. An anticline is an antiform in which oldest beds occur at the core but syncline is a synform in which youngest beds occur at the core. A synclinal anticline is a fold having the shape of a syncline but the oldest beds at the core. ...
... and the limbs dip towards each other and converse condition antiform. An anticline is an antiform in which oldest beds occur at the core but syncline is a synform in which youngest beds occur at the core. A synclinal anticline is a fold having the shape of a syncline but the oldest beds at the core. ...
A gravity investigation of the Middleton granite, near Inverurie
... Granite in this area. The mapping also indicates that elsewhere the eastern margin of the Bennachie subcrop is controlled by a north-south fault; there are only minor indications of this fault in the gravity data, suggesting that its throw is small. Residual Bouguer anomaly highs flank the Middleton ...
... Granite in this area. The mapping also indicates that elsewhere the eastern margin of the Bennachie subcrop is controlled by a north-south fault; there are only minor indications of this fault in the gravity data, suggesting that its throw is small. Residual Bouguer anomaly highs flank the Middleton ...
Formation and Evolution of Granite Magmas During
... amphibolite-facies conditions of metamorphism. Orthopyroxene has not been observed. Retrograde greenschistfacies mineral assemblages are developed in some late shear zones. The Ti content of amphiboles coexisting with a Ti-saturating phase increases with temperature (Spear, 1981). Results from 27 Op ...
... amphibolite-facies conditions of metamorphism. Orthopyroxene has not been observed. Retrograde greenschistfacies mineral assemblages are developed in some late shear zones. The Ti content of amphiboles coexisting with a Ti-saturating phase increases with temperature (Spear, 1981). Results from 27 Op ...
Carbonates and associated sedimentary rocks of the Upper Visgan
... Carboniferous rocks in western Cape Breton Island flank the Cape Breton Highlands. They also underlie large areas in the Sydney Basin and in central parts of the island. These strata range in age from latest Devonian to latest Carbonif erous (Bell and Howie, 1990) and provide the local record of se ...
... Carboniferous rocks in western Cape Breton Island flank the Cape Breton Highlands. They also underlie large areas in the Sydney Basin and in central parts of the island. These strata range in age from latest Devonian to latest Carbonif erous (Bell and Howie, 1990) and provide the local record of se ...
The Architecture, Chemistry, and Evolution of Continental Magmatic
... 2.4. Major Continental Arcs of the Americas Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a c ...
... 2.4. Major Continental Arcs of the Americas Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a c ...
Guidebook
... The Crystalline-Mesozoic Zone is built up of basement shearing nappes, each of them showing large developed metamorphic formations covered by a Mesozoic or Permo-Mesozoic sedimentary envelope. The nappes, of Meso-Cretaceous age, cover each other. They are (up/down) the Bucovinian Nappe, the Subbucov ...
... The Crystalline-Mesozoic Zone is built up of basement shearing nappes, each of them showing large developed metamorphic formations covered by a Mesozoic or Permo-Mesozoic sedimentary envelope. The nappes, of Meso-Cretaceous age, cover each other. They are (up/down) the Bucovinian Nappe, the Subbucov ...
the form of the fongen-hyllingen gabbro complex, trondheim region
... In the Hyllingen area the gabbrojnorites grade eastwards into diorite with a decrease in the anorthite content of the plagioclase, to give oligo clase-andesine compositions. Amphibole is the major primary mafic mineral, together with minor amounts of biotite. Along the rather poorly exposed easterJ ...
... In the Hyllingen area the gabbrojnorites grade eastwards into diorite with a decrease in the anorthite content of the plagioclase, to give oligo clase-andesine compositions. Amphibole is the major primary mafic mineral, together with minor amounts of biotite. Along the rather poorly exposed easterJ ...
Interpretation of an Aeromagnetic Survey of the Amchitka Island
... the steeper gradients of theoretical anomalies a r e positioned near the ends of flows or sills that have been terminated by faulting. Drill sites were selected in areas away from gradients considered to be fault related. Nearly all prominent anomalies over land and many over water can be reasonably ...
... the steeper gradients of theoretical anomalies a r e positioned near the ends of flows or sills that have been terminated by faulting. Drill sites were selected in areas away from gradients considered to be fault related. Nearly all prominent anomalies over land and many over water can be reasonably ...
Evolution of the continental crust
... sedimentary and igneous records for crustal evolution indicates that it may take up to one billion years for new crust to dominate the sedimentary record. Combining models for the differentiation of the crust and the residence time of elements in the upper crust indicates that the average rate of cr ...
... sedimentary and igneous records for crustal evolution indicates that it may take up to one billion years for new crust to dominate the sedimentary record. Combining models for the differentiation of the crust and the residence time of elements in the upper crust indicates that the average rate of cr ...
Landslides in Eastern Honshu Induced by the 2011 Off the Pacific
... a narrow river valley. The Ou Range defines the volcanic front of Honshu (Ujiie-Mikoshiba et al., 2006): a 500-km ridge with many Quaternary stratovolcanoes. Since the late Miocene, voluminous magmatic intrusions have been uplifting the Ou Range along its adjoining Uwandaira (east) and Senya (west) ...
... a narrow river valley. The Ou Range defines the volcanic front of Honshu (Ujiie-Mikoshiba et al., 2006): a 500-km ridge with many Quaternary stratovolcanoes. Since the late Miocene, voluminous magmatic intrusions have been uplifting the Ou Range along its adjoining Uwandaira (east) and Senya (west) ...
PRESIDENTIAL ADDRESS Patterns of mineral
... ages is greater than the duration of contact metamorphism, the ages of Mnz from the And and sillimanite (Sil) zones of contact aureoles test the prediction that they date the age of the And isograd. Specifically, if these monazites formed during metamorphism, their isotopic age should match the crys ...
... ages is greater than the duration of contact metamorphism, the ages of Mnz from the And and sillimanite (Sil) zones of contact aureoles test the prediction that they date the age of the And isograd. Specifically, if these monazites formed during metamorphism, their isotopic age should match the crys ...
Landform evolution in the Nagar region, Hispar Mustagh Karakoram
... Himalaya and the Karakoram, which occurred mostly in the Late Cainozoic (Gansser 1964, 1983) a#er the time span of orogenic movements of the nappe character and a#er intervals of regional high-pressure and/or high-temperature rocks metamorphism. Zones of deep-seated igneous rocks in the eastern Kara ...
... Himalaya and the Karakoram, which occurred mostly in the Late Cainozoic (Gansser 1964, 1983) a#er the time span of orogenic movements of the nappe character and a#er intervals of regional high-pressure and/or high-temperature rocks metamorphism. Zones of deep-seated igneous rocks in the eastern Kara ...
Equatorial Segment of the Mid-Atlantic Ridge: initial results of the
... a cluster of fracture zones - Cape Verde, Marathon, Mercury, Vema, Doldrums, Vemadsky and Sierra Leone - in the North, and a similar cluser of fracture zones - St. Paul, Romanche and Chain - in the South. During recent decades, following the publication of the 5th edition of the General Bathymetric ...
... a cluster of fracture zones - Cape Verde, Marathon, Mercury, Vema, Doldrums, Vemadsky and Sierra Leone - in the North, and a similar cluser of fracture zones - St. Paul, Romanche and Chain - in the South. During recent decades, following the publication of the 5th edition of the General Bathymetric ...
Geology of Great Britain
The geology of Great Britain is renowned for its diversity. As a result of its eventful geological history, Great Britain shows a rich variety of landscapes across the constituent countries of England, Wales and Scotland. Rocks of almost all geological ages are represented at outcrop, from the Archaean onwards.