Seimic analysis of Carboniferous rift basin and Triassic growth
... two tectonic realms; (i) Carboniferous rifting in Central Spitsbergen, and (ii) shallow Triassic extensional basins of the SE Svalbard region. The study of the Carboniferous Billefjorden Trough in Sassenfjorden-Tempelfjorden and from Reindalen, focus on the rift infill with associated wedge and lent ...
... two tectonic realms; (i) Carboniferous rifting in Central Spitsbergen, and (ii) shallow Triassic extensional basins of the SE Svalbard region. The study of the Carboniferous Billefjorden Trough in Sassenfjorden-Tempelfjorden and from Reindalen, focus on the rift infill with associated wedge and lent ...
The origin of metamorphic core complexes and detachment faults
... ductilely stretching rocks are cut periodically by faults when large earthquakes take place. When such a catastrophic event occurs, the normally ductile rocks at depth are cut by the downwards propagating normal fault. A transient stress rise results, which must be subsequently relaxed by ductile fl ...
... ductilely stretching rocks are cut periodically by faults when large earthquakes take place. When such a catastrophic event occurs, the normally ductile rocks at depth are cut by the downwards propagating normal fault. A transient stress rise results, which must be subsequently relaxed by ductile fl ...
Crustal radial anisotropy across Eastern Tibet and the Western
... indeed, is present between stations located within eastern Tibet. [7] The objective of this paper is to map crustal radial anisotropy across all of eastern Tibet (Figure 1), extending the results into adjacent areas north and east of the high plateau for comparison. Rayleigh and Love wave phase velo ...
... indeed, is present between stations located within eastern Tibet. [7] The objective of this paper is to map crustal radial anisotropy across all of eastern Tibet (Figure 1), extending the results into adjacent areas north and east of the high plateau for comparison. Rayleigh and Love wave phase velo ...
Paleozoic–Mesozoic Porphyry Cu(Mo) and Mo(Cu) Deposits within
... other hand, some researchers consider the subduction-metasomatized mantle lithosphere as a possible source of Mo [3]. Copper is generally considered to be derived from the mantle [1,4]. Nevertheless, some researchers suggest a hybridized lower continental crustal source of Cu [5]. Porphyry Cu–Mo dep ...
... other hand, some researchers consider the subduction-metasomatized mantle lithosphere as a possible source of Mo [3]. Copper is generally considered to be derived from the mantle [1,4]. Nevertheless, some researchers suggest a hybridized lower continental crustal source of Cu [5]. Porphyry Cu–Mo dep ...
Thematic Article A bathymetric overview of the Mariana forearc
... number of reasons. They overlie subducted lithosphere and sediments where these are ®rst squeezed, and so represent sites where ¯uids and matter begin to be transferred from the subducting to the overlying plate. Forearcs are the best place to reconstruct arc history. The accretionary wedge, if pres ...
... number of reasons. They overlie subducted lithosphere and sediments where these are ®rst squeezed, and so represent sites where ¯uids and matter begin to be transferred from the subducting to the overlying plate. Forearcs are the best place to reconstruct arc history. The accretionary wedge, if pres ...
Differential preservation in the geologic record of intraoceanic arc
... preserved, in the translation from modern processes to the ancient record of intraoceanic arcs. Composition of accreted arc terranes differs as a function of arc–continent collision geometry. ‘Forwardfacing’ collision can accrete an oceanic arc on to either a passive or an active continental margin, ...
... preserved, in the translation from modern processes to the ancient record of intraoceanic arcs. Composition of accreted arc terranes differs as a function of arc–continent collision geometry. ‘Forwardfacing’ collision can accrete an oceanic arc on to either a passive or an active continental margin, ...
Not Getting the Drift - Personal webpages at NTNU
... too ignorant of the laws governing the direction of subterranean forces, to determine whether such a crisis be within the limits of possibility. At the same time, it may be observed, that no distribution of land can well be imagined more irregular, or, as it were, capricious, than that which now pre ...
... too ignorant of the laws governing the direction of subterranean forces, to determine whether such a crisis be within the limits of possibility. At the same time, it may be observed, that no distribution of land can well be imagined more irregular, or, as it were, capricious, than that which now pre ...
Late Palaeozoic lam pro phyres and as so ci ated mafic subvolcanic
... post-collisional extension in the Carboniferous. The lamprophyres (minettes, vogesites, spessartites, kersantites) and associated mafic rocks (monzonites, micromonzodiorites) were emplaced as dyke swarms and as scattered veins that cut the crystalline basement and, locally, the overlying molasse dep ...
... post-collisional extension in the Carboniferous. The lamprophyres (minettes, vogesites, spessartites, kersantites) and associated mafic rocks (monzonites, micromonzodiorites) were emplaced as dyke swarms and as scattered veins that cut the crystalline basement and, locally, the overlying molasse dep ...
High-Sr Volcanic Domes from the Lassen
... garnet in the melting assemblage. Partial melting is consistent with published thermal calculations that demonstrate emplaced basaltic magmas in the lower continental crust as the heat source to induce melting. Although some geochemical characteristics of the Onion Butte dacites (high Sr, high Sr ...
... garnet in the melting assemblage. Partial melting is consistent with published thermal calculations that demonstrate emplaced basaltic magmas in the lower continental crust as the heat source to induce melting. Although some geochemical characteristics of the Onion Butte dacites (high Sr, high Sr ...
The life cycle of suprasubduction zone ophiolites
... [1] Abstract: Suprasubduction zone (SSZ) ophiolites display a consistent sequence of events during their formation and evolution that suggests that they form in response to processes that are common to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation ...
... [1] Abstract: Suprasubduction zone (SSZ) ophiolites display a consistent sequence of events during their formation and evolution that suggests that they form in response to processes that are common to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation ...
Shervais, J.W., 2001, Birth, Death, and Resurrection: The Life Cycle
... [1] Abstract: Suprasubduction zone (SSZ) ophiolites display a consistent sequence of events during their formation and evolution that suggests that they form in response to processes that are common to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation ...
... [1] Abstract: Suprasubduction zone (SSZ) ophiolites display a consistent sequence of events during their formation and evolution that suggests that they form in response to processes that are common to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation ...
state of knowledge of the geothermal provinces of the
... During these first movements the area is under an Ethiopian rift tectonic pattern with N-S extension faults system (Gaulier and Huchon 1991). There then followed a period of slow expansion during which the Mabla rhyolite outcrop formed (15 Ma) in a large senestral shear zone. Oldest Ethiopian struct ...
... During these first movements the area is under an Ethiopian rift tectonic pattern with N-S extension faults system (Gaulier and Huchon 1991). There then followed a period of slow expansion during which the Mabla rhyolite outcrop formed (15 Ma) in a large senestral shear zone. Oldest Ethiopian struct ...
Fulltext - ETH E-Collection
... formed as a result of NE-dipping subduction of the Neotethys ocean beneath the European continental margin during the Late Cretaceous. This magmatic arc is associated with some of Europe’s largest porphyry Cu-Au and epithermal Cu-Au deposits. However, the ore deposits are not evenly distributed with ...
... formed as a result of NE-dipping subduction of the Neotethys ocean beneath the European continental margin during the Late Cretaceous. This magmatic arc is associated with some of Europe’s largest porphyry Cu-Au and epithermal Cu-Au deposits. However, the ore deposits are not evenly distributed with ...
Rhenium^Osmium Isotope and Platinum-Group Element
... isotope systematics determined for the entire preserved stratigraphy of the 127 Ga Muskox intrusion provide an exceptional view of magma chamber processes and mineralization in the main plutonic system of the Mackenzie large igneous province (LIP). We present new Re^Os isotope data for the intrusio ...
... isotope systematics determined for the entire preserved stratigraphy of the 127 Ga Muskox intrusion provide an exceptional view of magma chamber processes and mineralization in the main plutonic system of the Mackenzie large igneous province (LIP). We present new Re^Os isotope data for the intrusio ...
Rhenium^Osmium Isotope and Platinum
... isotope systematics determined for the entire preserved stratigraphy of the 127 Ga Muskox intrusion provide an exceptional view of magma chamber processes and mineralization in the main plutonic system of the Mackenzie large igneous province (LIP). We present new Re^Os isotope data for the intrusio ...
... isotope systematics determined for the entire preserved stratigraphy of the 127 Ga Muskox intrusion provide an exceptional view of magma chamber processes and mineralization in the main plutonic system of the Mackenzie large igneous province (LIP). We present new Re^Os isotope data for the intrusio ...
Adakitic Dacites Formed by Intracrustal Crystal Fractionation of
... Most of the magmatism at convergent plate margins originates in the high-temperature region of the asthenospheric mantle wedge as a consequence of fluxing by fluids liberated from subducted oceanic crust. Erupted magmas derived directly by melting of the oceanic crust are rare for a number of reason ...
... Most of the magmatism at convergent plate margins originates in the high-temperature region of the asthenospheric mantle wedge as a consequence of fluxing by fluids liberated from subducted oceanic crust. Erupted magmas derived directly by melting of the oceanic crust are rare for a number of reason ...
Chapter 7
... pockets, but some detected compositional differences (e.g. different Al-Ca ratio, fig 5.15) and the small dimensions of the films suggest that the films could have a different source and properties than the melt phase in larger pockets and should strictly be described as ultrathin amorphous films. T ...
... pockets, but some detected compositional differences (e.g. different Al-Ca ratio, fig 5.15) and the small dimensions of the films suggest that the films could have a different source and properties than the melt phase in larger pockets and should strictly be described as ultrathin amorphous films. T ...
Three lithospheric transects across the Alps and their forelands
... geology. Fig. 3 presents a schematic reconstruction of these paleogeographic realms for Triassic, Jurassic and Cretaceous times. Of course, assignment of basement complexes, such as of the Lepontine dome of Southern Switzerland and northern Italy, to paleogeographic domains may appear rather specula ...
... geology. Fig. 3 presents a schematic reconstruction of these paleogeographic realms for Triassic, Jurassic and Cretaceous times. Of course, assignment of basement complexes, such as of the Lepontine dome of Southern Switzerland and northern Italy, to paleogeographic domains may appear rather specula ...
PDF
... oceanic lithosphere (intra-oceanic arcs) and continental lithosphere (Andean-type arcs). Because they are located at convergent plate boundaries, intra-oceanic arcs collide with other tracts of thickened crust to form increasingly large and differentiated “composite” arcs. These are recognized in an ...
... oceanic lithosphere (intra-oceanic arcs) and continental lithosphere (Andean-type arcs). Because they are located at convergent plate boundaries, intra-oceanic arcs collide with other tracts of thickened crust to form increasingly large and differentiated “composite” arcs. These are recognized in an ...
The Influence of Lithospheric Flexure Induced by Volcano Loading
... toward the volcanoes of Ross Island, typical of the geometry of other basins formed by volcano loads in ocean basins. The Erebus Basin is underfilled, with only ~325 m of infill, compared with >2000 m of fill typically found in moats around ocean island volcanic chains. Like stratal sequences of oth ...
... toward the volcanoes of Ross Island, typical of the geometry of other basins formed by volcano loads in ocean basins. The Erebus Basin is underfilled, with only ~325 m of infill, compared with >2000 m of fill typically found in moats around ocean island volcanic chains. Like stratal sequences of oth ...
Ascent of the ultrahigh-pressure Western Gneiss Region, Norway.
... rocks is an inherent and fundamental dynamic aspect of collisional orogenesis that affects a panoply of Earth processes including, but not limited to, exchange of material between the crust and mantle, generation and collapse of mountain belts, formation of continental crust, and tectonic plate moti ...
... rocks is an inherent and fundamental dynamic aspect of collisional orogenesis that affects a panoply of Earth processes including, but not limited to, exchange of material between the crust and mantle, generation and collapse of mountain belts, formation of continental crust, and tectonic plate moti ...
Lower Continental Crust. - UCSB Earth Science
... To characterize the composition of continental granulite-facies terrains, Rudnick & Presper (1990) assembled a database of rock compositions from Archean and post-Archean terrains recrystallized at >0.6 GPa. Huang et al. (2013) updated this database and added a compilation of amphibolite-facies samp ...
... To characterize the composition of continental granulite-facies terrains, Rudnick & Presper (1990) assembled a database of rock compositions from Archean and post-Archean terrains recrystallized at >0.6 GPa. Huang et al. (2013) updated this database and added a compilation of amphibolite-facies samp ...
42. Rifting and the Volcanic-Tectonic Evolution of the Izu
... This paper focuses on the processes of arc rifting in the context of the volcanic, structural, and sedimentologic evolution of the Izu-Bonin-Mariana arc-trench system. Middle and late Eocene supra-subduction zone magmatism formed a vast terrane of boninites and island arc tholeiites (>300 × 3000 km) ...
... This paper focuses on the processes of arc rifting in the context of the volcanic, structural, and sedimentologic evolution of the Izu-Bonin-Mariana arc-trench system. Middle and late Eocene supra-subduction zone magmatism formed a vast terrane of boninites and island arc tholeiites (>300 × 3000 km) ...
GEOLOGIC STRUCTURE OF THE UPPERMOST OCEANIC CRUST
... found in orogenic belts (e.g., Nicolas 1989). Ophiolite complexes are commonly highly dismembered, but many of them can be reconstructed as the type of layered structure expected in oceanic lithosphere (Casey & Karson 1981, Casey et al. 1983, Harper 1984, Moores & Vine 1971, Pallister & Hopson 1981) ...
... found in orogenic belts (e.g., Nicolas 1989). Ophiolite complexes are commonly highly dismembered, but many of them can be reconstructed as the type of layered structure expected in oceanic lithosphere (Casey & Karson 1981, Casey et al. 1983, Harper 1984, Moores & Vine 1971, Pallister & Hopson 1981) ...
Mantle plume
A mantle plume is a mechanism proposed in 1971 to explain volcanic regions of the earth that were not thought to be explicable by the then-new theory of plate tectonics. Some such volcanic regions lie far from tectonic plate boundaries, for example, Hawaii. Others represent unusually large-volume volcanism, whether on plate boundaries, e.g. Iceland, or basalt floods such as the Deccan or Siberian traps.A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. The currently active volcanic centers are known as ""hot spots"". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. Another hypothesis for unusual volcanic regions is the ""Plate model"". This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension.