Global tectonic significance of the Solomon
... Oceanic plateaus, areas of anomalously thick oceanic crust, cover about 3% of the Earth’s seafloor and are thought to mark the surface location of mantle plume ‘‘heads’’. Hotspot tracks represent continuing magmatism associated with the remaining plume conduit or ‘‘tail’’. It is presently controvers ...
... Oceanic plateaus, areas of anomalously thick oceanic crust, cover about 3% of the Earth’s seafloor and are thought to mark the surface location of mantle plume ‘‘heads’’. Hotspot tracks represent continuing magmatism associated with the remaining plume conduit or ‘‘tail’’. It is presently controvers ...
Volcanogenic Massive Sulfide Deposits
... deep marine conditions and back-arc spreading during which the deposits formed, and then a return to compression with closure and uplift of the basin. In many cases, a strip of back-arc crust is left attached to an aggregate of colliding arcs or caught between an active margin and a continent, thus ...
... deep marine conditions and back-arc spreading during which the deposits formed, and then a return to compression with closure and uplift of the basin. In many cases, a strip of back-arc crust is left attached to an aggregate of colliding arcs or caught between an active margin and a continent, thus ...
Stratigraphy and Host Rock Controls of Gold Deposits of the
... The Carlin trend is a 40-mile (65 km) long north-northwest alignment of sedimentary rock-hosted disseminated gold deposits in northeast Nevada. Total gold production from the trend exceeded 50 million ounces (156 t) in 2002. Most of the reserves and gold production are located in the northern one-th ...
... The Carlin trend is a 40-mile (65 km) long north-northwest alignment of sedimentary rock-hosted disseminated gold deposits in northeast Nevada. Total gold production from the trend exceeded 50 million ounces (156 t) in 2002. Most of the reserves and gold production are located in the northern one-th ...
Estimating the Viscosity of Rock Bodies
... Estimating the Viscosity of Rock Bodies - A Comparison Between the Hormuz- and the Namakdan Salt Diapirs in the Persian Gulf, and the Tso Morari Gneiss Dome in the Himalaya to put extrusion rates at known coordinates and calculate the viscosity of the Hormuz diapir considering it to have a perfectl ...
... Estimating the Viscosity of Rock Bodies - A Comparison Between the Hormuz- and the Namakdan Salt Diapirs in the Persian Gulf, and the Tso Morari Gneiss Dome in the Himalaya to put extrusion rates at known coordinates and calculate the viscosity of the Hormuz diapir considering it to have a perfectl ...
provenance analysis and detrital zircons: keys to - ETH E
... Two main detrital zircon ages have been identified in the Eocene-Oligocene sedimentary rocks of the Neh Accretionary Complex. Abundant Upper Cretaceous detrital zircons with Hf isotopic compositions similar to oceanic crust and depleted mantle suggest an intra-oceanic island arc provenance. Eocene d ...
... Two main detrital zircon ages have been identified in the Eocene-Oligocene sedimentary rocks of the Neh Accretionary Complex. Abundant Upper Cretaceous detrital zircons with Hf isotopic compositions similar to oceanic crust and depleted mantle suggest an intra-oceanic island arc provenance. Eocene d ...
Crustal structure and evolution of the Mariana intra
... the mantle-derived basalt magma forms the initial arc crust, which is most simply composed of differentiated basalt and cumulate layers. This model regards the basaltic materials underplated at the bottom of the crust as a part of the “crust.” The differentiated basalt layer is then remelted by basa ...
... the mantle-derived basalt magma forms the initial arc crust, which is most simply composed of differentiated basalt and cumulate layers. This model regards the basaltic materials underplated at the bottom of the crust as a part of the “crust.” The differentiated basalt layer is then remelted by basa ...
IODP Proposal Cover Sheet
... The spatial and temporal evolution of arc magmas within a single oceanic arc is fundamental to understanding the initiation and evolution of oceanic arcs and the genesis of continental crust, which is one key objective of the IODP ISP. The Izu-Bonin-Mariana arc has been a target for this task for ma ...
... The spatial and temporal evolution of arc magmas within a single oceanic arc is fundamental to understanding the initiation and evolution of oceanic arcs and the genesis of continental crust, which is one key objective of the IODP ISP. The Izu-Bonin-Mariana arc has been a target for this task for ma ...
lithosphere 2006 - Helsingin yliopisto
... References of Lithosphere Symposia Publications Pesonen, L.J., Korja, A. and Hjelt, S.-E., 2000 (Eds.). Lithosphere 2000 - A Symposium on the Structure, Composition and Evolution of the Lithosphere in Finland. Programme and Extended Abstracts, Espoo, Finland, October 4-5, 2000. Institute of Seismolo ...
... References of Lithosphere Symposia Publications Pesonen, L.J., Korja, A. and Hjelt, S.-E., 2000 (Eds.). Lithosphere 2000 - A Symposium on the Structure, Composition and Evolution of the Lithosphere in Finland. Programme and Extended Abstracts, Espoo, Finland, October 4-5, 2000. Institute of Seismolo ...
magnetite and ilmenite from some finnish rocks
... The first two of these rocks are anorogenic, practically unmetamorphosed late Precambrian igneous rocks, the others are metamorphosed Svecofennian deep-seated rocks. In olivine diabase and gabbroanorthosite the Fe-Ti oxides are xenomorphic filling the spaces between other minerals (Fig. 2). Thus, th ...
... The first two of these rocks are anorogenic, practically unmetamorphosed late Precambrian igneous rocks, the others are metamorphosed Svecofennian deep-seated rocks. In olivine diabase and gabbroanorthosite the Fe-Ti oxides are xenomorphic filling the spaces between other minerals (Fig. 2). Thus, th ...
Geology of East-Central Idaho
... (Ruppel, 1975; Aleinikoff et al., 1996; Sears et al., 1998; Winston et al., 1999, this volume). The Belt Supergroup rift basin formed across much of east-central Idaho and western Montana (Winston and Link, 1993). Its irregular but roughly north-trending eastern margin lies about 150 mi east of the ...
... (Ruppel, 1975; Aleinikoff et al., 1996; Sears et al., 1998; Winston et al., 1999, this volume). The Belt Supergroup rift basin formed across much of east-central Idaho and western Montana (Winston and Link, 1993). Its irregular but roughly north-trending eastern margin lies about 150 mi east of the ...
M40-49-8-7-eng - Publications du gouvernement du Canada
... are distributed along volcanic arcs, spreading ridges, grabens, fault scarps, and fracture zones, and are interbedded with greywacke, turbidites, metalliferous sediments, and volcanic rocks (Gross, 1959a, 1965, 1973, 1983a). Algomatype iron-formation and other associated stratafer lithofacies are wi ...
... are distributed along volcanic arcs, spreading ridges, grabens, fault scarps, and fracture zones, and are interbedded with greywacke, turbidites, metalliferous sediments, and volcanic rocks (Gross, 1959a, 1965, 1973, 1983a). Algomatype iron-formation and other associated stratafer lithofacies are wi ...
A Dynamic Model of Rifting Between Galicia Bank and Flemish Cap
... during rifting (e.g., Dunbar and Sawyer, 1989). Weaknesses in the upper and middle crust (crustal weaknesses) tend to produce short-lived extensional provinces during the early stages of rifting, whereas deep seated weaknesses (mantle weaknesses) control the location where lithospheric necking deve ...
... during rifting (e.g., Dunbar and Sawyer, 1989). Weaknesses in the upper and middle crust (crustal weaknesses) tend to produce short-lived extensional provinces during the early stages of rifting, whereas deep seated weaknesses (mantle weaknesses) control the location where lithospheric necking deve ...
as a PDF - University of Innsbruck
... arates the Southern and the Central or Northern Alps. These rocks have been subdivided into a northern and a southern domain, respectively. The latter extends beyond the state border to northern Slovenia. In both the Carnic and Karawanken Alps systematic research started soon after the foundation of ...
... arates the Southern and the Central or Northern Alps. These rocks have been subdivided into a northern and a southern domain, respectively. The latter extends beyond the state border to northern Slovenia. In both the Carnic and Karawanken Alps systematic research started soon after the foundation of ...
Geology of the Kimberley Region, Western Australia: The East
... by combined teams of Bureau of Mineral Resources and Geological Survey of Western Aus tralia geologists between 1962 and 1967: the results of the first three years' mapping—of the southeastern part of the Kimberiey region—are given in this Bulletin. Isotopic age deter minations were made on rocks ...
... by combined teams of Bureau of Mineral Resources and Geological Survey of Western Aus tralia geologists between 1962 and 1967: the results of the first three years' mapping—of the southeastern part of the Kimberiey region—are given in this Bulletin. Isotopic age deter minations were made on rocks ...
here - GeoPRISMS
... spectrum of stages of continental breakup, with increased emphasis on the interplay between surface processes, sedimentation, and continental evolution. It will include early-stage rifts but also the study of passive margins, which archive the entire history of rift zone construction and evolution. ...
... spectrum of stages of continental breakup, with increased emphasis on the interplay between surface processes, sedimentation, and continental evolution. It will include early-stage rifts but also the study of passive margins, which archive the entire history of rift zone construction and evolution. ...
Low seismic velocity layers in the Earth`s crust beneath Eastern
... suggests that low-velocity layers in the Earth’s crust exist not only beneath the Baikal rift zone, where such a layer was found earlier by Deep Seismic Sounding (DSS), but also beneath Early Paleozoic Sayan – Baikal, Paleozoic Mongolian, Early Mesozoic Mongolia – Okhotsk fold areas, and beneath the ...
... suggests that low-velocity layers in the Earth’s crust exist not only beneath the Baikal rift zone, where such a layer was found earlier by Deep Seismic Sounding (DSS), but also beneath Early Paleozoic Sayan – Baikal, Paleozoic Mongolian, Early Mesozoic Mongolia – Okhotsk fold areas, and beneath the ...
Petrological models of magma evolution and deep crustal structure
... the Moho may represent a density [ 181 and/or a rheological [ 191 trap that inhibits the ascent of partial melts. We explore a range of Moho depths (lo- 17 km) which are appropriate to the oceanic environment. We then compare the crustal velocities structure observed beneath oceanic plateaus and hot ...
... the Moho may represent a density [ 181 and/or a rheological [ 191 trap that inhibits the ascent of partial melts. We explore a range of Moho depths (lo- 17 km) which are appropriate to the oceanic environment. We then compare the crustal velocities structure observed beneath oceanic plateaus and hot ...
Document
... basalt outcrop lineaments associated with bounding faults of sedimentary basins have been identified. The margins of the Tyrone Igneous Complex and the internal structure of the complex itself are revealed in stunning detail and many new faults and sheared rocks identified. Within the adjacent Dalra ...
... basalt outcrop lineaments associated with bounding faults of sedimentary basins have been identified. The margins of the Tyrone Igneous Complex and the internal structure of the complex itself are revealed in stunning detail and many new faults and sheared rocks identified. Within the adjacent Dalra ...
Ar– Ar ages of intrusions in East Greenland: Rift-to
... 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 56–54 Ma, 50–47 Ma and 37–35 Ma. In the Kangerlussuaq Fjord, which coincides with a major tectonic lineament possibly the failed ar ...
... 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 56–54 Ma, 50–47 Ma and 37–35 Ma. In the Kangerlussuaq Fjord, which coincides with a major tectonic lineament possibly the failed ar ...
Tectonic stress field of the continental United States
... (between WNW and ENE). In the Colorado Plateau interior and the southern Great Plains, the least horizontal stress is NNE, roughly perpendicular to that in surrounding areas. The state of stress in these two regions may be related to pronounced lateral variations in lithosphere thickness beneath the ...
... (between WNW and ENE). In the Colorado Plateau interior and the southern Great Plains, the least horizontal stress is NNE, roughly perpendicular to that in surrounding areas. The state of stress in these two regions may be related to pronounced lateral variations in lithosphere thickness beneath the ...
Non-plume magmatism and tectonics during the opening of the
... the SE USA portion of the rift zone must have ended before the start of Jurassic time. Later uplift with erosion created a major hiatus and unconformity between early and late Mesozoic sediments of the Atlantic coastal plain, but this event is relatively uniform across eastern North America and it p ...
... the SE USA portion of the rift zone must have ended before the start of Jurassic time. Later uplift with erosion created a major hiatus and unconformity between early and late Mesozoic sediments of the Atlantic coastal plain, but this event is relatively uniform across eastern North America and it p ...
Zircon Behaviour in Deeply Subducted Rocks
... of the rock, but must be linked to P–T conditions. In order to link ages to metamorphic conditions, a number of methods can be used. Initially and most commonly, the shape and internal zoning of zircon have been used to distinguish between inherited and metamorphic zircon. A Th/U ratio < 0.1 has lon ...
... of the rock, but must be linked to P–T conditions. In order to link ages to metamorphic conditions, a number of methods can be used. Initially and most commonly, the shape and internal zoning of zircon have been used to distinguish between inherited and metamorphic zircon. A Th/U ratio < 0.1 has lon ...
Crustal thickness variation in south
... Crustal thicknesses have been determined by receiver function analysis of broadband teleseismic waveforms recorded during the Broadband Experiment Across the Alaska Range (BEAAR). Typical crust beneath the northern lowlands is 26 km thick, while beneath the mountains it is 35–45 km thick. The transi ...
... Crustal thicknesses have been determined by receiver function analysis of broadband teleseismic waveforms recorded during the Broadband Experiment Across the Alaska Range (BEAAR). Typical crust beneath the northern lowlands is 26 km thick, while beneath the mountains it is 35–45 km thick. The transi ...
Thematic Article Tethyan ophiolites and Pangea break-up
... oceanic basin was a new, developing branch of the Paleotethys Ocean. Alternatively, the basin could have formed as an incipient opening of a new ocean, the Eastern Mesozoic Tethys or ‘Neotethys’, which, during the Triassic, began to separate Gondwana (Adria Promontory) from Laurasia. The location of ...
... oceanic basin was a new, developing branch of the Paleotethys Ocean. Alternatively, the basin could have formed as an incipient opening of a new ocean, the Eastern Mesozoic Tethys or ‘Neotethys’, which, during the Triassic, began to separate Gondwana (Adria Promontory) from Laurasia. The location of ...
- Wiley Online Library
... Suppe [1981, 1984, 1987] calculated that the leading edges of both construction (in the south) and collapse (in the north) are both proceeding southward at about 100 mm/yr. Thus latitude is commonly considered to be grossly correlative to orogenic maturity in Taiwan. Conventional wisdom is that if o ...
... Suppe [1981, 1984, 1987] calculated that the leading edges of both construction (in the south) and collapse (in the north) are both proceeding southward at about 100 mm/yr. Thus latitude is commonly considered to be grossly correlative to orogenic maturity in Taiwan. Conventional wisdom is that if o ...
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.