47. the ocean/continent transition beneath the iberia abyssal plain
... The west Iberia continental margin is a nonvolcanic rifted margin which, following rifting that began in the Late Triassic, broke away from Newfoundland in the Early Cretaceous as rifting propagated from south to north. The ocean/continent transition off Newfoundland seems to occur ~50 km seaward of ...
... The west Iberia continental margin is a nonvolcanic rifted margin which, following rifting that began in the Late Triassic, broke away from Newfoundland in the Early Cretaceous as rifting propagated from south to north. The ocean/continent transition off Newfoundland seems to occur ~50 km seaward of ...
Commentary on schematic geological map of Antarctica Scale 1:10
... has been, the fact that only about 2% of the continent's bedrock is not covered by ice , and thus accessible to surface examination . A subsidiary problem is the difficult access to these outcrops , many of which are in large cliff faces (Fig.l) or isolated nunataks adjacent to which the ice surface ...
... has been, the fact that only about 2% of the continent's bedrock is not covered by ice , and thus accessible to surface examination . A subsidiary problem is the difficult access to these outcrops , many of which are in large cliff faces (Fig.l) or isolated nunataks adjacent to which the ice surface ...
On the origin and tectonic significance of the intra-plate
... The objective of this article is to examine the available evidence of intra-plate tectonic episodes of ‘‘Grenvillian-type age”, affecting the South-American continent, assessing their possible causal correlation with the tectonic processes occurring within the orogenic belts active at their margins. ...
... The objective of this article is to examine the available evidence of intra-plate tectonic episodes of ‘‘Grenvillian-type age”, affecting the South-American continent, assessing their possible causal correlation with the tectonic processes occurring within the orogenic belts active at their margins. ...
Convergence and Collision
... high, rim the western edge of South America (Figure 17.1a). Along the range, powerful volcanoes occasionally spew clouds of ash skyward. Halfway around the world, Mt. Everest, the highest mountain in the Himalayan chain (and in the world), rises 8.5 km above sea level (Figure 17.1b). At its peak, ai ...
... high, rim the western edge of South America (Figure 17.1a). Along the range, powerful volcanoes occasionally spew clouds of ash skyward. Halfway around the world, Mt. Everest, the highest mountain in the Himalayan chain (and in the world), rises 8.5 km above sea level (Figure 17.1b). At its peak, ai ...
Evolution of the Paleo-Asian Ocean (Altai−Sayan Region, Central
... phengite ages are 540±24 and 576±11 Ma (schists from serpentinitic melange). The K−Ar amphibole age of the garnet amphibolite (Chagan−Uzun massif) is 535± −24 Ma and Ar−Ar amphibole ages from the eclogitic part are 636± 10 Ma and 627± Ma. The K−Ar amphibole age of island-arc ophiolites is 523±23 Ma. ...
... phengite ages are 540±24 and 576±11 Ma (schists from serpentinitic melange). The K−Ar amphibole age of the garnet amphibolite (Chagan−Uzun massif) is 535± −24 Ma and Ar−Ar amphibole ages from the eclogitic part are 636± 10 Ma and 627± Ma. The K−Ar amphibole age of island-arc ophiolites is 523±23 Ma. ...
Evolution of the Eastern Alps
... were stacked. Indicators from structural geology show a WNW directed movement of Adria and a subduction of the Piedmont Ocean to the ESE, respectively (Pfiffner, 2010). Crystalline Austroalpine nappes show HP alteration which implies transportation of the continental material to high depths (>30 km) ...
... were stacked. Indicators from structural geology show a WNW directed movement of Adria and a subduction of the Piedmont Ocean to the ESE, respectively (Pfiffner, 2010). Crystalline Austroalpine nappes show HP alteration which implies transportation of the continental material to high depths (>30 km) ...
54. Regional Geology of the Goban Spur Continental Margin
... All available geophysical data have been integrated with the Leg 80 drilling results to produce a regional geological synthesis of the Goban Spur passive continental margin. The thin sediment sequence overlying basement is divided into three seismostratigraphic sequences. The lowest of these, sequen ...
... All available geophysical data have been integrated with the Leg 80 drilling results to produce a regional geological synthesis of the Goban Spur passive continental margin. The thin sediment sequence overlying basement is divided into three seismostratigraphic sequences. The lowest of these, sequen ...
translation 3820
... and transparency are both low in comparison with the Kuroshio. The colour of the Kuroshio for example, is normally greater than 3 but that of the Oyashio is less than 4. The California current which runs southwards along the west coast of North America is the Eastern Boundary Current of the Northern ...
... and transparency are both low in comparison with the Kuroshio. The colour of the Kuroshio for example, is normally greater than 3 but that of the Oyashio is less than 4. The California current which runs southwards along the west coast of North America is the Eastern Boundary Current of the Northern ...
101 Questions and Answers Concerning
... basaltic in composition, that this basalt had been generated at a mid-ocean ridge via partial melting of mantle rock below as part of the seafloor spreading process, and that all of crustal basement rocks of today’s ocean floor were no older than Mesozoic in age. Among the implications were that the ...
... basaltic in composition, that this basalt had been generated at a mid-ocean ridge via partial melting of mantle rock below as part of the seafloor spreading process, and that all of crustal basement rocks of today’s ocean floor were no older than Mesozoic in age. Among the implications were that the ...
accepted manuscript
... The alternative, more appropriate term „Central Asian Orogenic Belt (CAOB)‟ is now more commonly used, because it covers the period 1.0 Ga to 250 Ma and includes ...
... The alternative, more appropriate term „Central Asian Orogenic Belt (CAOB)‟ is now more commonly used, because it covers the period 1.0 Ga to 250 Ma and includes ...
Cenozoic magmatism in the western Ross Embayment:
... between the circular symmetry expected for a plume stressinduced perturbation and the surface linear expression of rifts [Tommasi and Vauchez, 2001]. Thus, the question about the causal relationships between plumes and extension is matter of debate. Indeed, since the original proposals of Wilson [19 ...
... between the circular symmetry expected for a plume stressinduced perturbation and the surface linear expression of rifts [Tommasi and Vauchez, 2001]. Thus, the question about the causal relationships between plumes and extension is matter of debate. Indeed, since the original proposals of Wilson [19 ...
Patagonia: where does it come from?
... is proposed that the Somuncurá Massif of northern Patagonia is the conjugate margin of the Pensacola Mountains in East Antarctica. The main episodes of deformation within the Cambrian-Ordovician Ross Orogeny are correlated, as well as the passive margin setting during the Silurian-Devonian, which in ...
... is proposed that the Somuncurá Massif of northern Patagonia is the conjugate margin of the Pensacola Mountains in East Antarctica. The main episodes of deformation within the Cambrian-Ordovician Ross Orogeny are correlated, as well as the passive margin setting during the Silurian-Devonian, which in ...
Metallogenesis of the world`s ocean against the background
... Abstract. This paper presents results of the studies on the metallogenesis of the deep-sea mineral resources and their sedimentary environment. Connections between the structure and evolution of the oceanic crust, with regard to the rules of occurrence and distribution of the ores, have been establi ...
... Abstract. This paper presents results of the studies on the metallogenesis of the deep-sea mineral resources and their sedimentary environment. Connections between the structure and evolution of the oceanic crust, with regard to the rules of occurrence and distribution of the ores, have been establi ...
Alteration of the oceanic lithosphere and its implications for seafloor
... related to spreading rates (Figure 1). The principle of a uniform crust, characterized by a “layer-cake” structure of basalt, diabase (sheeted dike complex) and gabbro, is based on early geophysical data and comparisons with ophiolites, and is commonly referred to as the “Penrose ophiolite model” or ...
... related to spreading rates (Figure 1). The principle of a uniform crust, characterized by a “layer-cake” structure of basalt, diabase (sheeted dike complex) and gabbro, is based on early geophysical data and comparisons with ophiolites, and is commonly referred to as the “Penrose ophiolite model” or ...
Alignment between seafloor spreading directions and absolute plate
... we refer to as skew following Toomey et al. [2007]. The set of isochrons from Müller et al. [2016] are spaced at irregular intervals corresponding to major, widely recognizable magnetic reversals (at 10.9 Ma, 20.1 Ma, 33.1 Ma, 40.1 Ma, 47.9 Ma, 55.9 Ma, 67.7 Ma, 83.0 Ma, 120.4 Ma, 126.7 Ma, and 130. ...
... we refer to as skew following Toomey et al. [2007]. The set of isochrons from Müller et al. [2016] are spaced at irregular intervals corresponding to major, widely recognizable magnetic reversals (at 10.9 Ma, 20.1 Ma, 33.1 Ma, 40.1 Ma, 47.9 Ma, 55.9 Ma, 67.7 Ma, 83.0 Ma, 120.4 Ma, 126.7 Ma, and 130. ...
accepted manuscript
... formation, whose plate boundary configuration remains uncertain. Paleomagnetic and magmatic studies suggest that the intra-oceanic arc was at equatorial latitudes during the Early Cretaceous before subduction resumed further north beneath the Eurasian margin (Lhasa terrane), with another hiatus in s ...
... formation, whose plate boundary configuration remains uncertain. Paleomagnetic and magmatic studies suggest that the intra-oceanic arc was at equatorial latitudes during the Early Cretaceous before subduction resumed further north beneath the Eurasian margin (Lhasa terrane), with another hiatus in s ...
California terranes
... The principal terrane-related tectonic events for California and surroundings include the following. 1. Rifting of the western North American margin occurred during the latest Proterozoic–earliest Cambrian, possibly from Antarctica-Australia (e.g., Schweickert and Snyder, 1981; Moores, 1991). The Ne ...
... The principal terrane-related tectonic events for California and surroundings include the following. 1. Rifting of the western North American margin occurred during the latest Proterozoic–earliest Cambrian, possibly from Antarctica-Australia (e.g., Schweickert and Snyder, 1981; Moores, 1991). The Ne ...
Caledonian igneous rocks of Great Britain
... This volume describes the igneous rocks of Scotland, England and Wales that were erupted, intruded or emplaced tectonically as a direct result of the Caledonian Orogeny (Figure 1.1). There is at present no agreed definition of the term ‘Caledonian’. It has, for example, been used universally to desc ...
... This volume describes the igneous rocks of Scotland, England and Wales that were erupted, intruded or emplaced tectonically as a direct result of the Caledonian Orogeny (Figure 1.1). There is at present no agreed definition of the term ‘Caledonian’. It has, for example, been used universally to desc ...
Hilliker 1 The Effects of the Farallon Plate Subduction Frank Hilliker
... the NMSZ. This disruption of mantle flow could be responsible for the seismic activity in the New Madrid location. Plate Tectonics occurs in all three dimensions. Since Plate Tectonics are the force behind building mountain ranges it stands to reason that subduction of plates can have displacement e ...
... the NMSZ. This disruption of mantle flow could be responsible for the seismic activity in the New Madrid location. Plate Tectonics occurs in all three dimensions. Since Plate Tectonics are the force behind building mountain ranges it stands to reason that subduction of plates can have displacement e ...
Subduction cycles under western North America during the
... have been studied in more detail than anywhere else in the world. Radiometric ages for tens of thousands of rocks provide extensive mileposts for times of change in tectonic and magmatic conditions. Increasingly detailed structural studies are finding many specific periods of deformation and changes ...
... have been studied in more detail than anywhere else in the world. Radiometric ages for tens of thousands of rocks provide extensive mileposts for times of change in tectonic and magmatic conditions. Increasingly detailed structural studies are finding many specific periods of deformation and changes ...
Deep-sea basins of the Atlantic ocean
... earlier than in the Southern one. The oceanic crust began to form, in both regions, in the south , and propagated later to the north [Pushcharovskii, 1994]. The Southern and Northern oceans were connected only in the Albian, that is, 100 million years ago, their isolated development lasting more tha ...
... earlier than in the Southern one. The oceanic crust began to form, in both regions, in the south , and propagated later to the north [Pushcharovskii, 1994]. The Southern and Northern oceans were connected only in the Albian, that is, 100 million years ago, their isolated development lasting more tha ...
Baltica in the Cryogenian, 850–630 Ma
... levels indicates sediment derivation from the S-SE (D. Roberts, unpublished data). Metasedimentary rocks within the overlying Havvatnet Nappe are cut by ca. 840–820 Ma old granites and pegmatites, while ca. 710 Ma migmatites occur within the Sørøy-Seiland Nappe at still higher structural levels. Imp ...
... levels indicates sediment derivation from the S-SE (D. Roberts, unpublished data). Metasedimentary rocks within the overlying Havvatnet Nappe are cut by ca. 840–820 Ma old granites and pegmatites, while ca. 710 Ma migmatites occur within the Sørøy-Seiland Nappe at still higher structural levels. Imp ...
Paleogeography, Southwestern US
... probably resembled modern SE Asia. As various tectonic blocks collided, orogenic (mountain-building) events were generated. This view shows what the region may have looked like during these collisional events. About 1.1 Ga North America was part of the supercontinent Rodinia. The Southwest possibly ...
... probably resembled modern SE Asia. As various tectonic blocks collided, orogenic (mountain-building) events were generated. This view shows what the region may have looked like during these collisional events. About 1.1 Ga North America was part of the supercontinent Rodinia. The Southwest possibly ...
Released Items from the ATLAST Plate Tectonics Teacher Assessment
... E. Since the supercontinent Pangaea split up about 200 million years ago, the shapes of continents have been somewhat modified, mostly by erosion, sea level changes, and mountain-building; this is why the present-day "fit" of the continents is less than perfect. F. Plate motion causes abutting plate ...
... E. Since the supercontinent Pangaea split up about 200 million years ago, the shapes of continents have been somewhat modified, mostly by erosion, sea level changes, and mountain-building; this is why the present-day "fit" of the continents is less than perfect. F. Plate motion causes abutting plate ...
Reference crust-mantle density contrast beneath Antarctica based
... average crust thickness in the West Antarctica was ~27 km. Average crust thickness of ~40 km was estimated for East Antarctica, with maximum crust thickness being ~45 km. These large differences could be explained by different tectonic and geological compositions of West and East Antarctica. Dalziel ...
... average crust thickness in the West Antarctica was ~27 km. Average crust thickness of ~40 km was estimated for East Antarctica, with maximum crust thickness being ~45 km. These large differences could be explained by different tectonic and geological compositions of West and East Antarctica. Dalziel ...
Pangaea
Pangaea or Pangea (/pænˈdʒiːə/) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from earlier continental units approximately 300 million years ago, and it began to break apart about 175 million years ago. In contrast to the present Earth and its distribution of continental mass, much of Pangaea was in the southern hemisphere and surrounded by a super ocean, Panthalassa. Pangaea was the last supercontinent to have existed and the first to be reconstructed by geologists.