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... Μ, Quaternary volcano; shaded area, Fossa Magna. Square shows the location of (b). The legend pertains to (b). Ueno Basalts rest on Nohi Rhyolite, except for the Kiyomi center, which lies on the Mino Zone sedimentary rocks. All of the basalt bodies are monogenetic scoria falls and lava flows, or dik ...
... Μ, Quaternary volcano; shaded area, Fossa Magna. Square shows the location of (b). The legend pertains to (b). Ueno Basalts rest on Nohi Rhyolite, except for the Kiyomi center, which lies on the Mino Zone sedimentary rocks. All of the basalt bodies are monogenetic scoria falls and lava flows, or dik ...
thrust systems - The Web site cannot be found
... collide, causing big damages such as mountain systems. In any case, horizontal transport and shear on shallow dipping thrusts predominates over vertical movements and the bulk result is crustal shortening and thickening taken up by compression structures. This is why, since the recognition of curren ...
... collide, causing big damages such as mountain systems. In any case, horizontal transport and shear on shallow dipping thrusts predominates over vertical movements and the bulk result is crustal shortening and thickening taken up by compression structures. This is why, since the recognition of curren ...
UHP metamorphism in garnet peridotite, Cuaba unit, Rio San Juan
... Garnet peridotite was discovered as well-rounded boulders up to 4 metres in diameter in Rio Cuevas. The coarse garnet peridotite is homogeneous in a given boulder and from one boulder to another. The distribution of the boulders and reconnaissance of bedrock geology restrict the source to an area of ...
... Garnet peridotite was discovered as well-rounded boulders up to 4 metres in diameter in Rio Cuevas. The coarse garnet peridotite is homogeneous in a given boulder and from one boulder to another. The distribution of the boulders and reconnaissance of bedrock geology restrict the source to an area of ...
Introduction to Metamorphism
... • Geothermometry indicates that the mineral compositions commonly preserve the maximum temperature ...
... • Geothermometry indicates that the mineral compositions commonly preserve the maximum temperature ...
Metamorphic reworking of a high pressure–low temperature
... of ocean basins as part of the Wilson Cycle (Wilson, 1960). Most sutures were assumed to be perpendicular to convergent directions since major dip slip motion is required to form HP rocks. However, many modern compressional terrane boundaries are not perpendicular to convergent directions, but obliq ...
... of ocean basins as part of the Wilson Cycle (Wilson, 1960). Most sutures were assumed to be perpendicular to convergent directions since major dip slip motion is required to form HP rocks. However, many modern compressional terrane boundaries are not perpendicular to convergent directions, but obliq ...
EAST AFRICAN RIFT SYSTEM
... Major boundary faults of the rift are also shown. Source map for this figure is the unpublished “Geological Map of the East African Rift Valleys” (1:2 million) (From: Mohr and Wood, 1976) ...
... Major boundary faults of the rift are also shown. Source map for this figure is the unpublished “Geological Map of the East African Rift Valleys” (1:2 million) (From: Mohr and Wood, 1976) ...
Chapter 16. Noble Gas Isotopes
... diverge in situ in their isotopic ratios, removing the requirement for ancient or large gas-rich reservoirs. The component that carries the high R signature may be a peridotite, or gas bubbles in a depleted olivine-rich cumulate. There are no consistent global correlations between He-isotopes and ot ...
... diverge in situ in their isotopic ratios, removing the requirement for ancient or large gas-rich reservoirs. The component that carries the high R signature may be a peridotite, or gas bubbles in a depleted olivine-rich cumulate. There are no consistent global correlations between He-isotopes and ot ...
ATLAS of plutonic rocks and orthogneisses in the Bohemian Massif
... was even found in the meteoritic and lunar samples (Bonnin et al. 2002). The multiple use of igneous rocks requires an increasingly better knowledge of the composition, internal structure, geometry and depth extent of the individual bodies. Igneous rocks have been quarried for building and sculpture ...
... was even found in the meteoritic and lunar samples (Bonnin et al. 2002). The multiple use of igneous rocks requires an increasingly better knowledge of the composition, internal structure, geometry and depth extent of the individual bodies. Igneous rocks have been quarried for building and sculpture ...
Crustal and Upper-mantle Structure Beneath Ice
... possible lower-mantle plume source (Emry et al. 2015). ...
... possible lower-mantle plume source (Emry et al. 2015). ...
Continent–ocean transition and voluminous magmatic underplating
... 2005), on the other hand, revealed extensive magmatic underplating and thickened oceanic crust, which would support models of larger than known underplating for the East Greenland Margin. The location of the continent–ocean boundary (COB) in this part of the East Greenland margin is the subject of f ...
... 2005), on the other hand, revealed extensive magmatic underplating and thickened oceanic crust, which would support models of larger than known underplating for the East Greenland Margin. The location of the continent–ocean boundary (COB) in this part of the East Greenland margin is the subject of f ...
Lower Continental Crust. - UCSB Earth Science
... (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 samples. We augmented their granulite data with additional analyses from the literature, and her ...
... (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 samples. We augmented their granulite data with additional analyses from the literature, and her ...
Serpentinization of the forearc mantle
... by [19]). More recently, two-dimensional ¢nite element models have been constructed for speci¢c subduction zones that more accurately predict slab and forearc temperatures down to V100 km or more (e.g., [20,21]). In these models the thermal structure of the forearc mantle is found to be most sensiti ...
... by [19]). More recently, two-dimensional ¢nite element models have been constructed for speci¢c subduction zones that more accurately predict slab and forearc temperatures down to V100 km or more (e.g., [20,21]). In these models the thermal structure of the forearc mantle is found to be most sensiti ...
Thermal and petrophysical characterization of the lithospheric
... heat flow and crustal seismic data show LAB depth varying from more than 130 km beneath the Pyrenees to less than 70 km beneath the western Mediterranean basins (Zeyen and Fernandez, 1994; Ayala et al., 1996, 2003; Roca et al., 2004). All these models however are based on a pure thermal approach in w ...
... heat flow and crustal seismic data show LAB depth varying from more than 130 km beneath the Pyrenees to less than 70 km beneath the western Mediterranean basins (Zeyen and Fernandez, 1994; Ayala et al., 1996, 2003; Roca et al., 2004). All these models however are based on a pure thermal approach in w ...
Cr-Pyrope Garnets in the Lithospheric Mantle. I
... of such garnets varies systematically according to the tectonothermal age of the crust intruded by the host volcanic rock. This work defined major differences in mantle composition between regions with Archean crust and younger areas, and indicated an evolution toward less depleted average lithosphe ...
... of such garnets varies systematically according to the tectonothermal age of the crust intruded by the host volcanic rock. This work defined major differences in mantle composition between regions with Archean crust and younger areas, and indicated an evolution toward less depleted average lithosphe ...
Thermal structure of the Costa Rica – Nicaragua subduction zone
... depth beneath Nicaragua (Protti et al., 1995; Husen et al., 2003). A 1500 km-long volcanic arc extends from southern Mexico to central Costa Rica, but there is no Holocene volcanism in southern Costa Rica (e.g., Carr et al., 1990; Leeman et al., 1994). The Cocos plate formed at two different spreadi ...
... depth beneath Nicaragua (Protti et al., 1995; Husen et al., 2003). A 1500 km-long volcanic arc extends from southern Mexico to central Costa Rica, but there is no Holocene volcanism in southern Costa Rica (e.g., Carr et al., 1990; Leeman et al., 1994). The Cocos plate formed at two different spreadi ...
Geophysical Journal International - E
... part of the Iberian Peninsula and represents one of the best exposed fragments of the European Variscan orogen (Fig. 1). We probe the southern part of the Iberian massif, which was formed by oblique compression between three tectonic blocks: the South Portuguese Zone (SPZ), the Ossa-Morena Zone (OMZ ...
... part of the Iberian Peninsula and represents one of the best exposed fragments of the European Variscan orogen (Fig. 1). We probe the southern part of the Iberian massif, which was formed by oblique compression between three tectonic blocks: the South Portuguese Zone (SPZ), the Ossa-Morena Zone (OMZ ...
Seismological observations in Northwestern South America
... that observations are consistent with the presence of two subduction segments in Colombia and contrasting values of crustal thickness. In Northern Colombia, at latitudes greater than 6°N, most of the seismic stations are associated with negative teleseismic travel time residuals, relative to a regio ...
... that observations are consistent with the presence of two subduction segments in Colombia and contrasting values of crustal thickness. In Northern Colombia, at latitudes greater than 6°N, most of the seismic stations are associated with negative teleseismic travel time residuals, relative to a regio ...
Lateral Density Inhomogeneities of the Continental and Oceanic
... According to our calculations, the FMS depth in Central and Southern Asia (Fig. 3) varies within a wide range of 2–7 km, which is explained by the modern tectonic activity in the AlpineHimalayan Fold Belt and by the rifting in the northeast framing of Africa. The shallowest level of the FMS depth i ...
... According to our calculations, the FMS depth in Central and Southern Asia (Fig. 3) varies within a wide range of 2–7 km, which is explained by the modern tectonic activity in the AlpineHimalayan Fold Belt and by the rifting in the northeast framing of Africa. The shallowest level of the FMS depth i ...
Geologic map of the Bachelor Mountain quadrangle
... The oldest rocks in the Bachelor Mountain quadrangle are maroon, red, purple, and whitish weathering, feldspathic quartzite of the Proterozoic Belt Supergroup exposed in the northwest corner of the map. These rocks dip uniformly to the northeast and are part of the Missoula Group (Coppinger, 1974). ...
... The oldest rocks in the Bachelor Mountain quadrangle are maroon, red, purple, and whitish weathering, feldspathic quartzite of the Proterozoic Belt Supergroup exposed in the northwest corner of the map. These rocks dip uniformly to the northeast and are part of the Missoula Group (Coppinger, 1974). ...
Melting of the Uppermost Metasomatized Asthenosphere Triggered
... Kuritani et al., 2011), even though the relative enrichment of LILE and LREE in comparison with HFSE is minor in the volcanic rocks of these back-arc regions. Back-arc volcanism in the Japan Sea area has been described as the ‘CircumJapan Sea Alkaline Rock Province’ (Tomita, 1935). Because of this v ...
... Kuritani et al., 2011), even though the relative enrichment of LILE and LREE in comparison with HFSE is minor in the volcanic rocks of these back-arc regions. Back-arc volcanism in the Japan Sea area has been described as the ‘CircumJapan Sea Alkaline Rock Province’ (Tomita, 1935). Because of this v ...
alleghanian plutonism in the eastern blue ridge
... (Under the direction of Dr. Kevin Stewart) The Alleghanian orogeny was caused by the closing of the Theic ocean basin and subsequent collision of Gondwana with Laurentia. The orientation of the subducted Theic oceanic lithosphere is unknown but may be recorded in Carboniferous magmatism recently dis ...
... (Under the direction of Dr. Kevin Stewart) The Alleghanian orogeny was caused by the closing of the Theic ocean basin and subsequent collision of Gondwana with Laurentia. The orientation of the subducted Theic oceanic lithosphere is unknown but may be recorded in Carboniferous magmatism recently dis ...
2.03 Sampling Mantle Heterogeneity through Oceanic Basalts
... Trace elements, on the other hand just replace a few atoms of the major elements in the crystal structures without affecting the phase assemblage significantly. They are essentially blind passengers in many mantle processes, and they are therefore immensely useful as tracers of such processes. Durin ...
... Trace elements, on the other hand just replace a few atoms of the major elements in the crystal structures without affecting the phase assemblage significantly. They are essentially blind passengers in many mantle processes, and they are therefore immensely useful as tracers of such processes. Durin ...
Composition of the Oceanic Crust - DukeSpace
... hundred kilometers in length are bounded by large-offset overlapping spreading centers. Nested within these primary magmatic segments are numerous secondary magmatic segments that share a common parental magma composition, and are bounded by smaller offset overlapping spreading centers. Detailed stu ...
... hundred kilometers in length are bounded by large-offset overlapping spreading centers. Nested within these primary magmatic segments are numerous secondary magmatic segments that share a common parental magma composition, and are bounded by smaller offset overlapping spreading centers. Detailed stu ...
GEOLOGIC STRUCTURE OF THE UPPERMOST OCEANIC CRUST
... crust change both the compositions of the rocks as well as the chemistry of the oceans. Seafloor spreading, probably initially at high rates, has been operating since Archean time, continuously “repaving” two thirds of our planet with new seafloor as older lithosphere is recycled at subduction zones ...
... crust change both the compositions of the rocks as well as the chemistry of the oceans. Seafloor spreading, probably initially at high rates, has been operating since Archean time, continuously “repaving” two thirds of our planet with new seafloor as older lithosphere is recycled at subduction zones ...
Multiple sulfur isotope composition of oxidized Samoan melts and
... No clear trend appears between δ 34 S and S abundance, or between δ 34 S and S speciation (Table S1). Instead, the δ 34 S values of reduced sulfur are correlated with source enrichment proxies such as 87 Sr/86 Sr (Fig. 6), with the exception of two glasses: 79-4 and 73-12. The former is the most evo ...
... No clear trend appears between δ 34 S and S abundance, or between δ 34 S and S speciation (Table S1). Instead, the δ 34 S values of reduced sulfur are correlated with source enrichment proxies such as 87 Sr/86 Sr (Fig. 6), with the exception of two glasses: 79-4 and 73-12. The former is the most evo ...
Baltic Shield
The Baltic Shield (sometimes referred to as the Fennoscandian Shield) is located in Fennoscandia (Norway, Sweden and Finland), northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton. It is composed mostly of Archean and Proterozoic gneisses and greenstones which have undergone numerous deformations through tectonic activity (see Geology of Fennoscandia map [1]). The Baltic Shield contains the oldest rocks of the European continent. The lithospheric thickness is about 200-300 km. During the Pleistocene epoch, great continental ice sheets scoured and depressed the shield's surface, leaving a thin covering of glacial material and innumerable lakes and streams. The Baltic Shield is still rebounding today following the melting of the thick glaciers during the Quaternary Period.