Gravity modeling of the lithosphere in the Calatrava
... for the intraplate volcanism occurred in the CVP because the crust shows a quasi-constant thickness. Density models suggest the existence of a sub-crustal, anomalous low-density block that could be underplated magmatic material at the base of the crust, suggesting that only a minor part of it intrud ...
... for the intraplate volcanism occurred in the CVP because the crust shows a quasi-constant thickness. Density models suggest the existence of a sub-crustal, anomalous low-density block that could be underplated magmatic material at the base of the crust, suggesting that only a minor part of it intrud ...
Causes and mechanisms of the 20112012 El Hierro (Canary Islands
... the main vent site. This eruption marked the end of a 40 years period of quiescence in the Canary Islands following the 1971 eruption of Teneguia in La Palma. [5] The El Hierro eruption is the first one that has been fully monitored in real time since the beginning of unrest, so the amount of informa ...
... the main vent site. This eruption marked the end of a 40 years period of quiescence in the Canary Islands following the 1971 eruption of Teneguia in La Palma. [5] The El Hierro eruption is the first one that has been fully monitored in real time since the beginning of unrest, so the amount of informa ...
Tectonic controls on the nature of large silicic calderas in volcanic arcs
... on specific tectonic characteristics. We find that caldera occurrence positively correlates with convergence rate except in arcs with backarc spreading, which have few or no calderas. Calderas located on oceanic and young continental crust are predominantly dacitic, whereas rhyolitic calderas are ma ...
... on specific tectonic characteristics. We find that caldera occurrence positively correlates with convergence rate except in arcs with backarc spreading, which have few or no calderas. Calderas located on oceanic and young continental crust are predominantly dacitic, whereas rhyolitic calderas are ma ...
Tracing the evolving flux from the subducting plate in the Tonga
... Drilling Program (ODP) Site 840, which record the variations in the chemistry of Tonga magmatism since 7 Ma. B/Be is variable (5.8 –122), in young Tonga-Kermadec Arc lavas. In contrast, glass shards from ⬃3 to 4 Ma old volcanic sediments at Site 840 have the highest B/Be values yet reported for arc ...
... Drilling Program (ODP) Site 840, which record the variations in the chemistry of Tonga magmatism since 7 Ma. B/Be is variable (5.8 –122), in young Tonga-Kermadec Arc lavas. In contrast, glass shards from ⬃3 to 4 Ma old volcanic sediments at Site 840 have the highest B/Be values yet reported for arc ...
Flood basalts, continental breakup and the dispersal of
... Received: 18 October 2000 – Revised: 27 December 2001 – Accepted: 4 March 2002 ...
... Received: 18 October 2000 – Revised: 27 December 2001 – Accepted: 4 March 2002 ...
Lecture 6
... The fault plane on the normal fault is generally very steep. In a normal fault the two involved blocks are (by gravity) pulling away from one another causing one of the fault blocks to slip upward and the other downward with respect to the fault plane (it is hard to determine whether both or just ...
... The fault plane on the normal fault is generally very steep. In a normal fault the two involved blocks are (by gravity) pulling away from one another causing one of the fault blocks to slip upward and the other downward with respect to the fault plane (it is hard to determine whether both or just ...
Iceland is cool: An origin for the Iceland volcanic province in the
... locus of spreading in Iceland, thought to be consistent with an eastward-migrating plume, and a maximum in crustal thickness and volcanic activity beneath central Iceland. The features quoted are, however, required by the complex tectonic history of the region, which is described in this section. Fo ...
... locus of spreading in Iceland, thought to be consistent with an eastward-migrating plume, and a maximum in crustal thickness and volcanic activity beneath central Iceland. The features quoted are, however, required by the complex tectonic history of the region, which is described in this section. Fo ...
File
... The fault plane on the normal fault is generally very steep. In a normal fault the two involved blocks are (by gravity) pulling away from one another causing one of the fault blocks to slip upward and the other downward with respect to the fault plane (it is hard to determine whether both or just ...
... The fault plane on the normal fault is generally very steep. In a normal fault the two involved blocks are (by gravity) pulling away from one another causing one of the fault blocks to slip upward and the other downward with respect to the fault plane (it is hard to determine whether both or just ...
File
... The fault plane on the normal fault is generally very steep. In a normal fault the two involved blocks are (by gravity) pulling away from one another causing one of the fault blocks to slip upward and the other downward with respect to the fault plane (it is hard to determine whether both or just ...
... The fault plane on the normal fault is generally very steep. In a normal fault the two involved blocks are (by gravity) pulling away from one another causing one of the fault blocks to slip upward and the other downward with respect to the fault plane (it is hard to determine whether both or just ...
Zuni–Bandera volcanism, Rio Grande, USA — Melt formation in
... 2. Geological setting Located in west central New Mexico (Fig. 1), the ZBVF comprises a sequence of mixed tholeiite and alkali basalt lava flows, spatter ramparts, scoria cones, small shields, maars, and collapse pits erupted through Proterozoic continental crust over the last 1.5 Ma (Anders et al., ...
... 2. Geological setting Located in west central New Mexico (Fig. 1), the ZBVF comprises a sequence of mixed tholeiite and alkali basalt lava flows, spatter ramparts, scoria cones, small shields, maars, and collapse pits erupted through Proterozoic continental crust over the last 1.5 Ma (Anders et al., ...
Deep structures and breakup along volcanic rifted margins: insights
... either post-orogenic collapse or back-arc settings close to oceanic spreading axis (Woodlark Basin) led Lundin and Doré (1997) to suggest that the NGR domal crustal structure may be the result of a crustal softening triggered by massive injections within the lower crust at an early stage of the con ...
... either post-orogenic collapse or back-arc settings close to oceanic spreading axis (Woodlark Basin) led Lundin and Doré (1997) to suggest that the NGR domal crustal structure may be the result of a crustal softening triggered by massive injections within the lower crust at an early stage of the con ...
On origin of near-axis volcanism and faulting at fast spreading mid
... formation of the abyssal hills. It has been suggested that outward-dipping faults can form at fast spreading ridges because of a less dramatic thickening of the brittle layer away from the ridge axis compared to slow spreading ridges [20,21]. However, it is unclear whether the reduced variability in ...
... formation of the abyssal hills. It has been suggested that outward-dipping faults can form at fast spreading ridges because of a less dramatic thickening of the brittle layer away from the ridge axis compared to slow spreading ridges [20,21]. However, it is unclear whether the reduced variability in ...
Earthquake Faults
... km below the Earth’s surface. It is the release of stored elastic energy caused by sudden fracture and movement of rocks inside the Earth. Part of the energy released produces seismic waves, like P, S, and surface waves, that travel outward in all directions from the point of initial rupture. These ...
... km below the Earth’s surface. It is the release of stored elastic energy caused by sudden fracture and movement of rocks inside the Earth. Part of the energy released produces seismic waves, like P, S, and surface waves, that travel outward in all directions from the point of initial rupture. These ...
Crust recycling in the sources of two parallel volcanic chains in
... references therein) (Figure 1). The Shandong Province is located in the southeast of the NCC. The Cenozoic alkaline magmatism in Shandong took place during two periods: 24.0–10.3 Ma and 8.7– 0.3 Ma (see the review by Luo et al., 2009). The early magmatism was profuse and characterized by large volca ...
... references therein) (Figure 1). The Shandong Province is located in the southeast of the NCC. The Cenozoic alkaline magmatism in Shandong took place during two periods: 24.0–10.3 Ma and 8.7– 0.3 Ma (see the review by Luo et al., 2009). The early magmatism was profuse and characterized by large volca ...
Structural Controls of the Tuscarora Geothermal Field Elko County
... km northwest of Elko, Nevada, in the northern part of the Basin and Range province ~15 km southeast of the Snake River Plain. Detailed geologic mapping, structural analysis, and well data, have been integrated to identify the structural controls of the Tuscarora geothermal system. The structural fra ...
... km northwest of Elko, Nevada, in the northern part of the Basin and Range province ~15 km southeast of the Snake River Plain. Detailed geologic mapping, structural analysis, and well data, have been integrated to identify the structural controls of the Tuscarora geothermal system. The structural fra ...
structural geology of the western branch of the east african rift
... developed in the Pan-African Mozambique Belt, which was a typical subduction/collision orogeny in the Cambrian. Much of the Western branch formed in older, early to middle Proterozoic Belts that, at least in part, characterized by regionally widespread granulite-facies metamorphism, which cause regi ...
... developed in the Pan-African Mozambique Belt, which was a typical subduction/collision orogeny in the Cambrian. Much of the Western branch formed in older, early to middle Proterozoic Belts that, at least in part, characterized by regionally widespread granulite-facies metamorphism, which cause regi ...
The Periadriatic lineament and the role of strike slip - RWTH
... The western part of the PL is explained by a retrotranslation thesis from Laubscher. Laubscher firms up his model of earlier analysis from Argand. The new model uses a step-by-step retrodeformation of the western Alps; it starts with the latest movement and goes to the oldest motions: The youngest p ...
... The western part of the PL is explained by a retrotranslation thesis from Laubscher. Laubscher firms up his model of earlier analysis from Argand. The new model uses a step-by-step retrodeformation of the western Alps; it starts with the latest movement and goes to the oldest motions: The youngest p ...
Convergence and Collision
... ridge, it is warm and relatively buoyant. But as lithosphere moves away from the ridge axis, it cools and the lithospheric mantle thickens, so that when lithosphere has aged more than 10 or 15 million years, it becomes negatively buoyant. In other words, old oceanic lithosphere is denser than underl ...
... ridge, it is warm and relatively buoyant. But as lithosphere moves away from the ridge axis, it cools and the lithospheric mantle thickens, so that when lithosphere has aged more than 10 or 15 million years, it becomes negatively buoyant. In other words, old oceanic lithosphere is denser than underl ...
Read the Paper. - Society of Economic Geologists
... geothermal systems occur within a rifted volcanic arc (~150 km long) dominated by silicic volcanism, and they occur in association with major faults near caldera structures or within accommodation zones that transfer extension between rift segments. The geothermal systems are hosted in a thick seque ...
... geothermal systems occur within a rifted volcanic arc (~150 km long) dominated by silicic volcanism, and they occur in association with major faults near caldera structures or within accommodation zones that transfer extension between rift segments. The geothermal systems are hosted in a thick seque ...
Lecture 47
... The lithosphere is the part of the Earth through which heat is conducted rather than convected. Mantle lithosphere (the subcontinental lithospheric mantle: SCLM) tends to have fast seismic velocities, suggesting is cold compared with the convective mantle. Xenoliths derived from these regions) are o ...
... The lithosphere is the part of the Earth through which heat is conducted rather than convected. Mantle lithosphere (the subcontinental lithospheric mantle: SCLM) tends to have fast seismic velocities, suggesting is cold compared with the convective mantle. Xenoliths derived from these regions) are o ...
Petrology and geochemistry of the Tertiary alkaline intrusive rocks at
... Europe. Either its parental magma originated in heterogeneous mantle with more distinct lithospheric signature or this magma reacted with the continental crust during its ascent and fractionation. Sodalite monzosyenite displays significantly higher 87Sr/86Sr ratios and its parental magma probably in ...
... Europe. Either its parental magma originated in heterogeneous mantle with more distinct lithospheric signature or this magma reacted with the continental crust during its ascent and fractionation. Sodalite monzosyenite displays significantly higher 87Sr/86Sr ratios and its parental magma probably in ...
Non-plume magmatism and tectonics during the opening of the
... Atlantic Ocean. Some geodynamic models attribute Early Mesozoic Atlantic rifting and magmatism to a large mantle plume. However, the central Atlantic basalts occur in overlapping provinces of distinct dike trends and compositional types, not as magmas generated from a single plume-style source. Cont ...
... Atlantic Ocean. Some geodynamic models attribute Early Mesozoic Atlantic rifting and magmatism to a large mantle plume. However, the central Atlantic basalts occur in overlapping provinces of distinct dike trends and compositional types, not as magmas generated from a single plume-style source. Cont ...
EAST AFRICAN RIFT SYSTEM
... Baker, B.H., Williams, L.A.J., Miller, J.A. and Fitch, F.J., 1971: Sequence and Geochronology of the Kenya Rift volcanics. Tectonophysics 11, 191-215. Baker, B.H., Mohr P.A., and Williams, L.A.J., 1972: Geology of the Eastern Rift System of Africa. The Geol. Soc. of America. Special Paper, 136, 67 p ...
... Baker, B.H., Williams, L.A.J., Miller, J.A. and Fitch, F.J., 1971: Sequence and Geochronology of the Kenya Rift volcanics. Tectonophysics 11, 191-215. Baker, B.H., Mohr P.A., and Williams, L.A.J., 1972: Geology of the Eastern Rift System of Africa. The Geol. Soc. of America. Special Paper, 136, 67 p ...
EAST AFRICAN RIFT SYSTEM
... The first eruptive rocks in the cycle, seen in Ethiopia and Kenya, were extensive alkali flood basalts generated from melts at depths of about or greater than 35 km. More saturated basalts (transitional between alkaline and tholeiitic) followed in the rifts generated at shallower depth. A final stag ...
... The first eruptive rocks in the cycle, seen in Ethiopia and Kenya, were extensive alkali flood basalts generated from melts at depths of about or greater than 35 km. More saturated basalts (transitional between alkaline and tholeiitic) followed in the rifts generated at shallower depth. A final stag ...
church_hall
... 1987, p. 44; Thibault 1987, p. 28). Thy (1987), however, claims that the less fractionated part of the stratiform unit is younger than the more fractionated part—which it nevertheless underlies. In this respect the plutonic series likely correlates with either the older low-Ti series of the BG and L ...
... 1987, p. 44; Thibault 1987, p. 28). Thy (1987), however, claims that the less fractionated part of the stratiform unit is younger than the more fractionated part—which it nevertheless underlies. In this respect the plutonic series likely correlates with either the older low-Ti series of the BG and L ...
Northern Cordilleran Volcanic Province
The Northern Cordilleran Volcanic Province (NCVP), formerly known as the Stikine Volcanic Belt, is a geologic province defined by the occurrence of Miocene to Holocene volcanoes in the Pacific Northwest of North America. This belt of volcanoes extends roughly north-northwest from northwestern British Columbia and the Alaska Panhandle through Yukon to the Southeast Fairbanks Census Area of far eastern Alaska, in a corridor hundreds of kilometres wide. It is the most recently defined volcanic province in the Western Cordillera. It has formed due to extensional cracking of the North American continent—similar to other on-land extensional volcanic zones, including the Basin and Range Province and the East African Rift. Although taking its name from the Western Cordillera, this term is a geologic grouping rather than a geographic one. The southmost part of the NCVP has more, and larger, volcanoes than does the rest of the NCVP; further north it is less clearly delineated, describing a large arch that sways westward through central Yukon.At least four large volcanoes are grouped with the Northern Cordilleran Volcanic Province, including Hoodoo Mountain in the Boundary Ranges, the Mount Edziza volcanic complex on the Tahltan Highland, and Level Mountain and Heart Peaks on the Nahlin Plateau. These four volcanoes have volumes of more than 15 km3 (3.6 cu mi), the largest and oldest which is Level Mountain with an area of 1,800 km2 (690 sq mi) and a volume of more than 860 km3 (210 cu mi). Apart from the large volcanoes, several smaller volcanoes exist throughout the Northern Cordilleran Volcanic Province, including cinder cones which are widespread throughout the volcanic zone. Most of these small cones have been sites of only one volcanic eruption; this is in contrast to the larger volcanoes throughout the volcanic zone, which have had more than one volcanic eruption throughout their history.The Northern Cordilleran Volcanic Province is part of an area of intensive earthquake and volcanic activity around the Pacific Ocean called the Pacific Ring of Fire. However, the Northern Cordilleran Volcanic Province is commonly interpreted to be part of a gap in the Pacific Ring of Fire between the Cascade Volcanic Arc further south and the Aleutian Arc further north. But the Northern Cordilleran Volcanic Province is recognized to include over 100 independent volcanoes that have been active in the past 1.8 million years. At least three of them have erupted in the past 360 years, making it the most active volcanic area in Canada. Nevertheless, the dispersed population within the volcanic zone has witnessed few eruptions due to remoteness and the infrequent volcanic activity.