The role of basement inheritance faults in the recent fracture system
... southeast (Maldonado et al. 1992). Both margins of one of the most relevant structures in the central Alboran Basin, the Alboran Ridge, are affected by faults trending in the same predominantly north-eastern direction. This system is probable the offshore extension of the Jebha Fault, which separate ...
... southeast (Maldonado et al. 1992). Both margins of one of the most relevant structures in the central Alboran Basin, the Alboran Ridge, are affected by faults trending in the same predominantly north-eastern direction. This system is probable the offshore extension of the Jebha Fault, which separate ...
hall_church_comments
... 01-Cpx-Plag-Opx-Amph (Dion 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謡 hich it nevertheless underlies. In this respect the plutonic series likely correlates with either the older lo ...
... 01-Cpx-Plag-Opx-Amph (Dion 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謡 hich it nevertheless underlies. In this respect the plutonic series likely correlates with either the older lo ...
Evidence for melting of garnet pyroxenite in the generation of
... Volcanic Suite, Kauai and the Honolulu Volcanic Series, Oahu to evaluate the role of pyroxenite melting in the generation of these highly enriched small-degree partial melts. Post-erosional lavas ...
... Volcanic Suite, Kauai and the Honolulu Volcanic Series, Oahu to evaluate the role of pyroxenite melting in the generation of these highly enriched small-degree partial melts. Post-erosional lavas ...
Crustal contributions to arc magmatism in the Andes of Central Chile
... Chile Trench (Fig. 1), and with the south end of the Sierras Pampeanas structural province of compressive crystalline-basement uplifts in the Argentine foreland (Jordan et al. 1983). A less-well-defined southerly segment boundary at 37~ was proposed by Swift and Carr (1974), but no unambiguous Benio ...
... Chile Trench (Fig. 1), and with the south end of the Sierras Pampeanas structural province of compressive crystalline-basement uplifts in the Argentine foreland (Jordan et al. 1983). A less-well-defined southerly segment boundary at 37~ was proposed by Swift and Carr (1974), but no unambiguous Benio ...
1 Origin and geodynamic relationships of the Late Miocene to
... occur in the convective asthenosphere within the garnet-spinel transition zone. Melting started ...
... occur in the convective asthenosphere within the garnet-spinel transition zone. Melting started ...
EPS116_chapter4
... Listric normal faults: concave upward faults whose dip decreases with increasing depth. Features of fault surfaces are variable and depend on the fault’s shape, the depth of movement, and brittle vs. ductile deformation. Surface features such as cataclastic rocks and slickensides are evidence of nor ...
... Listric normal faults: concave upward faults whose dip decreases with increasing depth. Features of fault surfaces are variable and depend on the fault’s shape, the depth of movement, and brittle vs. ductile deformation. Surface features such as cataclastic rocks and slickensides are evidence of nor ...
EAST AFRICAN RIFT SYSTEM
... stress builds up for a long period of time (centuries) to breaking limit. Overstretched zone of weakness opens up along pre-existing faults and basalt intrudes into them at depth (dyking). Fissure eruptions may occur depending of magma supply. The caldera (central) volcanoes of the rift are underlai ...
... stress builds up for a long period of time (centuries) to breaking limit. Overstretched zone of weakness opens up along pre-existing faults and basalt intrudes into them at depth (dyking). Fissure eruptions may occur depending of magma supply. The caldera (central) volcanoes of the rift are underlai ...
Author`s personal copy
... Voluminous intermediate to silicic composition volcanic rocks were generated throughout the southern Rocky Mountains, western U.S., during the mid-Tertiary “ignimbrite flare-up”, principally at the San Juan and Mogollon-Datil volcanic fields. At both volcanic centers, radiogenic isotope data have be ...
... Voluminous intermediate to silicic composition volcanic rocks were generated throughout the southern Rocky Mountains, western U.S., during the mid-Tertiary “ignimbrite flare-up”, principally at the San Juan and Mogollon-Datil volcanic fields. At both volcanic centers, radiogenic isotope data have be ...
Activity 1 Where are the Volcanoes?
... down beneath the continents. Look at Figure 2 to see an example.The Nazca Plate, moving eastward from the East Pacific Ridge, slides down beneath the west coast of South America.The plate is heated as it sinks into the much hotter rocks of the deep Earth.The heat causes fluids, especially water, to ...
... down beneath the continents. Look at Figure 2 to see an example.The Nazca Plate, moving eastward from the East Pacific Ridge, slides down beneath the west coast of South America.The plate is heated as it sinks into the much hotter rocks of the deep Earth.The heat causes fluids, especially water, to ...
The Yellowstone magmatic system from the
... volcanic system (1). The Yellowstone volcanic field that sits less than ~10-km depth. Large arrays for teleseismic at the eastern end of the plain is the youngest manifestation tomography can only focus on mantle images and poorly of the hotspot, and is characterized by extensive resolved crustal st ...
... volcanic system (1). The Yellowstone volcanic field that sits less than ~10-km depth. Large arrays for teleseismic at the eastern end of the plain is the youngest manifestation tomography can only focus on mantle images and poorly of the hotspot, and is characterized by extensive resolved crustal st ...
Continental geotherm and the evolution of rifted margins
... should have a resolvable effect on subsidence. The influx of hot asthenosphere from the global ridge system should not only initiate melting and the formation of oceanic crust, but also cause simultaneous transient thermal uplift of the margin, providing an explanation for the breakup unconformity f ...
... should have a resolvable effect on subsidence. The influx of hot asthenosphere from the global ridge system should not only initiate melting and the formation of oceanic crust, but also cause simultaneous transient thermal uplift of the margin, providing an explanation for the breakup unconformity f ...
the karoo volcanic rocks and related intrusions in
... in South Africa (Cleverly & Bristow 1979), only a narrow sliver of these fine-grained, low-MgO basalts are exposed north of the Singuédzi River on the Mozambican side of the border. At this location, the Sabie River basalts occur in weathered outcrops as massive rocks, lacking amygdules or other feat ...
... in South Africa (Cleverly & Bristow 1979), only a narrow sliver of these fine-grained, low-MgO basalts are exposed north of the Singuédzi River on the Mozambican side of the border. At this location, the Sabie River basalts occur in weathered outcrops as massive rocks, lacking amygdules or other feat ...
Mantle temperature control on composition of arc magmas along the
... south-to-north change of their compositions from moderately fractionated basalt-andesite tholeiitic series to highly fractionated basalt-rhyolite calc-alkaline series including highmagnesian andesites near the slab edge. Localized slab melting at the slab edge cannot explain these regional geochemic ...
... south-to-north change of their compositions from moderately fractionated basalt-andesite tholeiitic series to highly fractionated basalt-rhyolite calc-alkaline series including highmagnesian andesites near the slab edge. Localized slab melting at the slab edge cannot explain these regional geochemic ...
Neogene-Recent rifting and volcanism in northern Tanzania
... some 200 M a . In Kenya, although there is as yet no evidence for rift-related magmatism older than around 25 Ma, there has been repeated magmatism since that time. In northern Tanzania, although the most recent igneous activity spans less than 10 Ma there have been two major episodes of magmatism, ...
... some 200 M a . In Kenya, although there is as yet no evidence for rift-related magmatism older than around 25 Ma, there has been repeated magmatism since that time. In northern Tanzania, although the most recent igneous activity spans less than 10 Ma there have been two major episodes of magmatism, ...
GUIDELINES FOR PAPERS
... geological equipment and Geographic Information Systems (GIS) advancements. Field mapping activity is usually carried out in four phases, which have a stepwise relationship: a) planning/research; b) field data collection; c) laboratory analysis and d) report writing. At the beginning of a geological ...
... geological equipment and Geographic Information Systems (GIS) advancements. Field mapping activity is usually carried out in four phases, which have a stepwise relationship: a) planning/research; b) field data collection; c) laboratory analysis and d) report writing. At the beginning of a geological ...
Westward propagation of the North Anatolian fault into the northern
... boundaries. Yet, propagation of plate-scale faults through the continental crust and lithosphere has received little attention, mainly because pertinent observations are scarce. The active rightlateral North Anatolian fault, a feature long considered a continental transform (Ketin, 1948; McKenzie, 1 ...
... boundaries. Yet, propagation of plate-scale faults through the continental crust and lithosphere has received little attention, mainly because pertinent observations are scarce. The active rightlateral North Anatolian fault, a feature long considered a continental transform (Ketin, 1948; McKenzie, 1 ...
7 Volcano-tectonic Interactions in Kyushu and Implications for Future
... The configuration of the subducting slab, as well as the laterally varying buoyancy properties of the subducting plate exert a major influence on the nature of volcanism and tectonic deformation in Kyushu. Given that these properties will tend to evolve spatially with time, we show a series of model ...
... The configuration of the subducting slab, as well as the laterally varying buoyancy properties of the subducting plate exert a major influence on the nature of volcanism and tectonic deformation in Kyushu. Given that these properties will tend to evolve spatially with time, we show a series of model ...
View paper
... unique because they bring us information about the earth interior. We can see the formation of effusive rocks at modern volcanoes. Effusive rocks are formed mainly within rifts and island arcs, rarely within foldbelts and platforms. The main types of effusive rocks are basalts (SiO 2 45-54%), andesi ...
... unique because they bring us information about the earth interior. We can see the formation of effusive rocks at modern volcanoes. Effusive rocks are formed mainly within rifts and island arcs, rarely within foldbelts and platforms. The main types of effusive rocks are basalts (SiO 2 45-54%), andesi ...
Planetary Atmospheres and Life
... early 1950s when the American geochemist Harold Urey and his graduate student Stanley Miller performed a famous experiment in which they synthesized possible prebiotic compounds from plausible early atmospheric gases (Miller, 1953, 1955). A diagram of Miller’s experimental apparatus is shown in Fig. ...
... early 1950s when the American geochemist Harold Urey and his graduate student Stanley Miller performed a famous experiment in which they synthesized possible prebiotic compounds from plausible early atmospheric gases (Miller, 1953, 1955). A diagram of Miller’s experimental apparatus is shown in Fig. ...
Geol 101: Physical Geology PAST EXAM QUESTIONS LECTURE 20
... PAST EXAM QUESTIONS LECTURE 20: CRUSTAL DEFORMATION II 20. Faults are most common at the boundaries between tectonic plates, such as in the: A. New Madrid region of Missouri B. East African Rift Valley C. circum-Pacific belt D. all of the above E. none of the above 20. An example of a A. B. C. D. E. ...
... PAST EXAM QUESTIONS LECTURE 20: CRUSTAL DEFORMATION II 20. Faults are most common at the boundaries between tectonic plates, such as in the: A. New Madrid region of Missouri B. East African Rift Valley C. circum-Pacific belt D. all of the above E. none of the above 20. An example of a A. B. C. D. E. ...
Physical volcanology of continental large igneous provinces: update
... common, expression of LIP events along continental margins, the large volumes of easily erodible primary volcaniclastic deposits result in these provinces also having a significant sedimentary signature in the geologic record. The inter-relationships between flood basalt lavas and volcaniclastic dep ...
... common, expression of LIP events along continental margins, the large volumes of easily erodible primary volcaniclastic deposits result in these provinces also having a significant sedimentary signature in the geologic record. The inter-relationships between flood basalt lavas and volcaniclastic dep ...
Research Focus: Crust formation in the western United
... resolution of the controversy. For example, inherited zircons in plutonic and volcanic rocks simply indicate that there was “communication” between older continental crust and the locus of magma production. The presence of inherited zircons does not require that older crust exists either in the area ...
... resolution of the controversy. For example, inherited zircons in plutonic and volcanic rocks simply indicate that there was “communication” between older continental crust and the locus of magma production. The presence of inherited zircons does not require that older crust exists either in the area ...
EPSL94HokeHelium3Alt.. - University of Colorado Boulder
... We report results of a regional survey of helium isotopes measured in water and gas samples in volcanic sulfataras and geothermal springs from the Central Andes of northern Chile and Bolivia between the latitudes 15°S and 23°S. The highest 3 H e / 4 H e ratios (reported as R / R A ratios: R = sample ...
... We report results of a regional survey of helium isotopes measured in water and gas samples in volcanic sulfataras and geothermal springs from the Central Andes of northern Chile and Bolivia between the latitudes 15°S and 23°S. The highest 3 H e / 4 H e ratios (reported as R / R A ratios: R = sample ...
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.