red rock canyon - Oklahoma Geological Survey
... walls, where it is emitted as springs and seeps. Ground water produced from local wells is of high quality; that is, a liter of water contains less than 500 mg oftotal dissolved solids. Well yields also are high: 100500 gallons per minute. The water table probably was near the level of the canyon fl ...
... walls, where it is emitted as springs and seeps. Ground water produced from local wells is of high quality; that is, a liter of water contains less than 500 mg oftotal dissolved solids. Well yields also are high: 100500 gallons per minute. The water table probably was near the level of the canyon fl ...
Late Variscan (Carboniferous to Permian) environments in the
... Structural fragments of newly formed epi-Variscan crust were incorporated in the paleo-Alpine Western Carpathian units. Like most of the other collisional fold belts, the Western Carpathians have been traditionally divided into external and internal structural zones. The age of the main Alpine event ...
... Structural fragments of newly formed epi-Variscan crust were incorporated in the paleo-Alpine Western Carpathian units. Like most of the other collisional fold belts, the Western Carpathians have been traditionally divided into external and internal structural zones. The age of the main Alpine event ...
Geochemistry of mafic rocks and melt inclusions and their
... there are at least two active off-axis hydrothermal sites and associated hydrothermal products, including silica-rich sulfides and their red oxides, and other hydrothermal siliceous products. The gap of the two sites is less than 1 km, and its distance from the spreading center is approximately 5 km ...
... there are at least two active off-axis hydrothermal sites and associated hydrothermal products, including silica-rich sulfides and their red oxides, and other hydrothermal siliceous products. The gap of the two sites is less than 1 km, and its distance from the spreading center is approximately 5 km ...
Tectonics of the Rio Grande Depression of central New Mexico
... embayrnents are recognized as sub-basin. These embayments ...
... embayrnents are recognized as sub-basin. These embayments ...
Geologic Structures
... Chances are small that the river flowing through your city will flood this spring, but if you lived to be 100 years old, you would probably see a catastrophic flood. In fact, many residents of the Midwest saw such a flood in the summer of 1993, and California residents experienced one in January 199 ...
... Chances are small that the river flowing through your city will flood this spring, but if you lived to be 100 years old, you would probably see a catastrophic flood. In fact, many residents of the Midwest saw such a flood in the summer of 1993, and California residents experienced one in January 199 ...
The track of the Yellowstone hot spot
... during the Mesozoic and earliest Tertiary orogenies (Sevier and Laramide) (Christiansen and Lipman, 1972; Wernicke and others, 1987; Molnar and Chen, 1983). (4) About 2 Ma, the Yellowstone hot spot left the thickened crust of the thrust belt and passed beneath the stable craton. ( 5 ) The plate marg ...
... during the Mesozoic and earliest Tertiary orogenies (Sevier and Laramide) (Christiansen and Lipman, 1972; Wernicke and others, 1987; Molnar and Chen, 1983). (4) About 2 Ma, the Yellowstone hot spot left the thickened crust of the thrust belt and passed beneath the stable craton. ( 5 ) The plate marg ...
Geology of the Jolon and Williams Hill Quadrangles Monterey County, California (USGS BUlletin 1181-Q 1965)
... Plutonic rocks of the pre-Tertiary basement complex crop out in two small areas near the Nacimiento River, and were reportedly reached in 13 wells drilled northeast of the San Antonio River in the Williams Hill quadrangle. The oldest sedimentary rocks that crop out in the map area are sandstone, con ...
... Plutonic rocks of the pre-Tertiary basement complex crop out in two small areas near the Nacimiento River, and were reportedly reached in 13 wells drilled northeast of the San Antonio River in the Williams Hill quadrangle. The oldest sedimentary rocks that crop out in the map area are sandstone, con ...
Red-bed copper deposits of the Quebec Appalachians
... Transfiguration red-bed sequence are Lower Silurian rocks of the Robitaille Formation deposited on deformed pre-Taconic rocks of the Humber Zone, above the Taconian unconformity (Bourque et al. 1995, Malo 2004). The Robitaille Formation is part of the lower terrigenous assemblage of the Chaleurs Gro ...
... Transfiguration red-bed sequence are Lower Silurian rocks of the Robitaille Formation deposited on deformed pre-Taconic rocks of the Humber Zone, above the Taconian unconformity (Bourque et al. 1995, Malo 2004). The Robitaille Formation is part of the lower terrigenous assemblage of the Chaleurs Gro ...
Memoir 36: Geology of Organ Mountains and southern San Andres
... describe sections of Paleozoic rocks that had not been described in detail or subdivided into up-to-date stratigraphic units, and finally 3) to investigate relationships between the Organ batholith and volcanic rocks in the southern Organ range, which recently were shown to be of the same age. Durin ...
... describe sections of Paleozoic rocks that had not been described in detail or subdivided into up-to-date stratigraphic units, and finally 3) to investigate relationships between the Organ batholith and volcanic rocks in the southern Organ range, which recently were shown to be of the same age. Durin ...
Pull-apart basins at releasing bends of the sinistral Late Jurassic
... Geological Sciences Department, California State Polytechnic University, Pomona, California 91768, USA ABSTRACT A 200–500-km-wide belt along the southwestern margin of cratonic North America is pervaded by northwest- and east-trending faults that flank basins containing thick deposits of locally der ...
... Geological Sciences Department, California State Polytechnic University, Pomona, California 91768, USA ABSTRACT A 200–500-km-wide belt along the southwestern margin of cratonic North America is pervaded by northwest- and east-trending faults that flank basins containing thick deposits of locally der ...
Geological Society of America Bulletin
... velocity structure of modern oceanic crust and its inferred layer-cake pseudostratigraphy came to be known as the “ophiolite model.” This analogy was confirmed at the first Penrose Conference on ophiolites in 1972 (Anonymous, 1972), whereby an ideal ophiolite sequence was defined to have a layer-cak ...
... velocity structure of modern oceanic crust and its inferred layer-cake pseudostratigraphy came to be known as the “ophiolite model.” This analogy was confirmed at the first Penrose Conference on ophiolites in 1972 (Anonymous, 1972), whereby an ideal ophiolite sequence was defined to have a layer-cak ...
Teachers guide to geologic trails in Delaware Water Gap National
... Burrowing suggests a low-energy tranquil environment; mudcracks indicate periods of desiccation. The concretions are probably caliche precipitated by evaporation at the surface. Fish scales in a few beds (seen near the tollbooth along I-80 in Pennsylvania) suggest marine transgressions onto the low- ...
... Burrowing suggests a low-energy tranquil environment; mudcracks indicate periods of desiccation. The concretions are probably caliche precipitated by evaporation at the surface. Fish scales in a few beds (seen near the tollbooth along I-80 in Pennsylvania) suggest marine transgressions onto the low- ...
The Architecture, Chemistry, and Evolution of Continental Magmatic
... Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a continuous belt of arc products (mostly intru ...
... Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a continuous belt of arc products (mostly intru ...
The Architecture, Chemistry, and Evolution of - Cin
... Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a continuous belt of arc products (mostly intru ...
... Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a continuous belt of arc products (mostly intru ...
from elte.hu
... Since the pure existence of such a volcano is poorly constrained, not surprisingly its dimensions are not clarified either: Schmincke (1993) proposed a 2500 m edifice height during the peak of volcanic activity, whereas Acosta et al. (2003) mentioned 2000 m elevation of the island after the first-stage ...
... Since the pure existence of such a volcano is poorly constrained, not surprisingly its dimensions are not clarified either: Schmincke (1993) proposed a 2500 m edifice height during the peak of volcanic activity, whereas Acosta et al. (2003) mentioned 2000 m elevation of the island after the first-stage ...
From oceanic plateaus to allochthonous terranes: Numerical
... 1361∗ 351 nodal points is non-uniform and contains a (1000 km wide) high-resolution area of 1 km ∗ 1 km in the centre of the domain. The rest of the model remains at a lower resolution (10 ∗ 10 km). The oceanic crust contains an oceanic plateau that moves with the oceanic lithosphere as it migrates ...
... 1361∗ 351 nodal points is non-uniform and contains a (1000 km wide) high-resolution area of 1 km ∗ 1 km in the centre of the domain. The rest of the model remains at a lower resolution (10 ∗ 10 km). The oceanic crust contains an oceanic plateau that moves with the oceanic lithosphere as it migrates ...
Petrology and tectonics of Phanerozoic continent formation: From
... observations give a three-dimensional view of the crust, which permits the petrogenesis and tectonics of Phanerozoic crust formation to be linked in space and time. Subduction of the Farallon plate beneath North America during the Triassic to early Cretaceous was characterized by trench retreat and ...
... observations give a three-dimensional view of the crust, which permits the petrogenesis and tectonics of Phanerozoic crust formation to be linked in space and time. Subduction of the Farallon plate beneath North America during the Triassic to early Cretaceous was characterized by trench retreat and ...
macpherson_hall_1999 Tectonic controls on arc magmatism
... in Sumatra and Java (Katili, 1975; Rock et al, 1982) while the oldest magmatic rocks in Nusa Tenggara are of Miocene age (Abbott and Chamalaun, 1978). The eastern part of this convergent zone is the Banda arc where the Australian continental margin is being subducted towards the north (Vroon et al, ...
... in Sumatra and Java (Katili, 1975; Rock et al, 1982) while the oldest magmatic rocks in Nusa Tenggara are of Miocene age (Abbott and Chamalaun, 1978). The eastern part of this convergent zone is the Banda arc where the Australian continental margin is being subducted towards the north (Vroon et al, ...
A long in situ section of the lower ocean crust: results of ODP Leg
... 18 km east of the present-day transform-slip zone and 95 km south of the SW Indian Ridge axis. At the time of accretion, however, it was only about 15 km from the active transform fault as there was subsequent transtensional extension across the transform due to a spreading direction change [6]. The ...
... 18 km east of the present-day transform-slip zone and 95 km south of the SW Indian Ridge axis. At the time of accretion, however, it was only about 15 km from the active transform fault as there was subsequent transtensional extension across the transform due to a spreading direction change [6]. The ...
The role of crustal and mantle sources in the genesis of granitoids of
... eruption of the Jurassic ignimbrites of Patagonia. Zircon U–Pb ages from this extensive volcanic province show that magmatism migrated away from the continental interior, where it began at c. 185 Ma, and reached the western margin of the Peninsula by 155 Ma (Pankhurst et al. 1999). In the adjacent E ...
... eruption of the Jurassic ignimbrites of Patagonia. Zircon U–Pb ages from this extensive volcanic province show that magmatism migrated away from the continental interior, where it began at c. 185 Ma, and reached the western margin of the Peninsula by 155 Ma (Pankhurst et al. 1999). In the adjacent E ...
and island arcs
... • CVZ - Precambrian metamorphic crust, 50-75 km thick • SVZ - Accreted Mesozoic and Cenozoic oceanic crust and island arcs,, 30-45 km thick These are separated by inactive gaps. This belt of igneous rocks developed over last 500 Ma and is commonly termed an Andeantype margin. Image source: Winter, 2 ...
... • CVZ - Precambrian metamorphic crust, 50-75 km thick • SVZ - Accreted Mesozoic and Cenozoic oceanic crust and island arcs,, 30-45 km thick These are separated by inactive gaps. This belt of igneous rocks developed over last 500 Ma and is commonly termed an Andeantype margin. Image source: Winter, 2 ...
early evolution of the North American Cordillera Baltican and
... and Siberia in mid-Palaeozoic time, termed here the Northwest Passage. Westward propagation of a narrow subduction zone coupled with a global change in plate motion, related to the collision of Gondwana with Laurentia– Baltica, are proposed to have led to initiation of subduction along the western p ...
... and Siberia in mid-Palaeozoic time, termed here the Northwest Passage. Westward propagation of a narrow subduction zone coupled with a global change in plate motion, related to the collision of Gondwana with Laurentia– Baltica, are proposed to have led to initiation of subduction along the western p ...
Volcano instability induced by strike
... systems with widely varying dike orientations (Siebert 1984). In some cases dikes are not present at all. Morever, Nakamura's model (1977), when applied to Indonesian volcanoes, was found not to be consistent with the regional sHmax stress direction (Bahar and Girod 1983). Bahar and Girod (1983) sho ...
... systems with widely varying dike orientations (Siebert 1984). In some cases dikes are not present at all. Morever, Nakamura's model (1977), when applied to Indonesian volcanoes, was found not to be consistent with the regional sHmax stress direction (Bahar and Girod 1983). Bahar and Girod (1983) sho ...
K-Fsp can be classified as Sanidine on the basis of low
... of unknown origin present in kimberlites are called macrocrysts or megacrysts. Macrocryst is a crystal of unknown origin 0.5-10 mm in size set in a fine-grained matrix of volcanic rocks. In kimberlites, olivine, phlogopite, Cr-diopside, chromite, ilmenite, and garnet are common macrocrysts. Macrocry ...
... of unknown origin present in kimberlites are called macrocrysts or megacrysts. Macrocryst is a crystal of unknown origin 0.5-10 mm in size set in a fine-grained matrix of volcanic rocks. In kimberlites, olivine, phlogopite, Cr-diopside, chromite, ilmenite, and garnet are common macrocrysts. Macrocry ...
Free State PTR_Final - South African Heritage Resources Agency
... specific attention is given to those geological processes that had some influence on the development of life. These units will be of specific importance to the palaeontological heritage of South Africa. 2.1 Ancient continental blocks and the Earliest Forms of Life The Kaapvaal Craton is one of the o ...
... specific attention is given to those geological processes that had some influence on the development of life. These units will be of specific importance to the palaeontological heritage of South Africa. 2.1 Ancient continental blocks and the Earliest Forms of Life The Kaapvaal Craton is one of the 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.