Geology and Resources of Fluorine in the United States
... Fluorine mineral resources are evaluated in this report in the perspective of the geochemistry of fluorine and the geologic environment of fluorine mineral deposits. Rapidly increasing demand and the possibility of shortages in supply of fluorspar and other fluorine products that are vital to the ec ...
... Fluorine mineral resources are evaluated in this report in the perspective of the geochemistry of fluorine and the geologic environment of fluorine mineral deposits. Rapidly increasing demand and the possibility of shortages in supply of fluorspar and other fluorine products that are vital to the ec ...
Origin and models of oceanic transform faults. Tectonophysics, 522
... first have seismic moment release one-two orders higher; their contribution into the total seismic budget of mid ocean ridges increases with higher spreading rate. The relationships between the seismic moment release, fault length and spreading rate are quite different for transform and rift parts of ...
... first have seismic moment release one-two orders higher; their contribution into the total seismic budget of mid ocean ridges increases with higher spreading rate. The relationships between the seismic moment release, fault length and spreading rate are quite different for transform and rift parts of ...
The Seismic Structure of Island Arc Crust
... (Taylor and Karner 1983), which weakens the lithosphere due to its high heat flow and the presence of melt in a locally thickened crustal section (Molnar and Atwater 1978; Kuzsnir and Park 1987). Although arc rifting primarily occurs on the back-arc side of the arc, it can also be centered on the ar ...
... (Taylor and Karner 1983), which weakens the lithosphere due to its high heat flow and the presence of melt in a locally thickened crustal section (Molnar and Atwater 1978; Kuzsnir and Park 1987). Although arc rifting primarily occurs on the back-arc side of the arc, it can also be centered on the ar ...
Analcime phenocrysts in igneous rocks: Primary or secondary
... analcime. Although the Crowsnest locality is noteworthy for its large fresh analcime crystals, such pristine analcime is actually rare within the formation. Most of the analcime is altered in some fashion. It might be stressedhere that the alteration of the analcime is not the well-known pseudoleuci ...
... analcime. Although the Crowsnest locality is noteworthy for its large fresh analcime crystals, such pristine analcime is actually rare within the formation. Most of the analcime is altered in some fashion. It might be stressedhere that the alteration of the analcime is not the well-known pseudoleuci ...
Rutile in eclogites as a mineral resource in the Sunnfjord
... in a number of elongated lenses up to 3-4 km long, surrounded by gneisses of amphibolitic to granitic composition, as well as numerous smaller eclogite bodies and eclogitised mafic layers in gneisses. The eclogites originated by high-pressure and temperature alteration of Proterozoic, Fe-Ti rich, ga ...
... in a number of elongated lenses up to 3-4 km long, surrounded by gneisses of amphibolitic to granitic composition, as well as numerous smaller eclogite bodies and eclogitised mafic layers in gneisses. The eclogites originated by high-pressure and temperature alteration of Proterozoic, Fe-Ti rich, ga ...
Reconstructing the Alps–Carpathians–Dinarides as a key to
... collisional orogen which joins at either end with the Apennines, Carpathians and Dinarides (Fig. 2). Despite alongstrike changes in thrust vergence, these mountain belts contain nearly continuous exposures of ophiolite and accretionary prisms that mark the remains of two oceanic basins, the Triassic ...
... collisional orogen which joins at either end with the Apennines, Carpathians and Dinarides (Fig. 2). Despite alongstrike changes in thrust vergence, these mountain belts contain nearly continuous exposures of ophiolite and accretionary prisms that mark the remains of two oceanic basins, the Triassic ...
Crustal Evolution of the GreatBasin and the Sierra
... Hildreth, 1981) and was named for the Monotony Tuff of southeastern Nevada. This type includes five large volume outflow sheets and one intracaldera tuff whose aggregate volume exceeds 12,000 knr' that were emplaced from about 31 to 27 Ma. The second compositional type, the Isom, was named after the ...
... Hildreth, 1981) and was named for the Monotony Tuff of southeastern Nevada. This type includes five large volume outflow sheets and one intracaldera tuff whose aggregate volume exceeds 12,000 knr' that were emplaced from about 31 to 27 Ma. The second compositional type, the Isom, was named after the ...
STP 3 & 4
... The Interior Coastal Plains begin at or near the contact between Quaternary and Tertiary sediments (Figures 2.5S.1-1 [References 2.5S.1-2 and 2.5S.1-3], 2.5S.1-5 [References 2.5S.18, 2.5S.1-9, 2.5S.1-10, 2.5S.1-11], and 2.5S.1-6 [Reference 2.5S.1-12]) and extend to the northwest 75-150 miles. The se ...
... The Interior Coastal Plains begin at or near the contact between Quaternary and Tertiary sediments (Figures 2.5S.1-1 [References 2.5S.1-2 and 2.5S.1-3], 2.5S.1-5 [References 2.5S.18, 2.5S.1-9, 2.5S.1-10, 2.5S.1-11], and 2.5S.1-6 [Reference 2.5S.1-12]) and extend to the northwest 75-150 miles. The se ...
Antigorite Peridotite, Metaserpentinite, and other
... insights into mantle serpentinization, slab^wedge interactions during low-angle subduction and mantle evolution. The NVF is located in the interior of the Colorado Plateau, which is a relatively stable block of continental lithosphere (Fig. 1). Laramide-related deformation began in the plateau inter ...
... insights into mantle serpentinization, slab^wedge interactions during low-angle subduction and mantle evolution. The NVF is located in the interior of the Colorado Plateau, which is a relatively stable block of continental lithosphere (Fig. 1). Laramide-related deformation began in the plateau inter ...
an example to sepiolite formation in volcanic belts by
... the vitric tuff. They are irregularly distributed showing gradation into tuff, mostly discontinuous and occasionally silicified, with variable dimensions. Manganese dendrites and staining are also observed within the sepiolite occurrences. Small scale channel deposits, 1-5 m wide, are found within t ...
... the vitric tuff. They are irregularly distributed showing gradation into tuff, mostly discontinuous and occasionally silicified, with variable dimensions. Manganese dendrites and staining are also observed within the sepiolite occurrences. Small scale channel deposits, 1-5 m wide, are found within t ...
Age, Origin and Emplacement of Diamonds
... rocks. It is also important to recognize that xenoliths in kimberlite and lamproite do not always represent with fidelity the mineralogy and pressure-temperature conditions of the mantle in which they are supposed to have formed, because extensive modification may take place as they react chemically ...
... rocks. It is also important to recognize that xenoliths in kimberlite and lamproite do not always represent with fidelity the mineralogy and pressure-temperature conditions of the mantle in which they are supposed to have formed, because extensive modification may take place as they react chemically ...
majalah perdana
... project is dominated by hydrothermal alteration (clay-chlorite-magnetite±epidote and carbonate). This alteration is typical of a propylitic alteration that is overprinted by later argillic-phyllic alteration. Most of the work has been concentrated on Randu Kuning area to follow up on encouraging res ...
... project is dominated by hydrothermal alteration (clay-chlorite-magnetite±epidote and carbonate). This alteration is typical of a propylitic alteration that is overprinted by later argillic-phyllic alteration. Most of the work has been concentrated on Randu Kuning area to follow up on encouraging res ...
Differential preservation in the geologic record of intraoceanic arc
... rate to the trench and convergence rate allow a thick sediment pile to ...
... rate to the trench and convergence rate allow a thick sediment pile to ...
mantle plumes and hot spots - The Centre for Earth Evolution and
... thought to form as lithospheric plates move over plumes. The active hotspot is at one end of the chain; radiometric dating has determined that the ages of the volcanics along the chain tend to increase with distance from the active hotspot. Interpretation of age data is complicated, because volcanic ...
... thought to form as lithospheric plates move over plumes. The active hotspot is at one end of the chain; radiometric dating has determined that the ages of the volcanics along the chain tend to increase with distance from the active hotspot. Interpretation of age data is complicated, because volcanic ...
Mechanism and timing of Pb transport from subducted oceanic crust
... from the basaltic crust of the subducting Louisville Seamount Chain. The dominant source of mantle Pb in arc lavas (at least in northern Tonga), is therefore subducted basaltic oceanic crust, rather than the overlying mantle wedge. The orientation of the Pb isotope arrays constrain the relative timi ...
... from the basaltic crust of the subducting Louisville Seamount Chain. The dominant source of mantle Pb in arc lavas (at least in northern Tonga), is therefore subducted basaltic oceanic crust, rather than the overlying mantle wedge. The orientation of the Pb isotope arrays constrain the relative timi ...
Bedrock geology in New England submarine canyons
... massive. The rocks exhibit solution cavities and are covered with' an abondance of sessile !ife forms. Sampie 780-4, from the base of the outcrop is a coarsegrained calcareous sandstone, the grains exhibiting oolitic coatings (Plate 2 f). We moved up this outcrop, documenting medium-scale festoon cr ...
... massive. The rocks exhibit solution cavities and are covered with' an abondance of sessile !ife forms. Sampie 780-4, from the base of the outcrop is a coarsegrained calcareous sandstone, the grains exhibiting oolitic coatings (Plate 2 f). We moved up this outcrop, documenting medium-scale festoon cr ...
Extensional Tectonics in the Basin and Range Province and the
... mapping supports previous interpretation of this structure as a piece of a single, laterally continuous fold, whose extensionally dismembered fragments form a key marker in reconstructions of Basin and Range extension. Such an interpretation suggests >100 km of west-north-west translation of the Gra ...
... mapping supports previous interpretation of this structure as a piece of a single, laterally continuous fold, whose extensionally dismembered fragments form a key marker in reconstructions of Basin and Range extension. Such an interpretation suggests >100 km of west-north-west translation of the Gra ...
as PDF
... The ancestral Late Palaeozoic – Early Mesozoic Tien Shan belt was reactivated in the Late Mesozoic and a new mountain belt was built at this time along the inherited structural fabric. This is clearly illustrated by the foreland sediments of this Mesozoic Tien Shan range: Jurassic to Cretaceous sedi ...
... The ancestral Late Palaeozoic – Early Mesozoic Tien Shan belt was reactivated in the Late Mesozoic and a new mountain belt was built at this time along the inherited structural fabric. This is clearly illustrated by the foreland sediments of this Mesozoic Tien Shan range: Jurassic to Cretaceous sedi ...
pdf file - University of Victoria
... More surprising is that lower crust flow has been concluded for the Basin and Range province of western United States which has a thin crust. In this area there are high crustal temperatures and a thin crust, averaging about 31 km (e.g., Klemperer et al., 1986; Levandowski et al., 2014). Both the th ...
... More surprising is that lower crust flow has been concluded for the Basin and Range province of western United States which has a thin crust. In this area there are high crustal temperatures and a thin crust, averaging about 31 km (e.g., Klemperer et al., 1986; Levandowski et al., 2014). Both the th ...
Downdip landward limit of Cascadia great earthquake rupture
... Cascadia great earthquakes off western North America. This limit is a primary control for ground motion hazard at near-coastal cities. The studies also provide information on the physical controls of subduction thrust rupture globally. The constraints are (1) “locked/ transition” zones from geodetic ...
... Cascadia great earthquakes off western North America. This limit is a primary control for ground motion hazard at near-coastal cities. The studies also provide information on the physical controls of subduction thrust rupture globally. The constraints are (1) “locked/ transition” zones from geodetic ...
Geophysical Journal International - E
... structure of the crust and lithospheric mantle. This was one of the motivations of the TopoIberia project (http://iberarray.ictja.csic.es/), a large-scale multidisciplinary research initiative to investigate the Earth’s structure and dynamics in Iberia and northern Morocco. In this work we analyse d ...
... structure of the crust and lithospheric mantle. This was one of the motivations of the TopoIberia project (http://iberarray.ictja.csic.es/), a large-scale multidisciplinary research initiative to investigate the Earth’s structure and dynamics in Iberia and northern Morocco. In this work we analyse d ...
the basic mineralogic, paragenetic and genetic
... sulphide deposits, the paragenetical relationships among the minerals, the order of their deposition and the genesis of single deposits, and the metallogeny of this region. In general, there exist three genetical groups of the described deposits, such as: a. Volcanic-sedlmentary-hydrothermal (Cu, Zn ...
... sulphide deposits, the paragenetical relationships among the minerals, the order of their deposition and the genesis of single deposits, and the metallogeny of this region. In general, there exist three genetical groups of the described deposits, such as: a. Volcanic-sedlmentary-hydrothermal (Cu, Zn ...
Reprint - Frederic MOUTHEREAU
... between the rheology and tectonic inheritance on the Arabian margin, plate kinematics, and change in boundary forces is needed here. The goal of this review paper is to investigate the dynamic evolution of the Zagros orogenic system during the Cenozoic, following a very active decade of acquisition ...
... between the rheology and tectonic inheritance on the Arabian margin, plate kinematics, and change in boundary forces is needed here. The goal of this review paper is to investigate the dynamic evolution of the Zagros orogenic system during the Cenozoic, following a very active decade of acquisition ...
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.