IgneousPet423-13Intro
... magmatic liquids. They represent aliquots of liquid that have escaped to the surface. The compositional variation observed in the liquids that the volcanic rocks represent is produced by varying degrees of crystal fractionation of a largely “gabbroic” mineral assemblage that now comprises plutonic i ...
... magmatic liquids. They represent aliquots of liquid that have escaped to the surface. The compositional variation observed in the liquids that the volcanic rocks represent is produced by varying degrees of crystal fractionation of a largely “gabbroic” mineral assemblage that now comprises plutonic i ...
Ophiolites: Figments of Oceanic Lithosphere? Geological Society
... Triassic, largely alkaline, basic volcanism. However, although this evidence is consistent with what is known and expected during the early stages of continental rifting we need not assume that the occurrence of Triassic volcanics necessarily marks the exact margin between continental and new oceani ...
... Triassic, largely alkaline, basic volcanism. However, although this evidence is consistent with what is known and expected during the early stages of continental rifting we need not assume that the occurrence of Triassic volcanics necessarily marks the exact margin between continental and new oceani ...
Brittle Deformation Events in the Lambert Glacier Region (East
... which represent the only area within Antarctica where rocks are accessible that far inland. One of the major aims of PCMEGA was focused on brittle deformation events linked to the development of the Lambert Graben and to possibly still older events. The latter, for instance, could be related to Late ...
... which represent the only area within Antarctica where rocks are accessible that far inland. One of the major aims of PCMEGA was focused on brittle deformation events linked to the development of the Lambert Graben and to possibly still older events. The latter, for instance, could be related to Late ...
Mantle Plumes, Hot Spots and Igneous Rocks
... In this part of the laboratory you will be asked to identify a variety of volcanic rocks based on their color and texture and, to a lesser extent, on their composition. The following is a description of the materials you will be asked to identify. Volcanic rocks (whether intrusive or extrusive rocks ...
... In this part of the laboratory you will be asked to identify a variety of volcanic rocks based on their color and texture and, to a lesser extent, on their composition. The following is a description of the materials you will be asked to identify. Volcanic rocks (whether intrusive or extrusive rocks ...
Lecture W12-W13-L28
... They are typically formed in continental rifts (decompression melting of the sub-rift mantle) – although intracontinental hotspots are also a possibility (more likely to produce CFB’s, though). In this case, melting of the lower crust is possible, but not quite understood. ...
... They are typically formed in continental rifts (decompression melting of the sub-rift mantle) – although intracontinental hotspots are also a possibility (more likely to produce CFB’s, though). In this case, melting of the lower crust is possible, but not quite understood. ...
Developing the plate tectonics from oceanic subduction to
... progresses have been also made by dynamic interpretations of isotope geochronological and geochemical data on UHP metamorphic rocks[13,14]. At the very beginning, a group of Chinese scientists were involved in the revolution of plate tectonics since the finding of coesite and diamond in terrigenous ...
... progresses have been also made by dynamic interpretations of isotope geochronological and geochemical data on UHP metamorphic rocks[13,14]. At the very beginning, a group of Chinese scientists were involved in the revolution of plate tectonics since the finding of coesite and diamond in terrigenous ...
ARCHITECTURE OF CONTINENTAL RIFTS Author: Susanne
... transition from brittle to ductile rock deformation takes place. Extensional faults which appear to be planar and inclined at 30° to 60° generate large magnitude earthquakes. Continental rifting is nearly always accompanied by a series of parallel dykes, volcanism along fissures and central volcanoe ...
... transition from brittle to ductile rock deformation takes place. Extensional faults which appear to be planar and inclined at 30° to 60° generate large magnitude earthquakes. Continental rifting is nearly always accompanied by a series of parallel dykes, volcanism along fissures and central volcanoe ...
Seismic Interpretation and Characterization of Igneous Rocks in Jan
... On seismic sections, igneous rocks in the study area are positive high-amplitude anomalies with similar polarity as the seabed reflection. Their high amplitude is due to the high difference in acoustic impedance between them and their sedimentary counterparts (Smallwood and Maresh, 2002; Alves et al ...
... On seismic sections, igneous rocks in the study area are positive high-amplitude anomalies with similar polarity as the seabed reflection. Their high amplitude is due to the high difference in acoustic impedance between them and their sedimentary counterparts (Smallwood and Maresh, 2002; Alves et al ...
Earth`s Crust
... composition is granite, which is much less dense than the mafic rocks of the oceanic crust ( Figure 1.3). Because it is thick and has relatively low density, continental crust rises higher on the mantle than oceanic crust, which sinks into the mantle to form basins. When filled with water, these bas ...
... composition is granite, which is much less dense than the mafic rocks of the oceanic crust ( Figure 1.3). Because it is thick and has relatively low density, continental crust rises higher on the mantle than oceanic crust, which sinks into the mantle to form basins. When filled with water, these bas ...
Lecture 47
... harzburgitic, harzburgite being a comparatively low-density peridotite. This subcontinental lithosphere is of variable thickness: it is only 10’s of km under tectonically active areas such as the Great Basin but is more than 200 km thick under the South African craton. Basalts from the lithosphere r ...
... harzburgitic, harzburgite being a comparatively low-density peridotite. This subcontinental lithosphere is of variable thickness: it is only 10’s of km under tectonically active areas such as the Great Basin but is more than 200 km thick under the South African craton. Basalts from the lithosphere r ...
Formation of Arizona Minerals through Geologic Time Jan C
... central Plomosa Mountains and examples in southern Arizona include native copper in the high potassium andesitic volcanics at La Colorado south of Arivaca. The Late Cretaceous, Early Laramide (Tombstone) phase (79-67 Ma) consists of lead-zincsilver mineralization associated with caldera development ...
... central Plomosa Mountains and examples in southern Arizona include native copper in the high potassium andesitic volcanics at La Colorado south of Arivaca. The Late Cretaceous, Early Laramide (Tombstone) phase (79-67 Ma) consists of lead-zincsilver mineralization associated with caldera development ...
The geosphere - Blinklearning
... Components of the crust (II): Rocks Rocks are natural aggregates made up of one or various different minerals. Rocks can be identified according to two criteria: • Composition of the minerals which form them: homogeneous and heterogeneus. • Texture or form in which the minerals are arranged in the r ...
... Components of the crust (II): Rocks Rocks are natural aggregates made up of one or various different minerals. Rocks can be identified according to two criteria: • Composition of the minerals which form them: homogeneous and heterogeneus. • Texture or form in which the minerals are arranged in the r ...
... and the Costal Range of the Philippine Sea plate (Fig. 1). It is considered as the collision suture between the two fastconverging plates (Ho, 1986; Tsai, 1986). The Longitudinal Valley extends for about 160 km along the north-northeast– south-southwest orientation with less than 10 km width in most ...
Derived From a Flow Model of Subduction
... A simple viscous flow model of a subduction zone is used to calculate the deformation within continental lithosphere above a subducting slab. Our formulation accounts for two forces that dominate the deformation in the overriding lithosphere: tectonic forces and buoyancy forces. The tectonic forcesa ...
... A simple viscous flow model of a subduction zone is used to calculate the deformation within continental lithosphere above a subducting slab. Our formulation accounts for two forces that dominate the deformation in the overriding lithosphere: tectonic forces and buoyancy forces. The tectonic forcesa ...
Faults, Block Rotations and the Origin of the Orava Basin
... (Serravallian). The NNW-SSE strike-slip fault in the Outer Western Carpathian wear reactivated during the late Miocene time of extension as the normal ones. The elevation of the Babia Góra and Pilsko and the present-day morphotectonic depression between these two mountains is probably related to the ...
... (Serravallian). The NNW-SSE strike-slip fault in the Outer Western Carpathian wear reactivated during the late Miocene time of extension as the normal ones. The elevation of the Babia Góra and Pilsko and the present-day morphotectonic depression between these two mountains is probably related to the ...
Americas, Asia will join to form a supercontinent
... In 50 million to 200 million years, Asia and the Americas will merge and form a supercontinent reminiscent of Pangaea, according to a new study by Yale University scientists. The study, published in Nature journal, predicts that Africa and Australia will join together as well. This shift in geograph ...
... In 50 million to 200 million years, Asia and the Americas will merge and form a supercontinent reminiscent of Pangaea, according to a new study by Yale University scientists. The study, published in Nature journal, predicts that Africa and Australia will join together as well. This shift in geograph ...
unit 2-tectonic landscapes-flash cards
... convergent boundaries (can also occur at oceanic-continental). - At these boundaries as the two plates meet, the force of the collision causes folding and faulting to occur - This results in uplift of rock and sediment squeezed during the collision. - The result is fold mountains such as the Himalay ...
... convergent boundaries (can also occur at oceanic-continental). - At these boundaries as the two plates meet, the force of the collision causes folding and faulting to occur - This results in uplift of rock and sediment squeezed during the collision. - The result is fold mountains such as the Himalay ...
GRANOPHILE METAL DEPOSITS - Department of Natural Resources
... i) Porphyry Copper - Cu, Cu-Mo, Cu-Au deposits; typical grades of 0.4-1% Cu; largest porphyry copper 1.5-3 Bt of 0.8-2% Cu. ii) Porphyry Molybdenum – Can be distinguished from Porphyry Copper deposits on Mo/Cu ratios (>1); molybdenum deposits ...
... i) Porphyry Copper - Cu, Cu-Mo, Cu-Au deposits; typical grades of 0.4-1% Cu; largest porphyry copper 1.5-3 Bt of 0.8-2% Cu. ii) Porphyry Molybdenum – Can be distinguished from Porphyry Copper deposits on Mo/Cu ratios (>1); molybdenum deposits ...
Lecture 23 - Igneous Rocks
... silica. Also applies to rocks containing abundant feldspathoids, such as nepheline. GRANITE Mafic rocks: mnemonic based on magnesium and ferrous/ferric. Synonymous with ferromagnesian, which refers to biotite, amphibole, pyroxene, olivine, and Fe-Ti oxides. BASALT Ultramafic rocks: very rich in Mg a ...
... silica. Also applies to rocks containing abundant feldspathoids, such as nepheline. GRANITE Mafic rocks: mnemonic based on magnesium and ferrous/ferric. Synonymous with ferromagnesian, which refers to biotite, amphibole, pyroxene, olivine, and Fe-Ti oxides. BASALT Ultramafic rocks: very rich in Mg a ...
Orta Anadolu`nun jeolojisi hakkında E. LAHN ÖZET: RAN 8).
... White and very gypsiferous. marls overly the coloured sandstones« The marls sometimes passe into 'mayfly limestones. This gypsiferous formation with its- white or red coloured strata predominates in Central Anatolia where it dominates the landscape of large areas of the country (The principal river ...
... White and very gypsiferous. marls overly the coloured sandstones« The marls sometimes passe into 'mayfly limestones. This gypsiferous formation with its- white or red coloured strata predominates in Central Anatolia where it dominates the landscape of large areas of the country (The principal river ...
here - Eric Twelker
... •Ductile deformation precedes brittle deformation of the same apparent age. •A tensional vein set and guide to ore—described by one worker as diagenetic—is associated with intense compressive folding. •The orebodies are complex in detail, but simple on a large scale. •Some areas—especially near ore ...
... •Ductile deformation precedes brittle deformation of the same apparent age. •A tensional vein set and guide to ore—described by one worker as diagenetic—is associated with intense compressive folding. •The orebodies are complex in detail, but simple on a large scale. •Some areas—especially near ore ...
metamorphism associated with extensional rifting of Gondwana
... discernible from interpretation of the sedimentary sequences deposited within the former continental margin. If the basement and cover of a former continental margin can be reconstructed, then an extensional event may be recognizable which is recorded by metamorphic rocks of lowpressure facies, with ...
... discernible from interpretation of the sedimentary sequences deposited within the former continental margin. If the basement and cover of a former continental margin can be reconstructed, then an extensional event may be recognizable which is recorded by metamorphic rocks of lowpressure facies, with ...
THE SHELBURNE FALLS ARC- LOST ARC OF THE TACONIC
... southern New Hampshire. The problem is that the crystallization ages for this part of the Bronson Hill arc are younger than the ca. 470 to 465 Ma 40Ar/39Ar Taconic cooling ages for Laurentian margin rocks reported by Laird and others (1984) in Vermont, and by Sutter and others (1985) in Massachusett ...
... southern New Hampshire. The problem is that the crystallization ages for this part of the Bronson Hill arc are younger than the ca. 470 to 465 Ma 40Ar/39Ar Taconic cooling ages for Laurentian margin rocks reported by Laird and others (1984) in Vermont, and by Sutter and others (1985) in Massachusett ...
5. Nooksack Valley
... geologic evolution. That course of evolution, as with that of the broader Pacific Northwest, includes the accretion (addition) of a number of “terrane” units to the western margin of the continent here. Those “terranes’ were largely island groups from the ancestral Pacific Basin, brought to our shores ...
... geologic evolution. That course of evolution, as with that of the broader Pacific Northwest, includes the accretion (addition) of a number of “terrane” units to the western margin of the continent here. Those “terranes’ were largely island groups from the ancestral Pacific Basin, brought to our shores ...
The Precambrian rocks of Southern Finland and Estonia (PDF
... the Atlantic Ocean. The volcanic activity in Iceland is also a consequence of this. Iceland is situated right on the mid-oceanic ridge, where two plates drift apart. Since the Earth is a sphere, on which continents are drifting and new oceanic crust is formed all the time, oceanic crust must also be ...
... the Atlantic Ocean. The volcanic activity in Iceland is also a consequence of this. Iceland is situated right on the mid-oceanic ridge, where two plates drift apart. Since the Earth is a sphere, on which continents are drifting and new oceanic crust is formed all the time, oceanic crust must also be ...
Great Lakes tectonic zone
The Great Lakes tectonic zone is bounded by South Dakota at its tip and heads northeast to south of Duluth, Minnesota, then heads east through northern Wisconsin, Marquette, Michigan, and then trends more northeasterly to skim the northern-most shores of lakes Michigan and Huron before ending in the Sudbury, Ontario, Canada, area.During the Late Archean Era the Algoman orogeny added landmass to the Superior province by volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Lake Huron region near Sudbury, Ontario, Canada.This crustal boundary is the Great Lakes tectonic zone. It is 1,400 km (870 mi) long, and separates the older Archean gneissic terrane to the south from younger Late Archean greenstone-granite terrane to the north.The zone is characterized by active compression during the Algoman orogeny (about 2,700 million years ago), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation during Phanerozoic time (the past 500 million years).Collision began along the Great Lakes tectonic zone (GLTZ) with the Algoman mountain-building event and continued for tens of millions of years. During the formation of the GLTZ, the gneissic Minnesota River Valley subprovince was thrust up onto the Superior province's edge as it consumed the Superior province's oceanic crust. Fragmentation of the Kenorland supercontinent began 2,450 million years ago and was completed by 2,100 million years ago. The Wyoming province is the continental landmass that is hypothesized to have rifted away from the southern Superior province portion of Kenorland, before moving rapidly west and docking with the Laurentia supercontinent 1,850 to 1,715 million years ago. Sedimentation from the GLTZ-rifting environment continued into the Penokean orogeny, which is the next major tectonic event in the Great Lakes region. Several earthquakes have been documented in Minnesota, Michigan's Upper Peninsula and Sudbury in the last 120 years along the GLTZ.