RELICT PLAGIOCLASE PHENOCRYSTS FROM AMPHIBO_ LITE
... the original unrecrystallized plagioclasegrains are preserved in a few of these rocks. These metavolcanic rocks are interlayered with metaconglomerateand paragneiss(Smith, et,al'.,1969). The relict phenocrystsnear Plevna Lake occur in the center of a lenselike metavolcanic flow which has a maximum o ...
... the original unrecrystallized plagioclasegrains are preserved in a few of these rocks. These metavolcanic rocks are interlayered with metaconglomerateand paragneiss(Smith, et,al'.,1969). The relict phenocrystsnear Plevna Lake occur in the center of a lenselike metavolcanic flow which has a maximum o ...
Gondwana Park draft1corr
... heritage. This proposal for Africa’s first Geopark covers an area of approximately 60 000 km² and is situated between 20º and 22º south and 13º and 16º east, in the central western part of Namibia with the Atlantic Ocean as its western boundary (see p. 10). The area boosts scenic landforms, palaeont ...
... heritage. This proposal for Africa’s first Geopark covers an area of approximately 60 000 km² and is situated between 20º and 22º south and 13º and 16º east, in the central western part of Namibia with the Atlantic Ocean as its western boundary (see p. 10). The area boosts scenic landforms, palaeont ...
Petrology and geochemistry of the Tertiary alkaline intrusive rocks at
... Field observations, petrography, geochemical data and the results of K–Ar dating are presented for Oligocene (c. 30–29 Ma) alkaline intrusions at the former township of Doupov (Duppau) in the central part of the Doupovské hory Volcanic Complex (DHVC). The Doupov Intrusive Complex (DIC) is a very lim ...
... Field observations, petrography, geochemical data and the results of K–Ar dating are presented for Oligocene (c. 30–29 Ma) alkaline intrusions at the former township of Doupov (Duppau) in the central part of the Doupovské hory Volcanic Complex (DHVC). The Doupov Intrusive Complex (DIC) is a very lim ...
Detrital Zircon Evidence for Mixing of Mazatzal Province Age
... particular are the Yavapai Province (1.70 – 1.78 billion years old) and the Mazatzal Province (1.60 – 1.69 billion years old). Between about 1.60 and 1.80 billion years ago these provinces were accreted along the continental margin across the central United States and Great Lakes, and into northeast ...
... particular are the Yavapai Province (1.70 – 1.78 billion years old) and the Mazatzal Province (1.60 – 1.69 billion years old). Between about 1.60 and 1.80 billion years ago these provinces were accreted along the continental margin across the central United States and Great Lakes, and into northeast ...
Setting Based Classification
... • Metamorphism often continues after major deformation ceases – Metamorphic pattern is simpler than the structural one • Pattern of increasing metamorphic grade from both directions toward the core area ...
... • Metamorphism often continues after major deformation ceases – Metamorphic pattern is simpler than the structural one • Pattern of increasing metamorphic grade from both directions toward the core area ...
fractured basement a case study
... • Hydrothermal activities are stronger along high displacement faults and seem to create sealing barrier between fault blocks ...
... • Hydrothermal activities are stronger along high displacement faults and seem to create sealing barrier between fault blocks ...
Geology, Mineral Deposits, and Geochemical and Radiometric
... miles northwest of the granite. The gneiss, which is gray to pinkish gray where fresh, is composed of quartz, pink orthoclase, and minor amounts of biotite and superficially resembles the granite. Southward, the gneiss grades into light-colored leucocratic schist and gneiss with residual marble beds ...
... miles northwest of the granite. The gneiss, which is gray to pinkish gray where fresh, is composed of quartz, pink orthoclase, and minor amounts of biotite and superficially resembles the granite. Southward, the gneiss grades into light-colored leucocratic schist and gneiss with residual marble beds ...
Summary of Northeast Asia geodynamics and tectonics*
... Fragment of part or all of a suite of deep-marine sedimentary rocks, pillow basalt, gabbro, and ultramafic rocks (former eugeoclinal eugeoclinal suite) that are interpreted as oceanic sedimentary and volcanic rocks and the upper mantle. Includes both inferred offshore oceanic and marginal ocean basi ...
... Fragment of part or all of a suite of deep-marine sedimentary rocks, pillow basalt, gabbro, and ultramafic rocks (former eugeoclinal eugeoclinal suite) that are interpreted as oceanic sedimentary and volcanic rocks and the upper mantle. Includes both inferred offshore oceanic and marginal ocean basi ...
Unit 1 Vocab Review
... layer or interlocking pieces are called tectonic plates. Since they are found on the thin outer layer, they are made of rock. These interlocking pieces are like a large jigsaw puzzle that are irregularly shaped and as they move, they get caught and release from each other, causing earthquakes. ...
... layer or interlocking pieces are called tectonic plates. Since they are found on the thin outer layer, they are made of rock. These interlocking pieces are like a large jigsaw puzzle that are irregularly shaped and as they move, they get caught and release from each other, causing earthquakes. ...
Crustal structure of the southern margin of the African - ePIC
... yeAfrica project. Refraction seismic experiments show that Moho depth decreases rapidly from over 40 km inland to around 30 km at the present coast before gently thinning out toward the Agulhas-Falkland Fracture Zone, which marks the transition zone between the continental and oceanic crust. In the ...
... yeAfrica project. Refraction seismic experiments show that Moho depth decreases rapidly from over 40 km inland to around 30 km at the present coast before gently thinning out toward the Agulhas-Falkland Fracture Zone, which marks the transition zone between the continental and oceanic crust. In the ...
DNR kettle dome fox
... The Kettle gneiss dome is one of several bodies of lineated and foliated high-grade metamorphic and syntectonic plutonic rocks that are commonly referred to as metamorphic core complexes (Davis and Coney, 1979) and that occupy extensive areas of north-central and northeastern Washington. The complex ...
... The Kettle gneiss dome is one of several bodies of lineated and foliated high-grade metamorphic and syntectonic plutonic rocks that are commonly referred to as metamorphic core complexes (Davis and Coney, 1979) and that occupy extensive areas of north-central and northeastern Washington. The complex ...
llyn dulyn
... conditions succeeded by high-energy alluvial braided streams, they provide persuasive evidence for emplacement in a subaerial environment. This interpretation contrasts markedly with that of Capel Curig GCR site where the tuffs have extended into a shallow-marine environment (Figure 6.34). ...
... conditions succeeded by high-energy alluvial braided streams, they provide persuasive evidence for emplacement in a subaerial environment. This interpretation contrasts markedly with that of Capel Curig GCR site where the tuffs have extended into a shallow-marine environment (Figure 6.34). ...
ManuscriptPDF
... strengthening of metapelitic layers relative to metapsammitic layers in amphibolite facies metaturbidites. ...
... strengthening of metapelitic layers relative to metapsammitic layers in amphibolite facies metaturbidites. ...
Merguerian, Charles, 2008h, Geology of the Cortlandt igneous
... In the Manhattan Prong, a basal unit (Layer I) of Proterozoic gneiss (the Fordham Gneiss, 1.1 billion years old) is overlain by Layer II, metasedimentary- and metavolcanic rocks that are inferred to have been deposited along the margin of the ancient North American continent in a long-disappeared o ...
... In the Manhattan Prong, a basal unit (Layer I) of Proterozoic gneiss (the Fordham Gneiss, 1.1 billion years old) is overlain by Layer II, metasedimentary- and metavolcanic rocks that are inferred to have been deposited along the margin of the ancient North American continent in a long-disappeared o ...
Crustal structure beneath the Indochina peninsula
... Copyright 2010 by the American Geophysical Union. 0094‐8276/10/2010GL044874 ...
... Copyright 2010 by the American Geophysical Union. 0094‐8276/10/2010GL044874 ...
Word - Manchester Geological Association
... Scottish and Irish Celts and covered the same area. The Dalradian succession is a thick sequence of sedimentary rocks with minor volcanics that formed on the southern margin of a continent from late Precambrian to late Cambrian times. In early Dalradian times sandstones, mudstones and carbonates acc ...
... Scottish and Irish Celts and covered the same area. The Dalradian succession is a thick sequence of sedimentary rocks with minor volcanics that formed on the southern margin of a continent from late Precambrian to late Cambrian times. In early Dalradian times sandstones, mudstones and carbonates acc ...
Eclogite Engine
... The rates at which basaltic magma is added to the continental crust have recently been revised upwards range to 3.7 km3 yr-1 ...
... The rates at which basaltic magma is added to the continental crust have recently been revised upwards range to 3.7 km3 yr-1 ...
Epithermal antimony, mercury, and gold deposits in the continental
... The epithermal Hg, Sb, and Au ore deposits of Haliköy, Emirli, and Küre are related to faults which strike preferentially NE-SW and NW-SE and are located diagonal to general striking of the rift zone of the Küçük Menderes (Fig. 1). In the eastern and northeastern part of these ore fields the calkalk ...
... The epithermal Hg, Sb, and Au ore deposits of Haliköy, Emirli, and Küre are related to faults which strike preferentially NE-SW and NW-SE and are located diagonal to general striking of the rift zone of the Küçük Menderes (Fig. 1). In the eastern and northeastern part of these ore fields the calkalk ...
Can we bridge geophysics,geochemistry & geodynamics?
... The rates at which basaltic magma is added to the continental crust have recently been revised upwards range to 3.7 km3 yr-1 ...
... The rates at which basaltic magma is added to the continental crust have recently been revised upwards range to 3.7 km3 yr-1 ...
Copper - Department of Natural Resources
... southwestern Avalon Zone and the Foxtrap prospect near St. John’s (Figure 2). ...
... southwestern Avalon Zone and the Foxtrap prospect near St. John’s (Figure 2). ...
Mercian 2005 v16 p138 Charnwood excursion, Carney 483KB
... to a pale cream, fine-grained lithology over several centimetres from the intrusion, and here Boulter and Yates (1987) found evidence for contact-related ‘metasomatism’ in the occurrence of mm-size, greygreen ‘thermal’ spots. These are restricted to certain sedimentary laminae, and in places have be ...
... to a pale cream, fine-grained lithology over several centimetres from the intrusion, and here Boulter and Yates (1987) found evidence for contact-related ‘metasomatism’ in the occurrence of mm-size, greygreen ‘thermal’ spots. These are restricted to certain sedimentary laminae, and in places have be ...
Ophiolites and Their Origins
... basins, from the rift–drift and seafloor spreading stages to subduction initiation and terminal closure. An ophiolite is emplaced either from downgoing oceanic lithosphere via subduction-accretion or from the upper plate in a subduction zone through trench–continent collision. Subduction zone tecton ...
... basins, from the rift–drift and seafloor spreading stages to subduction initiation and terminal closure. An ophiolite is emplaced either from downgoing oceanic lithosphere via subduction-accretion or from the upper plate in a subduction zone through trench–continent collision. Subduction zone tecton ...
Did Paleo-Tethyan anoxia kill arc magma fertility for
... deposits compared with the Paleo-Tethyan suite. DISCUSSION AND CONCLUSIONS Because porphyry Cu deposits require relatively oxidized, hydrous magmas to form, it has been proposed that their almost exclusive global restriction to Phanerozoic arc rocks reflects the delay of deep ocean oxidation, and th ...
... deposits compared with the Paleo-Tethyan suite. DISCUSSION AND CONCLUSIONS Because porphyry Cu deposits require relatively oxidized, hydrous magmas to form, it has been proposed that their almost exclusive global restriction to Phanerozoic arc rocks reflects the delay of deep ocean oxidation, and th ...
Update and economic significance of geological mapping in the
... zones of cohesive mylonite and ultramylonite that contain steeply plunging stretching and quartz-ribbon lineations, and preserve kinematic evidence of northeastover-southwest dip-slip shear. These fabrics are generally overprinted by chloritic mylonite and tectonite that contain shallow lineations a ...
... zones of cohesive mylonite and ultramylonite that contain steeply plunging stretching and quartz-ribbon lineations, and preserve kinematic evidence of northeastover-southwest dip-slip shear. These fabrics are generally overprinted by chloritic mylonite and tectonite that contain shallow lineations a ...
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.