BANDED GNEISSES OF EIGHT LOCALITIES G eneral S tatemen t.
... and "migmatic granites", which occur west of the Hang o area were formed by granitization. Still later, H ARME ( e. g., 1958), described similar rocks elsewhere in southern Finland and considered them to be possibly venetic but more likely arteritic on the basis of "addition of juvenile potassium" b ...
... and "migmatic granites", which occur west of the Hang o area were formed by granitization. Still later, H ARME ( e. g., 1958), described similar rocks elsewhere in southern Finland and considered them to be possibly venetic but more likely arteritic on the basis of "addition of juvenile potassium" b ...
2200 million years of crustal evolution: the baltic shield
... synforms and antiforms. During the next two phases, under retrograde amphibolite-facies conditions, first E-W-trending folds were formed and than NE-trending folds were superposed on the previous structures. The results are complex fold interference patterns typical of high-grade terrains. U-Pb ages ...
... synforms and antiforms. During the next two phases, under retrograde amphibolite-facies conditions, first E-W-trending folds were formed and than NE-trending folds were superposed on the previous structures. The results are complex fold interference patterns typical of high-grade terrains. U-Pb ages ...
pdf - Geological Society of Malaysia
... The Eastern ~elt is largely underlain by Carboniferous and Permian clastics and volcanics. A phase of regional metamorphism, folding and uplift probably occurred.in the late Palaeozoic (Permian?) followed by deposition of an older series of continental deposits such as the Murau and Redang conglomer ...
... The Eastern ~elt is largely underlain by Carboniferous and Permian clastics and volcanics. A phase of regional metamorphism, folding and uplift probably occurred.in the late Palaeozoic (Permian?) followed by deposition of an older series of continental deposits such as the Murau and Redang conglomer ...
Advances in the geology of the Tobacco Root Mountains, Montana
... (1) a quartzofeldspathic gneiss complex with associated metasupracrustal rocks (the combined Indian Creek and Pony–Middle Mountain Metamorphic Suites) that originated in a continental arc setting between 3.35 and 3.2 Ga with subsequent sedimentation and (2) mafic metavolcanic rocks with intercalated ...
... (1) a quartzofeldspathic gneiss complex with associated metasupracrustal rocks (the combined Indian Creek and Pony–Middle Mountain Metamorphic Suites) that originated in a continental arc setting between 3.35 and 3.2 Ga with subsequent sedimentation and (2) mafic metavolcanic rocks with intercalated ...
chapter 2
... of new terrain has been added to the western edge of the continent, representing most of Washington State, British Columbia and Alaska. These new lands are largely ocean-floor and volcanic island rocks, brought here by the processes of plate tectonics, and added (accreted) to the edge of the continen ...
... of new terrain has been added to the western edge of the continent, representing most of Washington State, British Columbia and Alaska. These new lands are largely ocean-floor and volcanic island rocks, brought here by the processes of plate tectonics, and added (accreted) to the edge of the continen ...
Polymetallic Sulphides - International Seabed Authority
... Most sites have been located in mid-ocean at the East Pacific Rise, the Southeast Pacific Rise and the Northeast Pacific Rise. Several deposits are also known at the Mid-Atlantic Ridge but only one has so far been located at the ridge system of the Indian Ocean. The paucity of known sulphide deposit ...
... Most sites have been located in mid-ocean at the East Pacific Rise, the Southeast Pacific Rise and the Northeast Pacific Rise. Several deposits are also known at the Mid-Atlantic Ridge but only one has so far been located at the ridge system of the Indian Ocean. The paucity of known sulphide deposit ...
No Slide Title
... METAMORPHIC ROCKS Generally form at conditions between those that form igneous and sedimentary rocks. ...
... METAMORPHIC ROCKS Generally form at conditions between those that form igneous and sedimentary rocks. ...
Gold Deposits and Their Geological Classification
... banded and stratiform massive lenses and adjacent stockwork zones but significant syntectonic sulphide veins are also present in deformed and metamorphosed deposits. The deposits occur in mixed submarine volcanic, volcaniclastic and sedimentary sequences in greenstone belts of all ages, typically me ...
... banded and stratiform massive lenses and adjacent stockwork zones but significant syntectonic sulphide veins are also present in deformed and metamorphosed deposits. The deposits occur in mixed submarine volcanic, volcaniclastic and sedimentary sequences in greenstone belts of all ages, typically me ...
Mantle transition zone thickness beneath Cameroon
... volcanic centres range in age from Eocene to Recent, and are generally alkaline massifs emplaced in a N30◦ trend, similar to more than 60 Paleocene to early Oligocene anorogenic plutonic complexes (Déruelle et al. 1991). The volcanism was initiated as early as 42 Ma, and became widespread along the ...
... volcanic centres range in age from Eocene to Recent, and are generally alkaline massifs emplaced in a N30◦ trend, similar to more than 60 Paleocene to early Oligocene anorogenic plutonic complexes (Déruelle et al. 1991). The volcanism was initiated as early as 42 Ma, and became widespread along the ...
Structure of the Lithosphere and the Sedimentary Record: Where do
... followed by an unconformity and rapid uplift after several million years. This is consistent with a model in which rapid sedimentation generates a negative thermal anomaly which temporarily offsets the positive, crustal, thermal anomaly generated by the impact event. Imaging the structure of crust b ...
... followed by an unconformity and rapid uplift after several million years. This is consistent with a model in which rapid sedimentation generates a negative thermal anomaly which temporarily offsets the positive, crustal, thermal anomaly generated by the impact event. Imaging the structure of crust b ...
Chapter 9 Proterozoic
... abundant bulbous structures known as stromatolites – Northern Michigan ...
... abundant bulbous structures known as stromatolites – Northern Michigan ...
geologic map (scale 1 :250000) of the penokean orogen, central
... Finally, the region henceforth referred to as the foldand-thrust belt (Fig. 1) contains a much larger proportion of volcanic rocks than was heretofore realized. Sizable areas formerly thought to be underlain by metasedimentary rocks or granitoid gneiss, because of their subdued magnetic signature, a ...
... Finally, the region henceforth referred to as the foldand-thrust belt (Fig. 1) contains a much larger proportion of volcanic rocks than was heretofore realized. Sizable areas formerly thought to be underlain by metasedimentary rocks or granitoid gneiss, because of their subdued magnetic signature, a ...
BELT OROGENESIS ALONG THE NORTHERN MARGIN Charles S
... Diabase and rhyodacite sills of Eocene age widely intruded the metasediments, and granitoids were extensively emplaced in the batholiths, causing a resetting of most of the older isotope dates to SO m.y. or younger. Extensive pegmatite subcordant intrusions into the metasediments are considered sync ...
... Diabase and rhyodacite sills of Eocene age widely intruded the metasediments, and granitoids were extensively emplaced in the batholiths, causing a resetting of most of the older isotope dates to SO m.y. or younger. Extensive pegmatite subcordant intrusions into the metasediments are considered sync ...
Bulletin of the Geological Society of Denmark, Vol. 39/3-4 pp. 179-197
... McGregor, V. R., Friend, C. R. L. & Nutman, A. P.: The late Archaean mobile belt through Godthåbsfjord, southern West Greenland: a continent-continent collision zone? Bull. geol. Soc. Denmark, vol. 39, pp. 179-197. Copenhagen, December 20th, 1991. In the Godthåbsfjord region of southern West Greenla ...
... McGregor, V. R., Friend, C. R. L. & Nutman, A. P.: The late Archaean mobile belt through Godthåbsfjord, southern West Greenland: a continent-continent collision zone? Bull. geol. Soc. Denmark, vol. 39, pp. 179-197. Copenhagen, December 20th, 1991. In the Godthåbsfjord region of southern West Greenla ...
Neogene-Recent rifting and volcanism in northern Tanzania
... 1988). The dykes, lavas and central complexes, with an areal extent of approximately 80 km from north to south and180 km from east to west (though it is is not known whether there are further intrusives or lavas under the inland ice to the north east of the province), were emplaced in three major ep ...
... 1988). The dykes, lavas and central complexes, with an areal extent of approximately 80 km from north to south and180 km from east to west (though it is is not known whether there are further intrusives or lavas under the inland ice to the north east of the province), were emplaced in three major ep ...
Tectonic controls on the distribution of large
... copper-gold deposits, which were developed at ca. 20 Ma, at the time when subduction of the PSCSP stopped (e.g. Mount Muro and Mirah). Other deposits developed between 13 and 9 Million Years ago and include one large porphyry copper-gold deposit (Mamut) and several low sulphidation epithermal deposi ...
... copper-gold deposits, which were developed at ca. 20 Ma, at the time when subduction of the PSCSP stopped (e.g. Mount Muro and Mirah). Other deposits developed between 13 and 9 Million Years ago and include one large porphyry copper-gold deposit (Mamut) and several low sulphidation epithermal deposi ...
Geology and Geotectonic Setting of the Basement Complex
... and 10oN and longtitudes 3oE and 6oE right in the equatorial rain forest region of Africa (Fig.1). The main lithologies include the amphibolites, migmatite gneisses, granites and pegmatites. Other important rock units are the schists, made up of biotite schist, quartzite schist talk-tremolite schist ...
... and 10oN and longtitudes 3oE and 6oE right in the equatorial rain forest region of Africa (Fig.1). The main lithologies include the amphibolites, migmatite gneisses, granites and pegmatites. Other important rock units are the schists, made up of biotite schist, quartzite schist talk-tremolite schist ...
nemei lake area - Publications Centre
... The map-area is occupied almost entirely by the Precambrian Kisseynew complex, a group of highly deformed paragneisses that are older than 1700 m.y. and extend over a wide area of Saskatchewan and adjacent Manitoba, north of Flin Flon (Bruce, 1930; Harrison, 1951). Garnet-biotite gneisses underlie m ...
... The map-area is occupied almost entirely by the Precambrian Kisseynew complex, a group of highly deformed paragneisses that are older than 1700 m.y. and extend over a wide area of Saskatchewan and adjacent Manitoba, north of Flin Flon (Bruce, 1930; Harrison, 1951). Garnet-biotite gneisses underlie m ...
Lithosphere, Earth`s Interior and Paleo-Environment
... Southern Granulite Terrain (SGT). The SGT is dominantly composed of late-Archaean granulites in the northern part whilst Proterozoic granulites in the southern part. These two major geological blocks, i.e. DC and SGT, are separated by orthopyroxene isograd. The DC is divided by Closepet granite (CG) ...
... Southern Granulite Terrain (SGT). The SGT is dominantly composed of late-Archaean granulites in the northern part whilst Proterozoic granulites in the southern part. These two major geological blocks, i.e. DC and SGT, are separated by orthopyroxene isograd. The DC is divided by Closepet granite (CG) ...
59 4. DESCRIPTION OF STUDY AREA 4.1. Physiography and
... HRSZ comprises EW striking, steeply northward-dipping thrusts and reverse faults, as well as several NE-SW striking strike-slip faults (Smit et al., 1992). The Hout River Shear Zone can be traced for over 250 km from west to east across the southern margin of the Limpopo Mobile Belt and acts as a co ...
... HRSZ comprises EW striking, steeply northward-dipping thrusts and reverse faults, as well as several NE-SW striking strike-slip faults (Smit et al., 1992). The Hout River Shear Zone can be traced for over 250 km from west to east across the southern margin of the Limpopo Mobile Belt and acts as a co ...
Geology, 39
... eclogite. However, considerable uncertainty surrounds the geologic environment in which melting took place. Commonly invoked options range between melting at the underside of oceanic plateaus above mantle plumes or melting of oceanic lithosphere during shallow subduction. Distinguishing between thes ...
... eclogite. However, considerable uncertainty surrounds the geologic environment in which melting took place. Commonly invoked options range between melting at the underside of oceanic plateaus above mantle plumes or melting of oceanic lithosphere during shallow subduction. Distinguishing between thes ...
Summary of Northeast Asia geodynamics and tectonics*
... continental-margin rocks, oceanic crust and overlying units, and oceanic mantle. Units are interpreted to have formed during tectonic juxtaposition in a zone of major thrusting of one lithosphere plate beneath another, generally in zones of thrusting along the margin of a continent or an island arc. ...
... continental-margin rocks, oceanic crust and overlying units, and oceanic mantle. Units are interpreted to have formed during tectonic juxtaposition in a zone of major thrusting of one lithosphere plate beneath another, generally in zones of thrusting along the margin of a continent or an island arc. ...
Proterozoic
... least clear that, about 1,000–830 Ma, most continental mass was united in the supercontinent Rodinia.[7] Rodinia was not the first supercontinent; it formed at about 1.0 Ga by accretion and collision of fragments produced by breakup of the older supercontinent, called Nuna or Columbia, which was ass ...
... least clear that, about 1,000–830 Ma, most continental mass was united in the supercontinent Rodinia.[7] Rodinia was not the first supercontinent; it formed at about 1.0 Ga by accretion and collision of fragments produced by breakup of the older supercontinent, called Nuna or Columbia, which was ass ...
wik ciółka
... The last three units form true Outer Carpathian realm of the Late Jurassic to Neogene age of the basin development. The Magura Basin has a different history. A part of this basin was incorporated into the Pieniny Klippen Belt, while another part shared the geodynamic history with the other Outer Car ...
... The last three units form true Outer Carpathian realm of the Late Jurassic to Neogene age of the basin development. The Magura Basin has a different history. A part of this basin was incorporated into the Pieniny Klippen Belt, while another part shared the geodynamic history with the other Outer Car ...
The Penokean orogeny in the Lake Superior region
... Formations). A thick succession of arc-derived turbidites constitutes most of the foreland basin-fill along with lesser volcanic rocks. In the southern fold and thrust belt tectonic thickening resulted in high-grade metamorphism of the sediments by 1830 Ma. At this same time, a suite of post-tectoni ...
... Formations). A thick succession of arc-derived turbidites constitutes most of the foreland basin-fill along with lesser volcanic rocks. In the southern fold and thrust belt tectonic thickening resulted in high-grade metamorphism of the sediments by 1830 Ma. At this same time, a suite of post-tectoni ...
Yilgarn Craton
The Yilgarn Craton is a large craton that constitutes the bulk of the Western Australian land mass. It is bounded by a mixture of sedimentary basins and Proterozoic fold and thrust belts. Zircon grains in the Jack Hills, Narryer Terrane have been dated at ~4.27 Ga, with one detrital zircon dated as old as 4.4 Ga.