Metamorphism and tectonics
... Precambrian the way we think it does today? Or is it a function of differences in geotherms prevailing at those times? Post-Eocene blueschists are also very rare or nonexistent. Can you think of a reason? ...
... Precambrian the way we think it does today? Or is it a function of differences in geotherms prevailing at those times? Post-Eocene blueschists are also very rare or nonexistent. Can you think of a reason? ...
The stratigraphic succession of Ghana
... structures that would give way-up indications are not always easy to find. Structures are often complex and, where different groups of rocks have been folded together, their relative ages and original relationships are difficult to unravel – unconformities can be obliterated for example, as they hav ...
... structures that would give way-up indications are not always easy to find. Structures are often complex and, where different groups of rocks have been folded together, their relative ages and original relationships are difficult to unravel – unconformities can be obliterated for example, as they hav ...
AM N Pz Scale 1:8 500 000 - Norges geologiske undersøkelse
... and metamorphosed in the Sveconorwegian orogeny (ca. 1140 – 900 Ma) and now form a series of crustal blocks separated by N-S trending deformation belts (Viola et al., 2013). One of the major features in the Sveconorwegian area is the Rogaland Anorthosite Province, S of Stavanger, which includes the ...
... and metamorphosed in the Sveconorwegian orogeny (ca. 1140 – 900 Ma) and now form a series of crustal blocks separated by N-S trending deformation belts (Viola et al., 2013). One of the major features in the Sveconorwegian area is the Rogaland Anorthosite Province, S of Stavanger, which includes the ...
From Ores to Metals
... makes a rock an ore declines. Thus, many mining districts have been mined over and over again, with each new period of mining attributable to an advance in technology. For an extended example, let us consider copper. Although we have, as yet, little direct evidence of the grade of ore used by the ea ...
... makes a rock an ore declines. Thus, many mining districts have been mined over and over again, with each new period of mining attributable to an advance in technology. For an extended example, let us consider copper. Although we have, as yet, little direct evidence of the grade of ore used by the ea ...
ES3210 - Gold Deposits
... Significant Au often present within Fe-rich sulfidized wallrock selvages, or silicified and arsenopyrite-rich replacement zones ...
... Significant Au often present within Fe-rich sulfidized wallrock selvages, or silicified and arsenopyrite-rich replacement zones ...
NWGS Priest River
... feldspar. Thick, concordant, sill-like masses of garnet amphibolite are also widespread. The protolith for the Hauser Lake Gneiss was a sedimentary sequence of pyritic feldspathic sandstones, siltstones, and argillites with intercalated mafic igneous bodies. Numerous workers have suggest that it is P ...
... feldspar. Thick, concordant, sill-like masses of garnet amphibolite are also widespread. The protolith for the Hauser Lake Gneiss was a sedimentary sequence of pyritic feldspathic sandstones, siltstones, and argillites with intercalated mafic igneous bodies. Numerous workers have suggest that it is P ...
Destruction of the North China Craton: a perspective based on
... The North China Craton (NCC), which is composed of the eastern NCC and the western NCC sutured by the Palaeoproterozoic Trans-North China Orogen, is one of the oldest continental nuclei in the world and the largest cratonic block in China. The eastern NCC is widely known for its significant lithosphe ...
... The North China Craton (NCC), which is composed of the eastern NCC and the western NCC sutured by the Palaeoproterozoic Trans-North China Orogen, is one of the oldest continental nuclei in the world and the largest cratonic block in China. The eastern NCC is widely known for its significant lithosphe ...
Metamorphic Facies
... IMPORTANT: Although rocks undergo metamorphism over increasing (or prograde) as well as decreasing (retrograde during exhumation process) set of P-T conditions, the assignment of a rock to a facies is always based on the peak metamorphic conditions it reached. The retrograde conditions are generall ...
... IMPORTANT: Although rocks undergo metamorphism over increasing (or prograde) as well as decreasing (retrograde during exhumation process) set of P-T conditions, the assignment of a rock to a facies is always based on the peak metamorphic conditions it reached. The retrograde conditions are generall ...
A Digital Atlas of Terranes for the Northern Cordillera
... A Digital Atlas of Terranes for the Northern Cordillera Maurice Colpron (Yukon Geological Survey) and JoAnne Nelson (BC Geological Survey) December 2011 – Copyright © 2011 – YGS/BCGS The framework of the Cordilleran orogen of northwestern North America is commonly depicted as a ‘collage’ of terr ...
... A Digital Atlas of Terranes for the Northern Cordillera Maurice Colpron (Yukon Geological Survey) and JoAnne Nelson (BC Geological Survey) December 2011 – Copyright © 2011 – YGS/BCGS The framework of the Cordilleran orogen of northwestern North America is commonly depicted as a ‘collage’ of terr ...
A Digital Atlas of Terranes for the Northern Cordillera
... A Digital Atlas of Terranes for the Northern Cordillera Maurice Colpron (Yukon Geological Survey) and JoAnne Nelson (BC Geological Survey) December 2011 – Copyright © 2011 – YGS/BCGS The framework of the Cordilleran orogen of northwestern North America is commonly depicted as a ‘collage’ of terr ...
... A Digital Atlas of Terranes for the Northern Cordillera Maurice Colpron (Yukon Geological Survey) and JoAnne Nelson (BC Geological Survey) December 2011 – Copyright © 2011 – YGS/BCGS The framework of the Cordilleran orogen of northwestern North America is commonly depicted as a ‘collage’ of terr ...
Science Article PDF - Geological Society of America
... Archean inliers, but was principally formed during the Paleoproterozoic Amazonian and Eburnean orogenies. The continuity of South American Neoproterozoic mobile belts across the Atlantic and the rifting ages of 800 Ma in the northern Cameroon region (Toteu et al., 1987) suggest that this general rif ...
... Archean inliers, but was principally formed during the Paleoproterozoic Amazonian and Eburnean orogenies. The continuity of South American Neoproterozoic mobile belts across the Atlantic and the rifting ages of 800 Ma in the northern Cameroon region (Toteu et al., 1987) suggest that this general rif ...
Table 1. Description of Geologic Units
... Well yield for supply wells in the Piedmont varies significantly, depending on the degree of weathering, topography, type of parent rock, well depth, and degree of fracturing and jointing encountered by the well. In Maryland, well yields overall range from 0 to 200 gallons per minute (gpm); however, ...
... Well yield for supply wells in the Piedmont varies significantly, depending on the degree of weathering, topography, type of parent rock, well depth, and degree of fracturing and jointing encountered by the well. In Maryland, well yields overall range from 0 to 200 gallons per minute (gpm); however, ...
Recognizing optimum Banded-Iron Formation
... Six gold deposits have been found at the Meliadine project: Gold mineralization is mostly in laminated quartz-vein, stockwork and sulphidized BIF. ...
... Six gold deposits have been found at the Meliadine project: Gold mineralization is mostly in laminated quartz-vein, stockwork and sulphidized BIF. ...
Continental collision and the tectono-sedimentary
... More than 100 presentations were given both in oral and poster format. The fundamental idea inspiring the Meeting was to discuss the interactions between colliding continental lithospheric plates. Already from the initial stages it was recognized that only an approach able to integrate the three com ...
... More than 100 presentations were given both in oral and poster format. The fundamental idea inspiring the Meeting was to discuss the interactions between colliding continental lithospheric plates. Already from the initial stages it was recognized that only an approach able to integrate the three com ...
Paleoproterozoic Metamorphism in the Northern Wyoming Province
... The identity of the 11.77-Ga terrane or microcontinent that may have collided with the northern Wyoming province along a generally SW-NE vector is difficult to specify. Evidence of 11.77-Ga crust in the western GFTZ and areas farther west, however, is quite abundant. For example, Leeman et al. (1985 ...
... The identity of the 11.77-Ga terrane or microcontinent that may have collided with the northern Wyoming province along a generally SW-NE vector is difficult to specify. Evidence of 11.77-Ga crust in the western GFTZ and areas farther west, however, is quite abundant. For example, Leeman et al. (1985 ...
Document
... important current lines of research aimed at expansion of mineral resources of not only copper and molybdenum but also Au, Ag, and Pt-group and some other rare metals. According to the modern concept, the largest metallogenic belts in the inner zone of the Circum-Pacific belt in northeastern Asia ar ...
... important current lines of research aimed at expansion of mineral resources of not only copper and molybdenum but also Au, Ag, and Pt-group and some other rare metals. According to the modern concept, the largest metallogenic belts in the inner zone of the Circum-Pacific belt in northeastern Asia ar ...
Geological History of Canada - McGraw Hill Higher Education
... in Canada, is underlain by the exposed part of the ancient core or craton of North America; this exposed part is called the Canadian Shield and consists predominantly of very old, Archean and Proterozoic rocks (figure 20.3A, B). These rocks range in age from 4 billion to approximately 1 billion year ...
... in Canada, is underlain by the exposed part of the ancient core or craton of North America; this exposed part is called the Canadian Shield and consists predominantly of very old, Archean and Proterozoic rocks (figure 20.3A, B). These rocks range in age from 4 billion to approximately 1 billion year ...
The Agulhas – Karoo Geoscience Transect: from a sheared margin
... Continents are known to be made up of a collage of displaced terranes of various origins that accumulate or accrete when continental margins are active. Today, oceanic plateaux, which can be extinct island arcs, extinct spreading ridges, seamounts, or disrupted fragments of continental crust, are pa ...
... Continents are known to be made up of a collage of displaced terranes of various origins that accumulate or accrete when continental margins are active. Today, oceanic plateaux, which can be extinct island arcs, extinct spreading ridges, seamounts, or disrupted fragments of continental crust, are pa ...
Mineral Deposit Research: Meeting the Global Challenge
... the number steeply decreases to the south. The central region shows two peaks at around 48 and 40° N, and a smaller number of deposits occurs in the northern part of the region where an extensive stable platform cover occurs. Large numbers of deposits in the western and central regions formed in the ...
... the number steeply decreases to the south. The central region shows two peaks at around 48 and 40° N, and a smaller number of deposits occurs in the northern part of the region where an extensive stable platform cover occurs. Large numbers of deposits in the western and central regions formed in the ...
Introduction - San Francisco State University
... The Marin Headlands terrane is part of the Franciscan Complex, lying east of the San Andreas Fault and just northwest of the Golden Gate Bridge. The Franciscan Complex exposed in our study area of Marin Headlands consists of pillow basalt, radiolarian chert and shale. These rocks were created at dif ...
... The Marin Headlands terrane is part of the Franciscan Complex, lying east of the San Andreas Fault and just northwest of the Golden Gate Bridge. The Franciscan Complex exposed in our study area of Marin Headlands consists of pillow basalt, radiolarian chert and shale. These rocks were created at dif ...
Diapirism, poly deformation and amoeboidal tee tonic patterns in the
... metamorphism which affected them are collectively termed the " Svecokarelidic orogeny " (Simonen 1971) . Svecokarelidic replaces the older individualized concepts of the "Svecofennidic orogeny" and the "Karelidic orogeny" (Simonen 1960). These supracrustal assemblages have been established as Proter ...
... metamorphism which affected them are collectively termed the " Svecokarelidic orogeny " (Simonen 1971) . Svecokarelidic replaces the older individualized concepts of the "Svecofennidic orogeny" and the "Karelidic orogeny" (Simonen 1960). These supracrustal assemblages have been established as Proter ...
Geology of the West Troms Basement Complex, northern Norway
... Kvaloya, these supracrustal rocks occur as intervening, narrow, steep , NNW-SSE striking belts within the gneisses. The northern half of Senja is underlain by a 30 km-wide shear belt called the Senja Shear Belt (SSB) (Fig. 1) (Tveten & Zwaan 1993). The SSB consists of paragneisses, commonly associat ...
... Kvaloya, these supracrustal rocks occur as intervening, narrow, steep , NNW-SSE striking belts within the gneisses. The northern half of Senja is underlain by a 30 km-wide shear belt called the Senja Shear Belt (SSB) (Fig. 1) (Tveten & Zwaan 1993). The SSB consists of paragneisses, commonly associat ...
Chapter 10—Early Paleozoic Events
... 4. A clastic wedge is a great mass of sedimentary rock representing sediments which have been shed off a rising mountain range during and after an orogenic event. The Queenston clastic wedge was shed off the Taconic Mountains during Early Paleozoic. 5. Sequence-bounding unconformities are the result ...
... 4. A clastic wedge is a great mass of sedimentary rock representing sediments which have been shed off a rising mountain range during and after an orogenic event. The Queenston clastic wedge was shed off the Taconic Mountains during Early Paleozoic. 5. Sequence-bounding unconformities are the result ...
A structural transect across the coastal mobile belt in the Brazilian
... accommodated kilometer-scale transport of crystalline basement, overturned kilometer-scale folds, sheath folds and penetratively developed gneissosity and schistosity. Isolated relics of an older folded fabric occur locally and may represent Transamazonian (2.2–2.0 Ga) deformation. The orogen is kin ...
... accommodated kilometer-scale transport of crystalline basement, overturned kilometer-scale folds, sheath folds and penetratively developed gneissosity and schistosity. Isolated relics of an older folded fabric occur locally and may represent Transamazonian (2.2–2.0 Ga) deformation. The orogen is kin ...
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.