Results 21 to 30 of about 2,601 (182)
Proterozoic, Archeam and other weeds in the Precambrian rock garden [PDF]
Bulletin of the Geological Society of Finland, 1970 The use of the terms Precambrian; Proterozoic, Algonkian, and Archean; Cryptozoic and Archeozoic; and Eocambrian, Infracambrian, and Subcambrian is discussed.
K. Rankama
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Evidence that the GOE was a prolonged event with a peak around 1900 Ma
Geosystems and Geoenvironment, 2022 The great oxygenation event (GOE), the first of two major rises in atmospheric oxygen in Earth history, was initially placed near the Archean-Proterozoic boundary (∼2500 Ma). More recently, the position of the GOE has been moved to between 2500 and 2300
Ross R. Large +5 more
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, 1997 The Proterozoic rocks form a major component of the supracrustal wedge in northern Yukon Territory and western District of Mackenzie. They are composed mostly of sedimentary, clastic rocks of lower greenschist facies and rest with profound unconformity upon crystalline igneous and metamorphic rocks of the Hudsonian basement.
D K Norris, L D Dyke
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International Journal of Geoheritage and Parks, 2019 The Pilbara region of Western Australia, covering some 500 km × 500 km, provides a diversity of Archaean to Proterozoic igneous rocks in a relatively compact area that records a younging southward crustal history of igneous activity, sedimentation, early
V. Semeniuk, M. Brocx
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Tektonika, 2023 Higher than average thermobaric ratios (temperature/pressure) of metamorphic rocks and abundant ‘dry’ ferroan magmatism including massif anorthosite suites are two enigmatic features of the mid-Proterozoic (1.85–0.85 Ga) that have unclear origins.
Nick Roberts +3 more
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Metamorphosed and deformed pillows from Losomäki: evidence of sub-aqueous volcanism in the Outokumpu association, eastern Finland [PDF]
Bulletin of the Geological Society of Finland, 1981 Pillow lavas, some highly deformed and now seen as banded diopside amphibolites and tremolite-epidote-chlorite rocks (»barren skarn»), occur within the lower Proterozoic Outokumpu rock association at Losomäki, 50 km N.W. of Outokumpu.
A.F. Park, D.R. Bowes
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Geology of Elu Inlet and Melville Sound, Nunavut, Arctic Canada
Journal of Maps, 2017 We present the results of helicopter- and field-based geological mapping of Elu Inlet and Melville Sound, Kitikmeot Region of Nunavut, Arctic Canada. The area includes a ∼150 km-wide belt of Proterozoic sedimentary rocks that unconformably overlie the ...
Alessandro Ielpi +3 more
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Thermal and Compositional Anomalies of the Australian Upper Mantle From Seismic and Gravity Data
Geochemistry, Geophysics, Geosystems, 2020 To discern temperature and compositional variations of the Australian upper mantle, we apply an integrative technique, which jointly interprets seismic tomography and gravity data.
Magdala Tesauro +2 more
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Notable Impact of Paleotectonic Stress on Gold Mineralisation in the West Qinling Orogen
Geological Journal, EarlyView.By applying fuzzy clustering and multiple inverse methods, we systematically processed the data of vein and fault slip in this ore deposit to reveal the transition of orogenic geological environment and paleotectonic stress field. Our research results show two different stress states: the northwest–southeast extensional stress field and the northeast ...
Hongyan Wang +3 more
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Геодинамика и тектонофизикаThe study of diverse mantle-derived igneous complexes is important for interpreting geodynamic events, ore deposits formation mechanisms, and ore-forming fluid sources.
A. A. Kravchenko +4 more
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