Results 31 to 40 of about 31,446 (282)
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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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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Proterozoic Milankovitch cycles and the history of the solar system
Proceedings of the National Academy of Sciences of the United States of America, 2018 Significance Periodic variations in Earth’s orbit and rotation axis occur over tens of thousands of years, producing rhythmic climate changes known as Milankovitch cycles.
S. Meyers, A. Malinverno
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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. It has
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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Geological Journal, EarlyView.The Pangkaimen Au–Ag deposits belong to the epithermal Au deposits, which are of great significance for guiding the research and development of this type of gold deposit. Metallogenic model diagram of Pangkaimen Au–Ag deposit. ABSTRACT The gold (Au) metallogenic belt in the northern Great Xing'an Range is characterised by the wide occurrence of the ...
Sheng Lu +8 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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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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