Precambrian glaciations and the evolution of the atmosphere [PDF]
Annales Geophysicae, 1994 Precambrian glaciations appear to be confined to two periods, one in the early Proterozoic between 2.5 and 2 Gyears BP (Before Present) and the other in the late Proterozoic between 1 and 0.57 Gyear BP. Possible reasons for these broad features of the
J. H. Carver, I. M. Vardavas
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On the ages of some granitoid and schist complexes in northern Finland [PDF]
Bulletin of the Geological Society of Finland, 1982 Contact observations and most radiometric datings indicate that the large complex of granitoid rocks and migmatites in Central Lapland is late Svecokarelian (Proterozoic) in age. The geological setting of the complex suggests, however, that it previously
R. Lauerma
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Geophysical Monograph Series, Page 137-165., 2020 This book is Open Access. A digital copy can be downloaded for free from Wiley Online Library.
Explores the behavior of carbon in minerals, melts, and fluids under extreme conditions
Carbon trapped in diamonds and carbonate-bearing rocks in subduction zones are examples of the continuing exchange of substantial carbon ...
Konstantin Litasov +3 more
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Earth's anomalous middle-age magmatism driven by plate slowdown
Scientific Reports, 2022 The mid-Proterozoic or "boring billion" exhibited extremely stable environmental conditions, with little change in atmospheric oxygen levels, and mildly oxygenated shallow oceans.
C. O’Neill +3 more
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A revision of the Proterozoic-Archean boundary of the Northern Bothnian schist belt with a discussion of the geochemistry of related basic metavolcanics [PDF]
Bulletin of the Geological Society of Finland, 1986 Geophysical analysis suggests the need for a revision of the eastern border of the early Proterozoic Northern Bothnian (or Kiiminki) schist belt. Recent geological field work has revealed places where the discordance and hiatus between Proterozoic and ...
Y. Kähkonen, E. Mattila, J. Nuutilainen
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When Proterozoic Crusts Became Thick: New Insights from Magma Petrology
Geosciences, 2018 The Earth’s continental crust represents the outermost envelope of the solid Earth, controlling exchanges within the geosphere and reflecting geodynamics processes.
Jérôme Ganne +7 more
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Early Ediacaran collision zone (ca. 620 Ma) in Saudi Arabia and Yemen inferred from aeromagnetic mapping [PDF]
LithosphereThe tectonic terranes in the Proterozoic outcrops in Saudi Arabia are separated from those in Yemen by extensive regions that are covered by Phanerozoic sedimentary rocks and Tertiary volcanics.
Moujahed Al-Husseini, Ian C.F. Stewart
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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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Archean versus Phanerozoic oceanic crust formation and tectonics: Ophiolites through time
Geosystems and Geoenvironment, 2022 A global compilation of structural, lithological, and geochemical data on a selection of Archean, Proterozoic and Phanerozoic magmatic complexes, interpreted as ophiolites, is presented.
Harald Furnes, Yildirim Dilek
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Enigmatic Mid‐Proterozoic Orogens: Hot, Thin, and Low
Geophysical Research Letters, 2021 Since the Archean, secular change in orogenic style is demonstrated through evolution of metamorphic conditions and geochemical proxies. Linked to orogenic style is the amount of crustal thickening and elevation, whereas orogenic vigor is related to the ...
Christopher J. Spencer +2 more
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