Results 71 to 80 of about 15,483 (211)
Eos, Transactions American Geophysical Union, 1984 A cross section of the Archean crust provided the focus of the 1983 Archean Geochemistry and Early Crustal Genesis Workshop that convened in Ottawa on August 10, 1983. Forty‐six geoscientists registered: 24 from the United States, 16 from Canada, three from Australia, and one each from West Germany, the Peoples' Republic of China, and Zimbabwe.
openaire +1 more source
Journal of the Geological Survey of BrazilGamma-ray spectrometry, as well as magnetic and gravity data, are used to investigate the geophysical signatures of the Archean nuclei of the Borborema Province.
Roberto Gusmão de Oliveira +6 more
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Diminished greenhouse warming from Archean methane due to solar absorption lines [PDF]
Climate of the Past, 2015 Previous research has shown that methane may have been sustained at high concentrations in the Archean atmosphere, helping to offset lower insolation and solve the faint young sun problem.
B. Byrne, C. Goldblatt
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Archean Quench-Texture Tholeiites
, 1974 Tholeiitic metabasalts and metaandesites from sub-greenschist metavolcanics in the Abitibi volcanic belt northeast of Noranda–Rouyn display delicate and ornamental crystals indicative of rapid or supercooling.
L. Gélinas +3 more
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Comparisons between Tethyan Anorthosite-bearing Ophiolites and Archean Anorthosite-bearing Layered Intrusions: Implications for Archean Geodynamic Processes [PDF]
, 2020 Elucidating the petrogenesis and geodynamic setting(s) of anorthosites in Archean layered intrusions and Tethyan ophiolites has significant implications for crustal evolution and growth throughout Earth history.
Polat, Ali, Sotiriou, Paul
core
UV radiation limited the expansion of cyanobacteria in early marine photic environments
Nature Communications, 2018 The means by which planktonic cyanobacteria were able to persist through the Archean despite high fluxes of UV radiation are unclear. Here, the authors show that Fe(III)-Si rich precipitates in the Archean photic zone could have provided early planktonic
Aleksandra M. Mloszewska +6 more
doaj +1 more source
Amphibole as window on the Archean mantle composition
, 2018 The Archean mantle is among the few reservoirs on Earth preserving records of the early differentiation of the planet. Because the Archean mantle is poorly preserved, only Archean komatiites and few other mantle-derived rocks of Archean age are the only ...
Langone A. +4 more
core +2 more sources
, 1979 Detailed petrographic comparison of Archean and Cenozoic hyaloclastites and pillows permits us to outline an analogous history of sea-floor metamorphism.
Erich Dimroth, Andreas P. Lichtblau
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Archean phosphorus liberation induced by iron redox geochemistry
Nature Communications, 2018 Phosphorus is presumed to have been a limiting nutrient in the Archean ocean due to binding to iron oxides. Here, the authors show the heating of iron with phosphate results in the reduction of phosphate to the ion phosphite, which is solubilized and ...
Barry Herschy +8 more
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The Archean Granitoid-Paleoproterozoic Unconformity: Superimposition of Alteration Events in Archean Granitoids, Gabon [PDF]
, 2013 International audienceThe Archean granitoids of the South Gabon, dated from 3.0-to-2.5 Ga, were examined along the Archean-Proterozoic unconformity. The petrography was based on mineralogical identification using electron microscopy, X-ray diffraction ...
El Albani, Abderrazak +8 more
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