Results 1 to 10 of about 9,495 (248)
Science Advances, 2020 What was the early atmosphere made of? We review what is known during the Archean eon, 4 to 2.5 billion years ago.
David C Catling, Kevin J Zahnle
exaly +3 more sources
Records of mantle geodynamics and atmospheric escape in Archean quartz. [PDF]
Sci AdvVayrac F +4 more
europepmc +2 more sources
Growth of the Archean sialic crust as revealed by zircon in the TTGs in eastern Finland [PDF]
Bulletin of the Geological Society of Finland, 2021 U–Pb age determinations on zircon from granitoids in the Archean of eastern Finland were conducted using the SIMS, LA-ICP-MS and TIMS techniques, with an emphasis on low-HREE granitoids.
Pentti Hölttä +5 more
doaj +1 more source
Secular change of tectonic setting in the Archean Takanen greenstone belt, northeastern Karelia Province, Fennoscandian Shield [PDF]
Bulletin of the Geological Society of Finland, 2023 The target of this study is the Takanen greenstone belt (TGB), a small 11-km-long and east-west oriented supracrustal belt in the northern Lentua complex of the Western Karelia Subprovince (eastern Finland).
Ville Järvinen +6 more
doaj +1 more source
BSGF - Earth Sciences Bulletin, 2023 The Sassandra-Cavally (SASCA) domain (SW Côte d’Ivoire) marks the transition between the Archean Kenema-Man craton and the Paleoproterozoic (Rhyacian) Baoule-Mossi domain.
Koffi Augustin Yao +9 more
doaj +1 more source
Shale Heavy Metal Isotope Records of Low Environmental O2 Between Two Archean Oxidation Events
Frontiers in Earth Science, 2022 Evidence of molecular oxygen (O2) accumulation at Earth’s surface during the Archean (4.0–2.5 billion years ago, or Ga) seems to increase in its abundance and compelling nature toward the end of the eon, during the runup to the Great Oxidation Event. Yet,
Chadlin M. Ostrander +9 more
doaj +1 more source
Novel Microbial Groups Drive Productivity in an Archean Iron Formation
Frontiers in Microbiology, 2021 Deep subsurface environments are decoupled from Earth’s surface processes yet diverse, active, and abundant microbial communities thrive in these isolated environments.
Cody S. Sheik +13 more
doaj +1 more source
Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland [PDF]
Bulletin of the Geological Society of Finland, 2020 Archean terranes are generally poorly exposed and structurally complicated, making models of geological evolution difficult to establish. Because of pervasive metamorphism, strong deformation, and poorly exposed bedrock, the stratigraphy, geochronology ...
Johanna Tepsell +9 more
doaj +1 more source
Геофизический журнал, 2023 The aim of the study, the results of which are presented in this article, is to study changes in the composition of hydrothermal fluid ore systems of the early Precambrian on the example of gold and uranium ore deposits of the Ukrainian shield in ...
Yu.O. Fomin +5 more
doaj +1 more source
Constraints over the age of magmatism and subsequent deformation for the Neoarchean Kukkola Gneiss Complex, northern Fennoscandia [PDF]
Bulletin of the Geological Society of Finland, 2020 The Archean crust in northern Fennoscandia preserves a fragmentary geological record, making direct correlation among Archean domains challenging. This study presents two new zircon U-Pb age determinations from the Archean Kukkola Gneiss Complex (KGC ...
Pietari Skyttä +6 more
doaj +1 more source