Results 1 to 10 of about 9,317 (244)
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
Low Temperature Magnetic Properties of the Late Archean Boolgeeda Iron Formation (Hamersley Group, Western Australia): Environmental Implications [PDF]
The origin of the iron oxides in Archean and Paleoproterozoic Banded Iron Formations is still a debated question. We report low and high temperature magnetic properties, susceptibility and saturation magnetization results joined with scanning microscope ...
Julie eCarlut +11 more
doaj +2 more sources
Archean crust-mantle geodynamic regimes: A review
The crust-mantle dynamic system of the formation and evolution of the early Earth crust is a frontier field in current Earth Science. This paper mainly introduces the popular dynamic models, comprising the stagnant-lid, mantle plume, sagduction, dripping,
Shuwen Liu +7 more
doaj +2 more sources
The Mantle Fe3+/ΣFe Ratio Has Doubled Since the Early Archean [PDF]
How mantle redox state developed, particularly the mantle source associated with mid-ocean ridge-like settings, remains a subject of ongoing debate. Here, we employ thermodynamic-thermomechanical numerical simulations to explore the redox properties of ...
Xiao-Xi Zhu +4 more
doaj +2 more sources
Archean phosphorus liberation induced by iron redox geochemistry
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 ...
Heather Abbott-Lyon +2 more
exaly +2 more sources
Growth of the Archean sialic crust as revealed by zircon in the TTGs in eastern Finland [PDF]
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]
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
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
Precambrian tsunamis in the light of the modern data
Background. In the geological history of the Earth, tsunami events attract particular research attention. Such events are assumed to have taken place already since the Precambrian period.
D. A. Ruban
doaj +1 more source
Some new insights into the geochronology of the Western Karelia Subprovince, Finnish Lapland [PDF]
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

