Results 91 to 100 of about 32,483 (245)

Geological and isotopic characteristics of granites from the Western Pernambuco-Alagoas Domain: implications for the crustal evolution of the Neoproterozoic Borborema Province

Brazilian Journal of Geology
The Western Pernambuco-Alagoas Domain is a complex tectonic domain of the Southern part of the Neoproterozoic Borborema Province. It borders the Northern margin of São Francisco Craton. U-Pb and Sm-Nd data discussed in this work show that, in the Western
Rodrigo Fabiano da Cruz, Márcio Martins Pimentel, Ana Cláudia de Aguiar Accioly, Joseneusa Brilhante Rodrigues   +3 more
doaj   +1 more source

Potassium Isotope Evidence for Origin of Archean TTG Rocks From Seawater‐Hydrothermally Altered Oceanic Crust

Geochemistry, Geophysics, Geosystems
Tonalite‐trondhjemite‐granodiorite (TTG) rocks constitute a crucial part of the Archean continental crust, yet their origins remain contentious. It is critical to decipher their source nature and hydration mechanism.
D.‐Y. Xiong, X.‐L. Wang, W. Li, Y.‐F. Zheng, C. R. Anhaeusser, A. Hofmann, D. Wang, J.‐Y. Li   +7 more
doaj   +1 more source

Atmospheric Evolution

, 2017
Earth's atmosphere has evolved as volatile species cycle between the atmosphere, ocean, biomass and the solid Earth. The geochemical, biological and astrophysical processes that control atmospheric evolution are reviewed from an "Earth Systems ...
AA Pavlov, AE Isley, AJ Ridgwell, AJ Watson, AJ Watson, AJ West, AL Roberson, AP Ingersoll, B Byrne, B Byrne, B Marty, B Marty, B Mills, BW Johnson, BW Johnson, C Dessert, C Goldblatt, C Goldblatt, C Goldblatt, C Goldblatt, C Goldblatt, C Sagan, C Sagan, C Sagan, CL Blattler, DAD Evans, DC Catling, DC Catling, DE Ibarra, DL Royer, DM Hunten, DR Hitchcock, DS Abbot, DV Kent, EE Stüeken, EG Nisbet, EG Nisbet, ET Wolf, G Feulner, GC Simpson, GE Bebout, HC Urey, HD Holland, J Farquhar, J Hartmann, J Leconte, JCG Walker, JCG Walker, JCG Walker, JD Haqq-Misra, JE Lovelock, JE Lovelock, JE Lovelock, JF Kasting, K Hamano, K Wallmann, KJ Zahnle, KJ Zahnle, KJ Zahnle, KR Anderson, L Li, L Li, LM Och, LR Kump, M Komabayashi, M Popp, M Voyer Le, ND Sheldon, R Barnes, R Buick, R Rye, R Wordsworth, RA Berner, RA Berner, RA Berner, RD Wordsworth, RE Zeebe, RT Pierrehumbert, S Chapman, S Nakajima, T Matsui, T Owen, TM Donahue, TM Lenton, TM Lenton, TW Lyons, VI Vernadsky, VI Vernadsky, WR Kuhn, Y Goddéris   +89 more
core   +1 more source

PALEOARCHEAN MAFIC ROCKS OF THE SOUTHWESTERN SIBERIAN CRATON: PRELIMINARY GEOCHRONOLOGY AND GEOCHEMICAL CHARACTERIZATION

Геодинамика и тектонофизика, 2017
The Siberian craton consists of Archean blocks, which were welded up into the same large unit by ca 1.9 Ga [Gladkochub et al., 2006; Rojas-Agramonte et al., 2011].
A. V. Ivanov, I. V. Levitsky, V. I. Levitsky, E. I. Demonterova, L Z. Reznitsky   +4 more
doaj   +1 more source

Marine Phosphate Level During the Archean Constrained by the Global Redox Budget

Geophysical Research Letters
Understanding the oceanic phosphate concentration is critical for understanding marine productivity and oxygen evolution throughout Earth history. During the Archean, estimates of marine phosphate levels range from scarce to enriched conditions. However,
Yasuto Watanabe, Kazumi Ozaki, Eiichi Tajika   +2 more
doaj   +1 more source

Early Archean tonalite gneiss in the upper peninsula of Michigan [PDF]

Geochronological results on tonalite gneiss of northern Michigan that is 3.56 Ga or slightly older is presented. Tonalitic augen gneiss and structurally overlying biotite gneiss and schist are exposed in a dome near Watersmeet.
Peterman, Z. E., Sims, P. K., Zartman, R. E.   +2 more
core   +1 more source

Non‐enzymatic glycolysis and pentose phosphate pathway‐like reactions in a plausible Archean ocean

Molecular Systems Biology, 2014
The reaction sequences of central metabolism, glycolysis and the pentose phosphate pathway provide essential precursors for nucleic acids, amino acids and lipids. However, their evolutionary origins are not yet understood.
Markus A Keller, Alexandra V Turchyn, Markus Ralser   +2 more
doaj   +1 more source

An archean suture zone in the Tobacco Root Mountains? (1984) Evolution of Archean Continental Crust, SW Montana (1985) [PDF]

The Lake Plateau area of the Beartooth Mountains, Montana were mapped and geochemically sampled. The allochthonous nature of the Stillwater Complex was interpreted as a Cordilleran-style continental margin.
Kain, L., Mogk, D. W.
core   +1 more source

Comments on “was hydrogen peroxide present before the arrival of oxygenic photosynthesis? The important role of iron(II) in the archean ocean”

Redox Biology
Recent research has hypothesized that hydrogen peroxide (H2O2) may have emerged from abiotic geochemical processes during the Archean eon (4.0–2.5 Ga), stimulating the evolution of an enzymatic antioxidant system in early life. This eventually led to the
Xiao Wu, Jianxi Zhu, Hongping He, Kurt O. Konhauser, Yiliang Li   +4 more
doaj   +1 more source

Archean metamorphic sequence and surfaces, Kangerdlugssuaq Fjord, East Greenland [PDF]

The characteristics of Archean metamorphic surfaces and fabrics of a mapped sequence of rocks older than about 3000 Ma provide information basic to an understanding of the structural evolution and metamorphic history in Kangerdlugssuaq Fjord, east ...
Kays, M. A.
core   +1 more source