Results 71 to 80 of about 2,811 (192)

Reconciling Coupled Thermal‐Water Evolution Models of Earth With Observations Through Variable Regassing Efficiency

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 9, September 2026.
Abstract Reconciling Earth's thermal evolution with geochemical observations remains a fundamental challenge, as parameterized convection models typically predict high present‐day Urey ratios inconsistent with geochemical estimates. Previous studies propose that if mantle water concentration varies inversely to mantle temperature, it would weaken the ...
Alexander B. Thames, Bradford J. Foley
wiley   +1 more source

Geological and isotope-geochemical criteria of evident presence of ancient continental crust in Primorye basement

open access: yesЛитосфера, 2018
The totality of structural-tectonic, lithologic-mineralogical, isotope-geochemical data on the geology of Primorye and adjacent territories of Northeast China and the Amur Region allows us to justify the criterions for the existence of an ancient sialic ...
Sergei O. Maksimov   +2 more
doaj   +1 more source

Past the First Date: Ensemble Concordant–Discordant Comparison for Zircon Pb‐Loss Analysis

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 9, September 2026.
Abstract Zircon uranium–lead (U–Pb) geochronology is a cornerstone of Earth science for resolving the timing of deep‐time processes, yet the U–Pb system does not always behave as a closed chronometer. Selective loss of radiogenic Pb during fluid alteration or thermal disturbance can shift isotopic ages and generate discordant analyses. Some zircon data
Lucy M. Mathieson   +1 more
wiley   +1 more source

Estratigrafía del Grupo Mina Verdun, Proterozoico de Minas, Uruguay

open access: yesLatin American Journal of Sedimentology and Basin Analysis
El objetivo del presente trabajo es el de presentar un cuadro estratigráfico para las sedimentitas del área del Cerro Verdún, Minas, Uruguay. Asimismo presentar algunas consideraciones sobre sus características sedimentológicas y sus estromatolitos, a ...
Daniel G. Poiré   +3 more
doaj  

Investigating Layered Cratonic Lithosphere in the Fennoscandian Shield

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 9, September 2026.
Abstract Cold, thick, and chemically depleted lithosphere with high seismic velocity and low attenuation characterizes continental cratons. However, discrepancies between xenolith‐based thermal constraints and those inferred from surface‐wave seismic models, together with the widespread observation of mid‐lithosphere discontinuities, challenge the ...
Yiran Huang   +2 more
wiley   +1 more source

Influence of Surface Processes on Intrarift Fault Displacement: 1.38 Million Years of Fault Slip Behavior in the Lake Malawi (Nyasa) Rift

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 9, September 2026.
Abstract Surface processes, including hydroclimate variations, affect crustal deformation and fault behavior. These controls are especially important for intrarift faults in continental rift systems, which accommodate substantial strain while experiencing large hydrological load variations beneath rift lakes.
J. M. Greenlee   +5 more
wiley   +1 more source

Geochronology of sillimanite-cordierite gneiss Atamanovo series of the South Yenisei Ridge (Russia)

open access: yesЛитосфера, 2017
The paper provides justification of Paleo Archaean age (3221 ± 15 Ma) of the granulite plutonic metamorphism that formed the Kan metamorphic complex of the Archaean crust in the Angara-Kan block of the Siberian craton. The age was defined on the basis of
A. M. Sazonov   +6 more
doaj   +2 more sources

The Detectability of CH4/CO2/CO and N2O Biosignatures Through Reflection Spectroscopy of Terrestrial Exoplanets

open access: yesThe Astronomical Journal
The chemical makeup of Earth’s atmosphere during the Archean (4–2.5 Ga) and Proterozoic eon (2.5–0.5 Ga) contrast considerably with the present-day: the Archean was rich in carbon dioxide and methane, and the Proterozoic had potentially higher amounts of
Armen Tokadjian, Renyu Hu, Mario Damiano
doaj   +1 more source

Building the Andean Crust at ∼35°S: Arc Geochemistry Reveals Cretaceous Thinning and Rapid Neogene Thickening

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 9, September 2026.
Abstract Quantification of the timing and mechanisms of crustal thickening in Cordilleran orogenic hinterlands remains challenging. We address this in the Andes using whole‐rock geochemistry and zircon petrochronology from a >70 Myr volcanic record in the Tinguiririca valley of Chile (∼35° ${}^{\circ}$S), which captures a pivotal transition from ...
Chance B. Ronemus   +8 more
wiley   +1 more source

Discussion of multiple formation mechanisms of saddle dolomites—Comparison of geochemical data of Proterozoic–Paleozoic dolomites

open access: yesEnergy Exploration & Exploitation, 2018
As important gas-bearing strata, Proterozoic–Paleozoic marine carbonate successions in the Sichuan Basin have experienced a long diagenetic history and multiphase hydrothermal activities.
Bo Peng   +8 more
doaj   +1 more source

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