Results 61 to 70 of about 2,944 (200)

Assessment and Correction of Non‐Linearity Effects for In Situ Rb‐Sr Geochronology Applied to High 87Rb/86Sr Mica

Geostandards and Geoanalytical Research, Volume 50, Issue 3, Page 601-624, September 2026.
Key Points Measurement of 86Sr at count rates < 1500 cps can result in statistical bias. Non‐linear signals in analogue detection mode (e.g., Rb) present a challenge for accurately dating high 87Rb/86Sr mica (> 1000). Accounting for these considerations, high 87Rb/86Sr mica are dated here with accuracies of ∼ 1%.
Duane C. Petts, William J. Davis, Simon E. Jackson, Jamie A. Cutts, Janina Czas, Alfredo Camacho   +5 more
wiley   +1 more source

Gamma Rays Signal the Vulnerability of Forest to Extreme Drought

Geophysical Research Letters, Volume 53, Issue 15, 16 August 2026.
Abstract Extreme drought and heat are driving forest die‐off globally, yet regional‐scale mapping of subsurface water storage capacity, governing forest vulnerability, remains a major challenge. Here, we demonstrate that airborne gamma‐ray spectrometry (GRS) of potassium (40K) decay provides a powerful proxy for subsurface constraints on water ...
Gavan S. McGrath, Joseph B. Fontaine, Richard Van Dongen, Katinka X. Ruthrof   +3 more
wiley   +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

Temperature fluctuations controlled episodic rockfall activity in the Rwenzori Mountains (Uganda) during the Holocene

Earth Surface Processes and Landforms, Volume 51, Issue 8, August 2026.
The alignment between rockfall deposit surface exposure 10Be ages and Holocene temperature records suggests that major rockfall events occurred episodically in response to climatic fluctuations. We conclude that temperature and its evolution enabled mechanical, chemical or bio‐chemical enhancement of fracture progression.
Audrey Margirier, Konstanze Stübner, Christoph Schmidt, Johannes Lachner, Georg Rugel, Salome Oehler, Pontien Niyonzima, Rosemary Nalwanga, Anne Voigtländer   +8 more
wiley   +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

Raman Line Scan Analyses and a New Hypothesis for the Formation of Anatase‐Hosting Microbialites: Study of the Stromatolites From Saint‐Jean‐de‐la‐Rivière, Cotentin, France

Journal of Raman Spectroscopy, Volume 57, Issue 8, Page 1463-1480, August 2026.
Micrometer analysis of millimeter lines of Raman spectra concludes in the association of anatase and graphitized organic matter (graphogen). The photosynthetic microorganisms at the origin of the microbialites produce O2, which is transformed by TiO2 into reactive species that, in turn, decompose the organic matter of the microorganisms. ABSTRACT Raman
Marie‐Paule Bassez
wiley   +1 more source

Vanadium Isotopic Compositions of the High‐3He/4He Baffin Island Lavas

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 8, August 2026.
Abstract The isotopic composition of vanadium (V) in hotspot lavas provides new insight into the source of deep mantle heterogeneities. We measured V isotopic compositions in Paleogene Baffin Island lavas, which erupted above the Iceland plume head, to constrain the mantle plume source. These lavas have V isotopic compositions that are lighter (−0.96 ± 
Jonas Kaare‐Rasmussen, Forrest Horton, Maureen Auro, Andy W. Heard, Sune G. Nielsen   +4 more
wiley   +1 more source

The Role of Magmatic Styles in Planetary Thermal Evolution Models

Journal of Geophysical Research: Planets, Volume 131, Issue 8, August 2026.
Abstract Previous studies that investigated the effects of magmatism on the interior dynamics, in particular for Earth‐sized planets, suggest that magmatism leads to more efficient mantle cooling. However, the extent to which different magmatic styles influence the thermal evolution of planets, and in particular smaller rocky bodies, has not yet been ...
C. Herrera, A.‐C. Plesa, J. Maia, D. Breuer   +3 more
wiley   +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

Uplift of the Transantarctic Mountains: Evidence for an Evolving and Long‐Lived Rayleigh‐Taylor Instability

Tectonics, Volume 45, Issue 8, August 2026.
Abstract Rayleigh‐Taylor instabilities within the upper mantle are investigated as a mechanism for the uplift of rift‐margin mountain ranges within the continents. Our focus is on the Transantarctic Mountains (TAM). These mountains form at the margin between East and West Antarctica and have been free from the effects of subduction for about 500 ...
Tim Stern, Simon Lamb, James D. P. Moore, Alec Yates   +3 more
wiley   +1 more source