Results 61 to 70 of about 1,482 (183)

Petrological implications of melanite in the rocks of the Morro de São João Alkaline Complex, Casimiro de Abreu, Rio de Janeiro, Brazil [PDF]

Brazilian Journal of Geology
This article presents a study of the titanium-rich andradite garnet, melanite, which occurs in the rocks of the Morro de São João Alkaline Complex, of Paleocene age, located in the district of Casimiro de Abreu, southeast of the state of Rio de Janeiro ...
Mariana Bessa Fagundes, Anderson Santos, Mauro Geraldes, Sérgio de Castro Valente, Eliane Guedes, Theresa Rocco Pereira Barbosa, Júlio Lopes   +6 more
doaj   +1 more source

High p–T Conditions as a Route to Multicomponent High‐Entropy Nitrides

Small Structures, Volume 7, Issue 7, July 2026.
High‐pressure, high‐temperature nitriding in a laser‐heated diamond anvil cell converts a single Ti40Zr20Nb20Hf5Ta15 at% high‐entropy alloy into multiple compositionally complex nitride phases, including the first multicomponent (Ti–Zr–Nb–Ta–Hf)3N4 as well as the M2N3 (orthorhombic Pnma) and M4N5 (tetragonal I4/m) high‐entropy nitrides (where M ...
L. Rogal, D. Laniel, X. He, Q. Zhang, T. B. Shiell, T. A. Strobel, U. D. Wdowik   +6 more
wiley   +1 more source

The Complexity of Deep Aqueous Fluids in Planetary Ultramafic Mantles

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 7, July 2026.
Abstract Planetary volatiles cycle through a planet's crust, mantle, and atmosphere, playing a crucial role in surface processes and habitability. Discussions of planetary volatiles traditionally focus on water, carbon, nitrogen, and sulfur, but fluids in contact with silicate rocks and ultramafic mantles can contain significant amounts of magnesium ...
Sophia E. Economon, Dimitri A. Sverjensky   +1 more
wiley   +1 more source

Forward Image Registration for Higher Level Interpretation of Zircon Provenance Based on Combined CL, U/Pb Age, and Geochemical Data

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 7, July 2026.
Abstract Most detrital zircon studies generate grayscale cathodoluminescence (CL) images, U/Pb dates, and variably extensive trace element concentration data. Yet the combined information contained in these data is rarely used for a higher‐level interpretation of zircon provenance, which still heavily relies on comparison of sample‐wide U/Pb age ...
Marco A. Acevedo Zamora, Balz S. Kamber, John T. Caulfield, Charlotte M. Allen, Justin S. Freeman   +4 more
wiley   +1 more source

MINERALOGY OF OLIVINE ROCKS AND CONDITIONS OF THEIR FORMATION (ZHOKHOV ISLAND, NEW SIBERIAN ISLANDS, RUSSIA) [PDF]

Минералогия
This paper is dedicated to results of microscopic study of minerals from xenoliths of mantle spinel lherzolites in Cenozoic basaltoids of Zhokhov Island (New Siberian Islands, Russia) using microanalysis and Raman spectroscopy, as well as the assessment ...
N.I. Ponomareva, L.P. Nikitina, V.N. Bocharov, N.S. Vlasenko, S.Y. Yanson, V.F. Proskurnin, A.N. Sirotkin, N.M. Stolbov   +7 more
doaj   +1 more source

Chemical Speciation Defines Archaeal Ammonia‐Oxidizer Distribution in Yellowstone Hot Springs

Journal of Geophysical Research: Biogeosciences, Volume 131, Issue 7, July 2026.
Abstract The hot springs of Yellowstone National Park (YNP) provide a natural laboratory for investigating the influence of chemical speciation and energy availability on the distribution of microbes. Among 133 inorganic chemotrophic energy supplies, total dissolved ammonia oxidation was consistently one of the highest across 63 YNP hot spring samples.
Katelyn Weeks, Elizabeth Trembath‐Reichert, Jordyn Robare, R. Vince Debes II, Alta E. G. Howells, Everett Shock   +5 more
wiley   +1 more source

The Origin of Carbonate Magmas Predating and Accompanying Main‐Phase LIPs Eruptions

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 7, July 2026.
Abstract Some large igneous provinces (LIPs) are associated with precursory carbonatite eruptions. Models for precursory carbonatites invoking partial melting of a carbonate metasomatized lithosphere appear implausible, given the long time needed for heat conduction from the plume head.
Cinzia G. Farnetani, Mark A. Richards
wiley   +1 more source

Evolution of Sulfur Concentration in the Deep Earth During the Proto‐Earth Growth: First‐Principles Study on the Sulfur Partitioning Between Metal and Silicate at High Pressure and Temperature

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 7, July 2026.
Abstract Sulfur (S) is one of the promising light elements that can explain the density deficit of the core. The degree of siderophile nature of S under high pressure and temperature (P,T) is the key to estimating the S content in the core. However, a significant discrepancy between the metal‐silicate partition coefficient of S extrapolated from ...
K. Itoh, T. Tsuchiya
wiley   +1 more source

Variscan thrusting in I- and S-type granitic rocks of the Tribeč Mountains, Western Carpathians (Slovakia): evidence from mineral compositions and monazite dating

Geologica Carpathica, 2015
The Tribeč granitic core (Tatric Superunit, Western Carpathians, Slovakia) is formed by Devonian/Lower Carboniferous, calc-alkaline I- and S-type granitic rocks and their altered equivalents, which provide a rare opportunity to study the Variscan ...
Broska Igor, Petrík Igor
doaj   +1 more source

New Terrestrial Native Iron Discovered on Earth's Surface

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 7, July 2026.
Abstract Native iron is a major common mineral in lunar samples and meteorites but rarely occurs on Earth's surface, as its stability requires highly reducing conditions with very low oxygen fugacity. To date, native iron has mainly been found in basalts, ophiolites, and deep hydrothermal systems.
Tingwei Zhang, Shuhui Cai, Zhipeng Zeng, Youqian Li, Shixia Yang, Chenglong Deng   +5 more
wiley   +1 more source