Results 131 to 140 of about 26,385 (251)
Abstract Magnesite (MgCO3) is a magnesium (Mg) carbonate mineral that records the aqueous environmental conditions of its formation. On Earth, magnesite forms in metamorphic, diagenetic or pedogenic environments, and distinguishing between these environments is critical for understanding the fluid chemistry during magnesite precipitation. Mg carbonates
E. L. Cardarelli +6 more
wiley +1 more source
Abstract The mechanisms by which new subduction zones form remain highly debated. Here we use Permo‐Triassic strata to evaluate potential mechanisms for initiation of the Talkeetna‐Bonanza Arc of the northern North American Cordillera. New mapping and analysis of Permian and Upper Triassic strata on the Alaska Peninsula suggest a period of uplift ...
Brandon M. Keough +2 more
wiley +1 more source
This study compared the reactivity of a plagioclase concentrate subjected to two processes: (1) direct acid leaching and (2) thermochemical treatment with ammonium sulfate followed by leaching.
Sameera Mohamed +5 more
doaj +1 more source
ABSTRACT The Carri Laufquen Lakes System is a highly alkaline, basalt‐hosted lacustrine environment in northern Patagonia, Argentina. Diverse morphologies of Late Pleistocene sub‐fossil stromatolites occur along the lakeshores. Using detailed optical and electron microscopy, spectroscopy and organic geochemical analyses, this study shows that ...
Victor Amir Cardoso Dorneles +8 more
wiley +1 more source
ABSTRACT Reconstructing the pressure–temperature–time (P–T–t) evolution of (ultra)high‐pressure rocks is essential for constraining subduction and collisional dynamics. Subduction zones are often investigated using basic eclogites, whereas nonbasic high‐pressure rocks remain comparatively understudied, potentially hindering a comprehensive ...
Otavio S. G. Silva +7 more
wiley +1 more source
Abstract We report the discovery of the second (Al,Cu)‐alloy–bearing micrometeorite, FB‐A2, recovered from Mount Gariglione (southern Italy), representing the sixth such occurrence worldwide. Although chondritic in nature, FB‐A2 differs markedly from previously described microspherules.
Giovanna Agrosì +6 more
wiley +1 more source
Abstract We present the first micrometer‐scale, phase‐resolved compositional characterization of impact melt glass from the Hapcheon crater (~1.4 km apparent diameter), the first confirmed impact structure on the Korean Peninsula, integrating EPMA‐WDS (5 μm spot), confocal Raman spectroscopy (<1 μm spot), XRD, and 40Ar/39Ar step‐heating geochronology ...
Jin‐Young Lee +2 more
wiley +1 more source
Direct Detection of Hydrogen Reveals a New Macroscopic Crustal Water Reservoir on Early Mars
Abstract The next great leap in Martian exploration is the return of samples to Earth. Maximizing their scientific value requires non‐destructive analytical techniques for early three‐dimensional characterization. Neutron computed tomography (CT), highly sensitive to hydrogen, complements conventional X‐ray CT and enables the detection of hydrous ...
Estrid Buhl Naver +15 more
wiley +1 more source
Corundum Discovered by SuperCam and the Perseverance Rover at Jezero Crater, Mars
Abstract Mars is primarily composed of mafic mineral assemblages and their alteration products, but small, scattered rocks strewn across the landscape offer clues to greater petrological diversity. While traversing the Jezero crater rim, the Perseverance rover encountered several plagioclase‐rich light‐toned float rocks.
A. M. Ollila +43 more
wiley +1 more source
Time‐dependent (Creep) Compaction in Volcanic Rocks
Abstract Porous volcanic rocks form volcanic edifices and host key geothermal reservoirs worldwide. When subjected to constant stress above dilatancy in the brittle regime, these materials undergo time‐dependent failure known as brittle creep. In the ductile regime, where deformation is compactive, time‐dependent compaction—compaction creep—has been ...
Kamal Bayramov +3 more
wiley +1 more source

