Iron redox cycling in metal-rich, hypersaline, anoxic brines plays a central role in the biogeochemical evolution of life on Earth, and similar brines with the potential to harbor life are thought to exist elsewhere in the solar system. To investigate iron biogeochemical cycling in a terrestrial analog we determined the iron redox chemistry and isotopic signatures in the cryoencapsulated liquid...

Obsidians found in silicic domes and rhyolitic tuffs are an ideal system to understand the formation conditions of calc-alkaline felsic magmas. The Optical Absorption Electron Paramagnetic Resonance (EPR) spectroscopic data presented this study demonstrate that Fe-speciation obsidians is different from observed other geological glasses (e.g., basaltic glasses) or synthetic Fe-bearing silicate g...

A recent phylogenomic study reported that the animal phylogeny was unresolved despite the use of 50 genes. This lack of resolution was interpreted as "a positive signature of closely spaced cladogenetic events." Here, we propose that this lack of resolution is rather due to the mutual cancellation of the phylogenetic signal (historical) and the nonphylogenetic signal (due to systematic errors) ...