Vol. 318, Issue 4, 2018

The deposition of large amounts of mixed-valence Fe minerals in iron formations during the Archean and Paleoproterozoic indicates that the Fe(II)aq (aqueous) content of coeval anoxic seawater was likely several...

Bentonites are the alteration product of volcanic tephra typically preserved in low-energy, sedimentary environments below baseline. Although volcanic tuffs occur throughout the Earth9s history, bentonites older than ca. 1.5 Ga...

During metamorphism, large quantities of fluids are mobilized and transported through the crust. Such fluids may interact with surrounding rock and serve as a medium for chemical transport. In this...