Impurity Analysis and Microstructure Along the Climatic Transition From MIS 6 Into 5e in the EDML Ice Core Using Cryo-Raman Microscopy

Microscale Rearrangement of Ammonium Induced by Snow Metamorphism

“…In principle, micropockets may be composed of salt deposits or liquid brine. In ice cores, for example, sulfate deposits appear to be common (Eichler et al, 2017(Eichler et al, , 2019. This might explain why we find sulfate at similar concentration ratio in the residual samples of natural snow as chloride, for which a very high solubility in ice crystals was found.…”

“…Furthermore, micropockets can host impurities in ice. They are potentially present in shock-frozen ice (Hullar and Anastasio, 2016), such as our artificial snow, as well as in ice cores (Eichler et al, 2017(Eichler et al, , 2019. In principle, micropockets may be composed of salt deposits or liquid brine.…”

Jarosite formation in deep Antarctic ice provides a window into acidic, water-limited weathering on Mars

“…Deep ice is affected by a progressive re-crystallization of the ice grains [33,34]. A consequence of re-crystallization is that impurities incompatible within the ice lattice accumulate at ice grain junctions [35] or within intra-grain µ-inclusions [34,36]. Atmospheric sulphates and sulfuric acid are strongly affected by remobilization in ice [35,37].…”

“…They are easily concentrated in isolated environments forming acidic brines whose eutectic temperature is below the pressure melting point of deep ice, allowing for the presence of aqueous fluids in the form of localized brines [35,34,37,38]. In deep ice, as a result of the increased temperature and ice metamorphism, the concentration and mobilization of impurities allows for the mixing of soluble and insoluble species, and for their interaction through englacial acid-base reactions [34,36,39,40]. Such small-scale environments promote chemical weathering of aeolian dust [36].…”

“…In deep ice, as a result of the increased temperature and ice metamorphism, the concentration and mobilization of impurities allows for the mixing of soluble and insoluble species, and for their interaction through englacial acid-base reactions [34,36,39,40]. Such small-scale environments promote chemical weathering of aeolian dust [36]. In addition, dust particles deposited at Talos Dome have a basaltic/doleritic signature and are rich in Fe [25,26], making deep TALDICE an environment suitable for jarosite precipitation.…”