Rock glaciers in the Central Eastern Alps – How permafrost degradation can cause acid rock drainage, mobilization of toxic elements and formation of basaluminite ...

• Main Authors: Wanner, Christoph, Moradi, Hoda, Ingold, Philipp, Cardenas Bocanegra, Miguel A., Mercurio, Romano, Furrer, Gerhard
• Format: Text
• Language: unknown
• Published: Elsevier Science 2023
• Subjects: 550 Earth sciences & geology; Ice; permafrost
• Online Access: https://dx.doi.org/10.48350/184604; https://boris.unibe.ch/184604/

Naturally occurring acid rock drainage (ARD) appears to be promoted in permafrost environments with pyritebearing host rocks. However, it is poorly understood how the interaction between solid ice, meltwater and pyrite causes the formation of sulfuric acid and the subsequent mobilization of toxic elements. To elucidate the governing processes and to assess the general hazard of ARD in permafrost areas in the context of global warming, we present chemical water analyses for six high-alpine surface waters downstream of intact rock glaciers in the Central Eastern Alps. In addition, we provide a detailed chemical and structural characterization of nanocrystalline Al-hydroxysulfate precipitates forming along the streams and serving as a visual manifestation of ARD. Finally, we show results from column experiments, experimentally simulating the interaction between water and pyrite-bearing paragneisses. Studying ARD on both, the field and laboratory scales, demonstrated that under field-site conditions intact rock ...