Mineral evolution and mineral niches of ammonium sulphates: the case of Pastora mine (Aliseda, Spain)


The uncommon association of ammonium sulphates identified in the Pastora abandoned mine is the result of a complex mineral evolution. By means of dissolution-(re)crystallisation reactions operating during large periods of time, ammonium minerals "adapt" to local spatio-temporal changes in physicochemical conditions. We found that during such an evolution, seasonal variations in temperature This is the peer-reviewed, 2 and humidity, the relative solubility of mineral species, and the presence of organic matter play a fundamental role. In addition, our work shows the existence of "mineral niches" and "mineral seasonality", which can be explained on the basis of the "mineral ecology" concept introduced by Hazen et al. (2015). Our investigation of the formation of hydrated sulphates, and particularly of ammonium sulphates, might be relevant to identify the existence of life in mineral formation environments.

American Mineralogist