(Mina Pedro de Valdivia, Pedro de Valdivia, Tocopilla, Antofagasta, Chile)
A nitrate deposit. Pueyo et al. (1998) mention "silicates (zeolites); calcite; Ca-, Na-, (K-) and Mg-sulfates; Na- and K Mg-nitrate-sulfates; nitratine; and small amounts of iodates, Na- and K Mg-iodate-sulfates, chromates, borates and perchlorates".
Ref.:
Pueyo, J. J., Chong, G. & Vega, M. (1998): Mineralogy and parental brine evolution in the Pedro de Valdivia nitrate deposit, Antofagasta, Chile. Revista Geologica de Chile 25, 3-15. (in Spanish)