The iron/manganese occurrences of the Desná Unit NE of the Sobotín Amphibolite Massif, Silesicum, Czech Republic: A reply to the paper of Kropáč et al. (2012)

Our reply deals with the investigations of Kropáč et al. (2012) concerning the evolution of Mn-rich garnetites (=coticules) in the Silesian Desná Unit which are closely associated with Fe-rich rocks. Pouba (1970) who described these mineralizations in greater detail, postulated an origin identical with banded iron-formations of the Algoma type. However, Mücke and Losos (2007) excluded a banded iron-formation origin for the magnetite mineralizations and came to the conclusion that these are connected with the Devonian amphibolite of the Sobotín Massif. The older garnetites were inferred to be identical with coticules and, therefore, are comparable with Mn-rich iron-formations of the Algoma type. Concerning the coticules, Kropáč et al. (2012) confirmed the same origin as proposed by us. For the magnetite-rich rocks, on the other hand, Kropáč et al. (2012) strictly followed Pouba (1970), but did neither present new results or data, nor considered the arguments of Mücke and Losos (2007). In this reply, the most important results of Mücke and Losos (2007) are discussed in comparison with banded iron-formations.