Caracterización petrológica de las magnesitas y las dolomías encajantes de edad Proterozoica Superior-Cámbrico Inferior, Grupo Ibor (Castañar de Ibor, Cáceres)

Abstract

Detailed petrographic observations of Upper Proterozoic -Lower Cambrian deposits of the Castañar de Ibor allows the characterization of the diagenetic history of these rocks. Craywackes, shales and limestones were deposited during the Upper Proterozoic-Lower Cambrian within a siliciclastic-carbonatic marine platform. Dolomite replaced mostly limestones, but also cemented the siliciclastic deposits. Later on magnesium-rich fluids circulating along stylolites, bedding planes and fractures partially produced the replacement of the dolostones and some siliciclastic beds. Finally a new dolomitisation phase produced replacement ofthe magnesite by dolomite and dolomite cementation