Efectos de la meteorización laterítica pretriásica en dolomías del Silúrico-Devónico de la Cordillera Costero Catalana (NE España)

Abstract

As result of tectonic uplift during the last stages (Permian) of the Hercynian orogeny, the outcropping rocks of Catalan Coastal Ranges (metamorphic, igneous and sedimentary rocks) were submitted to extensive chemical weathering under warm, humid climatic conditions that produced a weathering profile. We study the weathering profiles developed in the siluro-devonian dolomites exposed between the Montseny and Carraf Massifs. A progressive reddening of the bedrock can be observed in outcrop, beginning in the finer-grained bedrocks or along fracture, bedding and foliation surfaces, and becoming homogeneous towards the top of the profiles. The intensity of chemical weathering increased from base to top, as evidenced by an enrichment of iron and aluminum silicates. We think that the mineralogical and textural evolution patterns presented here are compatible with the lateritic-type weathering profiles reported in granitic rock of the same period