Distribution of authigenic albites in a limestone succession of the Helvetic domain, eastern Switzerland

Abstract

A new occurrence of authigenic albite was found in a Jurassic sedimentary succession of the Glarus Nappe near Walenstadt (eastern Switzerland). The euhedral shape and the chemical purity of these albites are evidence for their authigenic origin. The crystals are irregularly distributed in the sediment, highlighting the importance of the host rock composition for albite authigenesis. The crystals occur exclusively in limestones with a carbonate content higher than 80 wt-%. A diagenetic or hydrothermal origin of albite authigenesis is discussed for the studied region. Clay mineral transformation appears to be an important source of ions for albite formation. © 2007 Birkhaueser.