Bozen quartz porphyry

Quartz porphyry is a mainly volcanic rock strata, which can reach a thickness of over 1500 metres in the Bozen area. In addition to the typical deposits from hot clouds of embers (Ignimbrite), one finds tufa laid down by flowing water and streams of mud, and even river and marine sediments with remains of plants. In the Bletterbach gorge the quartz porphyry forms steep terraces with high vertical walls.