Stavelot Massif
The massif consists of early Paleozoic ( late Cambrian and Ordovician in age ) metamorphic rocks , mostly quartzites and phyllites . 
<triplet> Cambrian <subj> Paleozoic <obj> part of <triplet> Ordovician <subj> Paleozoic <obj> part of <triplet> quartzite <subj> metamorphic rock <obj> subclass of <triplet> phyllite <subj> metamorphic rock <obj> subclass of