The northern paragneiss zone contains lenses of various lithologies, such as calcareous schists, amphibolite, eclogite, peridotite (mostly thoroughly serpentinized) and gabbro.
The name is derived from the Lherz Massif, an alpine peridotite complex (also known as orogenic lherzolite complex), (the type locality) at Étang de Lers, near Massat in the French Pyrenees; Lherz is the archaic spelling of this location.