The maar is located precisely at a SE-NW disruption in the basal complex. The Lower Devonian, structureless Ulmen tier with sand-, siltstone and clay slate is cropping out. Particularities The Jungferweiher is to the north of the Ulmen maar. It fills a shallow depression tilted toward the south. This previously silted up prior dry maar was flooded in 1942 by damming up the Nollenbach. Since then, water has been draining into the Ulmen maar and serves the Cochem-Zell district with drinking water. Since 1989 this water from the Jungferweiher has been treated, removing the phosphor from agriculture! The Jungferweiher along with the Ulmen maar is a nature conservancy known for its abundance in migratory birds!