It preserves fossils dating back to the early Cretaceous period.

The massive reef limestones cap ridges that are steep on one side but dip gently on the other.

However, careful study of the fossils has yielded an age of Aptian to middle Albian.

The alternating shale and limestone beds contain fossil echinoids, the foraminifer Orbitolina, the gastropod Lunatia praegrandis Roemger, and small oysters.

The upper part of the formation contains massive fossil bioherm reefs.