Within the stratigraphic sequence it overlies Jurassic rocks in a syn-rift unconformity, and underlies the Alacón Formation.

The formation is up to 150 metres thick and is divided into three distinct unconformity bounded units, which are called the Lower, Middle and Upper Blesa Sequences.

The Lower Blesa sequence varies greatly in thickness from less than 10 m up to 100 m is divided up into two members, the lower Cabezo Gordo Member, which consists of red clays and the upper Morenillo Member, which consists of limestones and marls, both of these sequences were deposited in a continental setting.

The Middle Blesa Sequence is of a fairly uniform 25-50 metre thickness.

The Upper Blesa Sequence is of variable thickness from 15–70 m. The lower 1–10 m consists of continentally derived clays and marls with sandstone and conglomerate intercalations while the upper 10–60 m are dominated by carbonates.