Reef dolomitic. Abundant marine cements
Capitan formation with lower slope facies and upper reef facies (about 180 m thick ).Reef growth interrupted by sandstone bed.
Biota: Sponges, bryozoans, algae (Archaeolithoporella, algal encrustations, rare stromatolites), Tubiphytes. 
Avarage porosity about 10 % (mostly vuggy). Maximum 25 %, 2 d permeability.
