Valuation of oyster concentrations

This work concerns three deposits of Ostreidae dated from the terminal Miocene in the South-East of Fez: deposit of the Tagrart hill (El Menzel region) deposit of Douar Sidi M''Barek (Bir Tam Tam region) and deposit of Douar Sidi Lahcen (Azzaba region).The systematic study allowed the recognition of two species: Ostrea lamellosa (Brocchi 1814) found only in the deposit of the Tagrart hill and Crassostrea gryphoides (Schlotheim 1813) present in the three deposits. The taphonomic analysis of the deposits has made it possible to relate the terminal Miocene ostreid concentrations in the southeast of Fez to variable paleoenvironments: between infralittoral for the C1 and C2 concentrations of Ostrea lamellosa (Brocchi 1814) from the Tagrart hill deposit and for the 2 concentrations of Crassostrea gryphoides from the Sidi M''Barek and Sidi Lahcen deposits and circalittoral for the C3 concentration of Crassostrea gryphoides (Schlotheim 1813) from the Tagrart hill deposit.