The Tereñes Formation or Tereñes Marl is a Late Jurassic (Kimmeridgian) geologic formation in Asturias, Spain.

The grey marls of the formation were deposited in a lagoonal environment at a muddy coast along a temporary inland sea.

The lower section of the formation comprises silty and chalky sandstones with desiccation cracks and ripple marks, then becomes a bituminous, prominently ostracod-bearing, pelecypod shell chalk, lime chalk marl and marl.

[1] Fossil tracks have been reported from the formation.

[2] The following fossils were reported from the formation:[1]