La Caja Formation

The La Caja Formation is a geologic formation in Mexico. It preserves fossils dating back to the Jurassic period. La Caja Formation is widespread in northeastern and central Mexico and known for their abundant and diverse well-preserved ammonites.

Lithologies of the La Caja Formation are siliciclastic (predominantly siltstone, shale and marl) and were deposited under hemipelagic conditions.