Castilletes Formation

The Castilletes Formation (Formación Castilletes, N1c) is a fossiliferous geological formation of the Cocinetas Basin in the northernmost department of La Guajira, Colombia. The formation consists of fossiliferous mudstones, siltstones and medium-grained to conglomeratic fossiliferous lithic to quartzitic sandstones. The Castilletes Formation dates to the Neogene period; Burdigalian to Langhian stages, Colloncuran and Friasian in the SALMA classification, and has a maximum thickness of 440 m.

Etymology
The formation was defined by Rollins in 1965 and named after the village of Castilletes.

Lithologies
The Castilletes Formation consists of fossiliferous mudstones, siltstones and medium-grained to conglomeratic fossiliferous lithic to quartzitic sandstones.

Stratigraphy and depositional environment
The Castilletes Formation overlies the Jimol Formation and is overlain by the Ware Formation. The age has been estimated to be Middle Miocene (16.7 to 14.2 Ma), Colloncuran and Friasian in the SALMA classification. The invertebrate fauna of the Castilletes Formation is highly similar not only to that of the underlying Jimol Formation, but also to the Cantaure Formation of Venezuela. The Castilletes Formation was deposited in a shallow marine (estuarine, lagoonal, and shallow subtidal) to fluvio-deltaic environment with strong fluvial influence. The Castilletes Formation correlates with the upper Cerro Pelado and Querales Formations of the Venezuelan Falcón Basin. This unit is also correlative with the Cantaure Formation of the Paraguaná Peninsula in Venezuela.