The Jimol Formation (Spanish: Formación Jimol, N1j) is a fossiliferous geological formation of the Cocinetas Basin in the northernmost department of La Guajira. The formation consists of calcareous lithic and fossiliferous sandstones, siltstones and mudstones. The Jimol Formation dates to the Neogene period; Burdigalian stage, Santacrucian in the SALMA classification, and has a maximum thickness of 203 metres (666 ft).