The Quebrada Monardes Formation is a geological formation in Chile dating back to the Early Cretaceous. It was deposited in warm, arid to semi-arid conditions. One portion (the Codocedo Limestone Member) preserves a perennial salt lake covering at least ; this lake dried up, leaving a large area of mudflats. Fossils of iguanodontian dinosaurs and ctenochasmatid pterosaurs have been found in the formation.