The Dorotea Formation was first described by Katz in 1963. The formation comprises
sandstones with frequent
conglomerate lenses, concretionary levels and
claystones. The Dorotea Formation includes calcareous sandstones with abundant marine invertebrate and fragmentary vertebrate fossils. Hervé et al. (2004) obtained a maximum radiometric age of 67.4 ± 1.5 Ma from detrital
zircons contained in sandstones of the Dorotea Formation. The
mudstones and
sandstones of the formation were deposited in a
fluvial environment. The formation conformably overlies the
Tres Pasos Formation and is
unconformably overlain by the
Lutetian to
Bartonian Man Aike Formation. The thickness of the formation ranges from in the
Sierra Baguales in the north to in the eponymous
Sierra Dorotea in the south. == Fossil content ==