Lohan Cura Formation

The Lohan Cura Formation is a geologic formation with outcrops in the Argentine provinces of Río Negro, Neuquén, and Mendoza. It is the second oldest Cretaceous terrestrial formation in the Neuquén Basin.

The Lohan Cura Formation unconformably overlies the terrestrial La Amarga Formation. In some places it also overlies the older marine Agrio and Bajada Colorada Formations of the Mendoza Group through the same Middle Miranican unconformity. It is in turn overlain by the Candeleros Formation of the Neuquén Group, separated by the Main Miranican unconformity. The Lohan Cura correlates with the Rayoso Formation in some areas.

Subdivision
The Lohan Cura Formation contains two members of roughly equal thickness. The lowermost member, Puesto Quiroga Member is approximately 85 m thick. The lowest sediments in this unit are conglomerates, overlain by sandstones and siltstones. The upper two-thirds of the member consists mainly of shales. The Cullín Grande Member is the upper member within the formation, about 92 m thick, which contains numerous sandstones displaying evidence of stream channels. Near the top of the sequence, siltstones and claystones become dominant.

Fossil content
Numerous tetrapod fossils have been recovered from the Cullín Grande Member of the Lohan Cura, including:
 * several turtles (including 2 species of Prochelidella)
 * rebbachisaurid sauropods (including Agustinia and Comahuesaurus)
 * Ligabuesaurus

The rebbachisaurid Rayososaurus comes from the correlating Rayoso Formation in this same area.