Lohan Cura Formation

Lohan Cura Formation
Stratigraphic range: late Aptian - Albian
Type Geological formation
Sub-units Puesto Quiroga Member
Cullín Grande Member
Underlies Candeleros Formation
Overlies La Amarga Formation
Agrio Formation
Bajada Colorada Formation
Thickness 177 m
Location
Region Río Negro, Mendoza & Neuquén Provinces
Country  Argentina

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 unconformity. It is in turn overlain by the Candeleros Formation of the Neuquén Group, separated by another unconformity. The Lohan Cura correlates with the Rayoso Formation in some areas.

Age

Era: Mesozoic
Period: Early Cretaceous
Faunal stage: late Aptian through Albian
Absolute Age: ~117 to ~100 mya

Composition

The Lohan Cura Formation contains two members of roughly equal thickness.

The lower (and therefore older) of the two is the Puesto Quiroga Member, approximately 85 meters thick. The lowest sediments in this formation 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 meters thick, which contains numerous stream channels in sandstone. By the top of the column, siltstones and claystones become dominant.

Paleontology

Numerous tetrapod fossils have been recovered from the Cullín Grande Member of the Lohan Cura, including:

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

Dinosaurs of the Lohan Cura Formation
Genus Species Presence Notes Images

Agustinia[1]

A. ligabuei[1]

Geographically located in the provincia de Nequen, Argentina.[1]

Dorsal sacral and caudal neural arches, hindlimb elements, and pelvic fragments (the latter misidentified as osteoderms).[2]
Agustinia

See also

References

  1. 1 2 3 Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 563-570. ISBN 0-520-24209-2.
  2. ↑ "Table 13.1," in Weishampel, et al. (2004). Page 267.
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