Rosario Group

Rosario Group
Stratigraphic range: Late Cretaceous
Type	Group
Sub-units	Lusardi Formation Cabrillo Formation Point Loma Formation
Underlies	Tertiary andesites, Quaternary deposits
Overlies	Mesozoic volcanic rocks
Thickness	1,200 m (3,900 ft)
Lithology
Primary	Marine mudstones, sandstones, conglomerates
Location
Region	Baja California, California
Country	Mexico, United States
Type section
Named for	El Rosario, Baja California

The Rosario Group is a Late Cretaceous geologic group in southwestern California (United States) and northwestern Baja California (Mexico). In older literature it was named Rosario Formation.[1]

The Cretaceous aged formations of the Rosario Group include the Point Loma Formation, Cabrillo Formation and Lusardi Formation, in ascending order.[2]

The sedimentary structures of the Rosario Group apparently were formed in a nearshore shelf environment, probably a local embayment.

Fossils

Some incomplete dinosaur fossils have been discovered in the Point Loma Formation dating back to the Cretaceous period of the Mesozoic Era.

See also

• Geology of San Diego County, California
• List of fossiliferous stratigraphic units in California

References

1. Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.
2. Michael P. Kennedy; George W. Moore (1971). "Stratigraphic Relations of Upper Cretaceous and Eocene Formations, San Diego Coastal Area, California". AAPG Bulletin. 55 (5): 709–722, 709–722. doi:10.1306/819A3C5A-16C5-11D7-8645000102C1865D. ISSN 0149-1423. Wikidata Q108701240.

Further reading

• JSTOR.org: "Dynamics of Late Cretaceous Rocky Shores (Rosario Formation) from Baja California, Mexico"; by Halard L. Lescinsky, Jorge Ledesma-Vázquez and Markes E. Johnson; SEPM Society for Sedimentary Geology; PALAIOS, Vol. 6, No. 2 (Apr., 1991), pp. 126–141.
• SDSU.edu: "Paleocurrent analysis of the Cretaceous Rosario Formation"; Bailey, Stephen Milton; 1966-08-10.