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Casma Group
Stratigraphic range: Albian-Cenomanian
Type	Geological group
Lithology
Primary	Limestone, marl, sandstone, conglomerate
Other	Gypsum, tuff
Location
Coordinates	10°54′S 76°48′W / 10.9°S 76.8°W / -10.9; -76.8
Region	Casma Province, Ancash Region
Country	Peru
Extent	West Peruvian Basin
Type section
Named for	Casma
Casma Group (Peru)

The Casma Group (Spanish: Grupo Casma) is a stratigraphic group of Cretaceous (Albian to Cenomanian) sedimentary formations exposed along the coast and within the Cordillera Occidental near Casma, Peru.

Description

The sediments of the Casma Group reflect deposition in two distinct environments of the West Peruvian Basin. Some sediments were deposited near the Casma Volcanic Arc in an intra-cratonic sedimentary basin that was occasionally connected to the ocean. Other sediments were deposited in what was once a continental platform bounded by reefs and with anoxic pockets.

Together with the Morro Solar and Imperial Groups, the Casma Group contains clastic volcanosedimentary material derivative of the Mesozoic Casma Volcanic Arc. The folding of the Casma Group sediments is the result of the Cretaceous Mochica Phase of the Andean orogeny. The group is intruded by plutons of the Coastal Batholith of Peru.

The Casma Group include the following lithologies: gypsum, limestone, marl, tuff, lava flows, sandstone and conglomerate.

References

1. ^ Compare et al, 1983
2. ^ Pfiffner & González, 2013

Bibliography

• Compare, Dominique; Adline, Ghilaine; Romani, Maurice; Angeles, Carlos (1983), "Contribución al estudio de las formaciones volcánicas y sedimentarias del Grupo Casma en la transversal del río Huara, Cuenca oeste-peruana", Bulletin de l'Institut français d'études andines (in Spanish), XII (1–2): 75–89, doi:10.3406/bifea.1983.1567, retrieved 2019-02-21
• Pfiffner, Adrian O.; Gonzalez, Laura (2013), "Mesozoic–Cenozoic Evolution of the Western Margin of South America: Case Study of the Peruvian Andes", Geosciences, 3 (2): 262–310, Bibcode:2013Geosc...3..262P, doi:10.3390/geosciences3020262, retrieved 2019-02-21

v t e Major South American geological features
Tectonic plates	Antarctic Caribbean Cocos Coiba Malpelo Nazca North Andes Scotia South American
Cratons and shields	Amazonian Craton Arequipa-Antofalla Craton Atlantic Shield Central Brazilian Shield Guiana Shield Paranapanema Block Río Apa Craton Río de la Plata Craton São Francisco Craton Uruguayan Shield
Structures undergoing subduction	Antarctic plate Carnegie Ridge Chile Rise Juan Fernández Ridge Malpelo Ridge Nazca plate Nazca Ridge
Faults and shear zones	Atacama Boconó Bucaramanga-Santa Marta Cochabamba Cordillera Blanca Córdoba Dolores-Guayaquil Domeyko Eastern Frontal Gastre Huincul Liquiñe-Ofqui Magallanes-Fagnano Meta Morón Oca-Ancón Pernambuco El Pilar Romeral San Ramón Sarandí del Yí Sierra Ballena Sobral El Tigre Trans-Brazilian
Rifts and grabens	Aguapeí Amazon Rift Asunción Rift Cuyo Rift Espino Neuquén Rifts Paramirim Salta Rifts
Sedimentary basins	Altiplano Amazon Andean foreland Central Brazil Chaco Colorado Cuyo Eastern Venezuela Golfo San Jorge Magallanes Malvinas Neuquén Pantanal Paraíba Paraná Salta Solimões
Orogenies	Andean Brasiliano Cariri Velhos Chonide Famatinian Gondwanide Juruá Pampean San Rafael Sunsás Terra Australis Tilcarian
Metallogenetic provinces	Bolivian Tin Belt Chilean Iron Belt Deseado Massif El Indio Gold Belt El Mutún Iron Quadrangle Lithium Triangle Pampean Pegmatite Province
Volcanism	Volcanic provinces Andean North Central South Austral Caribbean Central Atlantic Paraná and Etendeka Hotspots Ascension Noronha hotspot Galápagos Juan Fernández San Felix Trindade

• Geologic groups of South America
• Geologic formations of Peru
• Lower Cretaceous Series of South America
• Upper Cretaceous Series of South America
• Cretaceous Peru
• Cretaceous volcanism
• Albian Stage
• Cenomanian Stage
• Limestone formations
• Marl formations
• Sandstone formations
• Conglomerate formations
• Tuff formations
• Geography of Ancash Region
• Geography of Lima Region