The Pisco Formation is a geologic formation located in

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

, on the southern coastal desert of Ica and

Arequipa Arequipa (; Aymara and qu, Ariqipa) is a city and capital of province and the eponymous department of Peru. It is the seat of the Constitutional Court of Peru and often dubbed the "legal capital of Peru". It is the second most populated cit ...

. The approximately thick formation was deposited in the Pisco Basin, spanning an age from the Middle Miocene up to the Early Pleistocene, roughly from 15 to 2 Ma. The

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...

aceous

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

s, diatomaceous

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...

conglomerate Conglomerate or conglomeration may refer to: * Conglomerate (company) * Conglomerate (geology) * Conglomerate (mathematics) In popular culture: * The Conglomerate (American group), a production crew and musical group founded by Busta Rhymes ** Co ...

s and

dolomites The Dolomites ( it, Dolomiti ; Ladin: ''Dolomites''; german: Dolomiten ; vec, Dołomiti : fur, Dolomitis), also known as the Dolomite Mountains, Dolomite Alps or Dolomitic Alps, are a mountain range located in northeastern Italy. They form pa ...

were deposited in a lagoonal to near-shore

environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...

, in bays similar to other Pacific South American formations as the Bahía Inglesa and Coquimbo Formations of Chile. Several specialists consider the Pisco Formation one of the most important

Lagerstätte A Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These for ...

n,Brand et al., 2004Brand et al., 2011 based on the large amount of exceptionally preserved marine fossils, including sharks (most notably

megalodon Megalodon (''Otodus megalodon''), meaning "big tooth", is an extinct species of mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Pliocene epochs. It was formerly thought to be a me ...

), penguins, whales, dolphins, birds, marine crocodiles and aquatic giant sloths. Famous fossils found in these layers include the giant raptorial sperm whale ''

Livyatan ''Livyatan'' is an extinct genus of macroraptorial sperm whale containing one known species: ''L. melvillei''. The genus name was inspired by the biblical sea monster Leviathan, and the species name by Herman Melville, the author of the famous ...

'',Lambert et al., 2010 the aquatic sloth '' Thalassocnus'',De Muizon et al., 2003 the sperm whale '' Acrophyseter'', and the walrus-like dolphin '' Odobenocetops''.De Muizon & Domning, 2002

Description

The Pisco Formation of the Pisco Basin consists of

aceous

s, diatomaceous yellow to gray

s and a basal

.Báez Gómez, 2006, p.65 The formation is deposited from Pisco in the north to Yauca in the south. The northern portion is known as the Ocucaje Area and the southern part as the Sacaco Area.Stucchi, 2007, p.368 The total thickness of the formation is estimated at .Altamirano Sierra, 2013, p.3 The formation unconformably overlies the Chilcatay and Caballas Formations.

Fauna

The Pisco Formation has provided a rich resource of marine fauna, including marine mammals like cetaceans and seals, large fishes, reptiles, and penguins.Báez Gómez, 2006, p.66 It is also one of the richest sites in the world for fossil

cetacean Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...

s, with close to 500 examples being found in the formation.Poma Porras et al., 2009, p.86 The oldest fossils of the aquatic sloth '' Thalassocnus'' (''T. antiquus'') come from the Aguada de Lomas horizon of the Pisco Formation and were dated at roughly 7 Ma. The youngest specimen (''T. carolomartini'') was found in the Sacaco horizon and dated to approximately 3 Ma.De Muizon et al., 2004, p.287 ''Thalassocnus'' was preyed upon by the probable

apex predator An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic le ...

s of the environment, ''

'' and

.Parham & Pyenson, 2010, p.231Bianucci et al., 2015, p.543 The youngest strata belonging to the formation have been dated at 2 Ma, corresponding to the Early Pleistocene (

Uquian The Uquian age is a period of geologic time (3.0–1.5 Ma) within the Pliocene and Pleistocene epochs of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Ensenadan The Ensen ...

). Fossils of the

Humboldt penguin The Humboldt penguin (''Spheniscus humboldti'') is a medium-sized penguin. It resides in South America, its range mainly contains most of coastal Peru. Its nearest relatives are the African penguin, the Magellanic penguin and the Galápagos p ...

were found in these deposits at the Yauca locality.Stucchi, 2007, p.370

Vertebrates

Invertebrates

Correlations

Laventan

References

Bibliography

* * * * * * * * * * * * * * * * * * * * * *

{{Commons category, Pisco Formation * A. Alván, J. Apolín, and C. Chacaltana. 2004. Los dientes de Seláceos (Condrichthyies) y su aplicación estratigráfica en Las Lomas de Ullujaya (Ica, Perú). XIII Congreso Peruano de Geología. Resúmenes Extendidos 595-598 * A. Collareta, O. Lambert, W. Landini, C. Di Celma, E. Malinverno, R. Varas-Malca, M. Urbina and G. Bianucci. 2017. Did the giant extinct shark ''Carcharocles megalodon'' target small prey? Bite marks on marine mammal remains from the late Miocene of Peru. Palaeogeography, Palaeoclimatology, Palaeoecology 469:84-91 * R. Esperante, L. Brand, K. E. Nick, O. Poma, and M. Urbina. 2008. Exceptional occurrence of fossil baleen in shallow marine sediments of the Neogene Pisco Formation, Southern Peru. Palaeogeography, Palaeoclimatology, Palaeoecology 257:344-360 * A. Gioncada, A. Collareta, K. Gariboldi, O. Lambert, C. Di Clema, E. Bonaccorsi, M. Urbina and G. Bianucci. 2016. Inside baleen: Exceptional microstructure preservation in a late Miocene whale skeleton from Peru. Geology * C. S. Gutstein, M. A. Cozzuol, A. O. Vargas, M. E. Suarez, C. L. Schultz and D. Rubilar-Rogers. 2009. Patterns of skull variation of Brachydelphis (Cetacea, Odontoceti) from the Neogene of the Southeastern Pacific. Journal of Mammalogy 90(2):504-519 * O. Lambert, A. Collareta, W. Landini, K. Post, B. Ramanssamy, C. Di Celma, M. Urbina and G. Bianucci. 2015. No deep diving: evidence of predation on epipelagic fish for a stem beaked whale from the Late Miocene of Peru. Proceedings of the Royal Society B 282:20151530 * J. Machare, T. DeVries, and E. Fourtanier. 1988. Oligo-Miocene transgression along the Pacific margin of South America: new paleontological and geological evidence from the Pisco basin (Peru). Géodyynamique 3(1-2):25-37 * R. Marocco and C. de Muizon. 1988. Los vertebrados del Neogeno de La Costa Sur del Perú: Ambiente sedimentario y condiciones de fosilización. Bulletin de l'Institut Français d'Études Andines 17(2):105-117 * C. de Muizon and D. P. Domning. 1985. The first records of fossil sirenians in the southeastern Pacific Ocean. Bulletin du Museum National d'Histoire Naturelle. Section C: Sciences de la Terre: Paléontologie, Géologie, Minéralogie, Paris: Muséum National d'Histoire Naturelle 7(3):189-213 * C. de Muizon. 1983. ''Pliopontos littoralis'' un nouveau Platanistidae Cetacea du Pliocene de la cote peruvienne. Comptes Rendus de l'Académie des Sciences Paris Série II (296)1101-1104 * C. de Muizon. 1978. ''Arctocephalus (Hydrarctos) lomasiensis'', subgen. nov. et nov sp., un nouvel Otariidae du Mio-Pliocene de Sacaco. Bulletin de l'Institute Français d'Études Andines 7(3-4):169-189 * M. Urbina and M. Stucchi. 2005. Los cormoranes (Aves: Phalacrocoracidae) del Mio-Plioceno de la Formacion Pisco, Peru. Boletin de la Sociedad Geologica del Peru 99:41-49 * R. M. Varas Malca and A. Valenzuela Toro. 2011. A basal monachine seal from the middle Miocene of the Pisco Formation, Peru. Ameghiniana 48(4):R216-R217 * T. J. DeVries. 2008. Pliocene and Pleistocene ''Fissurella'' Bruguiére, 1789 (Gastropoda: Fissurellidae) from Southern Peru. The Veliger 50(2):129-148 * T. J. DeVries. 2007. Cenozoic Turritellidae (Gastropoda) from southern Peru. Journal of Paleontology 81(2):331-351 * T. J. DeVries, L. T. Groves, and M. Urbina. 2006. A new early Miocene Muracypraea Woodring, 1957 (Gastropoda: Cypraeidae) from the Pisco Basin of southern Peru. The Nautilus 120(3):101-105 * T. J. DeVries. 2003. ''Acanthina'' Fischer von Waldheim, 1807 (Gastropoda: Muricidae), an ocenebrine genus endemic to South America. The Veliger 46(4):332-350 * T. J. DeVries. 1997. Neogene ''Ficus'' (Mesogastropoda: Ficidae) from the Pisco Basin (Peru). Boletín de la Sociedad Geológica de Perú 86:11-18 Geologic formations of Peru Miocene Series of South America Pliocene Series of South America Pleistocene Peru Neogene Peru Uquian Chapadmalalan Montehermosan Huayquerian Chasicoan Mayoan Laventan Colloncuran Sandstone formations Siltstone formations Conglomerate formations Dolomite formations Tuff formations Lagoonal deposits Tidal deposits Shallow marine deposits Paleontology in Peru Formations Formations