Pisco Basin#Chilcatay Formation

{{Infobox sedimentary basin

| name = Pisco Basin

| other_name = Cuenca de Pisco

| named_for = City of Pisco, Peru

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| image_caption = Pisco Basin is located in the southern part of coastal Peru

| pushpin_map = Peru

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| coordinates = {{coord|14|15|S|76|0|W|display=inline,title}}

| location = Western South America

| region =

| country = Peru

| state = Ica Region

| cities = Pisco

| onoffshore = Both

| boundaries =

| partof = Circum-Pacific forearc basins

| seas = Eastern Pacific Ocean

| rivers = Pisco River

| lakes =

| area = {{convert|300|km|mi|abbr=on}}

| basin_type = Forearc basin

| orogeny = Andean

| age = Eocene–Pliocene

| stratigraphy = Stratigraphy

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Pisco Basin ({{langx|es|Cuenca de Pisco}}) is a sedimentary basin extending over {{convert|300|km|mi}} in southwestern Peru.Solís Mundaca, 2018, p.1 The basin has a 2-kilometre (1.25-mile) thick sedimentary fill, which is about half the thickness of more northern foreland basins in Peru.

The oldest known sediments are the Eocene sandstones of the Caballas Formation, while the youngest deposits, the fossiliferous Pisco Formation, date to the Early Pleistocene.{{refn|group=note|later publications give a younger top date}} In relation to present-day, topography the fill of Pisco Basin makes the upper part of the Coastal Cordillera of southern Peru, the coastal plains, the Ica-Nazca Depression and the Andean foothills.León et al. 2007, p. 7.

The basin is renowned for hosting various highly fossiliferous stratigraphic units; the Pisco Formation has provided a wealth of marine mammals (including sloths), birds, fish and other groups, as have the Chilcatay, Otuma and Paracas Formations.

Stratigraphy

class="wikitable" style="text-align:center;font-size: 9pt" \|+ Stratigraphy of Pisco Basin{{refn\|group=note\|Based on "DeVries (1998) as presented by León et al. (2007)"León et al. 2007, p. 44.}} ! Age !! SALMA{{refn\|group=note\|See SALMA Bibliography for sources}} !! colspan="2" \| UnitsDunbar et al., 1990 !! Environment !! LithologyDeVries et al., 2017León et al. 2007, p. 45.
style="background-color: {{period color\|pleistocene}};" \| Pleistocene	Uquian	rowspan=2 colspan="2" \| Pisco	rowspan=2 \| Lagoonal to near-shore	rowspan=2 \| Bioclastic conglomerate, sandstone
style="background-color: {{period color\|serravallian}};" \| Middle Miocene	Colloncuran
style="background-color: {{period color\|burdigalian}};" \| Early Miocene	Colhuehuapian	rowspan=2 colspan="2" \| Chilcatay	rowspan=2 \| Marine	rowspan=2 \| Siltstone, sandstone
style="background-color: {{period color\|chattian}};" \| Late Oligocene	Deseadan
style="background-color: {{period color\|rupelian}};" \| Early Oligocene Late Eocene	Tinguirirican Divisaderan	colspan="2" \| Otuma	Marine embayment	Bioclastic sandstone, sandstone, silty sandstone, mudstone, dolomitic sediment
style="background-color: {{period color\|priabonian}};" \| Late Eocene	Divisaderan	rowspan="2" \| Paracas	Yumaque		Mudrock, phosphatic shale, diatomite, porcellanite, chert
style="background-color: {{period color\|bartonian}};" \| Late Eocene	Mustersan	Los Choros	Inner shelf, shoreface, intertidal	Bioclastic conglomerate, sandstone, siltstone, mudrock
style="background-color: {{period color\|lutetian}};" \| Eocene	Casamayoran	colspan="2" \| Caballas	Fluvial	Sandstone, tuff, coal

Tectonic and sedimentary evolution

The basin developed in a setting of extensional tectonics from Eocene to the Late Miocene with short-lived episode of basin inversion in the Middle Miocene.León et al. 2007, p. 146. Late Pliocene and Pleistocene uplift of the basin may be consequence of the subduction of Nazca Ridge.León et al. 2007, p. 145.

Sedimentary strata of the basin shows evidence for a series of marine transgressions during the last 50 million years.DeVries, 1998 These marine transgressions occurred in a sequence 41-34 Ma, 31-28 Ma, 25-16 Ma, 15-11 Ma, 10-5 Ma, and 4-2 Ma. The end of most of the marine transgressions is thought to be associated either with global sea level falls or compressional events in the Andes.

= Oligo-Miocene transgression =

The marine Oligo-Miocene (25–16 Ma) marine transgression is evidenced by a series of sedimentary strata containing fossils of marine diatoms, Peruchilus snails and Pitar and Cucullaea clams.Macharé et al., 1988 Oligo-Miocene marine environments in the Pisco Basin range from littoral to shelf. Moquegua Basin southeast of Pisco Basin appear to have been unaffected by the transgression.

Within the Andean margin contemporary marine transgressions are also known from southern Chile, Patagonia and Colombia. As such the marine transgression is thought to represent a regional phenomenon with the steadily rising central Andes being an exception.

Paleontology

= Pisco Formation =

= Chilcatay Formation =

class="wikitable sortable" ! Group !! Fossils !! Notes
Mammals	Chilcacetus cavirhinus, Huaridelphis raimondii, Incacetus broggii, Inticetus vertizi, Macrosqualodelphis ukupachai, Notocetus vanbenedeni, cf. Kentriodon sp., Cetotheriidae indet., Eurhinodelphinidae indet., Mysticeti indet., Odontoceti indet., Pinnipedia indet., Physeteroidea indet., Squalodelphinidae indet.	{{center\|[https://paleobiodb.org/classic/displayCollResults?collection_no=124919 Ullujaya] at Fossilworks.org[https://paleobiodb.org/classic/displayCollResults?collection_no=167732 Ullujaya 2] at Fossilworks.org [https://paleobiodb.org/classic/displayCollResults?collection_no=45484 Santa Rosa] at Fossilworks.org[https://paleobiodb.org/classic/displayCollResults?collection_no=100330 Zamaca] at Fossilworks.org}}
Birds	Palaeospheniscus sp.	{{center\|}}
Reptiles	Testudines indet.	{{center\|}}
Fish	Carcharhinus cf. brachurus, Carcharodon hastalis, Carcharodon subauriculatus, Hemipristis cf. serra, Isurus desori	{{center\| [https://paleobiodb.org/classic/displayCollResults?collection_no=113250 Cerro Buque M2] at Fossilworks.org[https://paleobiodb.org/classic/displayCollResults?collection_no=113249 Cerro Buque M8] at Fossilworks.org}}

= Otuma Formation =

class="wikitable sortable" ! Group !! Fossils !! Notes
Mammals	Cynthiacetus peruvianus, Basilosauridae indet.	{{center\|[https://paleobiodb.org/classic/displayCollResults?collection_no=63838 Paracas Bay] at Fossilworks.org[https://paleobiodb.org/classic/displayCollResults?collection_no=73779 Archaeocete Valley, Otuma, AV-10] at Fossilworks.org}}
Birds	Icadyptes salasi, Inkayacu paracasensis, Spheniscidae indet.	{{center\|[https://paleobiodb.org/classic/displayCollResults?collection_no=73818 Ullujaya Valley] at Fossilworks.org[https://paleobiodb.org/classic/displayCollResults?collection_no=100331 Bajada del Diablo] at Fossilworks.org [https://paleobiodb.org/classic/displayCollResults?collection_no=98346 Paracas Reserve] at Fossilworks.org}}
Fish	Engraulis sp., Sardinops sp.	{{center\|}}

= Paracas Formation =

class="wikitable sortable" ! Group !! Fossils !! Notes
Mammals	Ocucajea picklingi, Supayacetus muizoni, Basilosauridae indet., Mystacodon selenensis, Peregocetus pacificus, Perucetus colossus	{{center\|[https://paleobiodb.org/classic/displayCollResults?collection_no=73780 Archaeocete Valley] at Fossilworks.org[https://paleobiodb.org/classic/displayCollResults?collection_no=90021 Archaeocete Valley, Paracas, AV-17] at Fossilworks.org [https://paleobiodb.org/classic/displayCollResults?collection_no=90022 Archaeocete Valley, Paracas, AV-19] at Fossilworks.orgLambert et al., 2017{{Cite journal \|last1=Lambert \|first1=Olivier \|last2=Bianucci \|first2=Giovanni \|last3=Salas-Gismondi \|first3=Rodolfo \|last4=Di Celma \|first4=Claudio \|last5=Steurbaut \|first5=Etienne \|last6=Urbina \|first6=Mario \|last7=de Muizon \|first7=Christian \|date=2019 \|title=An Amphibious Whale from the Middle Eocene of Peru Reveals Early South Pacific Dispersal of Quadrupedal Cetaceans \|journal=Current Biology \|volume=29 \|issue=8 \|pages=1352–1359.e3 \|doi=10.1016/j.cub.2019.02.050 \|pmid=30955933 \|bibcode=2019CBio...29E1352L \|issn=0960-9822\|hdl=11581/425570 \|hdl-access=free }}{{Cite journal \|last1=Bianucci \|first1=Giovanni \|last2=Lambert \|first2=Olivier \|last3=Urbina \|first3=Mario \|last4=Merella \|first4=Marco \|last5=Collareta \|first5=Alberto \|last6=Bennion \|first6=Rebecca \|last7=Salas-Gismondi \|first7=Rodolfo \|last8=Benites-Palomino \|first8=Aldo \|last9=Post \|first9=Klaas \|last10=de Muizon \|first10=Christian \|last11=Bosio \|first11=Giulia \|last12=Di Celma \|first12=Claudio \|last13=Malinverno \|first13=Elisa \|last14=Pierantoni \|first14=Pietro Paolo \|last15=Villa \|first15=Igor Maria \|date=2023-08-02 \|title=A heavyweight early whale pushes the boundaries of vertebrate morphology \|url=https://www.nature.com/articles/s41586-023-06381-1 \|journal=Nature \|volume=620 \|issue=7975 \|language=en \|pages=824–829 \|doi=10.1038/s41586-023-06381-1 \|pmid=37532931 \|bibcode=2023Natur.620..824B \|issn=1476-4687\|hdl=10281/434998 \|hdl-access=free }}}}
Birds	Perudyptes devriesi	{{center\|[https://paleobiodb.org/classic/displayCollResults?collection_no=73817 Quebrada Perdida] at Fossilworks.org}}
Fish	Pristis sp., Myliobatis sp., Clupeiformes sp.	{{center\|{{Cite journal \|last1=Collareta \|first1=Alberto \|last2=Tejada-Medina \|first2=Luz \|last3=Chacaltana-Budiel \|first3=César \|last4=Landini \|first4=Walter \|last5=Altamirano-Sierra \|first5=Alí \|last6=Urbina-Schmitt \|first6=Mario \|last7=Bianucci \|first7=Giovanni \|date=2020-03-17 \|title=A rhinopristiform sawfish (genus Pristis) from the middle Eocene (Lutetian) of southern Peru and its regional implications \|url=http://paleopolis.rediris.es/cg/20/05/index.html \|journal=Carnets Geol. \|language=en \|volume=20 \|issue=5 \|pages=91 \|doi=10.4267/2042/70759 \|issn=1634-0744\|hdl=20.500.12544/2621 \|hdl-access=free }} }}

Notes and references

= Notes =

= References =

= Bibliography =

;Stratigraphy

{{citation |last1=DeVries |first1=Thomas J. |last2=Urbina |first2=Mario |last3=Jud |first3=Nathan A. |year=2017 |title=The Eocene-Oligocene Otuma Depositional Sequence (East Pisco Basin, Peru): Paleogeographic and Paleoceanographic Implications of New Data |url=http://tramite.ingemmet.gob.pe/BusquedaGeodoc/images/biblioteca/BSGP-112-14.pdf |journal=Boletín de la Sociedad Geológica del Perú |volume=112 |pages=014–038 |accessdate=2020-03-09}}
{{citation |last1=Dunbar |first1=Robert B. |last2=Marty |first2=Richard C.|last3=Baker |first3=Paul A. |year=1990 |title=Cenozoic marine sedimentation in the Sechura and Pisco basins, Peru |url= |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=77 |issue=3–4 |pages=235–261 |doi= 10.1016/0031-0182(90)90179-B |bibcode=1990PPP....77..235D }}

== Geology publications ==

{{citation |last1=León |first1=Walter |last2=Aleman |first2=Antenor|last3=Rosell |first3=Walter|last4=Torres |first4=Víctor|last5=de la Cruz |first5=Orlando |year=2007 |title=Estratigrafía, sedimentología y evolucón tectónica de la cuenca Pisco Oriental |url=https://en.calameo.com/books/000820129bcf92c95fda9 |language=Spanish |publisher=Estudios Regionales, Serie D |volume=27 |pages=1 |accessdate=2020-03-09}}
{{citation |last=Devries |first=T.J. |year=1998 |title=Oligocene deposition and Cenozoic sequence boundaries in the Pisco Basin (Peru) |url= |journal=Journal of South American Earth Sciences |volume=11 |issue=3 |pages=217–231 |doi= 10.1016/S0895-9811(98)00014-5|bibcode=1998JSAES..11..217D }}
{{citation |last1=Macharé |first1=José |last2=Devries |first2=Thomas |last3=Barron |first3=John|last4=Fourtanier |first4=Élisabeth |year=1988 |title=Oligo-Miocene transgression along the Pacifie margin of South America: new paleontological and geological evidence from the Pisco basin (Peru) |url=http://horizon.documentation.ird.fr/exl-doc/pleins_textes/cahiers/geodyn/26017.pdf |journal=Geódynamique |volume=3 |issue=1–2 |pages=25–37 |doi= |accessdate=2020-03-09}}

== Paleontology publications ==

{{citation |last=Solís Mundaca |first=Flavio Alejandro |year=2018 |title=Bioestratigrafía e implicancias paleoceanográficas de las diatomeas de la sección Cerro Caucato, Formación Pisco, Ica, Peru (MSc. thesis) |url=http://repositorio.upch.edu.pe/bitstream/handle/upch/3733/Bioestratigrafia_SolisMundaca_Flavio.pdf?sequence=1&isAllowed=y |publisher=Universidad Peruana Cayetano Heredia |pages=1–158 |accessdate=2018-09-10}}
{{citation |last1=Lambert |first1=O. |first2=M. |last2=Martínez Cáceres |first3=G. |last3=Bianucci |first4=C. |last4=Di Celma |first5=R. |last5=Salas Gismondi |first6=E. |last6=Steurbaut |first7=Mario |last7=Urbina |first8=C. |last8=de Muizon |year=2017 |title=Earliest Mysticete from the Late Eocene of Peru Sheds New Light on the Origin of Baleen Whales |url=https://www.researchgate.net/publication/316871589 |journal=Current Biology |volume=27 |issue=10 |pages=1–7 |doi=10.1016/j.cub.2017.04.026 |pmid=28502655 |bibcode=2017CBio...27E1535L |accessdate=2019-02-04|hdl=11581/396095 |hdl-access=free }}

class="wikitable" style="text-align:center;font-size: 9pt" \|+ Stratigraphy of Pisco Basin{{refn\|group=note\|Based on "DeVries (1998) as presented by León et al. (2007)"León et al. 2007, p. 44.}} ! Age !! SALMA{{refn\|group=note\|See SALMA Bibliography for sources}} !! colspan="2" \| UnitsDunbar et al., 1990 !! Environment !! LithologyDeVries et al., 2017León et al. 2007, p. 45.
style="background-color: {{period color\|pleistocene}};" \| Pleistocene	Uquian	rowspan=2 colspan="2" \| Pisco	rowspan=2 \| Lagoonal to near-shore	rowspan=2 \| Bioclastic conglomerate, sandstone
style="background-color: {{period color\|serravallian}};" \| Middle Miocene	Colloncuran
style="background-color: {{period color\|burdigalian}};" \| Early Miocene	Colhuehuapian	rowspan=2 colspan="2" \| Chilcatay	rowspan=2 \| Marine	rowspan=2 \| Siltstone, sandstone
style="background-color: {{period color\|chattian}};" \| Late Oligocene	Deseadan
style="background-color: {{period color\|rupelian}};" \| Early Oligocene Late Eocene	Tinguirirican Divisaderan	colspan="2" \| Otuma	Marine embayment	Bioclastic sandstone, sandstone, silty sandstone, mudstone, dolomitic sediment
style="background-color: {{period color\|priabonian}};" \| Late Eocene	Divisaderan	rowspan="2" \| Paracas	Yumaque		Mudrock, phosphatic shale, diatomite, porcellanite, chert
style="background-color: {{period color\|bartonian}};" \| Late Eocene	Mustersan	Los Choros	Inner shelf, shoreface, intertidal	Bioclastic conglomerate, sandstone, siltstone, mudrock
style="background-color: {{period color\|lutetian}};" \| Eocene	Casamayoran	colspan="2" \| Caballas	Fluvial	Sandstone, tuff, coal