Huitrera Formation

{{Infobox rockunit

| name = Huitrera Formation

| image =Fm_Huitrera_Chacay_3.jpg

| caption =

| type = Geological formation

| period = Ypresian

| age = Early Eocene (Casamayoran)
{{fossilrange|54.69|53.79}}

| prilithology = Mudstone, sandstone

| otherlithology = Andesites, dacitic & rhyolitic ignimbrites, volcanic breccias, tuffs & trachybasalts

| namedfor = Cerro Huitrera

| namedby = Ravazzoli & Sesana

| year_ts = 1977

| region = Neuquén & Río Negro Provinces

| country = Argentina

| coordinates = {{coord|41.0|S|71.2|W|display=inline,title}}

| paleocoordinates = {{coord|43.5|S|61.2|W|display=inline}}

| unitof =

| subunits =

| underlies = Collón Curá Formation

| overlies = Angostura Colorada Formation

| thickness = Up to {{convert|1300|m|ft|abbr=on}}

| extent = Neuquén Basin

| area =

| map = {{Location map+ | Argentina

| relief = 1

| width = 250

| float = center

| places =

{{Location map~ | Argentina

| lat_deg = -41.0

| lon_deg = -71.2

| mark = Orange pog.svg

| marksize = 12

}}

| map_caption =

}}

The Huitrera Formation is a geological formation in the Neuquén Basin in northern Patagonian Argentina whose strata date back to the Early Eocene of the Paleogene, or Casamayoran in the South American land mammal age classification.

The formation is together with the Reyhuau basalts part of the Pilcaniyeu Belt, a volcanic belt active in Paleocene to middle Eocene times.Fernández Paz et al., 2020

Description

The Huitrera Formation was first defined by Ravazzoli and Sesana in 1977. The name has been used to identify various volcaniclastic sequences, among others in the Ñirihuau fold-and-thrust belt.Escosteguy & Franchi, 2010, p.420 The up to {{convert|1300|m|ft}} thick formation comprises mudstones and sandstones deposited in a crater lake environment. Part of the formation comprises andesites, dacitic and rhyolitic ignimbrites, volcanic breccias, tuffs and trachybasalts.Prez & Massafero, 2013, p.228

The formation was initially described as Late Eocene to Early Oligocene, but was later dated to 54.24 ± 0.45 Ma, meaning the Huitrera Formation is Ypresian, or in the SALMA classification, Casamayoran in age.

Fossil content

The following macrofossils were reported from the formation:[https://paleobiodb.org/classic/displayStrata?geological_group=&formation=Huitrera&group_formation_member=Huitrera Huitrera Formation] at Fossilworks.org

Birds
Ueekenkcoracias{{Cite journal|last1=Degrange |first1=F. J. |last2=Pol |first2=D. |last3=Puerta |first3=P. |last4=Wilf |first4=P. |title=Unexpected larger distribution of Paleogene stem-rollers (Aves, Coracii): new evidence from the Eocene of Patagonia, Argentina |year=2021 |journal=Scientific Reports |volume=11 |issue=1 |pages=Article number 1363 |doi=10.1038/s41598-020-80479-8 |pmid=33446824 |pmc=7809110 |bibcode=2021NatSR..11.1363D }}
Amphibians
Llankibatrachus truebaeBáez & Pugener, 2003
Patagopipa corsoliniiAranciaga et al., 2019
Insects
Odonata
Inacayalestes aikunhuapi
Beetles
Thesaurus punctatusJin et al., 2020 (originally Catogenus)Ramírez et al., 2016
Flora
Menispermites calderensisJud et al., 2018
Raiguenrayun curaBarrera et al., 2012
Cupressaceae indet.
Podocarpaceae indet.
Lauraceae indet.

The formation has also provided many pollen, analyzed in 2003 by Melendi et al.Melendi et al., 2003

References

= Bibliography =

{{Cite journal |title=The late Eocene–early Miocene El Maitén Belt evolution: Magmatic response to the changing subduction zone geodynamics |journal=Journal of South American Earth Sciences |url=http://rid.unrn.edu.ar/bitstream/20.500.12049/7023/1/Fern%c3%a1ndez%20Paz%20etal_2020_JSAES_Review%20El%20Mait%c3%a9n%20Belt.pdf |last1=Fernández Paz |first1=Lucía |volume=103 |last2=Iannelli |first2=Sofía B. |doi=10.1016/j.jsames.2020.102713 |year=2020 |last3=Echaurren |first3=Andrés |last4=Ramos |first4=Miguel |last5=Bechis |first5=Florencia |last6=Litvak |first6=Vanesa D. |last7=Encinas |first7=Alfonso |last8=Kasemann |first8=Simone |last9=Lucassen |first9=Friedrich |last10=Folguera |first10=Andrés|bibcode=2020JSAES.10302713F }}
{{citation |first1=Mengjie |last1=Jin |first2=Andreas |last2=Zwick |first3=Adam |last3=Ślipiński |first4=John W. M. |last4=Marris |first5=Michael C. |last5=Thomas |first6=Hong |last6=Pang |year=2020 |title=A comprehensive phylogeny of flat bark beetles (Coleoptera: Cucujidae) with a revised classification and a new South American genus |journal=Systematic Entomology |volume=45 |issue=2 |pages=248–268 |doi=10.1111/syen.12392|bibcode=2020SysEn..45..248J }}
{{citation |first1=Alexis M. |last1=Aranciaga Rolando |first2=Federico L. |last2=Agnolin |first3=Julián |last3=Corsolini |year=2019 |title=A new pipoid frog (Anura, Pipimorpha) from the Paleogene of Patagonia. Paleobiogeographical implications |url=https://www.researchgate.net/publication/333807609 |journal=Comptes Rendus Palevol |volume=18 |issue=7 |pages=725–734 |doi=10.1016/j.crpv.2019.04.003 |doi-access=free|bibcode=2019CRPal..18..725R }}
{{citation |first1=Nathan A. |last1=Jud |first2=Ari |last2=Iglesias |first3=Peter |last3=Wilf |first4=Maria A. |last4=Gandolfo |year=2018 |title=Fossil moonseeds from the Paleogene of West Gondwana (Patagonia, Argentina) |journal=American Journal of Botany |volume=105 |issue=5 |pages=927–942 |doi=10.1002/ajb2.1092 |pmid=29882954|hdl=11336/183708 |hdl-access=free }}
{{citation |first1=Leonardo C. |last1=Ramírez |first2=Juan |last2=Corsolini |first3=Osvaldo |last3=Di Iorio |year=2016 |title=First fossil record of parasitic flat-bark beetle (Coleoptera: Passandridae) from the Eocene of Patagonia, Argentina |journal=Ameghiniana |volume=53 |issue=2 |pages=160–169 |doi=10.5710/AMGH.29.11.2015.2920|hdl=11336/13059 |hdl-access=free }}
{{citation |last1=Prez |first1=Horacio |last2=Massaferro |first2=Gabriela |year=2013 |title=Geología y geomorfología del tramo superior del Arroyo Comallo, Río Negro |url=http://gaea.org.ar/contribuciones/Contribuciones2014/Prez.pdf |journal=Contribuciones Científicas GÆA |volume=26 |pages=221–234 |accessdate=2020-06-13}}
{{citation |last1=Barreda |first1=V.D. |first2=L. |last2=Palazzesi |first3=L. |last3=Katinas |first4=J.V. |last4=Criscri |first5=M.C. |last5=Telleria |first6=K. |last6=Bremer |first7=M.G. |last7=Passala |first8=F. |last8=Bechis |first9=R. |last9=Corsolini |year=2012 |title=An extinct Eocene taxon of the daisy family (Asteraceae): evolutionary, ecological and biogeographical implications |journal=Annals of Botany |volume=109 |issue=1 |pages=127–134|doi=10.1093/aob/mcr240 |pmid=22179952 |pmc=3241571 }}
{{citation |last1=Escosteguy |first1=Leonardo |last2=Franchi |first2=Mario |year=2010 |title=Estratigrafía de la región de Chapelco, Provincia del Neuquén |url=http://www.scielo.org.ar/pdf/raga/v66n3/v66n3a12.pdf |journal=Revista de la Asociación Geológica Argentina |volume=66 |pages=418–429 |accessdate=2020-06-13}}
{{citation |last1=Báez |first1=Ana M. |last2=Pugener |first2=L. Analia |year=2003 |title=Ontogeny of a new Palaeogene pipid frog from southern South America and xenopodinomorph evolution |journal=Zoological Journal of the Linnean Society |volume=139 |issue=3 |pages=439–476 |doi=10.1046/j.1096-3642.2003.00085.x|doi-access=free}}
{{citation |last1=Melendi |first1=D.L. |first2=L.H. |last2=Scafati |first3=W. |last3=Volkheimer |year=2003 |title=Palynostratigraphy of the Paleogene Huitrera Formation in N-W Patagonia, Argentina |journal=Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen |volume=228 |issue=2 |pages=205–273|doi=10.1127/njgpa/228/2003/205 }}