Araguainha crater
{{Short description|Impact crater in Brazil}}
{{Infobox terrestrial impact site
| name = Araguainha crater
| other_name = Araguainha dome
| photo = Araguainha crater LC08 L1TP 224072 20200518 20200820 02 T1.jpg
| photo_size = 240px
| photo_alt =
| photo_caption = Landsat image of the Araguainha crater (May 2020)
| map = Brazil
| map_alt =
| map_caption = Location of the crater in Brazil
| map_size =
| location = Paraná Basin
| label =
| label_position =
| coordinates = {{coord|16|48|S|52|59|W|region:BR_type:landmark_scale:200000|display=inline,title}}
| coordinates_ref =
| confidence = Confirmed
| diameter = {{convert|40|km|mi|abbr=on}}
| depth =
| rise =
| imp_size =
| age = 254.7 ± 2.5 Ma
Permian–Triassic boundary
| exposed = Yes
| drilled = No
| bolide =
| translation =
| language =
| pronunciation =
| topo =
| access =
| country = Brazil
| state = Goiás, Mato Grosso
| province =
| district =
| municipality = Araguainha & Ponte Branca
}}
The Araguainha crater or Araguainha dome is an impact crater on the border of Mato Grosso and Goiás states, Brazil, between the villages of Araguainha and Ponte Branca.{{Cite Earth Impact DB |name=Araguainha |access-date=2017-10-09}} With a diameter of {{convert|40|km|mi}}, it is the largest known impact crater in South America.
The crater has most recently been dated to {{nowrap|254.7 ± 2.5 million}} years ago, when the region was probably a shallow sea. The margins of error of this date overlap the time of the Permian–Triassic extinction event, one of the largest mass extinction events in Earth's history.{{cite book |last1=Svetsov |first1=Vladimir |last2=Shuvalov |first2=Valery |date=17 November 2019 |title=Trigger Effects in Geosystems |url=https://link.springer.com/book/10.1007/978-3-030-31970-0 |editor-last1=Kocharyan |editor-first1=Gevorg |editor-last2=Lyakhov |editor-first2=Andrey |chapter=Trigger Effect of an Asteroidal or Cometary Impact at the Permian–Triassic Boundary |chapter-url=https://link.springer.com/chapter/10.1007/978-3-030-31970-0_62? |publisher=Springer Proceedings in Earth and Environmental Sciences |pages=589–596 |doi=10.1007/978-3-030-31970-0_62 |isbn=978-3-030-31969-4|s2cid=210344171 }}{{cite journal |last1=Tohver |first1=Eric |last2=Cawood |first2=P. A. |last3=Riccomini |first3=Claudio |last4=Lana |first4=Cris |last5=Trindade |first5=R. I. F. |date=1 October 2013 |title=Shaking a methane fizz: Seismicity from the Araguainha impact event and the Permian–Triassic global carbon isotope record |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018213003313 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=387 |pages=66–75 |doi=10.1016/j.palaeo.2013.07.010 |bibcode=2013PPP...387...66T |access-date=29 November 2022}} The impact punched through Paleozoic sedimentary units belonging to the Paraná Basin formations, and exposed the underlying Ordovician granite basement rocks. It is estimated that the crater was initially {{convert|24|km|mi}} wide and {{convert|2.4|km|mi}} deep, which then widened to {{convert|40|km|mi}} as its walls subsided inwards.
Description
File:Araguainha - State of Mato Grosso, Brazil - panoramio (1168).jpg
File:Araguainha crater oblique x5.jpg image of Araguainha crater draped over digital elevation model (5× vertical exaggeration); screen capture from NASA World Wind]]
Araguainha is a complex crater with annular and radial faults, exposed to the surface and eroded, cut through by the Araguaia River. The crater has an uplifted central core, shaped like an elliptical basin, consisting of exposed basement granite. Surrounding this core is a ring of shocked granite and overlying breccias; then another ring of ridges and mountains, {{convert|6.5|km|mi}} in diameter and up to {{convert|150|m|ft|abbr=on}} high, consisting of folded and steeply tilted Devonian sandstones. This central region is surrounded by an annular depression floored by rocks from Devonian and Carboniferous sandstone formations. The outer rim of the crater consists of remnants of semi-circular grabens in highly deformed Permo-Carboniferous sediments. Evidences of impact origin include shatter cones, impact breccias, and shocked quartz.{{cite journal |author=Crósta, Álvaro P. |author-link=Álvaro Penteado Crósta |title=Araguainha dome - The largest astrobleme in South America |date=1 July 1999 |editor1=Schobbenhaus, C. |editor2=Campos, D.A. |editor3=Queiroz, E.T. |editor4=Winge, M. |editor5=Berbert-Born, M. |journal=Sítios Geológicos e Paleontológicos do Brasil |url=http://sigep.cprm.gov.br/sitio001/sitio001english.htm |access-date=29 January 2014 |archive-date=25 June 2013 |archive-url=https://archive.today/20130625232558/http://sigep.cprm.gov.br/sitio001/sitio001english.htm |url-status=dead }}
Access and conservation
The Araguainha Dome can be reached by car from Goiânia or from Cuiabá. An unpaved state road, between Ponte Branca and Araguainha, cuts across the central uplift, as does the Araguaia River. As of 1999, the local residents were not yet aware of the dome's nature and scientific importance.
Dating and interpretation
The earliest report on the Araguainha structure was published by Northfleet et al. (1969),{{cite journal |author1=Northfleet, A.A. |author2=Medeiros, R.A. |author3=Muhlmann, H. |year=1969 |title=Reavaliação dos dados geológicos da Bacia do Paraná. |journal=Boletim Técnico da Petrobrás |volume=12 |pages=291–346}} who interpreted it as an uplift of the Phanerozoic sediments caused by a Cretaceous syenite intrusion. A geological reconnaissance survey by Silveira Filho and Ribeiro (1971){{cite report |author1=Silveira Filho, N.C. |author2=Ribeiro, C.L. |year=1971 |title=Informações geológicas preliminares sobre a estrutura vulcânica de Araguainha, Mato Grosso |publisher=DNPM / Distrito Centro-Leste |type=relatório interno}} noted the occurrence of lavas, breccias, and tuffs around the central core and deduced that Araguainha was a crypto-volcanic structure. Dietz and French (1973){{cite journal |author1=Dietz, R.S. |author1-link=Robert S. Dietz |author2=French, B.M. |year=1973 |title=Two probable astroblemes in Brazil |journal=Nature |volume=244 |issue=5418 |pages=561–562|doi=10.1038/244561a0 |bibcode=1973Natur.244..561D |s2cid=4167202 }} reported the occurrence of impact breccias and shocked quartz, and recognized the structure as an impact crater. A detailed study of the crater by Crósta et al. (1981){{cite journal |author1=Crósta, A.P. |author2=Gaspar, J.C. |author3=Candia, M.A.F. |year=1981 |title=Feições de metamorfismo de impacto no Domo de Araguainha |journal=Revista Brasileira de Geociências |volume=11 |issue=3 |pages=139–146|doi=10.25249/0375-7536.1981139146 |doi-broken-date=2024-11-02 |doi-access=free |url=https://ppegeo.igc.usp.br/index.php/rbg/article/download/12261/11819 }} and Crósta (1982){{cite thesis |author-link=Álvaro Penteado Crósta |author=Crósta, A.P. |year=1982 |title=Mapeamento geológico do Domo de Araguainha utilizando técnicas de sensoriamento remoto |publisher=Instituto Nacional de Pesquisas Espaciais (INPE) |place=São José dos Campos |type=Mestrado}} reported further petrological and mineralogical evidence of the impact. Further geomorphologic evidence was published by Theilen-Willige (1981).{{cite journal |author=Theilen-Willige, B. |year=1981 |title=The Araguainha impact structure, Central Brazil |journal=Revista Brasileira de Geociências |volume=11 |issue=2 |pages=91–97|doi=10.25249/0375-7536.19819197 |doi-broken-date=2024-11-02 |doi-access=free }} A magnetic survey was conducted by Fischer and Masero (1994).{{cite journal |author1=Fischer, G. |author2=Masero, W. |year=1994 |title=Rotational properties of the magnetotelluric impendance tensor – the example of the Araguainha impact crater, Brazil |journal=Geophysical Journal International |volume=119 |issue=2 |pages=548–560|doi=10.1111/j.1365-246X.1994.tb00141.x |bibcode=1994GeoJI.119..548F |doi-access=free }}
Dome formation was first dated (at {{nowrap|243 ± 19 million}} years ago, with Rb-Sr method) by Deutsch et al. (1992).{{cite journal |author1=Deutsch, A. |author2=Buhl, D. |author3=Langenhorst, F. |year=1992 |title=On the significance of crater ages: New ages for Dellen (Sweden) and Araguainha (Brazil) |journal=Tectonophysics |volume=216 |issue=1–2 |pages=205–218|doi=10.1016/0040-1951(92)90167-5 |bibcode=1992Tectp.216..205D }} Engelhardt et al. (1992){{cite journal |author1=Engelhardt, W. v. |author2=Matthäi, S.K. |author3=Walzebuck, J. |year=1992 |title=Araguainha impact crater, Brazil. 1. The interior part of the uplift |journal=Meteoritics |volume=27 |pages=442–457|doi=10.1111/j.1945-5100.1992.tb00226.x }} published a detailed study of the uplifted core and a revised date of about 246 million years ago, later revised to about 244 million years ago. Most recently it was dated by Tohver et al. (2012) at {{nowrap|254.7 ± 2.5 million}} years ago.
Effects
Recent dating by Tohver et al. (2012), to {{nowrap|254.7 ± 2.5 million}} years ago, places the impact at dates overlapping estimates for the Permo-Triassic boundary.{{cite journal |title=Geochronological constraints on the age of a Permo–Triassic impact event: U–Pb and {{sup|40}}Ar / {{sup|39}}Ar results for the 40 km Araguainha structure of central Brazil |author1=Tohver, E. |author2=Lana, C. |author3=Cawood, P.A. |author4=Fletcher, I.R. |author5=Jourdan, F. |author6=Sherlock, S. |author7=Rasmussen, B. |author8=Trindade, R.I.F. |author9=Yokoyama, E. |author10=Souza Filho, C.R. |author11=Marangoni, Y. |display-authors=6 |journal=Geochimica et Cosmochimica Acta |volume=86 |date=1 June 2012 |pages=214–227 |doi=10.1016/j.gca.2012.03.005 |bibcode=2012GeCoA..86..214T}} and the Permian–Triassic extinction event.
Much of the local rock was oil shale. The estimated energy released by the Araguainha impact is insufficient to be a direct cause of the global mass extinction, but the colossal local earth rifting would have released huge amounts of oil and gas from the shattered rock. The resulting sudden global warming might have precipitated the Permian–Triassic extinction.{{cite press release |title=Biggest extinction in history caused by climate-changing meteor |publisher=University of Western Australia |newspaper=University News |date=31 July 2013 |url=http://www.news.uwa.edu.au/201307315921/international/biggest-extinction-history-caused-climate-changing-meteor}}
References
{{Reflist|25em}}
{{Portal|Brazil|Geology}}
External links
- {{cite web |url=https://www.unb.ca/passc/ImpactDatabase/images/araguainha.htm |title=Araguainha |website=Earth Impact Database}}
- {{cite web |url=https://maps.google.com/maps?ll=-16.822128,-52.996674&spn=0.386581,0.451813&z=6&t=k&hl=en |title=Satellite image of the Araguainha region |website=Google Maps}}
- {{cite web |url=http://sigep.cprm.gov.br/sitio001/sitio001english.htm |title=Araguainha dome |access-date=2014-01-29 |archive-date=2013-06-25 |archive-url=https://archive.today/20130625232558/http://sigep.cprm.gov.br/sitio001/sitio001english.htm |url-status=dead }}
{{Impact cratering on Earth}}
Category:Impact craters of Brazil
Category:Permian impact craters
Category:Permian–Triassic extinction event