Serra da Cangalha

Serra da Cangalha is a meteorite crater (astrobleme) in the State of Tocantins, near to the border of Maranhão State, in northeastern Brazil.

The crater is between 12 and 13 km in diameter, making it the second-largest known crater in Brazilcite conference
author = McHone, J F.; Dietz, R S.
year = 1992
title = Earth's multiple impact craters and astroblemes (abstract)
booktitle = XXIII Lunar and Planetary Science
publisher = Lunar and Planetary Institute
location = Houston
pages = 887--888
url = http://adsabs.harvard.edu/abs/1992LPI....23..887M] . Its age is estimated to be about 220 million years (Triassic period). The name means "Pack-Saddle Mountains" in Portuguese.

Description

The outer perimeter is a circular inward scarp about 12 km in diameter on the largely undisturbed Cretaceous and upper Silurian sediments of the Parnaíba basin, breached on the west, north, and south sides by drainage valleys. Within the perimeter there is a series of concentric circular valleys and a central basin, all at roughly the same elevation, separated by ring walls. Shuttle Radar Topography Mission imagery shows a faint ring about 11 km in diameter, a second ring of gentle hills about 5--6 km in diameter, and an inner ring of steeper hills, about 3 km in diameter and up to 420 m high, open to the northwest, surrounding a central basin about 2.2 km in diametercite web
title = Cratera da Serra da Cangalha
author = R. Gregio
year =
accessdate = 2007-09-24
url = http://rgregio.astrodatabase.net/cratera_serra_cangalha.htm] cite conference
title = A SRTM Investigation of Serra da Cangalho [sic] Impact Structure, Brazil
author = W.U. Reimold;
coauthors = G.R.J. Cooper; R. Romano; D. Cowan; C. Koeberl
booktitle = Lunar and Planetary Science XXXV
year = 2004
url = http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1232.pdf
accessdate = 2007-09-24] .

The impact origin is attested by the presence of impact breccias, quartzite shatter cones and shocked quartz. The meteorite is believed to have struck the surface at a low oblique angle, 25 to 30 degrees on dry land. Radial faults are present inside the crater, and some extend up to 16 km from the center.Disturbed and steeply inclined sediments from the Carboniferous and Devonian periods occur within the crater. A magnetic survey of the structure indicates that deformation within the crater extends to a depth of about 2 kmcite journal
title = The Serra da Cangalha astrobleme as revealed by ASTER and SRTM orbital data
author = R. Almeida Filho
coauthors = F.R. Moreira; C.H.Beisl
journal = International Journal of Remote Sensing
year = 2003,
volume = 24,
number = 00,
pages = 1--6
url = http://mtc-m12.sid.inpe.br/col/sid.inpe.br/sergio/2005/06.17.18.34/doc/raimundo4.pdf
accessdate = 2007-09-24] cite journal
title = Magnetotelluric investigation of the Serra da Cangalha impact crater, Northeast Brazil
author = W. Masero;
couathors = P.-A. Schnegg; S.L. Fontes
accessdate = 2007-09-24] cite conference
title = A magnetotelluric investigation of the Serra da Cangalha impact crater structure, Brazil
author = Adekunle Adepelumi
coauthors = Jean M. Flexor; Sergio L. Fontes; Pierre-A. Schnegg] .

History and studies

The identification of the structure as an impact crater was first published in 1973 by R.S. Dietz and B.M. Frenchcite journal
author = Dietz, R.S.
coauthors = French, B.M.
title = Two probable astroblemes in Brazil
year = 1973
journal = Nature
volume = 244
number = 5418
pages = 561--562
doi = 10.1038/244561a0] cite journal
author = Crósta, A. P.
title = Impact structures in Brazil
journal = Research in Terrestrial Impact Structures
editor = J. Pohl
publisher = Friedrich, Vieweg & Sohn
address = Braunschweig/Wiesbad
pages = 30--38
year = 1987] .Shatter cones were reported by Beatty in 1980cite journal
author = Beatty J. K.
year = 1980
title = Crater hunting in Brazil
journal = Sky and Telescope
volume = 59
pages = 464-–467] .Impact breccias, impact melting, and shocked quartz were reported by McHone in his 1986 thesis cite book
author = McHone J. F.
year = 1986
title = Terrestrial impact structures: Their detection and verification with new examples from Brazil
note = Ph.D. thesis
publisher = University of Illinois at Urbana-Champaign, Urbana, Illinois
pages = 210] .A magnetic survey of the structure was published by A.A. Adepelumi and others in 2005 cite journal
author = Adepelumi, A. A.
coauthors = Fontes, S.L.; Schnegg, P.A.; Flexor,J.M.
title = An integrated magnetotelluric and aeromagnetic investigation of the Serra da Cangalha impact crater, Brazil
journal = Physics of the Earth and Planetary Interiors
volume = 150
number = 1
pages = 159--182
year = 2005
doi = 10.1016/j.pepi.2004.08.029] .

References

External links

* [http://www.unb.ca/passc/ImpactDatabase/images/serra-da-cangalha.htm Earth Impact Database]