Earth:Serra da Cangalha
 Serra da Cangalha crater | |
| Impact crater/structure | |
|---|---|
| Confidence | Confirmed |
| Diameter | 12–13 km (7.5–8.1 mi) |
| Age | <300 Ma |
| Exposed | Yes |
| Drilled | Yes |
| Location | |
| Location | Parnaíba Basin |
| Coordinates | [ ⚑ ] : 8°5′S 46°52′W / 8.083°S 46.867°W |
| Country | Brazil |
| State | Tocantins |
  Location of the crater in Brazil | |
Serra da Cangalha is an impact crater in the State of Tocantins, near the border of Maranhão State, in north/northeastern Brazil.[1] The crater is between 12 and 13 kilometres (7.5 and 8.1 mi) in diameter, making it the second-largest known crater in Brazil.[2] Its age is estimated to be about 220 million years (Triassic period).[3] The name means Pack-Saddle Mountains in Portuguese.
Description
The outer perimeter is a circular inward scarp about 12 kilometres (7.5 mi) in diameter on the largely undisturbed Cretaceous and upper Silurian sediments of the Parnaíba basin,[4] 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 kilometres (6.8 mi) in diameter, a second ring of gentle hills about 5 to 6 kilometres (3.1 to 3.7 mi) in diameter, and an inner ring of steeper hills, about 3 kilometres (1.9 mi) in diameter and up to 420 metres (1,380 ft) high, open to the northwest, surrounding a central basin about 2.2 kilometres (1.4 mi) in diameter.[5][6][7]
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.[7] 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 kilometres (1.2 mi).[3][5][6][8][9]
History and studies
The identification of the structure as an impact crater was first published in 1973 by R.S. Dietz and B.M. French.[10][11] Shatter cones were reported by Beatty in 1980.[12] Impact breccias, impact melting, and shocked quartz were reported by McHone in his 1986 thesis.[13] A magnetic survey of the structure was published by A.A. Adepelumi and others in 2005.[6]
See also
References
- ↑ "Serra da Cangalha". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. http://www.passc.net/EarthImpactDatabase/New%20website_05-2018/serra-da-cangalha.html. Retrieved 2017-10-09.
- ↑ McHone, J. F.; Dietz, R. S. (1992). "Earth's multiple impact craters and astroblemes (abstract)". Houston: Lunar and Planetary Institute. pp. 887–888. Bibcode: 1992LPI....23..887M.
- ↑ 3.0 3.1 R. Almeida Filho; F.R. Moreira; C.H.Beisl (2003). "The Serra da Cangalha astrobleme as revealed by ASTER and SRTM orbital data". International Journal of Remote Sensing 24: 1–6. http://mtc-m12.sid.inpe.br/col/sid.inpe.br/sergio/2005/06.17.18.34/doc/raimundo4.pdf. Retrieved 2007-09-24.
- ↑ De Castro, David L.; Fuck, Reinhardt A.; Phillips, Jeffrey D.; Vidotti, Roberta M.; Bezerra, Francisco H. R.; Dantas, Elton L. (2014). "Crustal structure beneath the Paleozoic Parnaíba Basin revealed by airborne gravity and magnetic data, Brazil on USGS". Tectonophysics 614: 18. doi:10.1016/j.tecto.2013.12.009. https://pubs.er.usgs.gov/publication/70118240.
- ↑ 5.0 5.1 R. Gregio. "Cratera da Serra da Cangalha". http://rgregio.astrodatabase.net/cratera_serra_cangalha.htm.
- ↑ 6.0 6.1 6.2 Adepelumi, A. A.; Fontes, S.L.; Schnegg, P.A.; Flexor,J.M. (2005). "An integrated magnetotelluric and aeromagnetic investigation of the Serra da Cangalha impact crater, Brazil". Physics of the Earth and Planetary Interiors 150 (1): 159–182. doi:10.1016/j.pepi.2004.08.029. Bibcode: 2005PEPI..150..159A. http://doc.rero.ch/record/5061/files/1_Schnegg_Pierre-Andr___-_An_integrated_magnetotelluric_20050905.pdf.
- ↑ 7.0 7.1 W.U. Reimold; G.R.J. Cooper; R. Romano; D. Cowan; C. Koeberl (2004). "A SRTM Investigation of Serra da Cangalho [sic] Impact Structure, Brazil". http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1232.pdf. Retrieved 2007-09-24.
- ↑ W. Masero; P.-A. Schnegg; S.L. Fontes. Magnetotelluric investigation of the Serra da Cangalha impact crater, Northeast Brazil.
- ↑ Adekunle Adepelumi; Jean M. Flexor; Sergio L. Fontes; Pierre-A. Schnegg. "A magnetotelluric investigation of the Serra da Cangalha impact crater structure, Brazil".
- ↑ Dietz, R.S.; French, B.M. (1973). "Two probable astroblemes in Brazil". Nature 244 (5418): 561–562. doi:10.1038/244561a0. Bibcode: 1973Natur.244..561D.
- ↑ Crósta, A. P. (1987). J. Pohl. ed. "Impact structures in Brazil". Research in Terrestrial Impact Structures (Braunschweig/Wiesbad: Friedrich, Vieweg & Sohn): 30–38. doi:10.1007/978-3-663-01889-6_2. ISBN 978-3-663-01891-9. Bibcode: 1987rtis.conf...30C.
- ↑ Beatty J. K. (1980). "Crater hunting in Brazil". Sky and Telescope 59: 464––467. Bibcode: 1980S&T....59..464B.
- ↑ McHone J. F. (1986). Terrestrial impact structures: Their detection and verification with new examples from Brazil. University of Illinois at Urbana-Champaign, Urbana, Illinois. p. 210.
 |  |
