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Praia Grande crater

Coordinates: 25°38′50″S 45°37′30″W / 25.64722°S 45.62500°W / -25.64722; -45.62500
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Praia Grande crater
Praia Grande crater is located in Brazil
Praia Grande crater
Location of the crater offshore Brazil
Impact crater/structure
ConfidenceProbable[1]
Diameter20 km (12 mi)
Age85.8 to 83.5 Ma
Santonian
ExposedNo
DrilledNo
Location
LocationSantos Basin
Coordinates25°38′50″S 45°37′30″W / 25.64722°S 45.62500°W / -25.64722; -45.62500[1]
CountryBrazil
StateSão Paulo

Praia Grande crater is a 20 kilometres (12 mi) diameter circular feature in the Santos Basin offshore Brazil. It is a possible impact crater that has been identified on 3D seismic by Petrobras in 2004. Further investigation is needed to obtain more information on the structure. The Russian Academy of Sciences lists the structure as a probable impact crater.[1]

Description

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The Praia Grande crater is located in the Santos Basin, approximately 200 kilometres (120 mi) southeast from the coastline of São Paulo State, Brazil. The identification of this structure is based on the interpretation of three-dimensional seismic data, acquired and processed in 2004 for petroleum exploration in a Petrobras concession block in the Santos Basin. The principal morphological elements, imposed on Upper Cretaceous rocks, are a structural high in the center of the crater, an adjacent ring syncline, and, externally, several concentric circular listric normal faults.

The structure is apparently well preserved from erosion, measures around 20 kilometres (12 mi) in diameter, and is buried by 4 kilometres (13,000 ft) of rocks deposited after the impact time, which occurred in the Santonian (85.8 to 83.5 Ma).[2] The central uplift is well defined, with a diameter of 4.5 kilometres (2.8 mi), which is surrounded by concentric annular troughs.[3] Further investigation is needed to acquire data on shock metamorphism and shatter cones.[4][5]

See also

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References

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  1. ^ a b c Mikheeva, 2017
  2. ^ Correia et al., 2005, p.439
  3. ^ Crósta & Vasconcelos, 2013, p.2
  4. ^ Exoss, 2017a
  5. ^ Exoss, 2017b

Bibliography

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  • Correia, Gustavo Alberto; Corrêa de Menezes, Jorge Rui; Vital Bueno, Gilmar; Jung Marques, Edmundo Julio (2005), "3D Seismic Interpretation of the Praia Grande Impact Structure – Upper Cretaceous of Santos Basin, Offshore Brazil", 9th International Congress of the Brazilian Geophysical Society & EXPOGEF, Salvador, Bahia, Brazil, 11-14 September 2005, 9th International Congress of the Brazilian Geophysical Society & EXPOGEF, Salvador, Bahia, Brazil, 11–14 September 2005, pp. 439–442, doi:10.1190/sbgf2005-091, retrieved 2017-10-10
  • Crósta, A.P.; Vasconcelos, M.A.R. (2013), "Update on the current knowledge of the Brazilian impact craters" (PDF), 44th Annual Lunar and Planetary Science Conference (1719), 44th Lunar and Planetary Science Conference: 1–2, Bibcode:2013LPI....44.1318C, retrieved 2017-10-10
  • Exoss, Citizen Science (2017a), Série: Astroblemas no Brasil – crateras de impacto brasileiras – MG e SP, Exoss Citizen Science, p. 1, retrieved 2017-10-10
  • Exoss, Citizen Science (2017b), Impact Crater Brazil - Crateras de impacto em MG e SP - Praia Grande, Exoss Citizen Science, pp. 00:50, retrieved 2017-10-10
  • Mikheeva, Anna (2017), The Complete Catalog of the Earth's Impact structures, Russian Academy of Sciences, p. 1, retrieved 2017-10-10