Santa Marta crater is a newly confirmed

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

in Piauí State, northeastern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. It is in diameter and it is estimated to have formed between 100 and 66 Ma, during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

Description

Its impact origin was first proposed by S. Master and J. Heymann in 2000 based primarily on satellite remote sensing data and was confirmed more than a decade later after conclusive evidence of

shock metamorphism Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events. The formation of similar features during explosive volcanism is generally discounted due to the lack of metamorp ...

such as

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of di ...

and

shatter cones Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions. They are evidence that the rock has been subjected to a shock with pressures in the ra ...

were found.A. P. Crósta and M. A. Vasconcelos (2013)
Confirmation Of The Impact Origin Of The Santa Marta Crater, Brazil
76th Annual Meteoritical Society Meeting

References

Impact craters of Brazil Cretaceous impact craters Cretaceous Brazil Landforms of Piauí Geology of Brazil {{Earth-crater-stub

Description

See also

References