Insights into the morphology, geometry, and post-impact erosion of the Araguainha peak-ring structure, central Brazil

Abstract

Research Article| September 01, 2007 Insights into the morphology, geometry, and post-impact erosion of the Araguainha peak-ring structure, central Brazil C. Lana; C. Lana 1Department of Geology, University of Stellenbosch, Private Bag X1, Matieland 7620, South Africa Search for other works by this author on: GSW Google Scholar C.R. Souza Filho; C.R. Souza Filho 2Departamento de Geologia e Recursos Naturais, Instituto de Geociencias, State University of Campina (UNICAMP), 13083-970, Brazil Search for other works by this author on: GSW Google Scholar Y.R. Marangoni; Y.R. Marangoni 3Instituto de Astronomia, Geofísica e Ciencias Atmosfericas, Universidade de Sao Paulo Rua do Matao, 1226, Cidade Universitaria, Sao Paulo, SP 05508-090, Brazil Search for other works by this author on: GSW Google Scholar E. Yokoyama; E. Yokoyama 3Instituto de Astronomia, Geofísica e Ciencias Atmosfericas, Universidade de Sao Paulo Rua do Matao, 1226, Cidade Universitaria, Sao Paulo, SP 05508-090, Brazil Search for other works by this author on: GSW Google Scholar R.I.F. Trindade; R.I.F. Trindade 3Instituto de Astronomia, Geofísica e Ciencias Atmosfericas, Universidade de Sao Paulo Rua do Matao, 1226, Cidade Universitaria, Sao Paulo, SP 05508-090, Brazil Search for other works by this author on: GSW Google Scholar E. Tohver; E. Tohver 3Instituto de Astronomia, Geofísica e Ciencias Atmosfericas, Universidade de Sao Paulo Rua do Matao, 1226, Cidade Universitaria, Sao Paulo, SP 05508-090, Brazil Search for other works by this author on: GSW Google Scholar W.U. Reimold W.U. Reimold 4Museum for Natural History (Mineralogy), Humboldt University, Invalidenstrasse 43, 10115 Berlin, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information C. Lana 1Department of Geology, University of Stellenbosch, Private Bag X1, Matieland 7620, South Africa C.R. Souza Filho 2Departamento de Geologia e Recursos Naturais, Instituto de Geociencias, State University of Campina (UNICAMP), 13083-970, Brazil Y.R. Marangoni 3Instituto de Astronomia, Geofísica e Ciencias Atmosfericas, Universidade de Sao Paulo Rua do Matao, 1226, Cidade Universitaria, Sao Paulo, SP 05508-090, Brazil E. Yokoyama 3Instituto de Astronomia, Geofísica e Ciencias Atmosfericas, Universidade de Sao Paulo Rua do Matao, 1226, Cidade Universitaria, Sao Paulo, SP 05508-090, Brazil R.I.F. Trindade 3Instituto de Astronomia, Geofísica e Ciencias Atmosfericas, Universidade de Sao Paulo Rua do Matao, 1226, Cidade Universitaria, Sao Paulo, SP 05508-090, Brazil E. Tohver 3Instituto de Astronomia, Geofísica e Ciencias Atmosfericas, Universidade de Sao Paulo Rua do Matao, 1226, Cidade Universitaria, Sao Paulo, SP 05508-090, Brazil W.U. Reimold 4Museum for Natural History (Mineralogy), Humboldt University, Invalidenstrasse 43, 10115 Berlin, Germany Publisher: Geological Society of America Received: 09 Nov 2006 Revision Received: 23 Mar 2007 Accepted: 23 Mar 2007 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2007) 119 (9-10): 1135–1150. https://doi.org/10.1130/B26142.1 Article history Received: 09 Nov 2006 Revision Received: 23 Mar 2007 Accepted: 23 Mar 2007 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation C. Lana, C.R. Souza Filho, Y.R. Marangoni, E. Yokoyama, R.I.F. Trindade, E. Tohver, W.U. Reimold; Insights into the morphology, geometry, and post-impact erosion of the Araguainha peak-ring structure, central Brazil. GSA Bulletin 2007;; 119 (9-10): 1135–1150. doi: https://doi.org/10.1130/B26142.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The 40-km-wide Araguainha structure is the largest and best-exposed complex impact crater in South America. It was excavated in flat-lying sediments of the intracratonic Paraná Basin, where target rocks are well exposed and have remained undeformed since the impact event ca. 245 Ma. Despite the excellent state of preservation and exposure, information available on the target rock stratigraphy, post-impact erosion, and morphology of the structure is limited. Our combined field observations and remote sensing analysis demonstrate that Araguainha preserves all features of a shallowly eroded peak-ring crater. The interior of the structure exposes a central peak surrounded by a 5-km-wide annular basin and two main ring features 10–12 and 14–18 km from the center. Analysis of the pre-impact stratigraphy, present morphology, and crater dimensions indicates that excavation related to the transient cavity formation was extensive in the annular basin, but minimal to nonexistent beyond the inner ring feature. The formation of the inner ring feature can be reconciled with compressional stresses during outward collapse of the central uplift and inward slumping of the crater walls. Regional stratigraphic data combined with field observations indicate two periods of post-impact erosion associated with exhumation of the Paraná Basin. We estimate that 250–350 m of fallback deposits and target rocks have been removed by erosion. Erosion also accounted for removal of the proximal ejecta immediately outside the rim of the structure. In contrast to previous suggestions that the impact took place in a shallow-marine environment, our observations are more consistent with an extremely shallow, brackish to freshwater lacustrine environment, with little effect on the developing impact crater. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.