Gamma-ray spectrometry of the Araguainha impact structure, Brazil: Additional insights into element mobilization due to hydrothermal alteration
Abstract We present the analysis of airborne and ground gamma-ray spectrometry signatures of the Araguainha impact structure, located in central Brazil, the largest impact structure in South America with ~ 40 km diameter. The airborne data are total gamma-ray counts per second collected along flight...
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| Format: | Article |
| Language: | English |
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Academia Brasileira de Ciências
2022-07-01
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| Series: | Anais da Academia Brasileira de Ciências |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652022000501101&tlng=en |
| _version_ | 1818047110598098944 |
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| author | EMILSON P. LEITE JOHANN LAMBERT MARCOS ALBERTO R. VASCONCELOS ALVARO P. CRÓSTA ALESSANDRO BATEZELLI |
| author_facet | EMILSON P. LEITE JOHANN LAMBERT MARCOS ALBERTO R. VASCONCELOS ALVARO P. CRÓSTA ALESSANDRO BATEZELLI |
| author_sort | EMILSON P. LEITE |
| collection | DOAJ |
| description | Abstract We present the analysis of airborne and ground gamma-ray spectrometry signatures of the Araguainha impact structure, located in central Brazil, the largest impact structure in South America with ~ 40 km diameter. The airborne data are total gamma-ray counts per second collected along flight lines spaced 1 km apart. The ground gamma-ray data are concentrations of potassium, uranium, and thorium isotopes calculated from radiations measured in three individual channels. The objectives are to distinguish lithologies within the structure, which have naturally distinctive radiogenic signatures, and identify potential post-impact hydrothermal alteration zones, as indicated by high K concentrations. Based on results obtained by numerical modeling of the crater formation, we infer the locations of potential occurrences of target rocks that may have undergone hydrothermal alteration as a result of the impact. The deviations from the background potassium concentration show significant anomalous K values at the center and in the northwestern crater rim, where high concentrations of U are also observed. The numerical model shows that ideal temperature conditions for hydrothermal fluid circulation were attained right after pos-impact gravitational stabilization. |
| first_indexed | 2024-12-10T10:00:35Z |
| format | Article |
| id | doaj.art-fa44954d90f2466d8902f5bdb4ea6585 |
| institution | Directory Open Access Journal |
| issn | 1678-2690 |
| language | English |
| last_indexed | 2024-12-10T10:00:35Z |
| publishDate | 2022-07-01 |
| publisher | Academia Brasileira de Ciências |
| record_format | Article |
| series | Anais da Academia Brasileira de Ciências |
| spelling | doaj.art-fa44954d90f2466d8902f5bdb4ea65852022-12-22T01:53:22ZengAcademia Brasileira de CiênciasAnais da Academia Brasileira de Ciências1678-26902022-07-0194310.1590/0001-3765202220210182Gamma-ray spectrometry of the Araguainha impact structure, Brazil: Additional insights into element mobilization due to hydrothermal alterationEMILSON P. LEITEhttps://orcid.org/0000-0003-1691-6243JOHANN LAMBERThttps://orcid.org/0000-0003-2483-0503MARCOS ALBERTO R. VASCONCELOShttps://orcid.org/0000-0002-4970-0484ALVARO P. CRÓSTAhttps://orcid.org/0000-0003-0485-1147ALESSANDRO BATEZELLIhttps://orcid.org/0000-0001-5324-7638Abstract We present the analysis of airborne and ground gamma-ray spectrometry signatures of the Araguainha impact structure, located in central Brazil, the largest impact structure in South America with ~ 40 km diameter. The airborne data are total gamma-ray counts per second collected along flight lines spaced 1 km apart. The ground gamma-ray data are concentrations of potassium, uranium, and thorium isotopes calculated from radiations measured in three individual channels. The objectives are to distinguish lithologies within the structure, which have naturally distinctive radiogenic signatures, and identify potential post-impact hydrothermal alteration zones, as indicated by high K concentrations. Based on results obtained by numerical modeling of the crater formation, we infer the locations of potential occurrences of target rocks that may have undergone hydrothermal alteration as a result of the impact. The deviations from the background potassium concentration show significant anomalous K values at the center and in the northwestern crater rim, where high concentrations of U are also observed. The numerical model shows that ideal temperature conditions for hydrothermal fluid circulation were attained right after pos-impact gravitational stabilization.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652022000501101&tlng=enAraguainhagamma-raygeophysicsimpact crater |
| spellingShingle | EMILSON P. LEITE JOHANN LAMBERT MARCOS ALBERTO R. VASCONCELOS ALVARO P. CRÓSTA ALESSANDRO BATEZELLI Gamma-ray spectrometry of the Araguainha impact structure, Brazil: Additional insights into element mobilization due to hydrothermal alteration Anais da Academia Brasileira de Ciências Araguainha gamma-ray geophysics impact crater |
| title | Gamma-ray spectrometry of the Araguainha impact structure, Brazil: Additional insights into element mobilization due to hydrothermal alteration |
| title_full | Gamma-ray spectrometry of the Araguainha impact structure, Brazil: Additional insights into element mobilization due to hydrothermal alteration |
| title_fullStr | Gamma-ray spectrometry of the Araguainha impact structure, Brazil: Additional insights into element mobilization due to hydrothermal alteration |
| title_full_unstemmed | Gamma-ray spectrometry of the Araguainha impact structure, Brazil: Additional insights into element mobilization due to hydrothermal alteration |
| title_short | Gamma-ray spectrometry of the Araguainha impact structure, Brazil: Additional insights into element mobilization due to hydrothermal alteration |
| title_sort | gamma ray spectrometry of the araguainha impact structure brazil additional insights into element mobilization due to hydrothermal alteration |
| topic | Araguainha gamma-ray geophysics impact crater |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652022000501101&tlng=en |
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