Atenção: Todas as denúncias são sigilosas e sua identidade será preservada.
Os campos nome e e-mail são de preenchimento opcional
Metadados | Descrição | Idioma |
---|---|---|
Autor(es): dc.creator | Yokoyama, Elder | - |
Autor(es): dc.creator | Trindade, Ricardo Ivan Ferreira da | - |
Autor(es): dc.creator | Lana, Cristiano de Carvalho | - |
Autor(es): dc.creator | Souza Filho, Carlos Roberto de | - |
Autor(es): dc.creator | Baratoux, D. | - |
Autor(es): dc.creator | Marangoni, Yára Regina | - |
Autor(es): dc.creator | Tohver, Eric | - |
Data de aceite: dc.date.accessioned | 2019-11-06T13:25:27Z | - |
Data de disponibilização: dc.date.available | 2019-11-06T13:25:27Z | - |
Data de envio: dc.date.issued | 2012-10-22 | - |
Data de envio: dc.date.issued | 2012-10-22 | - |
Data de envio: dc.date.issued | 2012 | - |
Fonte completa do material: dc.identifier | http://hdl.handle.net/123456789/1708 | - |
Fonte: dc.identifier.uri | http://educapes.capes.gov.br/handle/capes/555075 | - |
Descrição: dc.description | The weakening mechanisms involved in the collapse of compleximpact craters are controversial. The Araguainhaimpact crater, in Brazil, exposes a complexstructure of 40 km in diameter, and is an excellent object to address this issue. Its core is dominated by granite. In addition to microstructural observations, magnetic studies reveal its internal fabric acquired during the collapse phase. All granite samples exhibit impact-related planar deformation features (PDFs) and planar fractures (PFs), which were overprinted by cataclasis. Cataclastic deformation has evolved from incipient brittle fracturing to the development of discrete shear bands in the center of the structure. Fracture planes are systematically decorated by tiny grains (< 10 μm) of magnetite and hematite, and the orientation of magnetic lineation and magnetic foliation obtained by the anisotropies of magnetic susceptibility (AMS) and anhysteretic remanence (AAR) are perfectly coaxial in all studied sites. Therefore, we could track the orientation of deformation features which are decorated by iron oxides using the AMS and AAR. The magneticfabrics show a regular pattern at the borders of the central peak, with orientations consistent with the fabric of sediments at the crater's inner collar and complex in the center of the structure. Both the cataclastic flow revealed from microstructural observations and the structural pattern of the magnetic anisotropy match the predictions from numerical models of compleximpactstructures. The widespread occurrence of cataclasis in the central peak, and its orientations revealed by magnetic studies indicate that acoustic fluidization likely operates at all scales, including the mineral scales. The cataclastic flow made possible by acoustic fluidization results in an apparent plastic deformation at the macroscopic scale in the core. | - |
Idioma: dc.language | en | - |
Direitos: dc.rights | O Periódico . Earth and Planetary Science Letters concede permissão para depósito deste artigo no Repositório Institucional da UFOP. Número da licença: 3315440555391 | - |
Palavras-chave: dc.subject | Microstructures | - |
Palavras-chave: dc.subject | Araguainha | - |
Palavras-chave: dc.subject | Magnetic anisotropy | - |
Palavras-chave: dc.subject | Compleximpact crater | - |
Palavras-chave: dc.subject | Weakening mechanism | - |
Título: dc.title | Magnetic fabric of Araguainha complex impact structure (Central Brazil): implications for deformation mechanisms and central uplift formation | - |
Aparece nas coleções: | Repositório Institucional - UFOP |
O Portal eduCAPES é oferecido ao usuário, condicionado à aceitação dos termos, condições e avisos contidos aqui e sem modificações. A CAPES poderá modificar o conteúdo ou formato deste site ou acabar com a sua operação ou suas ferramentas a seu critério único e sem aviso prévio. Ao acessar este portal, você, usuário pessoa física ou jurídica, se declara compreender e aceitar as condições aqui estabelecidas, da seguinte forma: