5 documents found, page 1 of 1
Quantifying rates of dome-and-keel formation in the Barberton granitoid-greenst...
Lana, Cristiano de Carvalho; Tohver, Eric; Cawood, Peter AnthonyThe Barberton granitoid-greenstone belt is a classic dome-and-keel province, characterized by kilometerscale gneiss domes and elongate keels of largely folded supracrustal rocks. Combined U–Pb SHRIMP data and structural mapping demonstrate that the geometry of the Barberton belt reflects events that occurred over ∼30 million year interval, from ca. 3230 and 3203 Ma. Early deformation with NW–SE shortening in th...
Shaking a methane fizz : seismicity from the Araguainha impact event and the Pe...
Tohver, Eric; Cawood, Peter Anthony; Riccomini, Claudio; Lana, Cristiano de Carvalho; Trindade, Ricardo Ivan Ferreira daThe Late Permian and Early Triassic periods are marked by large fluctuations in the carbon isotope record, but the source(s) of the disturbance to the global carbon cycle and the link to the end-Permian mass extinction arewidely debated. This contribution explores the possible isotopic effects of an impact event into the hydrocarbon-rich rocks of the Paraná–Karoo Basin. Recent U–Pb and 40Ar/39Ar dating of the 4...
Magnetic fabric of Araguainha complex impact structure (Central Brazil) : impli...
Yokoyama, Elder; Trindade, Ricardo Ivan Ferreira da; Lana, Cristiano de Carvalho; Souza Filho, Carlos Roberto de; Baratoux, D.; Marangoni, Yára ReginaThe 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 ex...
Synsedimentary tectonics in the permocarboniferous glacial deposits of West Fal...
Tohver, Eric
The continental record of Ediacaran volcano-sedimentary successions in southern...
Tohver, Eric