Recent tectonic and morphostructural evolution of Byers Peninsula (Antarctica): insight into the development of the South Shetland Islands and Bransfield Basin

• Main Authors: Alfaro, P., López Martínez, Jerónimo, Maestro González, Adolfo, Galindo Zaldívar, Jesús, Durán-Valsero, J. J., Cuchí-Oterino, José Antonio
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidad Complutense de Madrid 2010
• Subjects: Antarctica; Byers Peninsula; Mesostructural analysis; Morphotectonics; Paleostress; South Shetland Islands; Antártida; Análisis mesoestructural; Morfotectónica; Paleoesfuerzos; Islas Shetland del Sur; Antarctic; Byers; Byers peninsula; Hero Fracture Zone; isla Livingston; islas Shetland del Sur; Livingston Island; península Byers; Shetland del Sur; South Scotia Ridge; South Shetland Trench; Sur Este; The Antarctic; Antarc*; Antártica
• Online Access: http://hdl.handle.net/10261/26787

[EN] Byers Peninsula forms the western extremity of the Livingston Island (Antarctica) in the continental South Shetland Block. This tectonic block is bounded by the South Shetland Trench to the north, the Bransfield back-arc basin to the south, and extends to the South Scotia Ridge on the east. Westwards it is connected to the Antarctic Plate by a broad deformation zone located at the southern end of the Hero Fracture Zone. In Byers Peninsula we analyzed more than 1,200 lineaments, and 359 fault planes from 16 sites, both in sedimentary and intrusive igneous rocks. Statistical analysis of lineaments and mesoscopic fractures, with a length varying between 31 and 1,555 m, shows a NW-SE maximum trend, with two NE-SW and ENE-WSW secondary maximums. Fault orientation analysis shows similar trends suggesting that most of the lineaments correspond to fractures. Due to the absence of striated faults and the lack of kinematic evidence on the regime in most of the analyzed faults we have used the Search Grid paleostress determination method. The results obtained allow us to improve and complete the data on the recent evolution of the South Shetland Block. In this complex geodynamic setting, Byers Peninsula has been subjected to NNW-SSE to NNE-SSW extension related to Bransfield Basine Antarcopening and NE-SW and NW-SE local compressions respectively associated to Scotia-Antarctic plate convergence and the South Shetland Trench subduction. [ES] La Península Byers se localiza en el extremo occidental de la Isla Livingston (Antártida) que pertenece al bloque continental de las Shetland del Sur. Este bloque tectónico está limitado al norte por la Fosa de las Shetland del Sur, al sur por la cuenca de trasarco de Bransfield, y hacia el este se extiende por la Dorsal Sur de Scotia. Hacia el oeste conecta con la placa Antártica a través de una amplia zona de deformación localizada en la prolongación meridional de la Zona de Fractura Hero. En este trabajo se han analizado conjuntamente más de 1.200 lineamientos, así como 359 ...