The active triple junction in the NE Antarctic Peninsula: new insights from NE Bransfield Strait and Elephant Island recent tectonic evolution

• Main Authors: Galindo Zaldívar, Jesús, Bohoyo, Fernando, Maestro González, Adolfo, López Martínez, Jerónimo, Morales-Ocaña, Cecilia, Schreider, Anatoly
• Format: Conference Object
• Language: unknown
• Published: Scientific Committee on Antarctic Research 2020
• Subjects: Antarctic; Antarctic Peninsula; Bransfield Strait; Drake Passage; Elephant Island; Shackleton; Shackleton Fracture Zone; South Shetland Trench; The Antarctic; Antarc*
• Online Access: http://hdl.handle.net/10261/237492

9th SCAR Open Science Conference and XXXVI SCAR Meetings. Hobart, Tasmania, Australia. 31 July - 11 August 2020 [EN] The northern margin of the Antarctic Peninsula is affected by the most recent tectonic activity related to the last stage of the opening of the Drake Passage. The subduction along the South Shetland Trench of the Former Phoenix Plate, now belonging to the Antarctic Plate, contributes to the detachment of the continental South Shetland Block from the Antarctic Peninsula and the development of the Bransfield Basin. The underthrusting of the active transpressive sinistral Shackleton Fracture Zone below this continental block shaped the active triple junction that determined the NE tip of the South Shetland Trench and the uplift of Elephant Island. This geological context produced changes in tectonic regime along the NE Antarctic Peninsula, including transcurrence associated to the Shackleton Fracture Zone, compressive deformations with reverse faults and large open folds related to subduction in the northern part of South Shetland Block and Elephant Island and extensional processes in Bransfield back arc basin and the southern part of Elephant Island. The analysis of the recent structures from multichannel seismic profiles, detailed bathymetric data, seismicity including earthquake focal mechanisms and paleostresses determined from mesofault population analysis, improves the knowledge of the recent tectonic evolution of the triple junction and highlights implications on the latest palaeoceanographic evolution of the Drake Passage