Tectonics of the triple junction at the southern end of the Shackleton Fracture Zone (Antarctic Peninsula)

The southern end of the Shackleton Fracture Zone is subducted below the South Shetland forearc, while the basal detachment of the forearc continues eastward of the Shackleton ridge as a thrust fault. The western boundary between the Antarctic/Scotia plates is located at the eastern margin of the Shackleton ridge, where an elongated depositional basin and a morphological trough delineates the contact. The boundary of the Antarctic/Scotia plates and the South Shetland forearc form a triple junction at the intersection of the Shackleton Fracture Zone with the trench, between these two plates, and an independent South Shetland block.