Has the formation of a slab window below the Antarctic Peninsula controlled its topographic evolution? ...

• Main Author: Twinn, Gary Peter
• Format: Doctoral or Postdoctoral Thesis
• Language: unknown
• Published: Birkbeck, University of London 2024
• Subjects: Alexander Island; Antarc*; Antarctic; Antarctic Peninsula; Palmer Land
• Online Access: https://dx.doi.org/10.18743/pub.00053226; https://eprints.bbk.ac.uk/id/eprint/53226

This thesis presents apatite (U-Th)/He and apatite fission-track thermochronology data to understand spatial and temporal changes in rock uplift and exhumation along and across the Antarctic Peninsula to determine how and when its high elevation developed. This is important to test tectonic models and to understand the elevation history as a precursor to ice nucleation and expansion in the Cenozoic. Easterly-directed subduction of the Phoenix Plate, including ridge-trench collisions, has been taking place along its western margin since the Late Cretaceous. Data from four east-west transects show how cooling rates varied with distance from the trench as well as with respect to the timing of the ridge-trench collisions on a south-north basis. Eastern Palmer Land preserves a record of uplift during the Late Cretaceous that coincides with changes in Phoenix Plate convergence rates and direction. In contrast, western Palmer Land and Alexander Island experienced a period of increased rates of cooling between c. 25 ...