Chapter 6 - The Antarctic Continent in Gondwana: a perspective from the Ross Embayment and Potential Research Targets for Future Investigations

Abstract

After a description of the main geological units and the present-day geotectonic setting before Gondwana amalgamation, this chapter summarises the tectonic evolution of the Antarctic continent from its inclusion as part of the Gondwana supercontinent to the breakup of this landmass and the repositioning of Antarctica at southern polar latitudes since the Early Cretaceous. The geological evolution of the Antarctic continent is then described considering two main time periods: (1) c. 600–450Ma, covering the processes which were active immediately before and during the amalgamation of Gondwana; and (2) c. 450–180Ma, including all the major events that occurred after the final stage of Gondwana amalgamation to the time immediately before the Gondwana breakup phase. A subsequent section is devoted to the 180Ma to recent time window during which present-day Antarctica and the other southern continents and surrounding oceanic basins formed as consequence of the fragmentation of Gondwana, and when tectonic processes led to the drift and dispersion of the various continental fragments. After a general overview of the most significant plate tectonic stages, and coeval magmatic products, the chapter reviews the main geological findings from the Ross Embayement region – one of the most investigated regions in Antarctica – the Transantarctic Mountains and the Ross Sea sector of the Western Antarctic Rift System. Persistent open problems, and potential research themes, are discussed in the Conclusions.