Scotia Arc

The northern border, the North Scotia Ridge, comprises (from west to east): Isla de los Estados at the tip of Tierra del Fuego, the Burdwood, Davis, and Aurora Banks; the Shag, South Georgia Island and Clerke Rocks.

An ancestral arc, which formed a separate subduction system, broke through this land bridge and started to form the Scotia Sea by eastward back-arc extension driven by subduction of the South American Plate (also located east of the Scotia Arc).

The uplift of the ridge initiated the eastward migration of the South Georgia microcontinent from Tierra del Fuego towards its current location.

Spreading in the West Scotia Sea also finally led to the rifting of the South Orkney microcontinent from the tip of the Antarctic Peninsula.

[4] The banks of the South Scotia Ridge are made of continental crust that rifted off the land bridge 40-30 Ma.

The banks on the northern Central Scotia Sea, on the other hand, are volcanic constructs overlaying an oceanic basement.