The

Andes Mountains subduction zone, the Antarctic Peninsula exhibits textbook subduction zone tectonic activity. The geologic and tectonic history of the Antarctic Peninsula spans millions of years. Throughout this span of time the plate configurations that essentially formed the Antarctic Peninsula shifted. These shifts changed the orientation of the peninsula itself, as well as the underlying volcanics associated with the subduction zone.^[1]

Geologic history of the Antarctic Peninsula

The geology of the Antarctic Peninsula has occurred within three different stages:

Pre-subduction stage of marginal basin deposition, later seperated by the Gondwanian orogeny,Permian-Late Triassic
The formation of two magmatic arcs, one proximal and one distal to the peninsula during the main subduction stage, middle Jurassic-Miocene.
The late subduction phase where the Bransfield Rift opens along with the back-arc basin, site of contemporaneous terrestrial and submarine volcanic activity, Oligocene-present day.

Pre-Subduction History

The oldest rocks found on the

Gondwanaland to the northeast. Source rocks assemblage was most likely a mixture of metamorphic, igneous, and sedimentary complexes.^[1]

Gondwanian orogeny

At this time the TPG sediments were folded and slightly metamorphosed, particularly at the peninsula's northernmost point. Retroarc thrusting was also occurring at that time. Both events were most likely caused by incipient stage subduction of the south-east

Gondwanaland. It is believed that the TPG rocks were uprooted from their original oceanic-type basement and are allochthonous with respect to underlying crystalline basement rock of the Antarctic Peninsula.^[1]

References

Una's Tits
Una's Tits
	Breast shaped hills
Coordinates	65°06′24″S 63°56′26″W / 65.10667°S 63.94056°W
Geography
	Una's Tits Antarctica
Climbing
First ascent	1999

^
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[Birkenmajer1-1] 
doi:10.1007/BF00210547 (inactive 2022-06-26).{{cite journal}}: CS1 maint: DOI inactive as of June 2022 (link
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[1]