Baltica data makes it difficult to locate the margin in the Arctic. Ordovician faunas indicate that most of Svalbard, including Bjørnøya, was part of Laurentia, but Franz Josef Land and Kvitøya (an eastern island of the Svalbard archipelago) most likely became part of Baltica in the Timanide Orogeny. The Taymyr Peninsula, in contrast, never was part of Baltica: southern Taymyr was part of Siberia whilst northern Taymyr and the Severnaya Zemlya archipelago were part of the independent Kara Terrane in the early Palaeozoic. The eastern margin, the Uralide orogen, extends from the Arctic Novaya Zemlya archipelago to the Aral Sea. The
Baltica for example, the curved margin north of the Urals running parallel to Novaya Zemlya was probably deformed during the eruption of the End-Permian Siberian Traps. Baltica's western margin is the Caledonide orogen which stretches northward from the Scandinavian Mountains across Barents Sea to Svalbard. Its eastern margin is the Timanide orogen which stretches north to the Novaya Zemlya archipelago. The extent of the Proterozoic continent are defined by the Iapetus Suture to the west; the Trollfjorden-Komagelva Fault Zone in the north; the Variscan-Hercynian suture to the south; the Tornquist Zone to the southwest; and the Ural Mountains to the east.