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
Severnaya Zemlya the islands, but adverse weather conditions forced them to turn southward when only an hour or two from viewing the archipelago's coastline. In the spring of 1931 Georgy Ushakov, accompanied by the geologist Nikolay Urvantsev, the veteran surveyor Sergei Zhuravlev, and the radio operator Vasily Khodov thoroughly surveyed Severnaya Zemlya during a two-year expedition to the archipelago. Ushakov and his team established a small base at Golomyanny – the western end of Sredniy Island, off October Revolution Island's western coast. From there they made multiple surveying trips into the interior and the coastlines of the larger islands. The first detailed