The discovery of the Sverdrup group of islands has greatly extended our knowledge of the Mesozoic rocks of the Arctic basin. The Franklin search parties discovered rocks of this age on the northern shores of the Parry islands; at Point Wilkie, in Prince Patrick island; Rendezvous Hill, near the northwestern extreme of Bathurst island and at Exmouth island and places in the vicinity, near the northwest part of North Devon. The explorations from the Fram now show that these are but the southern edge of a wide basin of these rocks which form the islands of King Oscar, Ellef and Amund Ringes, while they constitute the lowlands of Axel Heiberg and the western shores of Ellesmere along both sides of Eureka sound. There they consist largely of sandstones with shales, schists and limestones.

As before stated, Schei hints that their eastern extension to the shores of Kennedy channel may be marked by the tilted and folded strata, classed by De Rance as the Cape Rawson Series, of supposed Cambrian age.