The crustal structure of Ellesmere Island, Arctic Canada-teleseismic mapping across a remote intraplate orogenic belt

Ellesmere Island in Arctic Canada displays a complex geological evolution. The region was affected by two distinct orogenies, the Palaeozoic Ellesmerian orogeny (the Caledonian equivalent in Arctic Canada and Northern Greenland) and the Palaeogene Eurekan orogeny, related to the opening of Baffin Bay and the consequent convergence of the Greenland plate. The details of this complex evolution and the present-day deep structure are poorly constrained in this remote area and deep geophysical data are sparse. Receiver function analysis of seven temporary broad-band seismometers of the Ellesmere Island Lithosphere Experiment complemented by two permanent stations provides important data on the crustal velocity structure of Ellesmere Island. The crustal expression of the northernmost tectonic block of Ellesmere Island (similar to 82A degrees aEuro"83A degrees N), Pearya, which was accreted during the Ellesmerian orogeny, is similar to that at the southernmost part, which is part of the Precambrian Laurentian (North America-Greenland) craton. Both segments have thick crystalline crust (similar to 35-36 km) and comparable velocity-depth profiles. In contrast, crustal thickness in central Ellesmere Island decreases from similar to 24-30 km in the Eurekan fold and thrust belt (similar to 79.7A degrees aEuro"80.6A degrees N) to similar to 16-20 km in the Hazen Stable Block (HSB; similar to 80.6A degrees aEuro"81.4A degrees N) and is covered by a thick succession of metasediments. A deep crustal root (similar to 48 km) at similar to 79.6A degrees N is interpreted as cratonic crust flexed beneath the Eurekan fold and thrust belt. The Carboniferous to Palaeogene sedimentary succession of the Sverdrup Basin is inferred to be up to 1-4 km thick, comparable to geologically-based estimates, near the western margin of the HSB.