A new siluro‐Devonian paleopole from Early Paleozoic rocks of the Franklinian basin, North Greenland Fold Belt

Abstract

Demagnetization of dolomitic shales, dolomites, and carbonate breccias of the Cambro‐Ordovician Kap Stanton Formation within the Franklinian basin sequence of the North Greenland Fold Belt yields a characteristic direction (declination/inclination is 16/−16, tilt corrected) from 14 of the 28 sites. A negative breccia test and positive local and regional fold tests bracket the age of the magnetization as postdepositional but pre‐Ellesmerian (pre‐Carboniferous). After rotating the corresponding paleopole (1°N, 302°E) to account for the Cretaceous‐Tertiary opening of the Labrador Sea, the Greenland pole remains removed by approximately 20° from the existing North American Apparent Polar Wander Path (APWP). However, the rotated paleopole (2°S, 284°E in North American coordinates) is similar to British Silurian and Devonian paleopoles in a Bullard et al. (1965) reconstruction (pole is 2°S, 322°E in British coordinates). We interpret our new paleopole as Late Silurian to Early Devonian in age, requiring a modification of previously published APWPs for Laurentia. If the age assignment is correct, the new paleopath for North America/Greenland and that for Great Britain can be brought into good agreement by closing the Atlantic Ocean, thus indicating that North America, Greenland, and Great Britain were assembled in a supercontinent in Late Silurian to Early Devonian time.