The rotations opening the Central and Northern Atlantic Ocean: compilation, drift lines, and flow lines (Int J Earth Sci 102:1357–1376)

Abstract

Strait and marked the Wegener Fault. Figure 1b depicts the present-day geography and geology of the region modified from Dawes (2009, Fig. 9). The mismatch between Ellesmere Island and Greenland in Fig. 1a is immediately apparent from the disruption of the two sedimentary basins—the Mesoproterozoic Thule and Paleozoic Franklinian—that straddle nares Strait. The component of the Thule Basin on Greenland is displaced from that on Ellesmere Island. The regional architecture of the Franklinian Basin depicted in Fig. 1b by cambrian to Devonian markers in Ellesmere Island and Greenland is destroyed and the cambro-Silurian, folded, deep-water trough of the Franklinian Basin on Greenland strikes into Paleoproterozoic gneiss on Ellesmere Island. Other misfits on a more detailed scale are listed by Dawes (2009). In addition, closure of the major seaways flanking Devon Island (Lancaster and Jones Sounds) likewise results in gross mismatches within canadian geology. Similar problems arising from the undoing of harmonious geology mar Greiner and neugebauer’s reconstructions at 84 and 52.65 Ma. Saalmann et al. (2005) described a Paleogene, nEtrending, strike-slip fault zone and later SE-directed thrusting on land in a 100-km-long stretch of the nE Ellesmere Island coastline. They considered this deformation to be a manifestation of the Wegener Transform Fault and plate boundary but admitted that the fault could not be traced farther south through southern nares Strait into Baffin Bay. Greiner and neugebauer have used Saalmann et al.’s findings to support their case for convergence of Greenland and Ellesmere Island and large-scale displacement along the Wegener Fault but fail to acknowledge that these Paleogene tectonic features are of limited regional significance and that, in any event, the amount of strike slip recorded on land is insufficient to account for the separation of Greenland from north America by spreading in Baffin Bay. Greiner and neugebauer (2013) have modeled the opening of the central and northern Atlantic Ocean using a computer program that generates paleogeographic reconstructions based on Euler rotational data, which in turn are derived from magnetic anomalies flanking oceanic spreading ridges. Here, we confine ourselves to a critique of Greiner and neugebauer’s results for the nares Strait—northern Baffin Bay region bordered by Greenland and the eastern canadian High Arctic. Reconstructions at or before 175, 84, and 52.65 Ma are shown in Greiner and neugebauer’s Figures 5, 6, 9, and 10. All these are strictly paleogeographic representations; none shows any surface geological feature. Greiner and neugebauer a priori consider Greenland to be an independent tectonic plate separated from Ellesmere Island—part of the north American plate—by a transform fault, the Wegener Fault, running through nares Strait. They accept the Wegener Fault as a proven structure and overlook abundant evidence that it is hypothetical (Oakey and Damaske 2006; Harrison 2006; Dawes 2009; Hansen et al. 2011; Rasmussen and Dawes 2011). They cite only one reference to geology relevant to their reconstructions, viz. Saalmann et al. (2005), to which we will return below. Figure 1a is a reproduction of part of Greiner and neugebauer’s Fig. 9 (reconstruction before 175 Ma) with four geological provinces shown, as well as their postulated north American plate boundary coinciding with nares