The Jan Mayen Microcontinent: Computers animations of the plate tectonic history
Abstract
Local reinterpretation of magnetic seafloor anomalies in the NE Atlantic (e.g. Gaina et al., EPSL, 2002), and the Arctic (Oakey et al, GSC-Open File, 1999) has led to a revised Tertiary plate model for the region. Our model suggests complete separation between the North American and Eurasian plates was established first in the Oligocene, when a southward propagating Arctic spreading system linked with a northward propagating Atlantic spreading system. The Arctic system consisted of the Nansen, Mohns, and Aegir Ridges, with a series of left-lateral offsets, around the Greenland craton. The Atlantic system consisted of the Reykjanes and Kolbeinsey Ridges and stepped right around Greenland for the same reason. The final configuration became one of opposed and overlapping propagating spreading systems, where both the Aegir and the Kolbeinsey spreading ridges were active, a concept discussed by Vogt (1986). This configuration resembles that seen for microcracks, mode 1 fractures, normal faults, rifts, and minor offsets along spreading axes (e.g. Macdonald and Sempere, JGR, 1984). The interaction of the spreading ridge system with the Iceland Hotspot, likely influenced the timing and style of rifting and break-up (e.g. Mueller et al., Geology, 2001). As a result of the overlapping tips of the Arctic and Atlantic spreading axes, the Jan Mayen microcontinent gradually became separated from East Greenland and rotated c. 50° counter clockwise in the process. Our reconstructions indicate that this separation and rotation started approximately at Chron 22 (49 Ma) and ended approximately at Chron 12 (30 Ma) when the Aegir Ridge became extinct. During its rotation, the Jan Mayen microcontinent formed a bridge between NW Europe (the Faroes area) and southern East Greenland for quite some time. Clearly, the presence of the Jan Mayen continental sliver must have influenced oceanic circulation patterns between the NE Atlantic and Norwegian-Greenland Sea. We present a series of computer graphic animations, using magnetic, gravity and bathymetric data, to illustrate this complex tectonic history and its implications.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.T12D1344R
- Keywords:
-
- 3035 Midocean ridge processes;
- 3040 Plate tectonics (8150;
- 8155;
- 8157;
- 8158)