Plate Tectonic Evolution of the Greenland-Scotland Ridge and Surrounding Regions

Abstract

A series of plate tectonic reconstructions is presented for the northeast Atlantic and Norwegian-Greenland Sea, showing key magnetic lineations, fracture zones, marginal escarpments and present day bathymetric contours. Under the assumption that the age relationships along the Greenland-Scotland Ridge (GSR) are similar to those across the Reykjanes Ridge, the GSR appears to have evolved in three phases: (i) From −56? to −44 Ma, there was a major transform zone along the northern flank of the GSR, offsetting the mid-oceanic ridge dextrally to the Norway Basin. A westward shift of axis over the GSR may have taken place before anomaly 22 time. A small amount of spreading between the southern Jan Mayen block and Greenland may have occurred. (ii) From −44 to −26 Ma, following an anticlockwise reorientation of spreading direction, the Jan Mayen block separated from Greenland. There was a ridge-ridge-transform triple junction over the GSR and complementary fan shaped spreading took place about the Kolbeinsey and Aegir axes. The present Icelandic insular platform began to form during this phase. (iii) From −26 Ma to the present time, following the extinction of the Aegir axis, the triple junction over the GSR has been replaced by a wide axial rift zone extending to the east of the main line of the Kolbeinsey and Reykjanes Ridges.