Basalt is mainly found in two areas of Greenland, in the western and eastern parts. These are found at similar latitude, and 30° apart. The convection rolls of lower mantle span 30° from east to west, so this leads attention to the history of tectonic events in the geological history of Greenland.
The separation from Baffinland and the Jan Mayen Ridge occurred due to the effect of two different hubs of convection rolls division lines (division lines of different layers coincide there). This occurred a long time ago, so these areas have drifted away from those hubs. One is now near Nuuk and the other under Iceland.
The western circle is at Disco Island, the eastern one at Scoresbysund. The Scoresbysund area has drifted away from the Icelandic hot spot, but is still found above convection rolls division lines extending to Iceland. The leads to thermal anomalies under the glacier of Greenland, as seen here: https://www.nasa.gov/feature/goddard/2018/nasa-scientist-reveals-details-of-icy-greenland-s-heated-geologic-past
To understand the background of this, we have to keep in mind that the Baffin Bay was formed first and the northernmost part of the Atlantic second. Let us have a look at the position of Greenland 60 million years ago when the Baffin Bay was forming:
Because of this, most geoloscientists think that a ‘hot spot’ did travel from W-Greenland to E-Greenland and from there to Iceland. The actual story, according to the convection rolls model, is different. First, a division line of lower mantle opened up the Baffin Bay, resulting in eastwards drift of Greenland. Then the other main division line, 30° farter to the east, where Iceland is now located, became more active. The N-Atlantic started to form with the development of the Ægir Ridge. Greenland started drifting along the track which has been measured accurately with GPS technology. https://www.lmi.is/static/files/utgefid_efni/Maelingar/isnet_endurmael_2016_skyrsla.pdf . According to the drift vectors in that report, Scoresbysund of Greenland has been drifting to the NW from the volcanically active center of Iceland for about 40 million years, as stated in this paper: https://www.geothermal-energy.org/pdf/IGAstandard/WGC/2010/0158.pdf. Therefore, the geoscientis seem to be a bit mistaken, counting these two ‘hot spots’ as one, and secondly, is has to be noticed that convection rolls division lines carry heat to these areas still today, and should not be thought of as ‘hot spot tracks’, as that is misleading.
Magic Magma 