Opening of the North Atlantic
Prior to the onset of seafloor spreading in the northeast Atlantic 55 million years ago, the hydrocarbon basins of Jameson Land, onshore East Greenland, and basins offshore western Norway, Shetland and in the North Sea, were located in close proximity to one another. Since that time they have gradually moved apart as a result of the plate tectonic movements that created Iceland and the surrounding ocean basins.
A part of this development was that the Jan Mayen Ridge was gradually separated from the continental shelf of Norway and Greenland and became isolated far from shore and surrounded by newly created ocean floor. This occured in parallel with the gradual emergence of Iceland and its surrounding insular shelf.
The topography and tectonic structures of the Jan Mayen Ridge (JMR) are caused and shaped by the the Mesozoic rifting initially, and of course primarily by the aforementioned opening of the Northeast Atlantic Ocean.
The opening of the Atlantic has several stages that are of importance to the JMR. The initial opening of the Norwegian-Greenland Sea, which took place east of the Jan Mayen Ridge during the Late Paleocene to Early Eocene that was associated with intensive and widespread volcanism and marked the whole of the North Atlantic region. Records of that are seen as Plateau basalts and large intrusions onshore along the East Greenland coast, and offshore on seismic records along the East Greenland and Norwegian shelfs. Depositions of volcanic basalts, many kilometers thick, are found in East Greenland close to the palaeo-geographic location of the Faroe Islands (Henrikson et al, 2008) but tend to be not as massive further to the North.
Complex faults at the eastern and western boundaries of the Jan Mayen Ridge were initiated during the period of continental drift and spreading ridge formation during the forming and spreading of the Aegir Ridge to the East of the JMR between the Early Eocene and the Early Oligocene.
The Kolbeinsey Ridge formed to the West of the JMR from the Early Miocene to present, leaving a time period, starting during the end of the Middle Eocene, and especially between the Early Oligocene and the Early Miocene, to explain for massive volcanic activity right around the JMR and large scale uplift and erosion of the high blocks within the ridge itself while the JMR moved over the Icelandic Hotspot. During that time fault and block separation increased in the southern parts of the ridge, forming the Southern Ridge Complex, primarily due to possibly two attempted propagation of the mid oceanic rift into the JMR, first during the Middle Eocene and again during the Early Oligocene, and finally possibly breaking through at an old weak zone along the western flank of the JMR, forming the Kolbeinsey Ridge as it is known today. These processes introduced extensive stretching and structural complexity to the JMR.
Since the beginning of seafloor spreading along the Kolbeinsey Ridge and moving away from the hot spot, the Jan Mayen Ridge area rotated anti-clockwise, causing slight reverse faulting and has been cooling down, causing the area to subside. That resulted in a change from a locally based erosion and deposition around the different blocks, to a basin depositional environment during the ridges subsidence.
Data Source Reference List
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Dinkelman, M.G., Granath, J.W. & Whittaker, 2010. The NE Greenland Continental Margin. GeoExpro, 7(6).
Gaina, C., Gernigon, L. & Ball, P., 2009. Palaeocene-Recent plate boundaries in the NE Atlantic and the formation of the Jan Mayen microcontinent. Journal of the Geological Society, 166, 1-16
Gernigon, L., Olesen, O., Ebbing, J., Wienecke, S., Gaina, C., Mogaard, J.O., Sand, M. & Myklebust, R., (2009). Geophysical insights and early spreading history in the vicinity of the Jan Mayen Fracture Zone, Norwegian-Greenland Sea. Tectonophysics, 468, 185-205.
Gunnarsson, K., 1990. Olíuleit á Jan Mayen-Hrygg, Presentation at the annual meeting of the National Energy Authority of Iceland.
Gunnarsson, K., Gudlaugsson, S.Þ. & Sand, Morten, 1989. Geology and hydrocarbon potential of the Jan Mayen Ridge. Orkustofnun, Reykjavík, OS-89036/JHD-07 & Oljedirektoratet, Stavanger, OD-89-91, 143 pp.
Henriksen, N., 2008. Geological History of Greenland - Four billion years of Earth evolution. Geological Survey of Denmark and Greenland (GEUS), Copenhagen, 272 pp.
Mjelde, R., Raum, T., Breivik, A.J. & Faleide, J.I., 2008. Crustal transect across the North Atlantic, Marine Geophysical Researches, 29, 73-87.
Müller, R.D., Sdrolias, M., Gaina, C., Steinberger, B. & Heine, C. 2008. Long-term sea-level fluctuations driven by ocean basin dynamics. Science, 319, 1357-1362. [Data used in GPlates 1.0].
Mosar, J., Lewis, G. & Torsvik, T.H., 2002. North Atlantic sea-floor spreading rates: implications for the Tertiary development of inversion structures of the Norwegian-Greenland Sea. Journal of the Geological Society, 159, 503-515.
Roberts, A.M., Corfield, R.I., Kusznir, N.J., Matthews, S.J., Hansen, E.-K., & Hopper, R.J., 2009. Mapping palaeostructure and palaeobathymetry along the Norwegian Atlantic continental margin: Møre and Vøring basins. Petroleum Geoscience, 15, 27-43.