Summary
Two main tectonic phases were responsible for the formation of the Jan Mayen Ridge microcontinent: (1) the opening of the Norway Basin in late Palaeocene/early Eocene times, and (2) subsequent rifting within the Greenland margin by which complete separation was achieved in early Miocene times. During the first phase the eastern ridge flank developed as a volcanic passive margin. The initial break-up was associated with flexuring and the formation of sequences of eastward-dipping basalt flows, which are considered equivalent to similar features beneath the Vøring and Faeroe-Shetland marginal highs off Norway. Rifting along the Greenland margin during the second phase was accompanied by uplift, listric normal faulting and the formation of large extensional fault blocks. To the W and S of the ridge a flat volcanic marker of probable earliest Miocene age covers the subsided rift and masks the ocean-continent transition. It was formed by a volcanic event of large magnitude, either as submarine lava flows or as a sill complex.
- © 1988 The Geological Society
Tectonic and volcanic events at the Jan Mayen Ridge microcontinent
