Читать книгу Biogeography in the Sub-Arctic - Группа авторов - Страница 21

The initial separation of the western and eastern plates lay close to the present east Greenland coastline. Continental separation often results in formation of micro‐continents, representing ‘splinters’ that remain isolated. The Rockall Plateau became such a micro‐continent, as did also a fragment further north between Iceland and Jan Mayen.

Figure 7 Map showing the break‐up pattern showing the eastward displacement of the central section separating the Vøring Plateau and the Faeroe Plateaux. The shading indicates the outcrop of the flood basalts on Greenland.

Source: Larsen et al. (1989).

Evolution of the oceanic lithosphere was attended by development of the transform faults. At least some of these were probably inherited from faulting on the continents prior to separation. Such faults not only separate different crustal segments, but the rifting style and average magma characteristics are liable to change across them. To the north of one of these, the Jan Mayen Fracture Zone, the mid‐ocean ridge is called the Mohns Ridge. The active Kolbeinsey and the extinct Ægir Ridge lay between this and the evolving Iceland–Faeroe Fracture Zone, whilst south of that (and Iceland) the mid‐ocean ridge is called the Reykjanes Ridge.