Geodynamic evolution of domes on the mid-Norwegian continental margin

The mid-Norwegian passive margin is characterized by a pattern of basinward stepping rifting. In the outer, Cretaceous and Early Tertiary part of the margin, a number of dome-shaped structures are present. Regionally, compressional domes are mapped in extensive parts of the Cretaceous-Tertiary depocentres of the NW European margins between mid-Norway and the northern Rockall Trough. In mid-Norway at least two dome types exist, and their development was spread over much of the Tertiary Era. Major phases include 1) latest Cretaceous-Early Tertiary syn-rift extensional doming, 2) mid-Tertiary post-break up compressional doming, 3) Neogene modification of dome flanks by differential loading from a large prograding glacio-marine sequence.<br>The first phase we attribute to the combination of regional extension and pronounced magmatic underplating of the margin. In the broadest sense of the term, this relates to the appearance of the Iceland “hotspot”. The second phase was associated with a major change in North Atlantic-Arctic plate configuration, which in turn coincided with apparent changes in activity of the Iceland hotspot. The third phase was largely an effect of differential sedimentary loading of thick and rapidly deposited glacio-marine prograding wedges, which indirectly relates to large scale Neogene epeirogenic uplifts on the Norwegian mainland.