| Summary: | Based on recent geological and geophysical information from the Norwegian\/Greenland Sea and North Sea areas, and on earlier geomorphological information interpreted in terms of regional drainage pattern evolution, it is concluded that the Møre-Jotunheimen and Norrbotten-Troms uplands may be erosional remnants of two large, pre-Tertiary, mantle plume-generated domal uplifts. These were centred on the adjacent parts of the present continental shelf and slope, where linear gravity highs and elongate sedimentary troughs may represent mantle plume-generated mafic intrusions and rifts. The mantle plume activity probably occurred in mesozoic time, possibly in the Jurassic, long before the onset of Early Tertiary ocean-floor spreading in the Norwegian\/Greenland Sea area. The inferred rifts and intrusions appear to form a northern extension of pre-splitting tectonic activity along the present North American and north-west European Atlantic margin. 34858
|
|---|