Seafloor Structure in the North Atlantic Region between the Kolbeinsey Ridge and the Jan Mayen Microcontinent

— Deep seismic sounding, continuous seismic profiling, and bathymetric data are used to discuss the structure of the Iceland Plateau and adjacent areas of the Norway–Greenland region. We tentatively suggest the existence of regional nearly NS-trending tectonic discontinuities; these are normal faults that make up the stepwise character of the Iceland Plateau. The steps are successively descending westward. The fault zones contain magmatic features in the form of dikes that penetrate the sediment in several cases, thus providing evidence of their young age. A rift feature confined to magnetic anomaly C5b is tentatively identified in the central Iceland Plateau based on some crustal peculiarities. The central Iceland Plateau and the southern Jan Mayen Basin show an increased heat flow (92–217 mW/m 2 ) whose lateral distribution suggests a boundary between the regions of increased and normal values. The boundary passes through the center of the Jan Mayen Basin and trends nearly NS. It seems to bound the zone of influence due to the Iceland mantle plume from the northeast at present.