**3.2 Profile C–D**

High seismic activity has been recorded in the area of collisional dislocations at the Svalbard plate margin (**Figure 6**). Heat flow values of about 80 mW/m<sup>2</sup> exceed the mean ones for the Barents Sea Rise, and in the area of Orly Trough, they reach peak values of ≈500 mW/m2 . The slow and gentle downwarping of this part of the Barents Sea plate to an almost horizontal plane resulted in the formation of the North Kara Basin [6].

Seismic data suggest that the crust is continental type, which is supported by low seismic wave velocities (5.6–6.0 km/s) in the granitic-gneissic layer. According to [8, 11], thinning of the crust and the influence of small flows of deep mantle fluids (compared to those that affected the South Barents Basin) gave rise

to slow eclogitization in the lower crust. This is supported by the mean heat flow (about 70 mW/m<sup>2</sup> ), with an anomalous increase up to 97 mW/m<sup>2</sup> . In the eastern part of profile C–D, there are only singular instances of heat flow data, and these are 50 mW/m<sup>2</sup> on average.

Seismic activity manifests itself in most of profile C–D, although it decreases moving from the junction zone between the Svalbard plate and the MOR. This may be related in part with the absence of permanently operating seismic stations in the Kara Sea region, because the model from [18] suggests that there should be weak seismicity at the junction of the Barents Sea and North Kara plates. The East Barents step zone (**Figure 4**) has the only seismic event recorded (lat 80.11, long 72.71, ML = 2.7), supposedly above the domain of high-velocity inhomogeneities in the lower and upper crusts (**Figure 6**).
