Palaeomagnetic investigation of the Upper Carboniferous clastic Hyrnefjellet Formation from opposite limbs of the Hyrnefjellet Anticline in southern Spitsbergen (Svalbard Archipelago) uncovered two components of NRM. Direction C1 (D = 224.6°; I = –27.9°; κ = 22.40; α95% = 5.6°) is of prefolding origin and most probably of near-primary origin. High Tb spectra above 575°C indicate hematite as the carrier of C1. Acquisition of the C1 component may be related to an early diagenetic crystallization of hematite, not excluding a detrital origin of the NRM. A paleopole calculated for the C1 component (F = 23.3°N; L= 147.7°E) falls into the Late Devonian–Early Carboniferous sector of APWP for Baltica. This result suggests that Svalbard remained in the present day orientation with respect to Baltica since the Carboniferous time. A second component with intermediate unblocking temperatures, determined in the Hyrnefjellet Formation deposits, is labelled C2. Its mean orientation for in situ position is D = 11.2°; I = 69.2° (κ = 44.05; α95% = 6.3°), thus being similar to Late Mesozoic directions for Baltica. After 100% tectonic correction for tilting of anticline limbs and axis, the C2 component orientation is D = 265.7°; I = 59.7°, thus being distant from any directions for Baltica. Detailed analysis suggest that the C2 component is most probably of synfolding origin, and it was formed during the Tertiary Alpine Tectonic Event.

A total number of 156 palaeomagnetic specimens of metacarbonates from 9 sites in Blomstrandhalvøya and Lovénøyane (Kongsfjorden, western Spitsbergen) and an additional 77 specimens of unmetamorphosed sediments infilling fractures (4 sites) within the Caledonian metamorphic basement of Blomstrandhalvøya were demagnetized. No relicts of pre-metamorphic magnetization were identified. The Natural Remanent Magnetization (NRM) pattern of metacarbonates is dominated by Caledonian (sensu lato) – Svalbardian and Late Mesozoic/Cenozoic secondary magnetic overprints carried by the pyrrhotite and magnetite/maghemite phases, respectively. The NRM of unmetamorphosed sediments infilling the karstic/tectonic fractures is dominated by hematite carrier. It revealed three stages of magnetization: Caledonian sensu lato, Carboniferous and Late Mesozoic/Cenozoic, which can be related to their initial fracturing, karstification and sedimentation or reactivation. As the majority of the palaeopoles calculated for the Kongsfjorden sites fit the 430 – 0 Ma sector of Laurussia reference path in an in situ orientation these results support the hypothesis that Blomstrandhalvøya and Lovénøyane escaped main Eurekan deformations. The potential rotation of the Kongsfjorden basement by any west dipping listric fault activity rotating the succession accompanying the opening of North Atlantic Ocean was not documented by the palaeomagnetic data presented here.