K–Ar illite and apatite fission track constraints on brittle faulting and the evolution of the northern Norwegian passive margin

Abstract

Determining the timing of post-Caledonian brittle faulting in northern Norway is important for the understanding of the extensional tectonic evolution of the north

Mid/Late Devonian-Carboniferous collapse basins on the Finnmark Platform and in the southwesternmost Nordkapp basin, SW Barents Sea

“…Thus, we argue that 1250 late/post-Caledonian extensional faulting linked to the collapse of the Caledonides essentially took place in the Mid/Late Devonian-Carboniferous and came to a halt towards the end of the late Carboniferous (Figure 10d). This presumed timing is consistent with recent K/Ar radiometric dating of brittle fault gouges in Western Troms (Davids et al, 2013) and in NW Finnmark (Torgersen et al, 2014;Koehl et al, 2016), as well as with radiometric dating of dolerite dykes in 1255 NW Finnmark (Lippard & Prestvik, 1997), eastern Finnmark (Guise & Roberts, 2002) and on the Kola Peninsula in Russia (Roberts & Onstott, 1995), which constrain significant extensional faulting activity onshore northern Norway and adjacent areas in Russia to the Late Devonianearly/mid Permian. Minor reactivation of major fault complexes occurred in the MesozoicCenozoic and are most likely associated with the rifting of the NE Atlantic (Faleide et al, 2008).…”

“…Late Devonian dolerite 320 dykes emplaced along brittle faults that trend NE-SW and N-S have been identified and dated in eastern Varanger Peninsula (Guise & Roberts, 2002) and on the Kola Peninsula (Roberts & Onstott, 1995). By comparison, Davids et al (2013) Townsend, 1987a;Johansen et al, 1994;Bugge et al, 1995;Zwaan, 1995;Gudlaugsson et al, 1998;Samuelsberg et al, 2003;Bergh et al, 2010). Late Paleozoic sedimentary deposits in the study area were penetrated by only a few exploration wells to which we tied our 335 seismic interpretation.…”

“…CC BY 4.0 License. & Roberts, 1987;Townsend, 1987a;Rykkelid, 1992;Lippard & Prestvik, 1997;Roberts & Lippard, 2005;Bergh et al, 2007;Hansen et al, 2012;Indrevaer et al, 2013;Davids et al, 2013).…”

“…The absolute age of post-Caledonian brittle faults onshore NW Finnmark is poorly constrained although a few contributions provide valid insights (Lippard & Prestvik, 1997;Davids et al, 2013;Torgersen et al, 2014;Koehl et al, 2016). Torgersen et al (2014) performed K/Ar dating of brittle fault gouge in the footwall of the LVF and obtained dominantly Carboniferous to 315 early Permian ages, as well as a subsidiary Early Cretaceous age for one of the faults.…”

Middle to Late Devonian–Carboniferous collapse basins on the Finnmark Platform and in the southwesternmost Nordkapp basin, SW Barents Sea

“…Multiple studies have reported post-Caledonian brittle faults in onshore coastal areas in Lofoten-Vesterålen, western Troms, and NW Finnmark (Roberts, 1971;Worthing, 1984;Lippard and Roberts, 1987;Townsend, 1987a;Rykkelid, 1992;Lippard and Prestvik, 1997;Roberts and Lippard, 2005;Bergh et al, 2007;Indrevaer et al, 2013;Davids et al, 2013). A common feature is the presence of rhombic, zigzag-shaped fault trends similar in geometry to offshore basin-bounding faults.…”