Proto-basement in Svalbard

Abstract

Candidates for possible Precambrian proto-basement throughout Svalbard are considered and evaluated. The paper provides a tectono-stratigraphic framework for consideration of new data. Proto-basement, in the sense of basement in Proterozoic time, implies the occurrence of a Precambrian tectonic event. Vendian rocks are widespread in Svalbard and, because there is no known Vendian major tectonic event, the search is narrowed to pre-Vendian rocks. The approach is primarily tectono-stratigraphic, to identify a significant break by unconformity, contrast in metamorphic facies and isotopic age determinations.The paper concludes that the following rock units are proto-basement: Isbj0mhamna and (newly defined) Eimfjellet groups, Nordbukta Group, Magnethf3gda Group, the Richarddalen Complex; the Atomfjella Complex, the Brennevinsfjorden Group and the granitoids related to the Kapp Hansteen Group and the Duvefjorden Complex. While considered unlikely to be proto-basement the following cannot be ruled out: the Mefonntoppane and Kistefjellet rocks and the Sigfredbogen unit, the blue-schist Vestgotabreen rocks, the Pinkie Formation and parts of the Kongsvegen Group.Terrane implications are consistent with the three terrane model of Harland & Wright (1979), modified by Harland et al. (1993); but the data presented here hardly constrain such a model. In so far as the conclusions here are valid the effect is to subtract from, rather than add to, the outcrops commonly mapped as likely proto-basement.

Sedimentary architecture during Carboniferous rift initiation – the arid Billefjorden Trough, Svalbard

“…Potentially, reactivation of older lineaments facilitated the thin-skinned mild growth faulting on Edgeøya (Articles 3 and 4; . Differences in thickness of Permian and Triassic deposits reported between wells of Edgeøya and Hopen (Harland, 1997) indicate higher subsidence in the southeast of the Svalbard Platform that potentially reflects a regional slope and deeper waters towards the shelf located southeast.…”

“…1; . A small and deep Edgeøya Basin was filled with up to 3 km of Carboniferous deposits (Harland, 1997). However the exact age of these basins remains unknown.…”

“…10 km (Fig. 10;Baelum & Braathen, 2012).The basement of the Ny Friesland High is formed by green schist to amphibolite metamorphic facies of Atomfjella Complex, deformed and metamorphosed during the Caledonian orogeny (Harland 1969(Harland , 1997Bazarnik et al, 2019). The metamorphic basement underlying the Billefjorden Trough exposes a few km wide shear zone of Caledonian age that predates the brittle deformation along BFZ (Harland 1974) and forms an important boundary of basement provinces (e.g.…”

Spatial Differences in the Chemical Composition of Surface Water in the Hornsund Fjord Area: A Statistical Analysis with A Focus on Local Pollution Sources

“…The geological substratum of the Fuglebekken and Revelva catchments belongs to the Svalbard Archipelago proto-basement (Hecla Hoek formation) [22,23]. The Fuglebekken catchment lies upon metamorphic rocks, formed from sediments rich in quartz and silicate with a secondary admixture of carbonates [22].…”

Architecture, deformation style and petrophysical properties of growth fault systems: the Late Triassic deltaic succession of southern Edgeøya (East Svalbard)

“…The Svalbard archipelago is the emergent, uplifted, northwestern margin of the Barents Shelf, with a geological record that includes: (1) the Caledonian Orogeny (and older events; Braathen et al, ), (2) Devonian crustal‐scale extension and later contraction, (3) Carboniferous rifting, (4) a relatively stable, long‐term subsiding platform sedimentation from Permian to Cretaceous with Late Triassic compression and regional uplift (Klausen, Müller, Slama, & Helland‐Hansen, ), (5) intrusive, mafic Late Cretaceous magmatism of the High Arctic Large Igneous Province (HALIP, see Maher, ; Senger, Tveranger, Ogata, Braathen, & Planke, ) and (vi) development of a Cenozoic transform margin (e.g. Harland, ). The emergence of the Svalbard archipelago above sea level is the combined product of: (1) Early Cretaceous magmatism and the associated uplift and unroofing in the northwestern Barents Shelf, (2) development of the WSFTB, (3) uplift and unroofing in the western areas during the Oligocene and eventually (4) rapid, glacial isostatic‐rebound during the Quaternary, which caused unroofing and consequent decompaction of the sedimentary succession (Corfu, Andersen, & Gasser, ; Minakov, Faleide, Glebovsky, & Mjelde, ; Nejbert, Krajewski, Dubinska, & Pecskay, ; Senger et al., ).…”