Geophysical investigations of the Stuoragurra postglacial fault, Finnmark, northern Norway

Olesen, Odleiv; Henkel, Herbert; Lile, Ole Bernt; Mauring, Eirik; Rønning, Jan Steinar

doi:10.1016/0926-9851(92)90001-2

Cited by 39 publications

(40 citation statements)

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“…Most of the Fennoscandian postglacial faults are thrusts with dip angles of about 30 -608 at the surface (Munier & Fenton 2004). Shallow drilling (, 500 m) has usually confirmed these observations (Bäckblom & Stanfors 1989;Olesen et al 1992;Roberts et al 1997;Kuivamäki et al 1998). Reflection seismic sounding of the Pärvie PG fault (Juhlin et al 2009) suggested that the structure comprises several faults.…”

Section: Deep Structure and Depth Extent Of Pg Faultsmentioning

confidence: 57%

“…Available literature mostly suggests that postglacial faults represent reactivation of pre-existing structures, with a long history that may extend back to the Precambrian (e.g. Olesen et al 1992;Kuivamäki et al 1998;Dehls et al 2000a;Munier & Fenton 2004). However, the details of reactivation (mechanisms, timing, etc.…”

Section: Articlementioning

confidence: 99%

“…Many PG faults in Fennoscandia have been studied with structural/tectonic investigations, ground geophysical surveys, reflection seismic studies, excavations, and a few with shallow drill holes (, 500 m) (Olesen et al 1992;Roberts et al 1997;Kuivamäki et al 1998;Bäckblom & Stanfors 1998;Olesen et al 2004;Lagerbäck & Sundh 2008;Juhlin et al 2009;Kukkonen et al 2009b). However, systematic in-situ information on PG faults at depth is still lacking.…”

Section: Articlementioning

confidence: 99%

“…The contemporary in situ stress field, which was influenced by deglaciation, resulted in active faulting of the bedrock in northern Fennoscandia (Lagerbäck 1979(Lagerbäck , 1990Olesen 1988;Johnston 1989;Muir-Wood 1989, 1993Olesen et al 1992Olesen et al , 2004Kuivamäki et al 1998;Wu et al 1999;Dehls et al 2000a;Ojala et al 2004;Lund 2005;Turpeinen et al 2008;Lagerbäck & Sundh 2008;Lund et al 2009). These faults are called postglacial or late-glacial faults depending on whether they formed in extramarginal or subglacial conditions.…”

Section: Introductionmentioning

confidence: 99%

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Postglacial Faults in Fennoscandia: Targets for scientific drilling

Kukkonen

Olesen

Ask

2010

GFF

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During the last stages of the Weichselian glaciation (ca. 9,000-15,000 years B.P.), reduced ice loads and glacially affected stress fields resulted in active faulting in Fennoscandia with fault scarps up to 160 km long and up to 30 m high. These postglacial (PG) faults are usually SE dipping, SW-NE oriented thrusts, and represent reactivated, pre-existing crustal discontinuities. Postglacial faulting indicates that the glacio-isostatic compensation is not only a gradual viscoelastic phenomenon, but also includes unexpected violent earthquakes, suggestively larger than other known earthquakes in stable continental regions. We explore here possibilities and benefits for investigating, via scientific drilling, the characteristics of postglacial faults in northern Fennoscandia, including their structure and rock properties, present and past seismic activity and state of stress, as well as hydrogeology and associated deep biosphere. The research is anticipated to advance science in neotectonics, hydrogeology and deep biosphere studies, and provide important information for nuclear waste disposal, petroleum exploration on the Norwegian continental shelf and studies of mineral resources in PG fault areas.

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Section: Deep Structure and Depth Extent Of Pg Faultsmentioning

confidence: 57%

Section: Articlementioning

confidence: 99%

Section: Articlementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Postglacial Faults in Fennoscandia: Targets for scientific drilling

Kukkonen

Olesen

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2010

GFF

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“…Until recently, the only aeromagnetic surveys of the land area of Finnmark dated back to the years [1959][1960][1961][1962][1963][1964][1965][1966][1967][1968][1969][1970][1971][1972]. A description of the vintage magnetic anomalies in parts of the county was first presented by Åm (1975), and this was expanded upon over a wider area by Olesen et al (1990Olesen et al ( , 1992. Since that time there have been considerable advances in data acquisition techniques and data processing procedures, but with attention focused largely on the Barents Sea offshore regions.…”

Section: Introductionmentioning

confidence: 99%

Multiphase mafic dykes in the Caledonides of northern Finnmark revealed by a new high-resolution aeromagnetic dataset

Nasuti¹,

Roberts²,

Gernigon³

2015

NJG

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New high-resolution aeromagnetic data from northern Finnmark provide confirmatory evidence for the existence of both metadolerite and unmetamorphosed dolerite dykes transecting the Caledonian nappes and subjacent (par)autochthonous lithostratigraphical successions from Magerøya in the west to Varanger Peninsula in the east. Three ages of mafic dykes are known from isotopic dating studies -Ediacaran, Late Devonian and Early Carboniferous -but actual dyke outcrop in the case of the two younger dyke sets is very limited. High-amplitude magnetic responses in two thrust sheets in northwestern Varanger Peninsula, north of the TKFZ and beneath the Tanahorn Nappe, are clearly shown to relate to swarms of Ediacaran metadolerite dykes. Individual dykes discontinuously exposed on the surface can be followed as linear positive magnetic anomalies over distances of 25 km inland. Their extent offshore is not discussed here because it is beyond our data coverage in this paper. In eastern Varanger Peninsula, 8-9 dolerite dykes of Late Devonian age occur in discontinuous or limited outcrop. The new aeromagnetic data show, however, that up to 20 such dykes can be identified in the subsurface in the region between Vardø and Syltefjorden based on their linear positive magnetic anomaly signatures. South of the TKFZ, two Late Devonian dolerite dykes, well known from small coastal outcrops, are clearly visible as linear positive magnetic anomalies both on land and offshore beneath the sea-floor of Varangerfjorden. The most spectacular manifestations of what we consider to represent blind dolerite dykes are seen in connection with linear positive magnetic anomalies relating to Early Carboniferous dolerite dykes exposed on Magerøya and western Digermul Peninsula. These prominent linear anomalies follow many of the mapped NW-SE-to WNW-ESE-trending faults that have disrupted the Caledonian nappes in this part of Finnmark, and some are continuous over distances of more than 100 km from Magerøya to western Varanger Peninsula. These particular dykes and faults have been interpreted as relating to a major period of extension and rifting that occurred in the SW Barents Sea and adjacent onshore areas of Norway in Carboniferous time.

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Geomorphological evidence of paleoseismicity: Surficial and underground structures of Pasmajärvi postglacial fault

Markovaara‐Koivisto

Ojala

Mattila

et al. 2020

Earth Surf Processes Landf

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The cyclic nature of glaciations and related postglacial faulting represents a risk for the deep geological disposal of spent nuclear fuel in areas likely to be affected by future glaciations. Seismic history was therefore studied by means of detecting geomorphological structures on airborne laser scanning digital elevation models and underground by excavating in an esker and trenching across a postglacial fault located in northern Fennoscandia. OLS dating and assessing the geomorphological structures was used for timing of the seismic history. The results suggest that the faulting of different segments in the Pasmajärvi complex is due to at least two late Weichselian events, which probably occurred both subglacially and postglacially. The most reliable input for the moment magnitude estimates was vertical slip profiles, and therefore these estimates (MW ≈ 6.4–6.9) are suggested. © 2020 John Wiley & Sons, Ltd.

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Geophysical investigations of the Stuoragurra postglacial fault, Finnmark, northern Norway

Cited by 39 publications

References 13 publications

Postglacial Faults in Fennoscandia: Targets for scientific drilling

Postglacial Faults in Fennoscandia: Targets for scientific drilling

Multiphase mafic dykes in the Caledonides of northern Finnmark revealed by a new high-resolution aeromagnetic dataset

Geomorphological evidence of paleoseismicity: Surficial and underground structures of Pasmajärvi postglacial fault

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