{{short description|Basement high and horst in the southwest of the Norwegian continental shelf}} [[File:Utsira Formation 01.png|thumb|260px|Map showing oil- and gasfields around Utsira High. To the west lies Vikinggraben and east the Norwegian trench.]] {{Location mark | type=thumb | image = North Sea map-en.png | width = 220 | label = | caption = Utsira High | x% = 43 | y% = 12 | mark = 175-free-google-maps-pointer.svg | mark_width = 14 }} '''Utsira High''' ({{langx|no|Utsirahøgda}}) is a basement high and horst in the southwest of the Norwegian continental shelf.<ref name=Fredinetal2017/> It lies east of the Viking Graben and west of the Stord and Egersund basins 190 km west of Stavanger.<ref name=Ribertetal2017>{{cite journal |last1=Riber |first1=Lars |last2=Dypvik |first2=Henning|last3=Sørlie |first3=Ronald |last4=Aal-E-Muhammad Naqvi |first4=Syed Asmar|last5=Stangvik |first5=Kristian|last6=Oberhardt |first6=Nikolas|last7=Schroeder |first7=Paul A.|date=2017 |title=Comparison of deeply buried paleoregolith profiles, Norwegian North Sea, with outcrops from southern Sweden and Georgia, USA — Implications for petroleum exploration |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=471 |pages=82–95 |doi=10.1016/j.palaeo.2017.01.043 }}</ref><ref name=Riberetal2015>{{cite journal |last1=Riber |first1=Lars |last2=Dypvik |first2=Henning |last3=Sørlie |first3=Ronald |date=2015 |title=Altered basement rocks on the Utsira High and its surroundings, Norwegian North Sea |url=http://njg.geologi.no/images/NJG_articles/NJG1_Vol95_1_Riber_Pr.pdf |journal=Norwegian Journal of Geology |volume=95 |issue=1 |pages=57–89 |access-date=February 3, 2018 |archive-date=February 13, 2018 |archive-url=https://web.archive.org/web/20180213022508/http://njg.geologi.no/images/NJG_articles/NJG1_Vol95_1_Riber_Pr.pdf |url-status=dead }}</ref> It was on the Balder oil field at the flank of the Utsira High that oil was first discovered in Norway in 1967.<ref name=Riberetal2015/>
The basement is of Utsira High is composed of granite that formed in Ordovician times.<ref name=Fredinetal2017>{{cite journal |last1=Fredin |first1=Ola |last2=Viola |first2=Giulio |last3=Zwingmann |first3=Horst |last4=Sørlie |first4=Ronald|last5=Brönner |first5=Marco |last6=Lie |first6=Jan-Erik |last7=Margrethe Grandal |first7=Else |last8=Müller |first8=Axel |last9=Margeth |first9=Annina|last10=Vogt |first10=Christoph|last11=Knies |first11=Jochen |date=2017 |title=The inheritance of a Mesozoic landscape in western Scandinavia |journal=Nature |volume= 8|article-number= 14879|doi=10.1038/ncomms14879 |pmid=28452366 |pmc=5477494 }}</ref> Parts of these granites contain saprolite and saprock that formed from weathering above sea level during the Early Mesozoic.<ref name=Ribertetal2017/> before they became buried in Late Jurassic and Early Cretaceous-aged sandstone.<ref name=Fredinetal2017/> These weathered rocks may be unconventional petroleum reservoirs.<ref name=Ribertetal2017/>
The strandflat at Bømlo island is considered a sedimentary rock-free equivalent to the Utsira High.<ref name=Fredinetal2017/>
==References== {{reflist}}
Category:Basement highs Category:Geology of Norway Category:Geology of the North Sea Category:Petroleum in Norway Category:Unconformities Category:Horsts (geology)
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