HEGRE GP
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Generell informasjon
Generell informasjon Attributt Verdi Litostrat. enhet Den litostratigrafiske enhetens offisielle navn.HEGRE GPNPDID for litostrat. enhet Sokkeldirektoratets entydige nøkkel for litostratigrafiske enheter.61Nivå Angir den litostratigrafiske enhetens nivå. Lovlige verdier: GROUP, FORMATION, MEMBER.GROUP -
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Beskrivelse
Hegre Group
NameFrom the bird (English: heron) of the same name. The pre-Rhaetian Triassic rocks of the Northern North Sea were earlier designated the Cormorant Formation by Deegan and Scull (1977), having UK well 211/21-1A (Shell) as a type well section. In this report this Triassic Unit is given group status, while the Cormorant Formation is only applied to certain areas where a subdivision of the Triassic is impossible. We suggest that the Cormorant Formation should refer to attenuated sequences confined to structural highs in the UK sector.Type areaThe type area is the East Shetland Basin, west of the Viking Graben. The group is illustrated by UK well 211/29-5 (Shell), and Norwegian wells 33/5-1 (Norsk Hydro), 33/12-2 and 33/12-5 (Mobil).ThicknessNo well has penetrated a complete Triassic succession. The maximum drilled sequence is 1839 m in well 33/12-5 .LithologyThe Hegre Group consists of intervals of interbedded sandstones, claystones and shales associated with sequences of dominantly sand or shale/claystone. Shales and claystones usually have reddish colours whereas the sandstones show a range in colour from white, light grey, orange to brick red. The grain size varies from very fine to very coarse and the sediments are in parts of a pebbly nature. The Hegre Group also has subordinate white limestone, anhydrite and brownishred marl.BoundariesThe Hegre Group is directly overlain by Cretaceous strata on some of the structural highs. Where Jurassic is present, the top of the Hegre Group is normally placed at the change from interbedded sandstones and shales of the Hegre Group to the relatively massive clean sandstones of the Statfjord Formation . This is normally represented by a change from an irregular sonic log response in the Hegre Group to a more regular or blocky one in the Statfjord Formation . In addition the upper boundary of the Hegre Group is often close to the top of abundant red beds in the section - see also the description of the Statfjord Formation . The base of the Triassic rocks is only penetrated on structural highs and close to the margins of the sedimentary basin. In these sections only late Triassic seems to be present, and hence the nature of the lower boundary of the Hegre Group is not yet established. It is realized that the Hegre Group cannot be given full formal definition until its base has been adequately defined, but we nevertheless offer the term for interim use.DistributionThe Hegre Group is apparently present in the whole Northern North Sea area. Its relationship to the Triassic units defined further south by Deegan and Scull (1977) is unclear. We therefore recommend that the term Hegre Group should only be used in the area north of 60°N. It is terminated to the west by major faults along the east flank of the East Shetland Platform and to the east by the Øygarden Fault Zone (Hamar et al., 1980). In the northeastern part of the North Sea area, where Precambrian/ Caledonian basement dips gently to the west, progressively younger Triassic sediments onlap basement in an easterly direction. In the east, on the Måløy Fault Blocks, Triassic strata are probably missing, but may have been preserved from erosion in N-S elongated basins to the east of the structural highs. Alternatively Triassic sediments might not have been deposited in this area. The thickness of the Hegre Group within the East Shetland Basin shows a general increase from the western flank toward the central part of the depositional basin. On the eastern flank thick Triassic deposits are found just west of the Øygarden Fault Zone, which may indicate that the Triassic sediments were deposited in an asymmetric basin.AgeThe Triassic sections penetrated in the Northern North Sea show ages from Late Triassic (early Rhaetian) to possibly Early Triassic (?Scythian).SubdivisionThe Hegre Group is divided into three formations: the (basal) Teist Formation, the Lomvi Formation and the Lunde Formation (top). The subdivision suggested here for the Triassic of the Northern North Sea is based on information from areas to the west of the Viking Graben. However, available data from the Horda Platform indicate that a subdivision is also possible in that area.Source-
Vollset, J. and Doré, A. G. (eds.) 1984: A revised Triassic and Jurassic lithostratigraphic nomenclature for the Norwegian North Sea. NPD-Bulletin No. 3, 53 pp.
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Brønnbaner som penetrerer
Brønnbaner som penetrerer 05.09.20133523355405.09.20155310554818.01.20193521359926.02.19943013307728.04.20133680371714.09.20153467351127.05.20193611374103.06.20132733300025.04.19923347338820.02.19853826440009.03.19864183427110.09.19904395456631.12.20115587567216.07.20115213542003.11.20123697380023.12.19883814390028.03.20132371240524.05.20142470261804.03.20142760281004.01.20192954314621.11.20112484253308.04.19783729377516.12.19784113432216.08.19763268350529.11.19773723382409.02.20113876393015.05.20153499357703.06.20153860392529.06.20153670377302.06.20193645379528.06.20194130420317.06.19783699376425.05.19813625373014.07.19812642296901.08.19822821320004.05.19863077315008.10.19923688384809.02.20012977308520.05.20153097318113.05.20212771278421.01.20101960230307.12.20122429264201.01.20132729289720.03.20131870198814.05.20141894198521.10.20133060310620.04.20153194331303.03.20152491263004.06.20152769289614.06.20153066321527.05.20152506264025.08.20151953209414.04.20164896533010.05.20191938222005.08.20203068315828.02.20233177325701.09.20111986213429.09.20112041210019.08.20111951214024.09.20111949198628.10.20111968209029.03.20121946212604.05.20122239236529.09.20122626265830.08.20121949195517.11.20121887198213.01.20131969200612.12.20121999206507.02.20132385250320.05.20132020205203.04.20141952198903.05.20142283231016.02.20142125218321.11.20132038211407.06.20131965207028.11.20162057214307.03.20131931193201.04.20141979198616.03.20141978199303.05.20131955223321.08.20132529260026.08.20141934270016.08.20151984235801.04.20181950206908.10.20212129214428.01.20121967204220.03.20131912199028.09.20131936210029.12.20131936208510.07.20162241235006.12.19822521278104.09.20152546265001.05.20132656273423.10.20212466265823.10.20102995304522.04.20193170354609.01.20203120325019.03.20202483280630.12.20192434271628.05.20212438269810.05.20212504273320.06.20212391263320.07.20212325258918.01.20152439259719.06.20152555292517.01.20162410247402.08.20162564262809.08.20183653370418.08.20184832489326.08.20184305440530.07.20182655276510.02.20233978415025.09.20152147222913.05.20192147223009.05.19824786483212.12.19955322558116.05.19804670477512.04.20093396433522.09.19793003317511.12.19792808289016.12.19823389347612.05.19903387347605.09.19843548397221.01.19853224330023.11.19853670369006.12.19913940398629.03.20122754406429.01.19824687481320.05.19844249430019.07.19852872298017.10.20093718376701.05.19755127518609.11.19792381243309.11.19812382243406.10.19802500260020.07.19802358260106.04.19812422503512.11.19822422503521.12.19802471253220.07.19812464252522.04.19842464252518.08.19823274337513.10.19832160237415.11.19792786290011.05.19802879498129.07.19812849293011.05.19862438261111.11.19832393250030.08.19842393250028.10.19832156397808.09.19842198223526.12.19832195225029.07.19842277229328.06.20213120328401.07.20081247130004.12.19961832313226.10.20191847201710.06.20152946353018.10.19792692382918.11.19814455452006.07.19793862390024.07.20124377444414.11.19742973299217.09.19752974307603.08.19872936295923.08.19742951435421.02.19762735457421.06.19764030461213.08.19813344374231.03.20183568368016.12.19792508291624.05.19802697359930.03.19824410446003.02.19832425380006.04.19843599391727.03.19862577328212.05.19872502295021.06.19942913311015.02.19972513344010.01.20104224432718.02.20102563276125.01.20102738306602.01.20114905501019.05.20154754482228.08.20024313436005.11.20124252433524.07.19842392290510.10.19842271247502.01.19852513341416.01.19852628311516.03.19853010314630.05.19852654368516.12.19852678352611.04.19862373276612.06.19862443324029.10.19862683300017.12.19872763278413.04.19882962299415.10.19902945298005.07.19942944297907.04.19913085311527.08.19923128317710.03.20092584270120.03.20092972302208.03.19863417361017.11.19863051324027.05.19923143356707.03.20033151357409.06.19912950415001.04.19913484354016.07.19925208546010.02.19935208546024.08.19923474362509.03.19933474362428.12.19923245353009.12.19933125347009.12.20013253334726.06.20094282444215.11.20153116387514.03.20144485458722.02.20196001606808.09.19782367246008.12.19783540372907.06.19792715280210.10.19872712279915.10.19792481260002.01.19802764278023.03.19802180225014.07.19832177224705.03.19812089215505.01.19822052339219.03.19822596264711.04.19834010404227.09.19834007403906.12.19832188221812.05.19863375378513.07.19873538375310.08.19873538374229.05.19953844394011.04.20014370495008.07.20014200486515.02.20053657464522.12.20043657464526.03.20177390781118.07.20024476454024.05.19974918493607.12.20103710374006.08.19843265336106.11.19872678385011.03.19913697372620.10.20122703294025.11.199418471950 -
Brønnbaner med kjerner
Brønnbaner med kjerner 25.04.19922120.02.19853309.03.19862610.09.1990804.03.20141016.08.19763714.07.198110701.08.19825709.02.20011921.01.20104107.12.20121320.03.201311814.05.20148320.04.20153003.03.20159627.05.20154425.08.201511710.05.20199329.09.20111219.08.20115624.09.20113329.03.2012704.05.2012429.09.20123230.08.2012617.11.20121813.01.20132207.02.20133520.05.20132103.04.20143703.05.20142216.02.20141421.11.20131607.06.20131107.03.2013116.03.20141503.05.20136926.08.20147416.08.20158001.04.20185228.01.2012720.03.20131128.09.20132729.12.20134506.12.19829409.01.20201419.03.2020830.12.20198810.05.20215220.06.202111012.04.20098406.04.1981811.05.1980311.05.19861310.06.20153018.10.19791013.08.19813916.12.19799003.02.198318206.04.19844827.03.19865412.05.198718315.02.199720818.02.20105425.01.20105202.01.20111124.07.198422302.01.19855230.05.19855716.12.198510311.04.1986512.06.198624308.03.1986927.05.19927909.06.199135516.07.1992824.08.19922209.12.19933215.11.201510705.01.19824512.05.198618913.07.19871606.11.198715111.03.19911420.10.201221