HOD FM
Export: PDF
-
General information
General information Attribute Value Lithostrat. unit The lithostratigraphic unit's official name.HOD FMNPDID lithostrat. unit Norwegian Offshore Directorate's unique id for lithostratigraphic units.66Level Indicates the lithostratigraphic unit's level. Legal values: GROUP, FORMATION, MEMBER.FORMATIONLithostrat. unit, parent The parent lithostratigraphic unit's official name. See also level. Will be empty if Level = GROUP. -
Level below
Level below Lithostrat. unit -
Description
Hod Formation
NameNamed by Deegan & Scull (1977) from the Hod Field in Norwegian block 2/11. The name Hod derives from one of the twelve principal gods in Norse mythology. Hod was a son of Odin.Well type sectionNorwegian well 1/3-1 from 4343 m to 3828 m, coordinates N 56°51'21.00", E 01°51'05.00" (Fig 5.24) . No cores.Well reference sectionsUK well 29/25-1 from 2225 m to 2012 m, coordinates N 56°18'10.00", E 01°51'48.80" (Fig 5.26) . No cores.
Norwegian well 2/8-8 from 2601 m to 2494 m, coordinates N 56°16'50.28", E 03°24'15.93" (Fig 5.28) . 36 m of cores discontinuously through the upper 78 m and lowermost 6 m of the formation.ThicknessThe formation is 515 m thick in the type well, 213 m in UK well 29/25-1 and 107 m in Norwegian well 2/8-8 . In the Norwegian sector, seismic interpretation indicates that the formation may reach a thickness of more than 700 m in the northwestern part of the Central Trough.LithologyIn the type well the formation consists of hard, white to light grey, crypto- to microcrystalline limestones which may become argillaceous or chalky in places. White, light grey to light brown, soft to hard chalk facies may dominate the formation or alternate with limestones. The limestones may be pink or pale orange. Thin, silty, white, light grey to green or brown, and soft, grey to black, calcareous clay/shale laminae are occasionally present. Pyrite and glauconite may occur throughout the formation and the latter may be common in the lower part.Basal stratotypeThe lower boundary is usually marked by a distinct log break to a lower gamma-ray response and higher velocity from the Blodøks Formation to the Hod Formation (Fig 5.24) . The boundary may be less distinct when the Blodøks Formation is more calcareous (Fig 5.31) .Characteristics of the upper boundaryThe upper boundary towards the Tor Formation is generally marked by a change in gamma-ray readings to a more constant and slightly lower level, and also by higher velocity, (Fig 5.24, 5.31) . The upper boundary may represent an unconformity in the Ekofisk area (e.g. Norwegian well 2/8-8 , (Fig 5.28) .DistributionThe formation is widely distributed in central and eastern parts of the central North Sea, passing laterally into sediments of the Herring and Flounder Formations to the west and the Tryggvason and Kyrre formations to the northwest.AgeTuronian to Campanian.Depositional environmentOpen marine with deposition of cyclic pelagic carbonates (periodites) and distal turbidites (Skovbro 1983 and d'Heur 1986).RemarksAn informal, tripartite subdivision of the Hod Formation into lower, middle and upper members is often possible in the southern part of the Central Trough in the Norwegian sector. The subdivision is based on the frequent presence of a higher clay content in the middle of the Hod Formation (Fig 5.24, 5.28, 5.29).Lower member of the HOD FormationThis unit constitutes the largest part of the Hod Formation and is a sequence of bioturbated laminated chalks with a low clay content. It occurs in Norwegian wells 1/3-1 from 4343 m to 4066 m, 2/8-8 from 2601 m to 2538 m and 1/9-1 from 3648 m to 3353 m.Middle member of the HOD FormationThis is a sequence consisting mainly of periodites, which generally have a greyish colour reflecting a marked increase in terrigenous clay. It is shown on well logs as an increase in gamma-ray readings. It occurs in Norwegian wells 1/3-1 from 4066 m to 4009 m, 2/8-8 from 2538 m to 2518 m and 1/9-1 from 3353 m to 3344m.Upper member of the HOD FormationThis unit constitutes another sequence dominated by periodites with minor allochthonous intercalations, but with a return to a low clay content. It occurs in Norwegian wells 1/3-1 from 4009 m to 3828 m, 2/8-8 from 2518 m to 2494 m and 1/9-1 from 3344 m to 3312 m.The Herring Formation of Deegan & Scull (1977) includes a similar lithology and was deposited at the same time as the Hod Formation. It is regarded here as the lower part of the Hod Formation. The Hod Formation is also equivalent in age to the Tryggvason and Kyrre formations (Fig 5.6) .Source-
Isaksen, D. and Tonstad, K. (eds.) 1989: A revised Cretaceous and Tertiary lithostratigraphic nomenclature for the Norwegian North Sea. NPD-Bulletin No. 5, 59 pp.
Footnotes-
1) Fritsen and Riis (unpublished) propose a subdivision of the original Hod Formation into three new formations: Narve, Thud and Magne formations.
References-
Fritsen, A. and Riis, F. (unpublished): A revised chalk lithostratigraphic nomenclature.
-
-
Wellbores penetrating
Wellbores penetrating 11.11.19683828434327.07.19693729402424.03.19833803385208.05.19833123316011.02.19853858456822.06.19913530358627.05.19973949437931.07.19983758389522.07.20104092507515.04.19743342392222.05.20023063307716.09.20164126522826.11.19723566414412.01.19733295338302.09.19901732174208.03.19933809465112.07.19923665414617.02.19773312364817.05.19873309364512.08.19773308345930.09.19783395365112.01.19783312345026.04.19913312345016.12.19783346345001.12.19823781388002.08.20033364370514.11.19723600374226.02.19783015312229.03.19803424352003.08.19823623371005.04.19833597374112.08.19843660378806.03.19853648378623.11.19853521361006.07.19913617376508.03.19923618378814.01.19923607378907.05.19973850405207.03.20093824406528.02.20095598571905.09.20133245328508.11.20193650383503.07.19823128322527.08.19822639275411.05.19833442349407.06.19883135321319.02.19923204326214.05.20103436348620.11.19712630267829.03.19723383344409.10.19733647375209.04.19743542374731.01.19894010454206.04.19904022455414.04.19904010454216.03.19904266479827.10.20034266479804.11.19913920457515.07.19923920457529.02.19923729418310.07.19943704443514.03.20083862467724.05.20123977451924.07.20123977451922.02.20153842423705.09.20154077479822.11.19703475355115.06.19723481361631.10.19723420349016.08.19783285359624.02.19843726408705.11.19883323336718.01.19923703407926.08.19933735429525.09.19933735429522.02.20023527369121.01.20093790425830.05.19692950305625.05.19803672381225.02.19833225339102.06.19903171340211.01.19973155323118.01.20193350352111.12.19703047329202.03.19713194374329.03.19732829296312.08.19733028331810.04.19743578389121.04.19793002317302.06.19803136336812.07.19803500396702.02.19813444405514.03.19903441405225.06.19883439389901.11.19913436389609.01.19903600415914.10.19913607416615.10.19903597397621.11.19903577414313.04.19912744296631.03.19913898450613.09.19913321398117.06.19923523416107.08.19922902309106.01.19943681409210.04.19953326347809.06.19993580407403.09.19722850316707.06.19732577277430.06.19752485260324.08.19752739281915.03.19762494260127.06.19762529263729.08.19762516263611.10.19762483261222.01.19912617284209.01.19963721375013.07.20122781283807.12.19723480355104.09.19793412347114.12.19893660383404.07.20083858408218.09.20143312343015.02.20213521367423.04.19763581405825.04.19933221356103.10.19692662286029.12.19742640275203.12.19772775302218.05.19782604281105.07.19792855292025.02.19823716407606.09.19863265359111.07.19913390385223.12.19933298365614.06.19944074409007.03.20193026305912.02.20192842294512.03.19873358369814.09.19903910418426.02.19942589266831.08.20122769290628.06.19782435261720.08.19782782301313.09.19732985321831.08.19813119328023.01.19903088324707.02.19922912304430.11.19963259335227.10.20083292338603.03.20133725379628.04.20133166347114.09.20153070335627.05.20193264355429.12.20102961311401.02.19852744292210.03.19862605298705.08.19712390263408.05.20082674280610.06.19692260238621.08.19932646282713.03.20083013312303.06.20132476267820.02.19903108324325.04.19922975310604.07.19933081326405.02.19692955309512.12.19833275336120.02.19853529362903.06.20063449354229.05.19712335237815.06.19683454370010.06.19823683386020.10.19823694382125.12.19833874420808.10.19843874420812.12.19833504365509.03.19863625387210.09.19903947414810.06.20073895407231.12.20114067475316.07.20114066464403.11.20123469362518.10.19683049310323.09.19762970302803.06.19773189325506.09.19773195326112.12.19773101314507.06.19813289332224.07.19813002307126.07.19883211333223.12.19883321339114.05.19903347342629.08.19913180328206.11.19913387348617.03.19965324562518.05.20123374387507.02.19721828189928.03.20131728200210.02.19761807193801.07.19692560257017.03.19802471251006.10.20102743289818.12.20112695284627.10.20112655273224.05.20142004211704.03.20142141235116.07.20141725182404.01.20192682273229.06.19752408250923.07.19712262229321.11.20111221122928.04.19871114144521.09.19871161142508.02.19901423186711.04.19941168154521.07.19951386179515.10.19961188162610.06.19971585210502.02.19981251213217.09.19991545186829.03.2010880115914.10.20191011130204.09.198669585209.12.2005910106919.05.19681690180419.08.19721730193520.08.19771650182529.06.19681530159719.08.19711745176606.05.19691445152512.07.2015932138226.06.1976535102517.01.19711021115319.08.19691356145524.02.19822920350608.04.19782904324016.12.19782967350707.12.19802877341907.09.20083053339913.10.20083053340229.11.19773018328509.06.19823050329008.06.19932984318805.04.19972838306913.06.20073138335423.07.20073134342027.05.20073123336706.04.20092976327713.03.20113284371519.12.20103130349709.02.20113081351715.05.20153045333003.06.20153149356329.06.20153205353626.12.20173731426002.06.20192982323328.06.20193032356207.01.19822998323721.10.20113114338130.05.19772955300617.06.19783041321403.04.19792869319814.06.19792887311211.04.19802964321007.09.19802952331729.04.19812937318025.05.19813000311514.07.19812524257107.11.19812733287127.02.19822979323327.05.19822593265027.06.19822889304001.08.19822606267224.08.19822586264330.03.19832612267902.03.19842843293109.11.19973476358402.02.19983558365425.07.19974050411329.04.19934047411020.03.19943195323923.05.19983743413813.03.20063036321103.01.20102730281106.09.19752884295427.02.19762425252522.12.19802675275231.10.19842621271204.05.19862615274004.11.19902548270807.01.19912685294214.07.19912626273829.07.19912626273608.10.19923187326004.11.19962850309719.05.19972922312809.02.20012558265131.03.20062581267523.03.20072904301704.02.20072904301707.11.20072900301320.05.20082737289601.07.20083432365521.05.20092676275221.06.20092724283616.05.20102541261029.05.20102731281318.07.20103897410820.05.20152644274913.05.20212337244510.12.19672926320321.11.19982008202006.12.19982101212013.11.20071913192510.10.20091913192508.09.20091888190221.01.20101917191805.04.20111913191513.05.20112064206720.03.20131850186014.05.20141878188325.08.20151934194326.12.20151981199911.04.20171961196223.08.20182233228322.06.20192298231010.05.20191923192905.08.20202549260509.08.19671838185004.10.20011851187228.09.20071814187515.12.20071802185913.05.20091803185520.09.20101669177501.09.20111621173729.09.20111672180419.08.20111667175024.09.20111823186628.10.20111710176629.03.20121668174704.05.20121885199006.09.20121747180129.09.20122233235330.08.20121647173013.01.20131675175412.12.20121720178707.02.20132067213816.06.20131916202820.05.20131678175608.08.20131710180803.04.20141777181703.05.20142053213316.02.20142030204121.11.20131924193907.06.20131641175528.01.20171855189128.11.20161744180212.12.20161747181708.03.19761549168228.06.20111577169418.07.20111675181207.03.20131572169116.07.20131575170908.11.20131538168601.04.20141641176616.03.20141641176724.12.20161532164710.01.20171557178615.01.20171557178629.07.19902739279307.03.20101876189503.05.20131948195121.08.20132377241326.08.20141932193316.08.20151982198407.03.20162352238508.02.19711756184828.01.20121616176920.03.20131673176428.09.20131648177829.12.20131927193010.07.20161840198512.07.20191771182222.08.20192125216119.01.19681548165424.09.19671955199530.03.19822535257927.07.19822311233206.12.19822408246503.08.19842467253624.07.19972419247829.12.19972606267619.01.20032687276503.01.20112201229104.09.20152465253329.10.19761791182913.08.19801850190001.05.20131941205112.07.19681600182914.07.19862475268301.08.19912523269801.12.19962250235010.08.19982172239827.11.20122549268531.10.19671660200623.07.19731819189720.08.19951271138026.08.19681370140823.10.20211154146723.10.19731085119511.06.19741085119524.03.19691805188030.06.19681361144717.05.19761640170021.06.19721130120603.02.19801157126610.07.2009984120915.08.2009984120826.08.2009984121001.01.19801161132631.03.197486098509.04.19783080355014.08.19783080355019.07.19862859321704.07.19701897191511.08.19921885189108.07.19722470254227.07.20092737278518.01.20152086210719.06.20152430245030.07.20182370245610.02.20232937319625.12.19911867189324.07.19921936194522.03.19931847187024.10.19941865187518.05.19952085213706.05.19972085213714.11.19951947195710.03.20082300231017.02.20131902193025.09.20151952196013.05.20191945197523.12.197317071908 -
Wellbores with cores
Wellbores with cores 17.02.1977830.06.19751215.03.19764327.06.19763911.10.1976713.07.2012129.12.1974903.12.19773618.05.19781210.03.19866505.08.19711810.12.1967908.09.20091421.01.2010105.04.2011013.05.2011120.03.2013428.09.20073915.12.20071403.05.20133