NORSK POLARINSTITUTT SKRIFTER NR. 146 B. FLOOD, D. G. GEE, A. HJELLE, T. SIGGERUD, T. S. WINSNES The geology of N ordaustlandet, northern and central parts WITH GEO LOGICA L MAP 1: 250 000 NO RS K PO LAR INSTITU TT OSLO 1969 DET KONGELIGE DEPARTEMENT FOR INDUSTRI OG HANDVERK NORSK POLARINSTITUTT Middelthuns gate 29, Oslo 3, Norway SALG AV B0KER SALE OF BOOKS Bokene selges gjennom bokhandlere, ell er The books are sold through bookshops, or bestilles direkte fra: may be ordered directly from: UN I VE R SITE T SF 0 R LA GE T Postboks 307 16 Pall Mall P.O. Box 142 Blindern, Oslo 3 London SW 1 Boston, Mass. 02113 Norway England USA Publikasjonsliste, som ogsa omfatter land­ List of publication, including maps and charts, og sjokart, kan sendes pa anmodning. may be sent on request. NORS K POLAR IN STITUTT SK RIFTE R NR. 146 B. FLOOD, D. G. GEE, A. HJE LLE , T. SIGGE RUD, T. S. WIN SNE S The geology of N ordaustlandet, northern and central parts WITH GEO LOGICAL MA P 1: 250 000 NORSK PO LAR INST ITUTT OS LO 1969 Manuscript received January 1969 Printed October 1969 Contents Page Page Abstract . .... ... ...... .... 5 Area 4. The north coast of Wahlenberg- General introduction. H fT. SIGGERUD.. 6 fjorden. ... .. ... .. .. .... ... .. ... 80 Discovery and topographical mapping .. 6 Area 5. West Rijpfjorden . .. .. 83 Geographical description . .. .. .. .. 7 Area 6. Rijpdalen-Innvika ...... .... 84 Earlier geological work ... .... .... 8 Area 7. Platenhalv0ya .... .. ...... 90 The 1965 expedition of Norsk Polarinstitutt 12 Area 8. Duvefjorden- Lcighbreen . .. 92 Logistics .....••................ 12 Synthesis . .. .. .. .. .. .. .. .. .. 93 The ice and weather conditions. .. 13 The geological field work . ... 14 Part Ill. Migmatite and syn-orogenic Acknowledgements . .. .. .. .. .. .. 17 granite rocks . .... ..... .... ... .. 97 Introduction to Part III ... ..... .... 97 Part I. Stratigraphy. " ................ 19 The Laponiahalv0ya and Sju0yane area. Introduction to Part I .... ....... 19 By A. HJELLE ...... ........ ... .... 98 The Kapp Sparre Formation, the Sveanor General . ... ........ .... 98 Formation, and the Murchisonfjorden Central Laponiahalv0ya-Sabinebukta. 99 Supergroup. By T. S. WINSNES......... 19 Ekstremhuken-Nordkapp-Sju0yane .. 102 West Nordaustlandet .... ....... .... 22 Comparison with the eastern area .. 104 The Kapp Sparre Formation . ..... 23 The Rijpdalen- Duvefjorden-Leighbreen The Sveanor Formation . .. ....... 25 area. By B. FLOOD and D. G. GEE .. .. .. 105 The Roaldtoppen Group . ..... .. 27 Metamorphism of the Botniahalv0ya The Celsiusberget Group . ..... ... 29 Group . ... .... .... ..... .. 105 The Franklinsundet Group . ...., 32 Contact relationships . ....... ... .. 106 Wahlenbergfjorden . ... .... .... 35 The migmatites, gneisses, and syn- Western Rijpfjorden . .. .. .. .. ... 36 orogenic granites . ...... .. ..... 112 Correlation with Spitsbergen ..... .. 38 Supracrustal inclusions . ... ... ..... 116 The Botniahalv0ya Group. By B. FLOOD 39 Meta-gabbro inclusions . .... ........ 118 Formation names and localities .. ... 40 Concluding remarks . .... ..... ... 120 Botniahalv0ya . ... .. ... ... 40 The Kapp Hansteen Formation . .. 41 Part IV. Post-orogenic granites The conglomerate . .. .. .. .. .. ... 49 By A. HJELLE .... .... ..... ...... 121 The Brennevinsfjorden Formation . 53 Introduction to Part IV . .. 121 Rijpfjorden-Wahlenbergfjorden . ... 54 The Brennevinsfjorden granite ..... ... 123 The Kapp Hansteen and Brennevins­ The Rijpfjorden granite . .. .. .. .. ... 124 fjorden Formations . ... 54 Genesis of the post-orogenic granites; The Austfonna Formation .. ...... 55 correlation with the syn-orogenic rocks. 128 The quartz porphyries . .. .. .. .. ... 57 Concluding remarks . .. .. .. .. .. ... 61 Part V. Isotopic age-determinations. The meta-gabbros . .. .. .. .. .. .. .. 63 By D. G. GEE ......•.................. 131 The Kapp Platen Formation. Introduction to Part V . .. .. .. .. .. .. 131 By T. S. WINSNES................ 64 The "Caledonian" age-determinations 132 The pre-Caledonian ages ..... .. 133 Part 11. Structure. By D. G. GEE ........ 67 Erratum . ... ........ .. ..... .. 135 Introduction to Part 11 . ..... ..... 67 Description of the areas . .. .. .. .. .. .. 69 Norsk sammendrag. Area 1. West Nordaustlandet. ... .. .. 69 (Summary in Norwegian) Av T. SIGGERUD 136 Area 2. Botniahalv0ya- Gerardodden. 74 References . ... ... ... ..... .... .... .... 138 Area 3. Laponiahalv0ya and Sju0yane 79 Plate . .. ..... .... ..... ....... 140 Abstract In 1965, Norsk Polarinstitutt sent an expedition to Nordaustlandet, geologically the least known part of the Svalbard archipelago. This paper contains the results of the reconnaissance in which the five authors took part, and includes data from previous works in an attempt to provide a general account of the Hecla Hoek complex of the island. Northern and central parts of Nordaustlandet contain a geosynclinal sequence of pre-Carboni­ ferous rocks, over 15 km thick, comparable with that described from neighbouring areas to the west. Beneath the Carboniferous unconformity, and intruded by Cretaceous(?) dolerites, the following succession has been established, with Cambrian and late Pre-Cambrian strata: Kapp Sparre Formation (Cambrian dolomites, limestones and shales, c. 800 m); Sveanor Formation (tillites and shales, c. 250 m); Murchisonfjorden Supergroup, composed of three groups, the Roaldtoppen Group - Rysso Formation (dolomites, c. 1000 m) and Hunnberg Formation (lime­ stones, c. 500 m), the Celsiusberget Group - Raudstup-Siilodd Formation (red and green marls and siltstones with subordinate dolomites, c. 500 m), Norvik Formation (grey-green silts and quartzites, c. 350 m) and Flora Formation (pink quartzites and subordinate red and green mud­ stones, c. 1250 m), and the Franklinsundet Group - Kapp Lord Formation (shales and quartzites, in part calcareous and with some limestones, c. 950 m), Westmanbukta Formation (red and green quartzites and mudstones, c. 600 m), and Persberget Formation (quartzites and subordinate grey shales, with a conglomerate at the base in the east, c. 400 m); the Botniahalveya Group-Austfonnal Kapp Platen Formations (quartzites, pelites and limestones with minor amphibolites, c. 3000 m + ), Brennevinsfjorden Formation (banded quartzites and pelites, conglomerate at the base in the west, c. 2000 m), and Kapp Hansteen Formation (volcanic rocks, c. 4000 m). The lowest part of the succession is migmatized. In general, the Botniahalveya Group was subject to greenschist facies metamorphism and this grade increases towards the contact with the migmatites with the incoming of biotite, garnet and, in one locality, andalusite and staurolite. The migmatite association, with accompanying syn-orogenic granitic rocks (quartz monzonite), contains supracrustal material which at least in part is derived from the Botniahalveya Group, but apparently not from the overlying stratigraphic units. Gabbros and quartz porphyries intruded the Kapp Hansteen and Brennevinsfjorden Formations prior to the regional metamorphism and deformation. After the deformation, granites intruded in two principal areas, Brennevinsfjorden and Rijp­ fjorden - Rijpdalen. None of these intrusive rocks have been recorded to penetrate the Murchison­ fjorden Supergroup and overlying rocks, only the older groups and the migmatites. The succession was folded in the Caledonian, developing a generally westerly asymmetric fold pattern, dominated by the following major structures: the Hinlopenstretet syncline, the Vestfonna anticline, the Loven syncline and the Rijpdalen anticline. In the lower part of the Rijpdalen anti­ cline, isoclinal folds exist which are folded by the anticline. It is possible that this earlier folding and accompanying metamorphism occurred prior to the deposition of the Murchisonfjorden Super­ group, implying the existence of a pre-Caledonian basement to the late Pre-Cambrian and Lower Palaeozoic sequences. A post-fold fracture pattern exists, including a system of major longitudinal faults and a conjugate system of WNW and WSW strike-slip faults. Isotopic age-determinations from the area are discussed in relation to the new geological data. General introduction BY T. SIGGERUD In 1965 Norsk Polarinstitutt sent an expedition to Nordaustlandet in the Svalbard archipelago. The expedition's aim was to study the geology of the pre­ Carboniferous areas, supposed to make up the bedrock over a greater part of the island (northern and central parts). The geology of this area was only known to a limited extent, and in many areas the work had been based on material collected by expeditions on which no geo­ logist took part. The most detailed information existed from the westernmost areas, where a stratigraphical scheme had been established for the sediments. Nordaustlandet is the large island situated north-east of Spitsbergen.1 For the purposes of this paper, we also include the surrounding smaller islands. The ' northern latitudes of the southernmost and northernmost points are 79°17 and 80°50' respectively. In longitude it reaches from 1r47' to 27°22' E. The surveyed area is about 15,000 km2 (Fig. 1). Discovery and topographical mapping Nordaustlandet was probably seen by whalers in the seventeenth and eigh­ ' teenth century. The first real expedition was W. E. PARRY S in 1827. Geographical investigations were carried out by the Swedish expedition in 1861 and the English (LEIGH SMITH) expeditions in 1871 and 1873. In 1873, after wintering in Spitsbergen, A. E. N