STUDIA GEOLOGICA POLONICA Vol. XUV, Warszawa lws Geological Jtesuit* of the Polish USl-ust, list, mo Spitsbergen Expedition. Edited by K. Btrkenmaier Pt. VII

UKD 551.7«.a.M/.78J.12.»2:S51.«.0Sl+531.3S.0511551.242.12(984-14 Ziemta Torella)

KRZYSZTOF BIRKENM A JER*

JURASSIC AND LOWER CRETACEOUS SEDIMENTARY FORMATIONS OF SW TORELL LAND, SPITSBERGEN

(Figs. 1—15; Tabs. 1, 2)

Contents

Abstract .... 7 Introduction 8 Adventdalen Group 8 Subdivision 8 Stratigraphical Sections 10 Janusfjellet Formation 18 Ingebrigtsenbukta Member 20 Brentskardhaugen Bed 24 Tirolarpasset Member 27 Polakkfjellet Bed . 29 Ullaberget Member 30 Helvetiafjellet Formation 31 Festningen Sandstone Member 33 „Upper Continental Series" 34 Carolinefjellet Formation 35 Discussion .... 35 Triassic-Jurassic Boundary in Torell' Land 35 Upper Kimmeridgian Sedimentary Break in Torell Land 36 Jurassic-Cretaceous Boundary in Torell Land 37 Facies and Thickness Variation 17 Janusfjellet Formation 37 Helvetiafjellet Formation 40 References — Literatura . 40 Streszczenie . 43

Abstract

The description of the Jurassic-Lower Cretaceous stratigraphical sequence subdivided into the Janusfjellet, the Helvetiafjellet and the Carolinefjellet for­ mations is given from SW Torell Land, Spitsbergen. A new marker bed — the Polakkfjellet Bed, is distinguished at the base of the Tirolarpasset Member (Ja-

* Geological Laboratory, Polish Academy of Sciences 31-002 Krakow Se- nacka 3 (Poland). ' Manuscript received September 30, 1973. ADVENTDALEN GROUP

nusfjellet Fm.). Breaks in sedimentation, the result of Meso- and Neocimmerian movements,' are recognized between the Rhaeto-Liassic be Geerdalen Member (Kapp Toscana Fm.) and the basal Callovian (resp. uppermost Bathonian-Callo- vian) unit of the marine Janusfjellet Formation, and another at the base of the Volgian (in Upper Kimmeridgian). Position of the axial zone of marine sedimen­ tary basin of the Janusfjellet Formation in Torell Land is discussed.

INTRODUCTION

The geological observations on the Jurassic and Lower Cretaceous sedi­ mentary sequence and rocks of SW Torell Land have been assembled by the author during the Polish Illrd International Geophysical Year and International Geophysical Co-operation Expeditions to Spitsbergen of 1958 and 196.0 (Leader Professor S. Siedlecki). A geological map to a 1:50,000 scale has been made in the area between Polakkbreen on the north and inner Hornsund on the south (Fig*. 1, 2), as a direct prolon­ gation of the map to the same scale made in 1934 by S. Z. Rozycki (1959) in NW Torell Land. South-west Torell Land is a highly glaciated area with comparatively poor exposures (mostly in nunataks) of the Jurassic and Lower Creta­ ceous rocks, often strongly folded in the zone of Tertiary diastrophism (Alpine fold belt of Spitsbergen — see Birkenmajer 1972b, c). The most complete, continuous exposures of the rocks in question are those at NE Polakkfjellet (on the north) and at E Hyrnefjellet (on the south). The Jurassic (mainly) and Lower Cretaceous fossils collected by the author in the course of mapping have been determined in papers by Kopik (1968) and Birkenmajer and Pugaczewska (1975). Preliminary information on the stratigraphic succession in SW Torell Land has been presented by Birkenmajer (1959, 1960a).

ADVENTDALEN GROUP

Subdivision

The Jurassic to Lower Cretaceous sequence of SW Torell Land be­ longs to the Adventdalen Group (name introduced by Parker 1967). Its subdivision into formations and members in the central depression of Spitsbergen is presented in Tab. 1 which is a modification of strati- graphic schemes of Nathorst (1910). Rozycki 1959K Suehan et al. (1965), Parker (1967), Harland (1969, Tab. VI). Flood e: al. ,1971) and Birken­ majer (1972a, Tab. 1). A new stratigraphic unit is introduced to the scheme, namely the Polakkfjellet Bed. which is a marker horizon at the base of the Tirolarpasset Member at Polakkfjellet and in NW Torell Land. SUBDIVISION 9

Fig. 1 of the investigated area (shaded) in Svalbard (A) and in Spits bergen (B) 10 ADVENTDALEN GROUP

Table 1 Stratigraphic scheme of the Adventdalen Group in Spitsbergen. Modi­ fied from Nathorst (1910), Rozycki (1959), Buchan et AL. (1965), Par­ ker (1967), Harland (1969) and Birkenmajer (1972a). Vertical hatching denotes major breaks in sedimentation

NW & SE TORELL LAND NORDENSKIOLD LAND Age I S NATHORST LAND I SABINE LAND

ALII AN Carolinefjellet Fm. APT-tAN

Lower "Upper Continental Series" Glitrefjellet MB. Cretaceous Helvetiafjellet BARREMIAN Fm. Festningen Sandstone Mb.

! HAUTERIVIAN Ullaberget Mb. Rurikfjellet Mb. VALANGINIAN Janusfjellet Tirolarpasset Mb. Fm.

(Aucella shales) Upper KIMMERIOGIAN Jurassic Agardhfjellet Mb OXFOROIAN Ingebrigtsenbukta Mb. CALLOVIAN Brentskardhauqen Bed TTT Middle BATHONIAN Jurassic BAJOCIAN Illiliilli. TOARCIAN -(Toarcian-and Bajocian fossils,, PLENSBACHM LOWEI Jurassic SINEMURIAN I^' B^rSauT'Ud,^ (Liassic) : HETTANGIAN ; i!iiiiMililJ^ RHAETIAN DE Geerdalen MB. Upper NORIAN Triassic CARNIAN Tschermakfjellet MB LADINIAN Middle Triassic

Stratigraphical Sections

Three stratigraphical sections are presented here, the ones best ex­ posed in the C^a investigated, and representing the widest range of the Jurassic-Lower Cretaceous stratigraphic column, namely the sections at E Hyrnefjellet, at S Fonnryggen and at NE Polakkfjellet (for localiza­ tion see Figs. 2, 3). The Hyrnefjellet section is a good exposure of strongly folded De­ vonian, Carboniferous, Permian, Triassic and Jurassic to Lower Creta­ ceous strata (see Birkenmajer 1960b, 1964, Fig. 2). The Jurassic-Lower Studia Geologica Polonica vol. XLIV

LEGEND

Faults and minor overthrusts

~M Major overthrusts

Carolinefjellet Formation }APTfA N fj^T^ "Upper continen- MXM tal series'* HELVETIA­ FJELLET Festningen Sand­ FORMATION stone Member {BARREMIAN)

Ullaberget Member and Tirolarpasset Member JANUSFJELLET Polakkfjellet Bed FORMATION Ingebrigtsenbukta (CALLOVIAN- Member -HAUTERIVIAN) Brent ska rdhaugen Bed KAPP TOSCANA De Geerdalen Member FORMATION Tschermakfjellet Mb. J (LADINIAN ^otnaheia Formation -> "HETTANGIAN) ] Sticky Keep Formation I GRIESBACHIAN Ivardebukta Formation] - ANISIAN

Upper Permian

Middle Carboniferous -Lower Permian

^SSSI Lower Carboniferous

Devonian

Hecla Hoek: Precambrian - Ordovician

Mesozoic dolerite

Somovbreen 77°10 o , —P -77 10 Glashaugen

Burgerbukta

0 Emoholmanc

-77 77°-

16° 20' 16°

Fig. 2 Simplified geological map of SW Torell Land Wydawnictwa Geologiczne 1975 r. Lub. Zakl. Graf. N. 525+75 wsw tNEjjW E|SW NE I WSW ENE|NWSE|WNW /» ESEJSW NE (Braemfjellet)

01 Luciakammen H ' Strykjernet 50 > Hyrnebreen Storbre«n

sea 5 level Burgerbu k ta

O z

Fig. 3 Geological cross-section between Luciakammen and Strykjernet, northern coast of Hornsund (after Birkenmaior 1979W

1 - Eocarnbrian; 2 - Lower Cambrian; 3 - Lower Ordovician (1-3 - Hecla Hoek succession); 4 - Devonian' S L!Z r/rh™ i to

HYRNEFJELLET

ENE NW SE : WNW ESE : WSW

> © Hyrnebreen a I D r> w o w o © ffl c 500m / / ©

Fig. 4 Geological structure of E Hyrnefjellet X — Lower Carboniferous: 2 — Middle Carboniferous; 3 — Upper Carboniferous and Lower Permian; 4 Upper Permian; 5 — Vardebukta Formation (Lower Triassic: Griesbachian); 6 - Sticky Keep Formation (Lower Triassic, upper part); 7 • Botneheia Formation (Anisian); X — Kapp Toscana Formation, Tschermakfjellet Member (Ladinian-Carnian); 9 — Kapp Toscana Formation, De Geerdalen Member (No- rian-Rhaetian-Hettangian); 10—13 — Janusfjellet Formation: 11 — Ingebrigtsenbukta Member (Callovian-Kimmeridgian) with Brentskardhaugen Bed (ltt) at the base; 12 — Tirolarpasset Member (Volgian-Valanginian); 13 — Ullaberget Member (Valanginian-Hauterivian); 14 — Helve- tiaf'iellet Formation, Festningen Sandstone Member (Barremian). Quaternary: 15 — Moraine; 16 — Talus; 17 Glacier. Thick lines denote faults and overthrusts STRATIGRAPHICAL SECTIONS 13

Cretaceous rocks are visible best on the SE slope of the mountain above Hyrnebreen and Treskelen (Fig. 4).

E Hyrnefjellet (Fig. 4)

Stratigraphy and lithology Thickness in metres Helvetiafjellet Fm., Festningen Sandstone Mb.: 6. Quartzite and quartzitic sandstone in beds 0.5—1.5 m thick, white, light grey or light greenish, often with rusty coating at the surface. Conglomerate intercalations frequent, consisting of white quartz pebbles, rounded or well rounded, 0.5 3.0 cm, occasionally up to 10 cm in diameter. In the middle part of the member, the sandstones and quartzites are often poorly bedded, yellowish, with poorly preserved plant remains. Some black arenaceous shale intercalations occur, mostly covered by scree. In the upper part of the member, the sandstones and quartzitic sandstones are fine-grained, often well laminated, in plates 0.5—1.5 cm thick, dark-green or greenish, grey-green if weathered with inter­ calations of black arenaceous shale ' 50—60

Janusfjellet Fm., Ullaberget Mb.:

5. Sandstone, fine-grained, in layers 2—50 cm thick, often shaly grey, greenish, sometimes glauconitic, intercalated with arenaceous shale in bands 5—50 cm thick, black or dark-green, with worm trails. Se­ veral intercalations of conglomerate 10—20 cm thick, with rounded quartz pebbles 0.5—2 cm in diameter occur . 10—20

Tirolarpasset Mb.:

4. Shale, argillaceous, sometimes arenaceous (silty), black, splitting into very fine plates. Clay-ironstone or sideritic dolomite intercalations 5—10 cm thick, red and yellow if weathered, occur infrequently . ca 69

Ingebrigtsenbukta Mb.:

3. Shale, argillaceous, often silty, black, with numerous fine mus¬ covite flakes visible at unevenly fractured surfaces. Rare intercalations of clay-ironstone or sideritic limestone 10—15 cm thick, black yellow if weathered. The lowermost part of the member (10—15 m thick), contains more silt. The shales become here more compact, but split into plates of uneven fracture 0.5—1.5 cm thick. Intercalations of clay-ironstone be­ come red if weathered ca 110 2. Brentskardhaugen Bed (thickness 0.4—0.5 m in the lower part of the slope; 0.2—0.3 m in the upper part of the slope): Lower part of the slope: Shale, black, very soft, with nume­ rous phosphorite concretions and pebbles, easily separable from the shale. The ratio of shale to phosphorite pebbles is 1:1. The average diameter of phosphorite pebbles is 2—5 cm, larger pebbles up to 14 ADVENTDALEN GROUP

20—25 cm in diameter being infrequent. The shape of pebbles is sphe­ roidal, ovoidal or elongated. The phosphorite pebbles are black, fine- -grain'ed inside, and whitish or grey at the surface. About one third of these contain a rich and comparatively well preserved fauna (see Birkenmajer & Pugaczewska 1974, Tab. 2), consisting of pelecypods (mainly), ammonites, large belemnite phragmocones, reptile bones and phosphoritized wood; shells of brachiopods and gastropods are less frequent. The fossils occur as moulds and imprints often covered with limonite. The Brentskardhaugen Bed rests immediately upon whitish quartzite of the Kapp Toscana Fm. (De Geerdalen Mb.: Rhae- to-Liassic). There is no angular unconformity visible, and the lower­ most phosphorite pebbles of the Brentskardhaugen Bed lie immedia­ tely upon quartzite and are strongly cemented with its surface. Upper part of the slope: Conglomerate bed with phospho­ rite pebbles 1—5 cm (rarely up to 20 cm) in diameter and with quartz pebbles 0.5—2 cm in diameter, cemented with red or yellow-red siderite with ferruginous ooids and with quartz grains. The conglo­ merate of the Brentskardhaugen Bed contacts immediately with whi­ tish quartzite or quartzitic sandstone of the Kapp Toscana Fm. (De Geerdalen Mb.: Rhaeto-Liassic), which is infiltrated with yellow limo- nitic substance down to about 0.5 m below its upper surface; limo- nite-filled fissures may continue lower still in the sandstone . . . 0.2—0.5

(Sedimentary hiatus)

Kapp Toscana Fm, De Geerdalen Mb. (thickness 98 m): lc Quartzite and quartzitic sandstone in bands 2—30 cm thick, yellowish, greenish in the upper part of the member and nearly black in the lower part of the member where plant remains may be found.

Rusty coating occurs at weathered surfaces. Intercalations of black shale 2—10 cm thick occur in the lower part of the member. Quartz conglomerate up to 10 cm thick with pebbles 1—10 cm in diameter and with numerous and well preserved reptilian bones (bonebed), and often with limonite concretions, occurs locally (discontinuously) at the top surface of the member. Mudflakes and mudcracks have been found in the upper part of the member. Vertical borings were found in the lower part of the 30 member lb. Shale, black, with sideritic limestone intercalation (1 m) grey, 2* yellow if weathered, in the upper part la. Sandstone, medium- or fine-grained, in plates 1-5 cm thick, grey grey-greenish, with a 3m-thick intercalation of black or grey¬ -greenish arenaceous shale in the middle. Plant remains occur in the sandstone above the shale intercalations, tabular and planar large-scale cross bedding occurs in the basal sandstone below the shale inter­ 39 calation (Tschermakfiellet Member, and Botneheia, Sticky Keep and Vardebukta for­ mations of the Triassic occur below the Kapp Toscana Formation). The S Fonnryggen section is a comparatively good exposure of the lowest part of the Ingebrigtsenbukta Member at the western side of Fonnryggpasset, in the western limb of a syncline (Figs. 2, 5). STRATIGRAPHICAL SECTIONS 15

Fig. 5 Schematic profile of the contact of the De Geerdalen Member and the Ingebrigtsenbukta Member at S Fonnryggen. Clay-iron­ stone intercalations in black

S Fonnryggen

(Fig. 5)

Stratigraphy and lithology Thickness in metres Janusijellet Fm.. Ingebrigttenbukta MB : 3 Black shale -A::-, intercalations 10—30 cm thick of biack or dark- -g:ey clay-ironstone. The lour lowest are iron-rich and weather red, the higher ones are iron-poor and weather yellow. The lowest of the clay-ironstone bands 10—20 cm thick contains ferruginous ooids and a poorly preserved gastropod resembling Pleurotomaria. It rests directly upon loose phosphorite pebble band of the Brentskardhaugen Bed In­ complete thickness 2. Brentefcordftauoen Bed: Developed as either cemented or loose band rich in phosphorite pebbles. In the first case it is a yellowish quartzitic sandstone 20 cm thick with numerous pebbles of well round­ ed and rounded quartz and light quartette 1—15 cm in diameter and black fine-grained spheroidal phosphorite pebbles of similar dimen­ sions, with fauna (pelecypods, ammonites etc. — see Birkenmajer & Pugaczewska 1974) and pieces of wood. In this case it contacts directly with quartzitic sandstone of the De Geerdalen Mb. In the other case, where the Brentskardhaugen Bed rests imme­ diately upon bonebed of the De Geerdalen Mb., it is 10—15 cm thick and consists of loose or very feebly cemented phosphorite pebbles of small dimensions (5—10 cm in diameter) with fauna (ammonites pele­ cypods, inarticulate brachiopods, gastropods etc. — see Birkenmajer & Pugaczewska op. cit.) and with pieces of phosphoritized wood 0 i Q 2 16 ADVENTDALEN GROUP

Fig. 6 Perspective view of NE Polakkfjellet as seen from Polakkbreen sfiellet Formation- 1 — Ingebrigtsenbukta Member; 2—3 — Tirolarpasset Member with p lakkfiellet Bed (2) at the base- 4 - Ullaberget Member. Helvetiafjellet Formation: 5 - Fest- ningen Sandstone Member (shale-sandstone complexes in black); 6 - "Upper continental series"; 7 — Carolinefjellet Formation

Fig. 7 Geological profile of NE Polakkf jellet, NW rib. For explanations see the text STRATIGBAPHICAL SECTIONS 17

(Sedimentary hiatus)

Kapp Toscana Fm., De Geerdalen Mb.:

1. The topmost beds of this member consist of yellow, limonitic or whitish, medium- to fine-grained quartzitic sandstone and quartzite with worm trails and plant remains, in layers 10—20 cm thick. The surface of layers often shows limonitic or manganese glaze. Reptilian bones occur here and there within the sandstones and also form a discontinuous bonebed 10—20 cm thick consisting of fragmentated rep­ tilian bones at the top of the member, just below loosely-cemented Brentskardhaugen Bed. Incomplete thickness 10 (Tschermakfjellet Member and Botneheia, Sticky Keep and Vardebukta for­ mations of the Triassic occur below the Kapp Toscana Formation on the western slopes of Fonnryggen).

The NE Polakkfjellet section is a good exposure of gently folded Jurassic and Lower Cretaceous strata (Figs. 2, 3, 6, 7). Farther SW and S Triassic and Permian sediments crop out. This section is a type locality for the Polakkfjellet Bed (Tirolarpasset Member).

NE Polakkf jellet

(See Fig. 7) Stratigraphy and lithology Thickness in metres Helvetia)jellet Fm., Festningen Sandstone Mb.:

(11—8 — thickness ca 17.5 m) 11. Sandstone, medium- or fine-grained, in layers 0.5—1 m thick, showing horizontal lamination and current bedding, highly jointed light-yellow or white ca 10.0 10. Conglomeratic sandstone: Sandstone, medium-grained, often quartzitic, light-yellow or whitish, with numerous quartz pebbles. Quartz pebbles rounded and well rounded, white or grey. Beds 10 and 11 conformable 0.5 9. Sandstone, medium- or fine-grained, often horizontally lami­ nated, in bands 0.3—0.8 m thick, light-yellow, with rusty coating at jointing surfaces 2.0 8. Sandstone, fine-grained, quartzitic, in very irregular layers 5—10 cm thick, fractured in cubes, light-green or greyish. Traces of plant rootlets and plant detritus in the form of coaly films occur in the sandstone which contains, moreover, numerous discoidal clay-ironstone concretions 0.2—1.0 m in diameter and 0.05—1.0 m thick, brownish¬ - rusty if weathered 5 0

'c.nusf jellet Fm., Ullaberget Mb.: (7—4 — thickness 65.0 m) 7. Covered with snow. At the slope fragments of silty shale and -gillaceous siltstone black and brownish-black, resembling bed 4

.U-e visible 40 0 6. Siltstone and arenaceous shale, black, rusty if weathered. The -iltstone splits into plates 0.5—1 cm thick, of uneven fracture . . 5 0 5. 4. Shale and argillaceous siltstone, black, brownish-black if 18 ADVENTDALEN GROUP weathered, often showing horizontal lamination and worm trails. Thin intercalations of brownish siltstone 0.5—1 cm thick, especially in the lower part (4) 20.0

Tirolarpasset Mb.:

(3—1 — thickness ca 27.5 m) 3. Shale, argillaceous, black, with rare, thin (0.5—1 cm) interca­ lations of black micaceous siltstone, with worm trails. Numerous small (1—3 cm in diameter), ovoidal or spheroidal black calcareous-marly concretions with a low content of phosphate occur 16.0 2. Shale, argillaceous, black 6.5 1. Polakkfjellet Bed: Sandstone marker horizon, base of the Tirolar­ passet Mb, well visible at distance as yellow band. Sandstone, medium- or coarse-grained (0.5—2 mm grain diameter, subrounded or rounded), sideritic, intensely yellow or orange-yellow if weathered. Grain strati­ fication poor, grain gradation rarely visible. Sandstone layers are 0.3— 0.5 m thick and are separated with thin black shale. Shaly clay-iron­ stone concretions 5—10 cm in diameter, orange-yellow or reddish¬ -yellow if weathered, occur in the top parts of sandstone layers. Few fine-conglomerate intercalations occur in the sandstone, consisting of black, bluish or whitish quartz pebbles (subrounded or rounded 0.2— 1 cm in diameter) and of blue Permian (?) chert (angular, up to 1.5 cm in diameter). Thracia cf. depressa (Sowerby) has been found in the sandstone ca 5.0

Ingebrigtsenbukta Mb.: .

(total thickness ca 150 m)

0. Shale, arenaceous or argillaceous, perfectly stratified, with uneven fracture, with fine muscovite flakes, black, but dark-brownish if weathered. Intercalations of clay-ironstone, black-blue at fresh sur­ face, yellow if weathered, forming lenticles up to several metres in diameter and up to 10 cm thick. Incomplete thickness .... over 20.0 (Lower part of the Ingebrigtsenbukta Member with the basal Brentskardhaugen Bed, and underlying Triassic formations are visible in the middle and western parts of Polakkfjellet).

Janusfjellet Formation

Name: The name Janusfjellet Formation (Subgroup of Parker 1967, type section not given) is here used in the sense of H. Major who has introduced this name in his Adventdalen geological map (1:100,000) printed in 1964 by Norsk Polarinstitutt but not yet published, for the Aucella (= Buchia) shale of the previous authors (e.g. Nathorst 1910; Orvin 1940).

Lit ho logy: The dominant sediment of the Janusfjellet Formation are thick predominantly black or dark-grey bituminous shales with subordinate clay-ironstone (sometimes also ferruginous oolite) and sand- JANUSFJELLET FORMATION 19

stone or siltstone intercalations, the latter being present mainly in its lowermost and the uppermost parts. Subdivision and Age. The sequence is subdivided in Sabine Land and E Nordenskiold Land into the lower Agardhfjellet Member (Formation of Parker 1967: uppermost Bathonian or basal Callovian to Lower Volgian) and the upper Rurikfjellet Member (Formation of Par­ ker 1967: Valanginian to Upper Hauterivian; see also Harland 1969) separated by a non-sequence and local unconformity, the break occurr­ ing between the Lower Volgian and the Valanginian. In Torell Land and southern Nathorst Land the Janusf jellet Forma­ tion is either continuous (SW part of Torell Land) or shows only a minor break at the base of the Volgian (NW Torell Land — Rozycki 1959).

WE SW NE

500m

Fig. 8 A. Schematic geological cross-section of W Somovfjella (610 m) 2 Botneheia Formation (Anisian) and Tschermakfjellet Member (Ladinian-Carnian Kapp Toscana Formation); 2 — De Geerdalen Member (Norian-Rhaetian-Hettangian Kapp Toscana Formation). Janusfjellet Formation: 3—i — Ingebrigtsenbukta Member with Brentskardhaugen Bed (3) at the base; 5 — Tirolarpasset Member B. Schematic geological cross-section of Spikarhovudet Janusf jellet Formation: 1 — Ingebrigtsenbukta Member; 2 — Tirolarpasset Member. Clay¬ -ironstone intercalations in black

The Formation is here subdivided (after Rozycki 1959; with modifica­ tions by Birkenmajer 1972a) into the lower Ingebrigtsenbukta Member (Callovian to Kimmeridgian), the middle Tirolarpasset Member (Volgian to Valanginian) and the upper Ullaberget Member (Valanginian to Haute­ rivian). Two marker beds are distinguished within the Janusfjellet Forma­ tion: the Brentskardhaugen Bed (Parker 1967; phosphorite conglomerate or Liassic conglomerate of the previous authors), with mainly Toarcian fossils in phosphorite pebbles as secondary deposit in the uppermost Bathonian or Lower Callovian (see Birkenmajer 1972a), at the base of he Agardhfjellet Member and the Ingebrigtsenbukta Member, and the 20 ADVENTDALEN GROUP

Polakkfjellet Bed (base of Volgian) at the base of the Tirolarpasset Mem­ ber (this paper). Boundaries: There is a sharp contact and even a minor break in deposition at the contact of the marine Janusfjellet Formation and the succeeding, mainly continental strata of the Helvetiafjellet Formation (Barremian). A sharp boundary and stratigraphic/sedimentological hiatus is recognized at the base of the marine Janusfjellet Formation against continental Rhaeto-Liassic deposits of the De Geerdalen Member (Kapp Toscana Formation). Distribution and Thickness: The distribution of the Janusfjellet Formation in SW Torell Land is shown in Fig. 2. The main exposures are at Polakkfjellet, at both sides of Fonnryggpasset (S Fon­ nryggen, W Somovaksla and Glashaugen), at Spikarhovudet, at Somov- fjella and Tvitoppen, around Kvalfangarbreen (E Foswinckelnuten, Kry- gernuten, S Kvalfinnen, W Trilingane, W Firlingane, E Triasnuten, Kru- seryggen. Condevintoppen and Condevinskardet), at E Hyrnefjellet and at Strykjernet (see Figs. 4—12). The thickness of the Janusfjellet For­ mation amounts to more than 240 m at Polakkfjellet but decreases to 180—190 m at Hyrnefjellet.

Ingebrigtsenbukta Member Name and Subdivision: The Ingebrigtsenbukta Member (Series of Rozycki 1959) is the lower member of the Janusfjellet For­ mation. It begins with the Brentskardhaugen Bed (see below) resting unconformably upon the Rhaeto-Liassic Kapp Toscana Formation (De- Geerdalen Member). Type area: Ingebrigtsenbukta and E Foldaksla area, Van Keulen- fjorden (see Rozycki 1959, PI. V, PI. VI: cross-section I, II; type section not given). Reference Sections: Jurakammen (Rozycki 1959, PI. V; PI. VI: cross-section X) and E Hyrnefjellet (Fig. 4). Lithology: The Member consists mainly of black argillaceous, bituminous, often silty shales (sometimes siltstones) with numerous fine muscovite flakes visible especially on unevenly splitting surfaces. Inter­ calations of black or black-blue clay-ironstone or sideritic limestone, usually 10—15 cm thick, occur in the shales at intervals from a few to a dozen or so metres. In the lowermost 10—15 m thick part of the Member, the clay-ironstone intercalations are more frequent, rich in iron, and weather red or rusty-red, higher up the amount of iron de­ creases and the clay-ironstone intercalations and lenticles (up to several metres in diameter and up to 40 cm thick) weather yellow. Ferruginous oolites may occur in the lowermost part of the Member, just above the Brentskardhaugen Bed. JANUSFJELLET FORMATION 21

Fauna and Age: Rozycki (1959) has distinguished within the Ingebrigtsenbukta Member the following Middle and Upper Jurassic stages: Callovian, Oxfordian and Kimmeridgian (Lower Kimmeridgian sensu Arkell 1956). A Lower Callovian ammonite fauna (not determined so far) has been reported by Rozycki (1959, p. 72, footnote) from a layer

NE e SW Foswinckel- JJ

Fig. 9 Schematic geological cross-section between Terta and Krygernuten. Horizontal scale approximate, vertical scale slightly exaggerated 1 — Hecla Hoek succession (Lower Ordovician) • 2 Devon a t « (Anisian) and TschermaWfjeUet Member (Ladinian and Carnian Kaon ^°tneheia Formation * — De Geerdalen Member (Norian-Rhaetian-Hettangian Kapp ' Toscana FoT^f rmatl°n'; ijellet Formation: 5-« - Ingebrigtsenbukta Member with Brentskardhaugen base; 7 _ Tirolarpasset Member and Ullaberget Member. Helvetiaf jellet Formation- l: - F t ningen Sandstone Member. Overthrusts and faults indicated by thicker lines

of ferruginous oolite overlying the Brentskardhaugen Bed at Ingebrig­ tsenbukta, Van Keulenfjorden. Elsewhere in Spitsbergen the base of the Buchia shale sequence is dated as uppermost Bathonian or Lower Callovian on Kepplerites fauna (see e.g. Parker 1967; Pcelina 1967). Higher up in the sequence have been found poorly preserved pele- cypods, Belemnites cf. canaliculatus Schl. and Quenstedtoceras aff lam- berti (Sow.). The Oxfordian fauna according to Rozycki (op. tit.) con­ sists of Amoeboceras nathorsti (Lundgr.), A. alternans (v. Buch) and pelecypods Scurria oblonga Desh., Astarte pumilla Sow. and Nucula sp. The Kimmeridgian fauna was represented in Rozycki's collection by Amoeboceras kitchini (Salf.) in the lower part and by Buchia bronni (Lah.) in the upper part. The fauna collected by the present author from the Ingebrigtsen­ bukta Member in SW Torell Land is poor (Birkenmajer & Pugaczewska 1975). From a lower part of the Member could derive the following fossils found in loose clay-ironstone concretions at Treskelen (below E Hyrnefjellet): Parallelodon sp. indet., Modiola cf. gibbosa Sowerby, Oxytoma (Oxytoma) inaequivalvis (Sowerby) and Thracia cf. lens (Agas- 22 ADVENTDALEN GROUP siz). Buchia bronni (Lahusen) has been found in the upper part of the Member, just below the Tirolarpasset Member at Spikarhovudet and W Somovfjella (peak 610 m, western slope); the latter is reported from the Kimmeridgian of NW Torell Land (Rozycki 1959) and from Oxford- ian and Kimmeridgian of Van Keulenf jorden and Sorkapp Land (Pceli- na 1965b, 1967). Amoeboceras (Euprionoceras) cf. kochi Spath found in a loose clay-ironstone concretion at Treskelen (below E Hyrnefjellet) has certainly derived from the upper part of the Ingebrigtsenbukta Mem­ ber. The above findings agree with Rozycki's placing the upper part of the Member within the Kimmeridgian. Boundaries: Sharp lower boundary and stratigraphical hiatus at the base of the Brentskardhaugen Bed (bottom of the Ingebrigtsen­ bukta Member). Sharp boundary and/or break in deposition at the con-

SW NE

ftvairannarbn 290 I

Fig. 10 Perspective view of southern slope of Braemf jellet. Scale approximate 1 — Devonian; 2 — Kapp Toscana Formation, De Geerdalen Member (Norian-Rhaetian Het tangian); 3—i — Janusfjellet Formation: Ingebrigtsenbukta Member with Brentskardhaugen Bed (3) at the base. Quaternary: 5 — Moraine; 6 — Talus. Thicker lines denote faults tact with the overlying Polakkfjellet Bed (Polakkfjellet and farther north). Transition from the Ingebrigtsenbukta to Tirolarpasset members to the south of PolakkfjeUet: the topmost shales of the Ingebrigtsen­ bukta Member often show the presence of secondary gypsum in SW Torell Land (see below). Distribution and Thickness: The distribution of the In­ gebrigtsenbukta Member in SW Torell Land is shown in Fig. 2. The main exposures are at Polakkfjellet, at both sides of Fonnryggpasset (S Fonnryggen and W Somovaksla), at Glashaugen, Somovfjella (peaks 525 m, 538 m, 660 m and 610 m — western slope), at Spikarhovudet, W Fasmerhagda, around Kvalfangarbreen (E Foswinckelnuten, S Kval- finnen, W Trilingane, W Firlingane, S Braemf jellet, E Triasnuten, E JANUSFJELLET FORMATION 23

~- x

Fig. 11 Perspective view of northern slope of Triasnuten. Scale approximate l . upper Carboniferous and Lower Permian' 2 Upper Permian • 3 Vardebukta Form­ ation (Lower Triassic: Griesbachian); 4 Sticky Keep Formation (Lower Triassic upper part); 5 — Botneheia Formation (Anisian); 6 — Kapp Toscana Formation (Ladinian-Het- tangian). Janusf jellet Formation: 7—S — Ingebrigtsenbukta Member with Brentskardhaugen Bed (7) at the base; 9 — Tirolarpasset Member. Quaternary: 10 — Moraine. Thick lines denote faults

Fig. 12 Schematic geological cross-section between Urnetoppen and Strykjernet. Horizontal scale approximate, vertical scale slightly exaggerated \ _ Lower Carboniferous; 2 — Middle Carboniferous • 3 Upper Carboniferous and Lower Permian; 4 Upper Permian; 5 Vardebukta Formation (Lower Triassic * Griesbachian)- S — sticky Keep Formation (Lower Triassic, upper part), Botneheia Formation (Anisian) and Tsehermakf jellet Member (Ladinian-Carnian, Kapp Toscana Formation); 7 — De Geerdalen Member (Norian-Rhaetian-Hettangian, Kapp Toscana Formation). Janusf jellet Formation¬ *—9 — Ingebrigtsenbukta Member with Brentskardhaugen Bed (S) at the base. Oveithrusts and faults indicated by thicker, lines 24 ADVENTDALEN GROUP

Kruseryggen, Condevintoppen and Condevinskardet), at E Hyrnefjellet and at Strykjernet (Figs 4, 5, 8—12) *. The thickness of the Member amounts to 150 m at Polakkfjellet and decreases to ca 110 m at Hyrnefjellet, to 60 m at S Fonnryggen and to 40 m at Somovfjella and Somovaksla.

Brentskardhaugen Bed

Name: The Brentskardhaugen Bed is a new name introduced by Parker (1967, type section not given) for the basal lithostratigraphic unit of the Jurassic marine succession (Janusfjellet Formation) in Spits­ bergen, known before as the „phosphorite conglomerate (bed)" or ..Liassic conglomerate" (see Frebold 1929a, b; 1930, 1951; Bodylevskij 1929: Ro­ zycki 1936, 1959; Orvin 1940; Birkenmajer 1959, p. 195, 1960a, Tab. 2, 1960b, 1964, Fig. 2; Pcelina 1965a, b, 1967; Kopik 1968). Lithology: The Brentskardhaugen Bed is a very thin band cha­ racterized by the presence of fossiliferous phosphorite pebbles. There are three lithological types of the Brentskardhaugen Bed in SW Torell Land: 1) Loose or feebly cemented fossiliferous phosphorite pebble-con­ centrate (S Fonnryggen); 2) Black shale, very soft, with fossiliferous phosphorite pebbles easily separable from the shale (E Hyrnefjellet, lower part of the slope); 3) Hard conglomerate with quartz and fossili­ ferous phosphorite pebbles cemented with arenaceous siderite with fer­ ruginous ooids (E Hyrnefjellet, upper part of the slope), grading into quartzitic sandstone with quartzite, quartz and fossiliferous phosphorite pebbles {loose blocks below the slope of E Hyrnefjellet, at Treskelen; S Fonnryggen). The details of structure of the Brentskardhaugen Bed are shown in Figs 13 and 14. The character of the sediment indicates that the Brentskardhaugen Bed is a pebble concentrate which derived from older, principally Toar- cian (possibly also Bajocian) fossiliferous phosphorite layer (layers) crushed and reworked (rounded) by the transgression of the Lower Cal- lovian (resp. uppermost Bathonian-Lower Callovian) sea. This could explain the fact that the pebbly bed often contains an admixture of re­ worked material from the underlying Kapp Toscana Formation (Upper Triassic-Hettangian) in the form of phosphoritized reptilian bones, quartz grains and quartz and quartzite pebbles and, sometimes, also from pre- -Mesozoic rocks (see Rozycki 1959; Birkenmajer 1972a). The appearance

* In a talk at the Norwegian Polar Institute in Oslo in December 1970, Dr V. N. Sokolov from the Institute of Geology of the Arctic (Leningrad) has kindly informed the author that according to the observations of the Russian geologists, at Strykjernet occur also higher members of the Janusfjellet Forma­ tion and the Festningen Sandstone Member. In 1958 the present author recognized there only the Ingebrigtsenbukta Member (see Fig. 3). JANUSFJELLET FORMATION 25

of phosphorite pebbles in black shale or in conglomerate cemented by arenaceous, red-weathering oolitic ironstone, both typical for the In­ gebrigtsenbukta Member sediments, is another proof of the above ex­ planation. Fauna and Age: The list of fossils from the phosphorite peb­ bles of the Brentskardhaugen Bed in SW Torell Land consists of in­ articulate brachiopods (1 taxon), gastropods (2 taxa), pelecypods (21 taxa) and ammonites (8 taxa) from the localities at S Fonnryggen and E Hyr-

- limonitic concretions

Fig. 13 Contact of the Brentskardhaugen Bed (conglomeratic band with phosphorite and quartz pebbles cemented with limonitic sandstone with ferruginous ooids) with the De Geerdalen Member. Loose block below the slope of E Hyrnefjellet nefjellet (determinations by Kopik 1968 and by Pugaczewska — in Bir­ kenmajer & Pugaczewska 1975): Linguist sp. indet Globularia sp indet Patella sp. indet., Nuculana (Praesaccella) cf. camelorum Cox Modiola cf. gibbosa Sowerby, Inoceramus (Mytiloides) amygdaloides Goldfuss Oxytoma (Oxytoma) inaequivalvis (Sowerby), Meleagrinella cf. echinata (Smith), Variamussium personatum (Zieten), Luciniola cf. pumila (Gold- fuss), Astarte sp. indet., Protocardia (Protocardia) striatula (Phillips) P. (P.) sp. indet., Tancredia sp. indet., Eotrapezium sp. indet. Corbula sp. indet., Pholadomya cf. hemicardia Roemer, Goniomya trapezicostata 26 ADVENTDALEN GROUP

(Pusch), G. cf. montanaensis Meek, G. literata (Sowerby), Machomya cf. jurensis (Dunker), Pleuromya cf. jurassi (Goldfuss), P. sp. indet,, Thracia cf. lens (Agassiz), Dactylioceras boreum Kopik, D. sp. nov. Kopik, D. sp. indet., Catacoeloceras cf. polare (Frebold), C. sp., Pseudolioceras cf. com­ pactile gradatum Buckman, P. compactile compactile (Simpson) and P. sp. (form juv.). In this collection the ammonites are clearly Toarcian, indicating at least two zones of the Middle Toarcian (sensu Dean et al. 1961), i.e. the Hildoceras bifrons Zone and the Haugia variabilis Zone, probably also the Grammoceras striatulum Subzone (Kopik 1968) of the basal Upper Toarcian (Grammoceras thouarsense Zone). The pelecypods

CM Fig. 14 Detail of the Brentskardhaugen Bed from E Hyrnefjellet locality Fossiliferous phosphorite pebbles in black; pre-Mesozoic limestones (Hecla Hoek) shaded; coarser quartz grains blank; arenaceous-ferruginous matrix stippled

have usually wider stratigraphic ranges, and two of them, both repre­ sentatives of the genus Goniomya, may indicate a somewhat younger, Middle Jurassic age of some of the phosphorite pebbles. Pcelina (1967, p. 137) found at Treskelen (probably E Hyrnefjellet section) also Leio- ceras sp. aff. opalinum (Reinecke) which is indicative of the Lower Aale- nian (= lowest Bajocian) Leioceras opalinum Zone; this ammonite genus lacks however from our rich collection of the same locality. From Van Keulenfjorden Pcelina (1965b, p. 159) reports also Cardinia cf. concinna (Sowerby), and from another locality in central Spitsbergen (Pcelina 1965a, p.' 138) Myophoria cf. lingonensis {Dumortier), which, in her opinion, resemble Pliensbachian species. From other localities in Spits­ bergen' evidences of Middle and Upper Toarcian, Lower Aalenian and Upper Bajocian fossils are known from phosphorite pebbles (see discus- JANUSFJELLET FORMATION 27

sion by Rozycki 1959; Pcelina 1967; Kopik 1968; Birkenmajer 1972a; Birkenmajer & Pugaczewska 1975); this indicates that the Brentskard­ haugen Bed fauna is a mixed one, derived from several Liassic and Middle Jurassic faunal zones, which occurs as secondary deposit in the Lower Callovian or uppermost Bathonian-Lower Callovian of the Janus- fjellet Formation. Boundaries: Lower boundary sharp (see Ingebrigtsenbukta Member). Upper boundary sharp or transitional (to black shale or clay¬ -ironstone of the Ingebrigtsenbukta Member). Distribution and Thickness: Despite its small thickness, not exceeding 0.5 m in SW Torell Land*, the Brentskardhaugen Bed may be found over the whole area investigated at the contact of the Rhaeto-Liassic De Geerdalen Member (Kapp Toscana Formation) and black shales of the Ingebrigtsenbukta Member (Janusfjellet Formation); it is the basal lithostratigraphic unit of the latter. Its distribution is shown in Fig. 2, the best exposures being at E Hyrnefjellet (thickness 0.2—0.5 m) and S Fonnryggen (thickness 0.1—0.2 m).

Tirolarpasset Member

Name and Subdivision: The Tirolarpasset Member (Series of Rozycki 1959) is the middle member of the Janusf jellet Formation. In the area of Polakkfjellet and farther north, in NW Torell Land, it begins with the Polakkfjellet Bed (see below) which is a marker hori­ zon; there it is separated from the Ingebrigtsenbukta Member by a mi­ nor break in sedimentation (in NW Torell Land). Type Area: Surroundings of Tirolarpasset, NW Torell Land (see Rozycki 1959, PI. V; PI. VI: cross-section VIII; type section not given) Reference Sections: Jurakammen (Rozycki 1959, PI. V; PL VI: cross-section X), NE Polakkf jellet (Fig. 7) and E Hyrnefjellet (Fig. 4). Lit ho logy: The Member consists of black, argillaceous, often bituminous, sometimes arenaceous (silty) shales, usually splitting into very fine plates (paper-shales). Dark-grey or grey-bluish clay-ironstone or sideritic dolomite intercalations 5—20 cm thick, red or yellow if weathered, occur at intervals from a few to a score or so metres in the lower part; some of these contain Buchia and Chondrites. In the upper part of the Member intercalations of black micaceous siltstones with worm trails, 0.5—1 cm thick, and scattered, black, ovoidal or spheroidal clay-ironstone and phosphorite balls 1—3 cm in diameter occur. Boundaries: The separation of the Tirolarpasset Member from

* Pcelina (1967, p. 136) gives the thickness of 1 m for inner Hornsund but this seems to be an inaccurate measurement. 28 ADVENTDALEN GHOUP the Ingebrigtsenbukta Member is easy only in the case of occurrence of the Polakkfjellet Bed at the base of the former member (NE Polakk­ fjellet). In other cases the lower boundary is approximate, transitional, and may be placed where compact, hard, micaceous silty shales of the Ingebrigtsenbukta Member become more soft and contain loose mica fla­ kes and silt particles (e.g. at Spikarhovudet). Another criterion for the top of the Ingebrigtsenbukta Member just below the Tirolarpasset Mem­ ber is the appearance of secondary gypsum (after pyrite) forming needles up to 0.5 mm long, which cover the weathered surface of shales with white films (e.g. at Somovfjella and Spikarhovudet). The upper boundary is transitional to the Ullaberget Member (vide). Fauna and Age: Rozycki (1959) has distinguished within the Tirolarpasset Member of NW Torell Land the following Upper Jurassic and Lower Cretaceous stages: Volgian, Berriasian, Lower Valanginian and Upper Valanginian (uppermost Valanginian exclusively). The Volgian stage was represented in Rozycki's collection by three assemblages. The lower one contained Dorsoplanites spp., i.a. D. cf. pan- deri (d'Orb.) and Buchia pallasi (Keyserl.); the middle contained Zara- iskites (Provirgatites) scythicus Vischn, Perisphinctes cf. polygyratus Pavl. and numerous Buchia; the upper contained Craspedites spp., e.g. C. cf. subtidus Trautsch. and numerous Buchia: B. volgensis (Lah.), B. trigonoides (Lah.) and B. lahuseni (Pavl.). The Berriasian stage was represented by Subcraspedites subpressulus Bogosl. and Buchia sp. The Lower Valanginian stage was represented by Polyptychites spp., i.a. P. perovalis Koen., Buchia okensis (Pavl.), B. subokensis (Pavl.), B. obliqua (Tullb.), B. terebratuloides var. regularis (Pavl.) and B. key- serlingi (Lah.). The Upper Valanginian stage was represented by Buchia sublaevis (Keyserl.) and B. contorta (Pavl.). The fauna collected by the present author from the Tirolarpasset Member of SW Torell Land is poor (see Birkenmajer & Pugaczewska 1975). Lagonibelus (Lagonibelus) submagnificus (Gustomesov) indicating a Lower Volgian age has been found at Spikarhovudet at the base of the Member. Thracia cf. depressa (Sowerby), a species resembling the Upper Oxfordian to Portlandian species T. depressa has been found in the basal Polakkfjellet Bed at NE Polakkfjellet. Buchia terebratuloides (Lahusen), B. cf. contorta (Pavlov) and B. cf. sublaevis (Keyserling) found in loose clay-ironstone concretions in a moraine at Treskelen (below E Hyrnefjellet) certainly came from the upper part of the Tiro­ larpasset Member of the neighbouring mountain^ The above fauna agrees with Rozycki's age boundaries for the Tirolarpasset Member as being Volgian to Valanginian. Distribution and Thickness: The distribution of the Tiro- JANUSFJELLET FORMATION 29 larpasset Member in SW Torell Land is shown in Fig. 2. The main exposures are at NE Polakkfjellet, on both sides of Fonnryggpasset (S Fonnryggen and W Somovaksla), at Spikarhovudet and Somovfjella (610 m peak, western slope), S Kvalfinnen, E Triasnuten, E Urnetoppen and E Hyrnefjellet (Figs. 4—9, 11, 12). The thickness of the Member amounts to ca 27.5 m at NE Polakkfjellet and to 60 m at E Hyrnefjellet.

Polakkfjellet Bed

Earlier investigations: Rozycki (1959, p. 74) found in the Jurakammen section (metres 192.65 to 238.99) between the Lower Kim­ meridgian and Lower Volgian shales a conglomerate containing large fragments of cream-yellow ferruginous sandstone with quartz gravel. He considered it to be a basal conglomerate of the Portlandian trans­ gression and assumed a regression of the sea during the Portlandian, stressing the lack of distinctly Upper Kimmeridgian faunas in the under­ lying shales. Name: After Polakkfjellet (77°15'N—16°06'E) in Torell Land, Spitsbergen (Sheet B 12 Torellbreen, 1:100,000). The Polakkfjellet Bed is a marker horizon at the base of the Tirolarpasset Member (Janus- fjellet Formation). Type Section: NE Polakkfjellet in Torell Land, Spitsbergen (Fig. 7). Reference Section: Jurakammen, NW Torell Land (Sheet B 12 Torellbreen, 1:100,000): NW branch of Waweltoppen (Rozycki 1959, p. 74, metres 192.65 to 238.99, PI. V). Thickness: ca 5 m in type section at Polakkfjellet (Fig. 7); 46.34 m in the Jurakammen section (Rozycki 1959, p. 74, figure not given). Lit ho logy: In the type section — sandstone, medium- or coarse¬ -grained (0.5—2 mm grain diameter, subrounded or rounded), sideritic, intensely yellow or orange-yeUow if weathered, forming a marker horizon well visible at a distance. Sandstone layers 0.3—0.5 m thick, separated with thin black shale. Shaly clay-ironstone concretions 5—10 cm in diameter, orange-yellow or reddish-yellow if weathered, occur m the top parts of particular sandstone layers. Few fine conglomerate intercalations occur in the sandstone, consisting of black, blue or whitish quartz pebbles (subrounded or rounded 0.2—1 cm in diameter) and of blue Permian (?) chert (angular, up to 1.5 cm in diameter). In the reference section at Jurakammen, NW Torell Land, the equi­ valent rock is developed as conglomerate consisting of yellow-weather­ ing ferruginous sandstone with quartz pebbles. The thickness given by Rozycki (op. cit.) is much greater there — about 46.5 m. Boundaries: In the type section the lower boundary is sharp 30 ADVENTDALEN GROUP against black arenaceous or argillaceous shale of the Ingebrigtsenbukta Member; the upper boundary is sharp against black argillaceous shale of the Tirolarpasset Member. Age and Fauna: In the Jurakammen section the conglomerate occurs between the Lower Kimmeridgian and Lower Volgian fossilife- rous shales and probably represents the base of Lower Volgian. The only fossil collected at the type locality is Thracia cf. depressa (Sower­ by). A comparable species is known from the Upper Oxfordian to Port­ landian stages. A Lower Volgian age may be suggested for the Polakk­ fjellet Bed at Polakkfjellet. Distribution: The Polakkfjellet Bed is known in the area between NE Polakkfjellet and Jurakammen (Waweltoppen) in Torell Land. South of Polakkfjellet it disappears, north of Polakkfjellet it grows in thickness.

Ullaberget Member Name: The Ullaberget Member (Series of Rozycki 1959) is the upper member of the Janusf jellet Formation. The name was taken by Rozycki from Ullaberget (520 m) on the northern coast of Van Keulen- fjorden (S Nathorst Land). Type area: Rozycki (1959, p. 76) refers to J. G. Andersson's section of 1898 (fide Nathorst 1910, Fig. 59) of Ullaberget <520 m) on the northern coast of Van Keulenfjorden, but the descriptions given by Rozycki (1959, pp. 76—77) refer to Jurakammen in NW Torell Land. The description of the Ullaberget section by Andersson (in Nathorst 1910, p. 363: lc — "zerfallende dunkle Schiefer... mit fast kugelformigen Kalkknollen...") is too schematic to be recommended for a type section, and there is no mention of sandstone and conglomeratic sandstone in­ tercalations which are typical for the Ullaberget "Series" sensu Ro­ zycki. Reference Section: Jurakammen in NW Torell Land (Ro­ zycki 1959, p. 76, metres 466.47 to 586.1; PI. V; PI. VI: cross-section X); NE Polakkfjellet (Fig. 7) and E Hyrnefjellet (Fig. 4). Lithology: In SW Torell Land — black and brownish-black shales often laminated and with worm trails, intercalated with thi'n siltstone of similar colouration (Polakkfjellet), and thin, fine-grained, grey or greenish, sometimes glauconitic sandstone alternating with arenaceous black or dark-green shales with worm trails (E Hyrne­ fjellet); several intercalations of fine conglomerate 10—20 cm thick with rounded quartz pebbles have been found at E Hyrnefjellet. Gene­ rally, in SW Torell Land, the member lacks clay-ironstone concretions, these being reported from NW Torell Land (Rozycki op. cit.). Age: No determinable fauna has been found in the Ullaberget Member either in NW or SW Torell Land. Rozycki (1959, pp. 76—77) HELVETIAFJELLET FORMATION 31 accepted an uppermost Valanginian age for the Member on comparison with the Festningen section in Isfjorden. However the recent finds of the Upper Hauterivian ammonites Simbirskites and Speetoniceras from the uppermost part of the Janusfjellet Formation (Rurikfjellet Member of central Spitsbergen and Ullaberget Member of Van Keulenfjorden and south Sarkapp Land) by Pcelina (1965a, b, 1967; see also Parker 1967, p. 502) may speak in favour of an uppermost Valanginian to Upper Hauterivian age of the Ullaberget Member in Torell Land. Boundaries: There is a transition from the Ullaberget Member to the underlying Tirolarpasset Member. The lower boundary of the Ullaberget Member is placed by the author at the bottom of a shale- -siltstone or shale-sandstone complex, showing the predominance of psammites. The upper boundary is sharp against the overlying mostly conti­ nental Festningen Sandstone Member (Helvetiafjellet Formation), and seems to be accompanied by a minor break in deposition (E Hyrne­ fjellet, possibly also at NE Polakkfjellet). Distribution and Thickness: The distribution of the Ullaberget Member in SW Torell Land is shown in Figure 2 together with the Tirolarpasset Member, as these two members are difficult to separate in the map due to the general absence of good exposures. The best exposures, where the boundary line was drawn between the di­ scussed members, are at NE Polakkfjellet (Fig. 7) and E Hyrnefjellet {Fig. 4). The thickness of the Ullaberget Member is 65 m at NE Polakk­ fjellet but decreases to 10—20 m at E Hyrnefjellet.

Helvetiafjellet Formation

Name: The name Helvetiafjellet Formation (Parker 1967, type section at Helvetiafjellet in Adventdalen) is here used for the "conti­ nental series" of Rozycki (1959). The name has been introduced by H. Major into his geological map of Adventdalen, 1:100,000 printed by Norsk Polarinstitutt in 1964 but not yet published. Subdivision and Lithology: In central Spitsbergen the Helvetiafjellet Formation includes the lower Festningen Sandstone Mem­ ber (Festungssandstein of A. Hoel, A. K. Orvin and H. Frebold) and the upper Glitrefjellet Member (Parker 1967). Rozycki (1959, pp. 77— 79, Pis. V, VI) subdivided his "continental series" of Lower Cretaceous age in NW Torell Land into the "continental series, lower part" (equi­ valent to the Festningen Sandstone Member) and "continental series, upper part", the latter differing from the "shore sandstone" of Ha- german (1925). In SW Torell Land the lower member of the Helvetiafjellet For- 32 ADVENTDALEN GROUP

mation (i.e. 'the Festningen Sandstone Member = "continental series, lower part" of Rozycki 1959) consists predominantly of light-coloured sandstones and quartzitic sandstones, often with quartz conglomerate intercalations. There is only one band of sandstone 50—60 m thick (with black shale intercalations in the upper part) at E Hyrnefjellet, but three bands of such sandstones from ca 5 to ca 20 m thick, sepa­ rated with shale-sandstone complexes ca 5—15 m thick (altogether about 50 m thick) appear at NE Polakkfjellet. Plant imprints, coaly shales and plant rootlets in sandstones may often be found in the member. The upper member of the Helvetiafjellet Formation in SW Torell Land consists of alternating shale and sandstone layers, altogether ca 50 m thick (NE Polakkfjellet), showing no resemblance to the "shore sandstone" of Hagerman (1925) from Kjellstromdalen in Van Mijen- fjorden. Parker's (1967) name the "Glitrefjellet Member" seems in­ adequate, as his Helvetiaf jellet section (op. cit, Fig. 3) shows the presence of 3 thick bands of massive sandstones of Festningen sandstone-type, which differ little from the Festningen sandstone at the base of for­ mation, and should be included into the Festningen Sandstone Member. Detailed observations on the relation of the Helvetiaf jellet For­ mation to the overlying Carolinefjellet Formation, including detailed subdivision of the former, have been made by the author in central Torell Land (between Polakkfjellet, Bendefjellet and Cholmfjellet) during his 1962 and 1966 field investigations sponsored by Norsk Polar- institutt, and will be published separately in the issues of this Insti­ tute. Until then the name "upper continental series" sensu Rozycki (1959) is retained in the present paper for the upper member of the Helvetiafjellet Formation. Age: Rozycki (1959, p. 78) found at the bottom of his "continental series, lower part" at Jurakammen some pelecypods, "probably Inoce- ramus (I. spitzbergensis Stolley ?)" which in his opinion could indicate the beginning of the Hauterivian, and he accepted a Hauterivian to Barremian age of his "continental series". Inoceramus shells have been found by the present author at Bendefjellet (central Torell Land) in the beds directly underlying the Festningen Sandstone Member, and com­ parable to the Ullaberget Member. The presently accepted age for the Helvetiafjellet Formation of central Spitsbergen is Barremian (Parker 1967; Harland 1969) as the upper part of the Janusf jellet Formation underlying the Festningen Sandstone Member yielded the Upper Hauter­ ivian ammonites (Pcelina 1965a, b — see above). A Barremian age is therefore suggested for the Helvetiafjellet Formation in SW Torell Land. Boundaries: The lower boundary of the Helvetiafjellet For­ mation in SW Torell Land is sharp against the Ullaberget Member (Ja­ nusf jellet Formation); a break in deposition between these two for- HELVETIAFJELLET FORMATION 33 mations seems there probable. The upper boundary (with the Caroline­ fjellet Formation) has not been investigated in detail at the only loca­ lity at NE Polakkfjellet: there seems to be a transition to the lowest shale complex of the Carolinef jellet Formation. Distribution and Thickness: The distribution of the Helvetiafjellet Formation in SW Torell Land is shown in Fig. 2. The main exposures are at NE Polakkfjellet (Fig. 7) and E Hyrnefjellet (Fig. 4); poor, strongly weathered Festningen Sandstone exposures are at Krygernuten and E Tvitoppen. The thickness of the Formation amounts to ca 100 m at NE Polakk­ fjellet (ca 50 m for the Festningen Sandstone Member and ca 50 m for the "upper continental series") and to 50—60 m at Hyrnefjellet (Festn­ ingen Sandstone Member only).

Festningen Sandstone Member

Name: The Festningen Sandstone Member (Parker 1967; Festungs- sandstein of A. Hoel, A. K. Orvin and H. Frebold; Festning Sandstone of Orvin 1940; type section at Festningsodden in Isfjorden; "continental series, lower part" or Festningen Sandstone of Rozycki 1959) is the lower member of the Helvetiafjellet Formation in SW Torell Land. Subdivision and Lithology: At E Hyrnefjellet the Mem­ ber consists of white, light-grey or light-greenish quartzite and quart­ zitic sandstone with frequent quartz conglomerate intercalations. Bed­ ding is poorly developed in the lower part of the Member (massive sandstone and quartzite) but is better visible in the upper part of the Member where sandstones become grey or greenish and are intercalated with black arenaceous shale. The Member forms here only one band 50—60 m thick. At NE Polakkfjellet the sandstone splits into three thick bands of the Festningen Sandstone-type separated by shale-sandstone complexes. The lower sandstone band is ca 20 m thick, the middle and the upper ones are about 5 m thick each, the intervening shale-sandstone com­ plexes are ca 5 and ca 15 m thick for the lower and upper ones respec­ tively. Plant imprints, coaly films and coal-shales and plant rootlets may often be found, especially at the bottom of the lower massive sand­ stone band and in the shale-sandstone complexes. Cross-bedding is characteristic and quartz conglomerate intercalations are frequent in the massive sandstone bands. Age: No fossils have been determined from the Member in quest­ ion in the area studied. A Barremian age is accepted on comparison with central Spitsbergen (see the preceding chapter: Helvetiafjellet Formation). Boundaries: The lower boundary of the massive Festningen 34 ADVENTDALEN GROUP

Sandstone at E Hyrnefjellet is sharp and shows no transition to the underlying Ullaberget Member (Janusfjellet Formation); a break in de­ position is here suggested. At NE Polakkfjellet the contact of the Fest­ ningen Sandstone Member with the Ullaberget Member was not ex­ posed. There, the bottom part of the lower massive sandstone band (lower part of the cliff — see Figs. 6, 7) is developed as irregularly bedded light-green or greyish fine-grained quartzitic sandstone with plant rootlets and plant detritus (coaly films), and with discoidal clay¬ -ironstone concretions. From a corresponding part of the Festningen Sandstone Member at Jurakammen in NW Torell Land Rozycki (1959, p. 78) reported pelecypods "probably Inoceramus (I. spitzbergensis Stol- ley ?)". The upper boundary of the Festningen Sandstone Member at NE Polakkfjellet has not been investigated in detail: there seems to be a transition to the "upper continental series" member. Distribution and Thickness: The distribution of the Festningen Sandstone Member in SW Torell Land is shown in Fig. 2. The main exposures are at NE Polakkfjellet (Figs. 6, 7), E Tvitoppen, Krygernuten and E Hyrnefjellet (Fig. 4). The thickness of the Member amounts to ca 50 m at NE Polakkfjellet and to 50—60 m at E Hyrne­ fjellet.

"Upper ContinentalSeries"

Name: The "upper continental series" is a provisional name for the upper member of the Helvetiafjellet Formation of SW Torell Land, corresponding to the "continental series, upper part" of Rozycki (1959) — see discussion in the preceding chapter (Helvetiafjellet Formation). Lithology: The member in question occurs only at NE Polakk­ fjellet where it consists of alternating light-grey or whitish plant-bear­ ing sandstones and black shales. No detailed observations have been made. Age: No fossils have been determined from the "upper continental series" of SW Torell Land. A Barremian age is suggested on comparison with Rozycki's (1959) "continental series, upper part" of NW Torell Land. Boundaries: The boundaries of the "upper continental series" have not been investigated in detail There seems to be a transition to the underlying Festningen Sandstone Member. Distribution and Thickness: The only occurrence of the "upper continental series" in the area studied is at NE Polakkfjellet (Figs. 2, 7), where the member is ca 50 m thick. CAROLINEFJELLET FORMATION 35

Carolinef j ellet Formation

Name: The Carolinef jellet Formation (name proposed by H. Major in connection with his geological map 1:100,000 Adventdalen, printed in 1964 by Norsk Polarinstitutt but not yet published; definition- given by Parker 1967; type locality at Langstakken in Van Mijenfjorden; Dentalienschichten of Nathorst 1910 = Ditrupa shale series of Rozycki 1959) is the youngest Lower Cretaceous lithostratigraphic unit in SW Torell Land. Lithology and Subdivision: At NE Polakkfjellet, the only exposure of the Carolinef jellet Formation in the area studied, the For­ mation consists of black arenaceous shales, which may be correlated with the shaly complex at the bottom of the Dalkjegla Member (the latter represented mostly by sandstones) of Parker (1967, Fig. 4 = lower lamina sandstone of Hagerman 1925). The equivalents to the Dalkjegla Member (Lower Aptian — see Nagy 1970) are present to the East of Polakkfjellet, at Blaklettane and Isskiltoppane. Age: A Lower Aptian age is suggested for the black shale at th<» bottom of the Carolinefjellet Formation at NE Polakkfjellet. Boundaries: There is either transition or break in deposition at the contact of the "upper continental series" and the Carolinefjellet Formation. The upper boundary of the Formation is exposed to the east of the area studied. There a hiatus covering Upper Albian to Mae- strichtian time span and a slight angular unconformity at the base of the overlying Tertiary beds (Firkanten Formation, Lower Paleocene) are recognized (see Birkenmajer 1972c). Distribution and Thickness: The only occurrence of th^ Carolinefjellet Formation in SW Torell Land is at NE Polakkfjellet (Fig. 6) where the thickness of its bottom shale amounts to ca 30 m..

DISCUSSION

Triassic-Jurassic Boundary in Torell Land

The Triassic-Jurassic boundary in Torell Land was studied by Ro­ zycki (1959) and the present author (1972a and the present paper). The main exposures investigated were illustrated from Tilasberget (Birken­ majer 1972a, Figs. 3, 4) in NW Torell Land, and from S Fonnryggen (Fig. 5) and E Hyrnefjellet (Figs. 4, 13) in SW Torell Land. The bottom unit of the marine Jurassic is there represented by the Brentskard­ haugen Bed (Ingebrigtsenbukta Member of the Janusfjellet Formation) the age of which was determined as Lower Callovian or uppermost 36 DISCUSSION

Bathonian. The Brentskardhaugen Bed rests directly upon the Rhaeto- -Liassic (resp. Rhaetian to Hettangian) De Geerdalen Member (Kapp Toscana Formation) and contains reworked material from the latter and, sometimes, also from the pre-Mesozoic formations (cf. Rozycki 1959, p. 68; Birkenmajer 1972a, p. 119). A characteristic feature of the Brentskardhaugen Bed is the presence of fossiliferous phosphorite peb­ bles with Middle and Upper Toarcian fossils, possibly also Bajocian fossils (Aalenian included). It is assumed that the area slightly sub­ sided during the Liassic and was flooded by a shallow sea during the Toarcian to Bajocian time which had formed thin phosphorite layers rich in fossils (condensed sedimentation). A new ingression of sea, con­ nected with world-wide transgression at the boundary of Bathonian and Callovian had crushed these phosphorite layers and the top part of the De Geerdalen Member elastics, the reworked material being in­ corporated in the conglomerate band at the base of the Buchia shale sequence of the Janusfjellet Formation. There is no angular unconformity to be observed in the exposures at the contact of the Brentskardhaugen Bed and the underlying De Geerdalen Member. The sedimentary hiatus between these two litho- stratigraphic units (Hettangian-Bathonian) could reflect synorogenic Meso-Cimmerian movements (cf. Birkenmajer 1972a, p. 119). In SW

Torell Land no deposits comparable with the Wilhelm0ya Formation (mixed marine-deltaic deposit) of supposedly Liassic, resp. Lower Liassic to Bathonian age {see Worsley 1973) have been found. In southern Serkapp Land the equivalents to the Brentskardhaugen Bed of Torell Land seem to be much thicker. Pcelina (1967, p. 137) described a 10 m thick sequence of elastics with phosphorite pebbles whose fauna is comparable with the Toarcian fauna of the analogous pebbles in the Brentskardhaugen Bed of Torell Land.

Upper Kimmeridgian Sedimentary Break in Torell Land

Rozycki (1959, p. 74) was the first to recognize a break in the mo­ notonous sequence of the Buchia shales (Janusfjellet Formation) between the Lower Kimmeridgian and Lower Volgian (= ± Lower Tithonian), corresponding to the Upper Kimmeridgian. The break is marked in the absence of Upper Kimmeridgian ammonite faunas and in the presence of a conglomerate band ca 46 m thick, which he considered to be the basal conglomerate of the Portlandian transgression. This break corres­ ponds to an early stage of Neocimmerian synorogenic movements and may be compared with the Deister phase. It seems that the uplift of the sea bottom which caused the Upper JURASSIC-CRETACEOUS BOUNDARY IN TORELL LAND 37

Kimmeridgian sedimentary/stratigraphic break was strongest on the north where a thick conglomerate of the Polakkfjellet Bed had develop­ ed at Jurakammen (NW Torell Land), but decreased southwards, as already at NE Polakkfjellet the equivalent sandstone (with conglome­ rate intercalations) is only ca 5 m thick, and finally died out still farther south (between Somovfjella and Hornsund) where there is no break in the sedimentary sequence of the Ingebrigtsenbukta Member and the Tirolarpasset Member.

Jurassic-Cretaceous Boundary in Torell Land

In central Spitsbergen folding and faulting took place between the Agardhfjellet and the Rurikfjellet deposition (Parker 1966, 1967). The break between these two members corresponds to the boundary of Jurassic and Cretaceous (?Upper Tithonian and Berriasian), i.e. probably to the Hils phase of Neocimmerian movements. Parker also demonstrated that at least part of the dolerite formation of Spitsbergen was intruded during this interval. No break in sedimentation at the Jurassic-Cretaceous boundary was found in Torell Land. As follows from the observations on lithological development and faunal succession in NW Torell Land by Rozycki (1959) and lithological succession in SW Torell Land by the present writer, there was a continuous sedimentation during the Volgian (Tithonian) to Lower Valanginian time span represented by the Tirolarpasset Mem­ ber {JanusfjeUet Formation). It is of interest to note, however, that a dolerite sill found at Jurakammen by Rozycki (1959, Fig. 13, PL V, PL VI, cross-section X) cuts through the Ingebrigtsenbukta Member and the underlying Rhaetian and older rocks, but not through the Tirolar­ passet Member; this could be interpreted in favour of Parker's dating the dolerite effusives in central Spitsbergen.

Facies and Thickness Variation

JanusfjeUet Formation

The facies of the JanusfjeUet Formation are considerably stable over the area investigated. The Brentskardhaugen Bed is present eve­ rywhere at the base of the Formation and its thickness is stable within the limits of 10—50 cm. The succeeding, predominantly shaly complex of the Ingebrigtsenbukta, Tirolarpasset and Ullaberget Members vary little between the exposures, the only major difference being the appearance of the Polakkfjellet Bed, a sandstone marker horizon at the base of the Tirolarpasset Member present only at Polakkfjellet and disappearing farther south. 38 DISCUSSION

The thickness of the Janusfjellet Formation generally increases from west (south-west) to east (north-east) from 180—190 m at E Hyrnefjellet to over 240 m at NE Polakkfjellet (Tab. 2), i.e. toward the axial part of the central depression of Spitsbergen which lies east of SW Torell Land. This trend is also marked in the thicknesses of the Ingebrigtsen­ bukta Member (110 m at E Hyrnefjellet and 150 m at NE Polakkfjellet) and of the Ullaberget Member (10—20 m at E Hyrnefjellet and 65 m at NE Polakkfjellet), but not in the thickness of the Tirolarpasset Member which is greatest at E Hyrnefjellet (60 m) and smallest at NE Polakk­ fjellet (27.5 m). In the latter case the reduction in thickness of the Tiro­ larpasset Member sediments could be connected with positive movements of the sea bottom and/or with a possible non-sequence at the base of the Polakkfjellet Bed.

Table 2 Thicknesses of the Janusfjellet Formation in ToreU Land (in metres)

NW Torell Land SW Torell Land (this paper) (after Rozycki 1959)

Reinodden, Jurakam- Member Somovfjella Ingebrigt­ E Hyr­ S Fonn­ NE Polakk­ men, Tiro­ & Somov- senbukta, nefjellet ryggen fjellet larpasset aksla Tilasberget area area

10—20 65 Ullaberget (mea­ — 150 119.5 sured) (measured) (calculated) (measured)

60 over 40 Tirolar­ over 60 (mea­ (calcula­ 27.5 400 274 passet sured) ted) (calculated) (measured) (calculated) (measured)

110 60 Ingebrigt­ 40 (mea­ (calcula­ 150 230—245 190—200 senbukta (calculated) (calculated) sured) ted) (measured) (measured)

Total 180-190 — 242.5 780—795 583.5—593.5

A marked decrease in thickness of the Ingebrigtsenbukta Member at S Fonnryggen, Somovfjella and Somovaksla down to 60—40 m, in the zone intermediate between the zones represented by the outcrops at E Hyrnefjellet (western marginal zone) and NE Polakkfjellet (axial zone of the basin), may be a local phenomenon; no comparable data are avail­ able from the middle and upper members of the Janusfjellet Formation of this area (Fig. 15). Much greater thicknesses of the Janusf jellet Formation as a whole and of its particular members in NW Torell Land appear from the data FACIES AND THICKNESS VARIATION 39

NE Polakkfjellet

E Hyrnefjellet

shale siltstone r^sj sandstone conglomerate

| I clay-ironstone, ——— sideritic bonebed 1 1 limestone,etc. Fig. 15 Comparison of lithological development and thicknesses of the Adventdalen Group in SW Torell Land

presented by Rozycki (1959: direct measurements given in the text, and calculations on his cross-sections, PI. VI) — see Tab. 2. The greatest thicknesses are distributed along the western part of NW Torell Land, to the west of the Pilsudskifjella anticline (Reinodden, Ingebrigtsenbukta and Tilasberget): 780—795 m, and a marked decrease in thickness is visible along the eastern slope of this anticline (Jurakammen, Tirolar­ passet): between ca 584 and ca 594 m. This may indicate that the axial zone of the sedimentary trough of the JanusfjeUet Formation lay in NW Torell Land to the west of the PilsudskifjeUa anticline. 40 REFERENCES — LITERATURA

The zone of maximum thicknesses of the Janusf jellet Formation, cor­ responding to the axial zone of the Callovian to Hauterivian marine basin, continues north of Van Keulenfjorden at Midterhuken (W Nathorst Land) and Festningsodden (W Isfjorden). At Midterhuken the sequence is 615 m thick (the basal Brentskardhaugen Bed included) and 625 m at Festningsodden (the basal Brentskardhaugen Bed missing). In the eastern part of the central depression of Spitsbergen which represented an eastern marginal zone of the Callovian-Hauterivian marine basin the thickness of the Janusfjellet Formation decreases to 490 m at Sassen- fjorden and to 375 m still farther east, in the area between Van Mijen- fjorden and Storfjorden (see data in Pavlov & Sokolov 1965 pp 46 47- Pcelina 1965a, p. 129).

Helvetiafjellet Formation

There is a marked change in composition of the Festningen Sand­ stone Member between its two extreme exposures at E Hyrnefjellet (western marginal zone) and NE Polakkfjellet (axial zone of the basin). At the former site, only one band of massive sandstone 50—60 m thick is present, while at the latter one it splits into three bands, successively about 20,5 and 5 m thick, separated by two shale-sandstone complexes, about 5 and 15 m thick (altogether about 50 m thick). Generally, the Festningen Sandstone Member can be regarded as a deltaic fan deposit, the exposures at Hyrnefjellet being formed closer to the source of elastics and those at Polakkfjellet — in a distal part of the alluvial fan.

REFERENCES — LITERATURA

ARKELL W. J, 1956. Jurassic geology of the world. Oliver & Boyd. Edinburgh¬ -London. BIRKENMAJER K, 1959. Report on the geological investigations of the Hornsund area, Vestspitsbergen, in 1958, Pt. II: The post-Caledonian succession. Bull. Acad. Polon. Sci., Sir. sci. chim., owl., geogr., 7 (3): 191—196. Varsovie. — 1960a. Course of the geological investigations of the Hornsund area, Vest- Spitsbergen, in 1957—1958. Studia Geol. Polon., 4: 7—35. Warszawa. — 1960b. Geological sketch of the Hornsund area (Supplement to the Guide for Excursion A 16 "Aspects of the Geology of Svalbard"). Int. Geol. Congr. 21 Sess. Norden (1960), 12 pp. Oslo. — 1964. Devonian, Carboniferous and Permian formations of Hornsund, Vest- Spitsbergen. Studia Geol. Polon., 11: 47—123. Warszawa. — 1972a. Megaripples and phosphorite pebbles in the Rhaeto-Liassic beds south of Van Keulenfjorden, Spitsbergen. Norsk Polarinstitutt Arbok 1970: 117— 127. Oslo. — 1972b. Alpine fold belt of Spitsbergen. Int. Geol. Congr. 24 Sess. Montreal, Sect. 3, pp. 282—292. Montreal. REFERENCES — LITERATURA 41

— 1972c. Tertiary history of Spitsbergen and continental drift. Acta Geol. Pol., 22 (2): 193—218. Warszawa. BIRKENMAJER K. & H. PUGACZEWSKA, 1975. Jurassic and Lower Cretaceous marine fauna of SW Torell Land, Spitsbergen. Studia Geol. Polon., 44. War­ szawa. BODYLEVSKIJ V. I. (BODYLEVSKY, V.), 1929. Faune du Dogger inferieur (?) provenant de Mohn Bay, sur la cote orientale du Spitzberg. Dokl. Akad. Nauk SSSR, 10: 256—258. Leningrad. BUCHAN S. H., A. CHALLINOR, W. B. HARLAND & J. R. PARKER, 1965. The Triassic stratigraphy of Svalbard. Norsk Polarinstitutt Skrifter Nr 135: 1—93. Oslo. DEAN W. T., D. T. DONOVAN & M. K. HOWARTH, 1961. The Liassic ammonite zones and subzones of the North-west European province. Bull. Brit. Mus. (Nat. Hist.), Geology, 4 (10): 437—505. London. FLOOD B., J. NAGY & T. S. WINSNES, 1971. Geological map of Svalbard, Sheet 1 G Spitsbergen, southern part. Norsk Polarinstitutt. Oslo. FREBOLD H., 1929a. Oberer Lias und unteres Callovien in Spitzbergen. Skr. Svalb. og Ish. Nr 20: 1—24. Oslo. — 1929b. Die Schichtenfolge des Jura und der Unterkreide an der Ostkuste siidwest-Spitzbergens. Abh. Naturw. Ver. Hamburg, 21 (3/4): 253—292. Ham­ burg. — 1930. Verbreitung und Ausbildung des Mesozoikums in Spitzbergen. Skr. Svalb. og Ish. Nr 31: 1—126. Oslo. — 1951. Geologie des Barentsschelfes. Abh. Deut. Akad. Wiss. Berl. (Kl. Math, u. Naturw.), 5: 1—151. Berlin. HAGERMAN T. H., 1925. Results of the Swedish expedition to Spitzbergen, 1924. II. Stratigraphic and structural investigations within south-western Spitz­ bergen. Geogr. Ann., 7: 195—221. Stockholm. HARLAND W. B., 1969. Contribution of Spitsbergen to understanding of tectonic evolution of North Atlantic region. In: North Atlantic — Geology and Con­ tinental Drift (a symposium, M. Kay ed.). Am. Ass. Petrol. Geol., Mem., 12: 817—851. Tulsa. KOPIK J., 1968. Remarks on some Toarcian ammonites from the Hornsund area, Vestspitsbergen. Studia Geol. Polon., 21: 33—51. Warszawa. NAGY J., 1970. Ammonite faunas and stratigraphy of Lower Cretaceous (Albian) rocks in southern Spitsbergen. Norsk Polarinstitutt Skrifter Nr 152: 1—58. Oslo. NATHORST A. G., 1910. Beitrage zur Geologie der Baren Insel, Spitzfoergens und des Kbnig-Karl-Landes. Bull. Geol. Inst. Uppsala, 10: 261—415. Uppsala. ORVIN A. K., 1940. Outline of the geological history of Spitsbergen. Skr. Svalb. og Ish. Nr 78: 1—57. Oslo. PARKER J. R., 1966. Folding, faulting and dolerite intrusions in the Mesozoic rocks of the fault zone of central Spitsbergen. Norsk Polarinstitutt Arbok 1964: 47—55. Oslo. — 1967. The Jurassic and Cretaceous sequence in Spitsbergen. GeoZ. Mag., 104: 487—505. Hertford. PAVLOV A. V. & V. N. SOKOLOV, 1965. K istorii formirovanija i razvitija za- padno-spicbergenskogo progiba. Mat. po Geol. Spicbergena (V. N. Sokolov red.), pp. 45—54. NauC.-Issled. Inst. Geol. Arktiki. Leningrad. PCELINA T. M., 1965a. Stratigrafija i osobennosti vescestvennogo sostava mezo- zojskich otlozenij centralnoj casti Zapadnogo Spicbergena. Mat. po Geol. 42 REFERENCES — LITERATURA

Spicbergena (V. Is.. Sokolov red.), pp. 127—148. Nauc.-Issled. Inst. Geol. Arktiki. Leningrad. — 1965b. Mezozojskie otlozenija rajona Van-Kejlen-Fjorda (Zapadnij Spicber- gen). Mot. po Geol. Spicbergena (V. N. Sokolov red.), pp. 149—173. Nauc.- Issled. Inst. Geol. Arktiki. Leningrad. — 1967. Stratigrafija i nekotorye osobennosti vescestvennogo sostava mezozoj- skich otlozenij juznych i vostofinych rajonov Zapadnogo Spicbergena. Mat. po Geol. Spicbergena (V. N. Sokolov red.), pp. 121—158. Nauc.-Issled. Inst. Geol. Arktiki. Leningrad. ROZYCKI, S. Z, 1936. Expedition polonaise a Spitsbergen, 1934. Przegl. Geogr., 15: 119—137. Warszawa. — 1959. Geology of the north-western part of Torell Land, Vestspitsbergen. Studia Geol. Polon., 2: 1—96. Warszawa. WORSLEY D. L, 1973. The Wilhelmeya Formation — a new lithostratigraphic unit for the Mesozoic of Eastern Svalbard. Norsk Polarinstitutt Arbok 1971: 7—16. Oslo. Krzysztof Birkenmajer

JURAJSKIE I DOLNOKREDOWE FORMACJE OSADOWE SW CZESCI ZIEMI TORELLA NA SPITSBERGENIE

Streszczenie

W artykule autor opisuje nastepstwo, rozprzestrzenienie oraz charakter. litolo- giczno-facjalny i faunistyczny jednostek litostratygraficznych wieku jurajskiego i dolnokredowego (osady morskie i ladowe) w poludniowo-zachodniej czesci Ziemi Torella na Spitsbergenie. Wyrozniono tarn nastepujace podstawowe formalne jed- nostki litostratygraficzne: formacje z JanusfjeUet (kelowej-hoteryw), formacje. z Helvetiafjellet (barrem) i nizsza. czesc formacji z Carolinefjellet (apt). Formacja z JanusfjeUet zostala podzielona wedlug Rozyckiego (1959) na trzy ogniwa (od dolu ku gorze): ogniwo z Ingebrigtsenbukta (kelowej-kimeryd), ogniwo z Tirolarpasset (wolg-walanzyn) i ogniwo z Ullaberget (walanzyn-hoteryw). W spa_gu ogniwa z Tirolarpasset wyrozniono nowy litostratygraficzny poziom przewodni — warstw

Zaklad Nauk Geologicznych Polskiej Akademii Nauk Pracownia Geologii Mlodych Struktur 31-002 Krakow, Senacka 3