Marine-lacustrine stratigraphy of raised coastal basins ... · (Ill) Lacustrine (gyttjajplant detritus), and (IV) Mixed (gyttja, mud and sand/gravel). Laminated transitional facies

Marine-lacustrine stratigraphy of raised coastal basins and postglacial sea-level change at Lyngen and Vanna, Troms, northern Norway

GEOFFREY D. CORNER & ERIK HAUGANE

Corner, G. D. & Haugane, E.: Marine-lacustrine stratigraphy of raised coastal basins and postglacial sea-level change at Lyngen

and Vanna, Troms, northem Norway. Norsk Geologisk Tidsskrift, Vol. 73, pp. 175-197. Oslo 1993. ISSN 0029-196X.

Lithostratigraphic and diatom analysis of core samples from 10 raised lake basins from an inner (Lyngen) and outer (Vanna)

coastal area of Troms, northem Norway, was made in order to reconstruct relative sea-level change during the Holocene and Late

Weichselian. A variety of facies types and facies sequences, controlled primarily by sea-level change and inftuenced also by climatic

factors, is recognized. Main facies types are: (I) Marine (mud and sand), (Il) Transitional (laminated gyttja or gyttja and silt),

(Ill) Lacustrine (gyttjajplant detritus), and (IV) Mixed (gyttja, mud and sand/gravel). Laminated transitional facies li, in nearly all

cases, is interpreted as having formed under meromictic limnic conditions following basin isolation from the sea, whereas

heterolithic mixed facies IV forms usually under littoral inftuence during ingression. Sea-level displacement curves are constructed

for Lyngen and Vanna based on radiocarbon-dated isolation and ingression contacts, elevation/inferred-age data for prominent

raised shorelines, and other data,. The evidence suggests that the Tapes transgression at Lyngen had a minimum amplitude of

2-3 m and peaked at ca. 7000 BP. Average rates of pre-Tapes (before 8500 BP) and post-Tapes (after 6000 BP) regression are

approximately 15 and 3 mm/year respectively at Lyngen, and lO and 1.5 mm/year respectively at Vanna.

Geoffrey D. Corner, Department of Geology, IBG, University of Tromsø, N-9037 Tromsø, Norway; Erik Haugane, University of Tromsø - Present address: Nopec a.s., Pirsenteret, N-7005 Trondheim, Norway.

The pattern of postglacial relative sea-levet change in northern Norway is known in broad outline based on a number of constructed shoreline diagrams (Marthinussen 1960, 1974; Anderson 1968, 1975; Møller & Sollid 1972; Sollid et al. 1973; Møller 1985, 1987) and sea-levet displacement curves (Marthinussen 1962; Donner et al. 1977; Corner 1980; Hald & Vorren 1983; Møller 1984, 1986, 1987; Vorren & Moe 1986). However, for large areas, no direct dating evidence exists as to the age of former postglacial sea-leve1s. In Troms, only two displacement curves før the Holocene have been constructed (Corner 1980; Hald & Vorren 1983) and both draw heavily on regionally interpolated ages rather than sitespecific data. Among major questions that remain to be answered are the rate of postglacial relative uplift prior to the Holocene, and the precise timing and geographical (landward) extent of the Tapes transgression.

In an attempt to obtain more precise data on shoreline displacement in the region, two areas in Troms were investigated using the method of identifying and dating isolation and ingression contacts in sediment cores retrieved from raised coastal takes (Hafsten 1960; Sutherland 1983; Kjemperud 1986). The method, used successfully in southern Norway (Stabell 1980; Kjemperud 198 1, 1986; Hafsten 1983; Lie et al. 1983; Krzywinski & Stabell 1984; Kaland 1984; Anundsen 1985; Svendsen & Mangerud 1987, 1990) and other glacio-isostatically raised areas, has not previously been applied systematically in northern Norway. Part of the study was there-

fore concerned with establishing a comparative basis for evaluating use of the method in this region.

Two main areas were chosen for study (Fig. 1): (l) Lenangsbotn-Jægervatn on the Lyngen peninsula (Fig. 2A; referred to below as Lyngen) which has an innerintermediate position on the coast relative to the centre of postglacial uplift; ( 2) the istand of Vanna, which occupies as an outer coastal position. Because of the paucity of suitable, accessible basins in the region, two subareas on Vanna (Skipsfjorddal and Vannareid, Figs. 2B, 2C), lying 8 km apart, were studied.

This paper presents the main stratigraphic results of the study and derived sea-levet displacement curves for the two areas. More general aspects relating to sedimentary facies, identification and interpretation of the isolation contact, and a model for basin isolation, will be treated in a separate paper (Haugane & Corner in prep.).

Regional setting and shorelines

The coastal area around Vanna was probably deglaciated between 13 000 and 15 000 BP, whereas Lyngen at Lenangsbotn was probably deglaciated shortly before the Skarpnes readvance of 12 000-12 500 BP (Andersen 1968, 1979; Vorren & Elvsborg 1979). Local glaciers existed nearby in both areas during the Late Weichselian, and exist today immediately east of the investigated area in Lyngen.

176 G. D. Corner & E. Haugane

Fig. /. Map of north Troms showing the location of the three investigated

subareas on Vanna and in Lyngen (cf. Fig. 2) and isobases for the Main

(Younger Dryas) shoreline ( continuous and dashed lines; after Marthinussen

1960; Andersen 1968) and the Tapes transgression maximum shoreline (dotted

lines; Møller 1967). Isobases for the Main shoreline refer to shore features formed

near high· tide leve l (ca. 1.5 m a. mean s.l.) whereas those for the Tapes shoreline

refer to the contemporaneous mean sea leve! (Møller 1989). The isobases should

nevertheless be considered approx.imate (±1-2 m) at this scale; in Lyngen the

plotted Tapes isobase is slightly too low ( see text).

The marine limit, assumed to have formed at the time of deglaciation, Iies approximately 57 m, 47 m and 40 m a.s.l. , at Lyngen, Skipsfjorddal and Vannareid, respectively. In all three areas, the 'Main' (Younger Dryas) and 'Tapes' (Middle Holocene) raised shorelines are distinct and form important morphostratigraphic markers (cf. Marthinussen 1960; Andersen 1968; Møller 1985, 1987, 1989). The Tapes shoreline, as referred to here, is the shoreline formed during the Tapes transgression maximum (TIM). At Lyngen, where detailed studies were carried out dose to the TIM level, the Tapes shoreline consists of either a terrace or notch at 20.5-21.5 m a.s.l., or a gravelly beach ridge at ca. 22.5 m a.s.l. These shoreline features Iie ca. 0.5 m higher in the slightly more exposed northern part of the area. The general elevation of this shoreline at 21-22 m a.s.l. is estimated to represent a contemporaneous mean sea-level of 20-20.5 m a.s.l. At Skipsfjorddal, the Tapes shoreline forms a broad, sandy beach-ridge complex (Fig. 3C) reaching ca. 12 m a.s.l.

The present, normal limit of wave action in the area, as indicated by the upper limit of drifted seaweed, Iies ca. 1.3 and 1.8 m a. mean s.l. at Lyngen and Vanna, respectively. Mean spring high-tide level is 1.25 m a. mean s.l.

Vegetation at Lyngen consists of bog, heath and scattered birch and pine stands. Bog is prevalent in the Vanna area which Iies dose to the tree line. The bedrock consists predominantly of schist and gabbro at Lyngen, and gneiss at Vanna.

•••••••• Tapes terrace/ridge ·-·-· Main shoreline ---- Marginal/hummocky

moraine limit

Skips fjord

(C)

NORSK GEOLOGISK TIDSSKRIFT 73 (1993)

Fig. 2. Maps showing topography, basin Iocation, distinct raised shorelines and

other features in the investigated areas: (A) Lenangsbotn-Jægervatn area, Lyn·

gen, sbowing basins L2-L5 which are situated on hummocky marginal moraine,

and coring stations (crosses) in basin LI (Lake Jægervatn); (B) Skipsfjorddal,

Vanna, sbowing basins SI-S4 and radiocarbon-dated palaeosol site (x) in sand

dune/blowout area (vertical shading); (C) Vannareid, Vanna, showing basin VI

(Lake Litlevatn). Bog shown by horizontal shading. Altitude in metres.


Figs. Ja and Jb.

Marine-lacustrine stratigraphy at Lyngen and Vanna, Troms 177

178 G. D. Corner & E. Haugane NORSK GEOLOGISK TIDSSKRIFT 73 (1993)

Fig. 3. Views of the investigated areas at Lyngen and Vanna: (A) Lyngen alps viewed towards the southeast, showing ice-covered Lake Jægervatn (basin LI) and

adjacent Late Weichselian local moraines; (B) basin L5 at Lenangsbotn, Lyngen, showing morainic substrate with partial peat cover (foreground); (C) Skipsfjorddal

showing the position of basin Sl and palaeosol locality 'x' in raised beachfdune area. The Main (M) and Tapes (T) shorelines are indicated by arrows.

Field and laboratory methods Basin threshold elevations, lake water-levels and raised shorelines were levelled using tide-leve!, reduced to mean sea-leve!, as base leve!. Levelled profiles started and ended at the same point in order to correct for closing errors, except at Vannareid where a single profile was carefully levelled.

Coring was carried out mainly on ice-covered !akes in winter, usually at the deepest part, using a simple 'Russian'-type sampler to locate the depth of the organicminerogenic sediment transition, and a Geonor K-200 piston corer with l-2 m long, 1 10 mm diameter, p1astic tubes, or l m long, 54 mm diameter, steel tubes for sample collection. Reconnaissance coring to find the organic-minerogenic sediment interface was carried out at several places in each lake in order to find the most suitable, flat-bottomed part of the lake for sampling. During the coring procedure, prenetration length was compared with core length in order to check for and avoid disturbance.

In the 1aboratory, cores in steel tubes were extruded mechanically and halved longitudinally, whereas those in plastic tubes were halved directly. After describing core lithology, a lO mm thick longitudinal slice of selected

parts of each core was x-radiographed. The organicminerogenic sediment proportions in the cores were estimated visually and, in some cases, recorded by tonedensity measurements on radiographs. Grain-size analysis was carried out by standard wet and dry sieving, and pipette analysis, using a modified U dden-Wentworth grade scale with the clay-silt boundary defined at 0.002 mm. Samples of ca. 5 mm3 volume were taken at various intervals, to as small as lO mm, for diatom analysis. Samples were treated with 30% hydrogen peroxide, the residue being mouiited on glass slides using NAFRAX cement, and studied under the microscope using phase-contrast illumination at x 1000 magnification. Photographs were taken for reference purposes. Identification of different taxa (and classification according to salinity to1erance) was made mainly with reference to Hustedt (1930, 1957), Cleve-Eu1er ( 1951-55) and Hendey ( 1964), as well as Florin ( 1982) and Foged ( 1978, 1982).

Dia to ms Diatoms are sensitive to chemical and physica1 changes in the water. A change from a marine to a 1acustrine

NORSK GEOLOGISK TIDSSKRIFT 73 (1993) Marine-lacustrine stratigraphy at Lyngen and Vanna, Troms 179

environment, and vice versa, has a drastic effect upon existing species. Although diatoms have been used with a high degree of confidence, as salinity indicators, it is not always possible to determine the precise environmental affinity of any given species. For several species, contradictory reports have been given as to what kind of environment they inhabit. In addition, the diversity of the environment in the shore zone may confuse the fossil record. In particular, the role of sea spray in transporting diatoms or affecting the salinity of small lakes may be important. Consequently, any change in the diatom flora is significant, but should be interpreted in conjunction with other environmental indicators (Palmer & Abbott 1986).

In this work diatoms have been classified conservatively into salinity classes according to Hustedt ( 1957) and plotted alphabetically on the frequency diagrams. The salinity classes are: polyhalobous (prefer salinity > 30o/oo), mesohalobous (salinity 30-0.2o/oo), oligohalobous halophilous (prefer slightly saline water), oligohalobous indifferent (prefer freshwater, tolerate slightly saline water), halophobous ( exclusively freshwater, salinity < 0.2o/oo). Abbreviations 'cf.' and 'ssp.' refer to slight divergence from species characteristics or uncertain identification owing to poor preservation, and to subspecies, respectively. Sampled levels are indicated by thin horizonta1 lines on the frequency diagrams. The diatom data are also presented as summary diagrams in which taxa belonging to each of the five salinity classes are grouped into three major groups: marine (polyhalobous and mesohalobous), brackish (ha1ophilous) and freshwater (indifferent and halophobous). This grouping differs slightly from previous practice but relates hetter to the hydrology of coastal waters in Troms where salinity values range from 33-29o/oo for full y marine water, through ca. 29-3o/oo for surface waters in fjords and sounds, to < ca. 0.4o/oo in lakes (Nordgård et al. 1983 and own measurements; cf. also Bøyum 1970). The pioneer freshwater Fragilaria spp., which can tolerate a wide range of salinity conditions (Hendey 1964) and occur in large numbers at the transition from marine to lacustrine conditions, is plotted separately on the frequency diagrams, except in the case of F. viresens var. subsalina which is assumed to be a typical brackish species (Stabell 198 1).

Facies and isolationjingression contacts Four main facies types (I-IV), differing in lithology, structure and fossil content, and related to predictable depositional environments controlled by sea-1evel change, are distinguished. A number of variants, which may owe their 1ithological character to factors other than sea-level change, are also distinguished. These are assigned to a group of miscellaneous facies (V), except where they lithologically resemble one of the main facies types. Figs. 8 and 16 illustrate examples of the main facies types.

Facies I (Marine) - bioturbated, occasionally weakly laminated mud and sandy mud, usually containing scattered ( ice- or seaweed-rafted) clasts, shells and marine diatoms. Single, thin, sand or gravelly sand beds may occur.

Facies Il (Transitional) - finely laminated, alternating layers of gyttja, gyttja and silt, or gyttja, silt and fine sand, usually occurring at the transition between minerogenic (facies l) and organic (facies Ill) units. Diatoms in this facies usually show an upward transition from marine to freshwater flora. The facies is interpreted as having formed immediately after isolation of the basin from the sea, in nearly all cases during a relative1y short-1ived meromictic ( sa1inity-stratified) limnic p hase (Haugane 1984; Haugane & Corner in prep.; cf. Strøm 1936; Anderson et al. 1985). The isolation contact, which represents the moment at which the basin threshold loses regu1ar contact with the sea, is therefore placed at the base of this unit. This interpretation of the laminated transitional unit and placement of the isolation contact differs from that employed in previous studies (e.g. Stahell 1980; Kjemperud 198 1, 1986; Lie et al. 1983; Kaland et al. 1984; Svendsen & Mangerud 1990) where common practise has been to interpret the laminated unit as representing a brackish phase occurring immediately before isolation, and to place the isolation contact at the top of this unit. Sea-level curves constructed using present and previous interpretations of the isolation contact will generally be displaced in time by an amount equivalent to the duration of deposition of the laminated unit. In two cases (basin S4 and probably also basin V I), facies Il sediment comprising laminated gyttja and siltsand, apparently formed under fully lacustrine conditions and represents episodes related to climatic factors rather than sea-level change.

Facies Ill (Lacustrine) - generally massive gyttja and plant detritus, occasionally weakly laminated and containing some silt or fine sand, and possessing a dominantly freshwater diatom flora. Plant detritus is defined as organic material containing identifiable plant material. It commonly occurs in the upper, less humified part of the lacustrine unit.

Facies IV (Mixed) - heterolithic, stratified organic (gyttja, plant detritus) and minerogenic (silt, sand, gravet) sediment, containing both marine and freshwater diatoms or only freshwater diatoms. The facies is interpreted as indicating wave influence at the threshold, either during an episodic storm surge, or during an ingression into the basin as a result of a transgression, in which case the ingression contact is placed at the base of the unit. In one case (basin L4), a variant of this facies is interpreted as having formed as a result of slumping.

Facies V (Diverse) - facies of diverse character and origin comprising gravet (basin S2), sand and organic-rich


sand (basin S3), sandy mud (S4) and laminated sandy mud (V I ) and interpreted as being related mostly to high rates of ( terrestrial) sediment influx.

Radiocarbon dating Radiocarbon dating was carried out mostly on gyttja/ plant detritus using the NaOH-soluble fraction, preferentially, in order to avoid problems caused by contamination with younger root material (Kaland et al. 1984). Shell dates are corrected for isotopic fractionation (to - 25o/oo PDB) and a marine reservoir age of 440 years in accordance with the standard used for the Norwegian coast (Mangerud & Gulliksen 1975). Dates from marine shells and freshwater gyttja should therefore be comparable. However, some of the dated gyttja samples, particularly those ha ving low negative {) 1 3C values (e.g. samples from basins S l and Vl; Table 1 ), may contain material of brackish (or mixed marinejfreshwater) rather than purely freshwater origin (cf. Gulliksen 1980). Dates from these samples may be too old by an amount equivalent to some, presently unknown, proportion of the marine reservoir age (S. Gulliksen pers. comm. 1993).

Raised basin sites and stratigraphy A total of 10 lake basins lying at various elevations between the marine limit and present sea-leve] were investigated (Fig. 2). The lakes mostly occupy morainic depressions and generally have reliable uneroded thresholds. Basins in Lyngen occupy moderately sheltered sites, whereas those of Vanna, especially in Skipsfjorddal, are more exposed.

The basins show considerable variation in facies and facies sequences (Fig. 4). Six of the ten basins provided datable evidence of sea-level change. Among these, two (L I , L5) contain a simple, regressive, I-Il-Ill facies se-

NORSK GEOLOGISK TJDSSKRJFf 73 ( 1993)

quence having clear isolation contacts, one (S l ) contains a variant (facies I-IV-Ill) of the simple regressive sequence, one (L3) contains a syngressive-regressive, IV-IlIll facies seqeunce, one (L2) contains a compound, transgressive-regressive, I-IV-I-Il-Ill facies sequence having ingression and isolation contacts, and one (VI) contains a compound I-Il-V-II-Ill facies sequence thought to reflect both climatic and sea-level change. The remaining four basins (L4, S2, S3, S4) contain sequences in which isolation contacts are absent or difficult to identify precisely. A brief description of the stratigraphy in these basins is given since they provide additional information on facies variations and palaeoenvironment.

Basin L l (Jægervatn), Lyngen, 2. 6 m a.s.l.

Lake Jægervatn (basin L I ) is a large, 50 m deep, glacial basin with a bedrock threshold (Fig. 3A). The lake is fed by several small streams, including glacial meltwater streams. Two 1 .8 m long cores, taken 20 m apart from a 7 m deep, flat bench on the northem side of the lake, show identical stratigraphy comprising a regressive, I-IlIll facies sequence (Fig. 5).

Unit A (marine facies l) - > 1 .5 m bioturbated, calcareous silty, fine to very fine sand, having a high content of bivalve shells and calcareous algae (Lithothamnion) which comprise the bulk of the sediment. The upper 5 cm of unit A is rich in organic material and lacks Lithothamnion fragments. Diatoms occur near the top of the unit where marine species and the salinity indifferent pioneer species Fragilaria spp., dominate. At lower levels (7.5-8 m depth) diatoms are partially dissolved and only Nitzschia punctata could be identified.

The Lithothamnion flora is symptomatic of stable marine, wave-protected, tidally-inftuenced conditions (Freiwald 1 99 1 ). Its absence in the upper part of the unit may have been caused by temperature or salinity

Table l. Radiocarbon dates from (a) raised basin sediment cores and (b) a palaeosol from Skipsfjorddal, and their relationship to former sea leve!. Sample depth ('Unitjdepth') in basins is given relative to lake leve!. Lab. ref. suffixes 'A' and 'B' refer to dated NaOH-soluble and insoluble fractions, respectively. Calibrated ages are according to Stuiver & Reimer (1986). 'Max' and 'Mean' sea level refer to estimated spring high-tide leve! and mean sea-leve!, respectively.

Sea leve! ( m. a present s.l.)

Unit/ Sam p le Sam p le 613C Radiocarbon Calibrated

Locality depth (m) Lab. ref. material wt(g) %o date (BP) date Event Max Mean

Basin LI A/7.1 T-4867 shells 3 + 1.0 830 ±90 ADI095-1290 Isolation1> � 2.6 � l

Basin LI B/7.0 T-4866A + B gyttja 4 - 21.3 1660 ± 160 AD200-570 Isolation 1> < 2.6 < l

Basin L2 B/6.5 T-5157 pl.detr. 5.3 - 26.7 7880 ± 100 7000-6590BC Pre·ingr. < 18-19 < 17

Basin L2 D/5.1 T-4580A gytt ja 1.8 - 23.3 6480 ± 90 5500-5330BC Isolation 20 18.5

Basin L4 Cf7.0 T-4651A pl.detr. 4.0 - 31.78 7580 ± 130 6510-6240BC Post-isol. < 24.4 < 23

Basin L5 Cf6.1 T-4868A gyttja 3.9 - 25.6 8960 ± 130 Isolation 30.0 28.5

Bas in Sl B/1.4 T-5191A gyttja 0.6 - 20.8 3680 ± 180 2350-1860BC Isolation 7.8 6

Basin S4 B/4.3 T-5160A gyttja 2.2 - 22.6 8200 ± 160 Post-isol. < 46.3 < 45

Basin VI A/5.6 T-5161 shells 2.7 + 1.0 12140 ± 300 Pre-isol. > 24.8 > 23

Bas in VI B/5.0 T-51598 pl.detr. 41.3 - 17.5 11480 ± 290 Isolation2> .;; 24.8 .;; 23

Basin VI D/4.6 T-51588 pl.detr. 76.6 - 19.7 11140 ± 130 Post-isot.2> 24.8 23

Skipsfjorddal 3.3 T-4954A humus 25.2 - 26.2 2160 ± 70 360-120BC Post-beach < 7 < 5.5

Skipsfjorddal 3.3 T-4954B humus 83.1 - 24.7 2340 ± 80 460-375BC

1 Dates inverted. T-4866 probably too old. 2 lsolation history uncertain. Dates probably also too old.

NORSK GEOLOGISK TIDSSKRIFf 73 (1993) Marine-lacustrine stratigraphy at Lyngen and Vanna, Troms 181

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Fig. 4. Summary diagram of the stratigraphy of lake basin cores showing sediment thickness, facies types, position of isolation and ingression contacts, radiocarbon

datings and basin threshold elevations.

changes, or by the influx of a predatory marine fauna as isolation approached and conditions changed.

Unit B (transitional facies II) - 0.07 m weakly laminated gyttja having a variable content of plant detritus and minerogenic material. The unit has a diffuse lower boundary and contains the same diatom flora in its lower part as in the underlying marine unit. A transition from marine to freshwater diatom species is seen at the very top of the unit. The typical marine minerogenk sediment and macrofauna of unit A is absent in this unit, which is interpreted as representing a meromictic transition to full lacustrine conditions at the sampling site.

Unit C (lacustrlne facies /Il) - 0.2 m sandy-silty gyttja, containing more minerogenic material than the underlying unit. lts lower part is laminated and contains a bed of the remains of the freshwater calcareous green alga Chara sp. Diatoms consist predominantly of freshwater species, with a small brackish component. Diversity is highest in the laminated lower part of the unit. The relatively high content of minerogenic material may reflect glacial meltwater input.

Isolation. - At present, sea water intrudes into Jægervatnet only under exceptional circumstances (cf. report in 'Nordlys' daily newspaper, 13 January, 1993), and in quantities insufficient to significantly affect the hydrology of this large lake. However, following isolation and the inevitable establishment of a meromictic hydrology in a basin of this size, a marine fauna and flora would · be expected to persist for a short time on the bench from

which the samples were taken. The isolation contact is therefore placed below facies Il, dose to the top of facies I (unit A). Radiocarbon-dated gyttjajplant detritus and shell fragments from above and below this level gave dates of 1660 ± 160 and 830 ± 90 BP, respectively (Table 1). These dates are mutually inverted indicating that at least one of them is erroneous. It is possible that the dated gyttja contains some marine or brackish-water material which would give too high an age. However, the age difference between the two samples is much greater than any potential error caused by the marine reservoir effect. The gyttja date is thought to be too old on account of the presence of resedimented plant material in the sample, a common source of error in lacustrine environments (Olsson 1979). The date of 830 ± 90 BP, from unit A, probably represents a dose maximum age for the isolation contact and dates a threshold isolation level dose to 2.6 m a. present mean s.l.

Basin L2, Lenangsbotn, Lyngen, 20.0 m a.s.l.

This 120 m diameter lake Iies in a broad morainic depression just 1.5 m below the Tapes shoreline and at the same level as the estimated Tapes mean sea level. Two 2.9 m long cores (A and B), taken 10 m apart from slightly northwest of centre of the basin, at a depth of 3.4-3.5 m, show essentially similar stratigraphy comprising a compound, transgressive-regressive I-IV-I-Il-Ill facies sequence (Figs. 6, 7, 8).

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l l l l

... ,..

l l l l li l li l ; l

l :l

l l

� ,

r

l l

E3 Thin gyttja

l

...... ,

L

l l

El Scattered clasts

[I] Shells

� r

l l il Ill

ill Ill 'li ill I ll lo l

� El El

...... """"" •

l

..... l 11 l

il

Laminat ed

Weakly laminated

Distinct boundary

Mud and sand l.t Jl Bioturbation El Gradational bound.

OD D e ee O

l ....: , ,....

..... l

J

o 30% L.u..J

."...

l l l; :l: l

'' ' ' l,

l'l, l l

DIA TOMS:

l

D o Halophobous ---O o Indifferent-

F

6 Halophilous --[g o Mesohalobous ....__.

• Polyhalobous------

t------

�-

--'

Bar.ren

Freshwater

Brackish

Marine

Fig. 6. Composite diatom diagram for adjacent cores (A and B, 10m apart) from basin L2, Lyngen. A slight gap or overlap in the stratigraphy between the two cores

rna y exist (cf. Fig. 7).


Marine

DIA TOMS/

-?- --- - SALINITY

Mud Sand o 50 100%

Core A

NORSK GEOLOGISK TIDSSKRIFf 73 (1993)

-- - -

DIATOMS/

-- - - SALINI TY

�li�� +l ��,..,.,;1-..,. CX) 1'--

' ' o 50 1 00%

- - - - - - - - Hiatus

Core B

SEA-LEVEL

CHANGE

�

Q) a:

o

o o D

lsolation

�t <lilllngression

g>o a: o

o

Fig. 7. Lithostratigraphy and diatom summary diagrams for adjacent cores (A and B) from basin L2, Lyngen, showing the position of the isolation and ingression

contacts, and interpreted sea-level change. Legend in Fig. 6.


-

E -

I ICl. w o

3.5

5.0

5.5

6.0

6.5

7.0

Fig. 8. X-radiographs showing facies l-IV in basin L2, core A (cf. Fig. 7).

Al tema ting organic·rich (dark) and minerogenic {light) layers show high con trast

in laminated units B and D.

partially dissolved shells. The diatom flora (Fig. 6) is dominated by marine species, but some freshwater speeies also occur. The unusually high content of plant detritus and freshwater diatoms in this marine unit may be due to the location of the basin near the former outlet of a stream some 400 m to the north.

Unit B (mixed facies IV) - ca. 0.4 m heterolithic unit comprising altemating, irregular laminae and lenses of gyttja, plant detritus, sand and pebbly sand (Fig. 8). The plant material mostly comprises mosses and wood fragments. Fragments of Mya truncata were found in the unit. The diatom flora consists of a mixed assemblage containing the same marine species as in the underlying unit, as well as several freshwater species.

Unit B evidently contains resedimented material derived from a variety of sources and represents an abrupt change in depositional conditions. Slumping seems unlikely as a sole explanation for the characteristics of this unit. Rather, the unit is thought to have formed during a marine incursion into the basin causing erosion, transport of plant material and littoral sand into the basin, and disturbance of lacustrine gyttja on the floor of the basin. Accordingly, any previously deposited transitional facies Il sediments, formed during prior isolation, must have been removed creating a hiatus between units A and B.

Unit C (marine facies I) - ca. 1.3 m bioturbated finingupward unit of silty fine sand - sandy silt, containing shell fragments and scattered, coarse sand grains. Weak lamination is preserved in the slightly coarser lower part of the unit, and the degree of bioturbation increases upwards. Apart from a few freshwater diatoms at the base, the unit is dominated by marine species.

Unit D (transitional facies Il) - 0.2-0.3 m laminated gyttja containing fine sand laminae (Fig. 8). The diatom flora changes from a marine assemblage in the lower part, similar to that in the underlying unit, to a freshwater assemblage in the upper part. Freshwater, calcareous algae (Chara sp.) occur at the top.

Unit E (lacustrine facies Ill) - 1.3-1.65 m gyttja grading into dy (gel-mud) towards the sediment-water interface. Freshwater diatoms dominate.

Isolationfingression. - The stratigraphy of basin L2 indicates what are probably two episodes of isolation, with an intervening ingression represented by marine unit C. The first isolation is recorded indirectly by the presence, in unit B (mixed facies IV), of resedimented lacustrine gyttja and plant detritus. These sediments must have formed originally when the threshold level was situated above the limit of storm-surge tides. Mean sea-level at that time probably lay below 17 m a.s.l. Unit B was deposited during a subsequent ingression, when storm waves overtopped the threshold at 20 m a.s.l., corresponding to an estimated mean sea-level of ca. 18-19 m a.s.l. A radiocarbon date of 7880 ± 100 BP, from resedimented plant detritus from unit B, gives an approximate age for the pre-ingression lacustrine phase and a maximum age for the marine ingression. Unit C represents an extended period during which sea leve) was situated above the threshold. The ingressiveftransgressive event


leading up to deposition of unit C most likely correlates with the forma ti on of the Tapes shoreline at 21-22 m a.s.l., in which case sea level probably lay only marginally above the threshold at that time. The slight fining-upwards texture in the lower part of unit C may reflect the changing process-regime at the threshold during the transgression, or possibly basin stabilization during the following syngression. Final isolation of the basin is placed at the boundary between marine unit C and transitional unit D. A radiocarbon dating from the base of unit D gave an age of 6480 ± 90 BP, which corresponds to a threshold isolation level of 20.0 m and an estimated mean sea level of ca. 18.5 m a.s.l.

Basin LJ, Lenangsbotn, Lyngen, 21m a.s.l.

Basin L3 is a small 20 x 50 m diameter, bog-encircled, 1.2 m deep lake situated in a sheltered morainic depression lying immediately behind the Tapes beach ridge. The threshold is obscured by bog, but is thought to consist of Tapes beach gravel lying just below the level of the lake (21.3 m a.s.l). No radiocarbon dating was made from the 4.2 m long core recovered from this lake, but the stratigraphy, a compound IV-11-III facies sequence (Fig. 9), is interesting on account of the lake's proximity to the Tapes shoreline.

Unit A (mixed facies I V) - > l m complex, irregularly bedded, partly laminated, partly bioturbated, partly deformed (folded) unit comprising predominantly silty sand with dispersed plant material, gravet and sand lenses, and some thin gyttja beds. Diatoms in the silty sand and gyttja suggest marine conditions.

Unit B (transitional facies Il) - 0.32 gyttja contammg scattered pebbles. Distinct lamination at the base of the unit becomes less distinct upwards and eventually disappears. Marine diatoms dominate. The upper boundary coincides with an abrupt colour change from light to dark brown, as well as a transition from dominantly marine to dominantly freshwater diatom species, including a small brackish component.

Unit C (lacustrine facies Ill) - 2.9 m gyttjafplant detritus containing mostly freshwater diatoms.

Isolationfingression. - Heterogeneous unit A (facies IV) resembles unit B in basin L2 (interpreted as an ingressive unit), except that it contains only marine and brackish diatoms, and is much thicker. The unit is interpreted as a littorally-influenced deposit, formed during the Tapes transgression and TIM syngression which gradually raised the level of the threshold at this basin. Unit B

Fig. 9. Lithostratigraphy and diatom summary diagram for basin L3, Lyngen,

showing the position of the isolation contact.


GRAIN-SIZE

DIS TRIBUTION md sd gv l [::::.·3· •• , .. r····

o 100%

-en>-��--oz �::i _<( Cl Cf)

w _.J a.. �

<( Cf) •

• • •

•

•

•

l •

•

l • •

•

•

o 100%

Leg end LITHOLOGY:

mm Plant detritus

� Gyttja

@] Scattered clasts

[l] Bioturbation

l t I j Mud and sand � Laminated

lao;:ol Grave! and sand B Distinct boundary

� Thin gyttja O Gradational bound.

DIA TOMS: CJ Barren

Halophobous --- ITTTTFffiTll Freshwater Indifferent -- lllJJ.1J..l.ll. Halophilous --� Brackish

Mesohalobous --� Polyhalobous ---� Marine


(facies Il) was formed following isolation; the unusual persistence of marine diatoms in this unit may be due to marine water infiltrating through permeable gravels m the threshold ridge.


This small, 40 x 60 m diameter, 3.2 m deep, moram1c basin Iies ca. 3 m above the Tapes shoreline. Two 5.1 m long co res (A and B, Fig. l 0), taken 5 m apart, show considerable differences (aberrant 1-III/I-IV-III facies sequence), suggesting disturbance by slumping. The isola-

/L4/ -E

I DIA TOMS 1-a.. >-w o 1-z 3.2 ::i N <( <( C/)

Core A

w _J a.. � <( C/) •

6' � o

er� �V '<� s .§

tion contact was not precisely located in this basin and only a minimum age for isolation was obtained. Stratigraphic correlation of the different units in the two cores is based on lithology and diatom assemblages (Haugane 1984).

Units A and B (marine facies /) - >0.75 m bioturbated, silty fine sand containing many pebbles, cobbles and shells, including Mya truncata in life position, capped by a thin, possibly uncomfortable, layer of plant detritus. The marine diatom flora can be divided into two assemblage zones (l and 2) dominated by marine species, with

.----- C ore B -------.

DIA TOMS >- w 1-z _J a..

F Lacustrine N _J � <( <(

5

7.0 •

• t---1:>7:=�".,..".,. • - -t------f...r'-.+.,L.,'.,I+-----L

7.5

'--+---,.---� • o 100%

Legend LITHOLOGY: Bm Plant detritus

æ Gyttja

�m:::: ::J Mud and sand

� Thin gyttja

EJ Scattered clasts

' ' ' ',

W Shells

� Bioturbation

..... ......... .......... ?

J J Weakly laminated

B Distinct boundary

G Gradational bound.

B Hiatus

<( C/)

f o

Mud Sand

DIA TOMS: O Barren

Halophobous --._IITTT'fTTTTTl Freshwater Indifferent -- llJ.ilEJillll Halophilous --� Brackish

Mesohalobous ----� Marine

Polyhalobous---

C/) •

• •

l •

100%

Fig. JO. Litho- and diatom stratigraphy iri adjacent cores (5 m apart) in basin L4, Lyngen. The suggested stratigraphic correlation, based on lithology and diatom

assemblages, indicates a major hiatus in core A and a slumped unit (C) in core B. The radiocarbon date provides a minimum age for basin isolation.


a barren zone between. Zone l is found in both cores, whereas zone 2 is found only in core B, indicating the presence of a hiatus above unit B in core A.

Unit C (mixed facies I V) - 0.35 m heterolithic unit, found only in core B, consisting mainly of a deformed bed of sandy plant detritus overlain by a cyclic set of three, laminated, coarsening-upward beds of mud to fine sand with gyttja. Marine diatoms dominate at all levels in the unit except in the gyttja layers, which contain freshwater species. Unit C shows characteristics which are not found in facies IV or facies Il sediments in other basins. The cyclic bedset and presence of both marine and freshwater diatoms indicate mixing and resedimentation of material, possibly by a tidal or storm influenced marine incursion into a previously isolated basin, or by repeated turbidite deposition caused by slumping within an already isolated basin.

Unit D (lacustrine facies Ill) - ca. 4 m predominantly plant detritus consisting mostly of mosses. Thin beds of gyttja and compact plant detritus occur at the base. Scattered, coarse sand clasts occur in

·the lower part in

both cores. Two different diatom assemblages, comprising a diverse freshwater flora in core B (zone 4) and a freshwater flora in core A (zone 5), indicate the presence


g:- ��· 6-�� 0 0 ,S GRAIN SIZE t ! Jit::: ;:f DISTRIBUTION IAJOMS/ Ø (j , "!(' � ' el sl sd D 45 Q � ' " " �-==l�;:;q SALINITY

. l l l l

6.0

o 100% o 100%

of a hiatus and slumping in this unit too. 7.0

Isolation. - The stratigraphy shows a rather abrupt change from marine to lacustrine conditions, represented primarily by an erosional hiatus in core A and a slumped unit (unit C) in co re B. Cyclic beds of uncertain genesis in unit C, containing marine and freshwater diatoms, were formed same time after isolation. A radiocarbon date of 7580 ± 130 BP from a bed (possibly displayed) of freshwater gyttja immediately overlying unit C, indicates that the basin was isolated at this time.


Basin L5 is 100 m in diameter, 4.5 m deep, partly covered by floating peat mats, and Iies 8.5 m above the Tapes shoreline (Fig. 3B). Reconnaissance coring revealed cobbles or boulders at a depth of ca. 7.5 m. Above this is a 3 m thick, simple, regressive, I-Il-Ill facies sequence (Fig. 11).

Units A and B (mixed facies l) - 1.15 m coarseningupward sequence consisting of a unit (A) of pebbly clay lacking shells or diatoms, overlain by a unit (B) of bioturbated, partly laminated, sandy clayey silt with scattered pebbles and a bed of gravelly sand. Organic material in the upper l cm is probably derived by inflltration from overlying gyttja. Diatoms first appear in the upper lO cm of unit B, being represented by distinctly marine species (Fig. 12). The sequence is interpreted as a marine, shallowing-upward sequence.

Fig. 11. Lithostratigraphy and diatom summary diagram for basin LS, Lyngen,

showing the position of the isolation contact. Legend in Fig. 12.

Unit C (transitional facies Il) - O. l m laminated gyttja containing same sand and silt laminae. A transition from a marine to a freshwater diatom flora is seen at the base of the unit.

Unit D (lacustrine facies Ill) - 1.5 m thick gyttjajplant detritus. The unit contains a freshwater diatom flora, including halophobous species, similar to that in the underlying unit.

lsolation. - A radiocarbon dating from the base of unit C which represents isolation of the basin, gave an age of 8960 ± 130 BP. This corresponds to a threshold isolation altitude of 30.0 m a.s.l., and an estimated mean sea-levet of 28.5 m a. present s.l.

Basin Sl, Skipsjjorddal, Vanna, 7.8 m a.s.l.

This 100 m diameter, 1.3 m deep lake occupies a shallow morainic hollow (Fig. 3C). It contains an estimated


0.5 m of postglacial sediment, comprising what is interpreted as a regressive I-IV-Ill facies sequence (Fig. 13).

Unit A (marine facies I) - 0.2 m well-sorted, bioturbated fine sand containing dispersed organic material, scattered pebbles, and a gravelly sand bed near the top. The unit contains no diatoms, but its lithology suggests a waveinftuenced marine origin.

Unit B (mixed facies I V) - O.l l m weakly laminated heterogeneous unit of black gyttjafplant detritus and sand, containing two beds of matrix-supported sandy grave!. The unit contains no diatoms. The organic material probably consists of marine, brown-algae detritus washed into the basin by storms. The grave! is interpreted as having been deposited by storm waves onto winter ice covering the lake, and subsequently metting out causing only minor disturbance to the loose, lakebottom detritus. At this exposed locality, winter ice would normally form only once the basin had been

Legend Mud Sand

LITHOLOGY:

raised into the upper intertidal zone. Unit B is therefore interpreted as having been deposited when the basin lay between neap high-tide level and the storm limit.

Unit C (lacustrine facies Ill) - 0.03 m brown gyttja. The diatom assemblage is dominated by freshwater species, but also contains brackish and marine species, despite the fact that this unit extends to the present sediment surface and is obviously lacustrine.

Iso/ation. - The succession indicates a transition from marine to lacustrine conditions. The unusual lithology and diatom assemblage of units B and C (facies IV and Ill) is probably related to the relatively high degree of wave exposure, with facies IV (unit B) replacing the more normal transitional facies Il. The isolation contact, placed at the base of unit B and dated to 3680 ± 180 BP, represents a threshold isolation altitude of ca. 7.8 m a.s.l. The obtained date may be slightly too old on account of the marine reservoir effect.

DIA TOMS:

-� � � 4.�0 20% ,w

- Plant detritus [ZLJ Bioturbation c=J Barren

m Gyttja � Laminated

l i\ j Mud and sand E;d Load east

JOo::;l Gravel and sand B Distinct boundary

@ Scattered clasts G Gradational bound.

Fig. 12. Diatom diagram for the upper part of the stratigraphy in basin L5 (cf. Fig. Il).

o Halophobous ---- � o Indifferent -llllltJuru Freshwater

A Halophilous --� Brackish

o Mesohalobous ----� • Polyhalobous --� Marine

- Low diversity ( < 3 species)


1.6

o

f

Gv

Barren

ti on

o 100%

Leg end LITHOLOGY: !mim Plant detritus

� Gyttja

�\\\:\:\: ;l Mud and sand

l\\:;t %\l Org;��drich

� Gravel and sand

DIA TOMS:


B Scattered

clasts

[l] Bioturbation

� Laminat ed

B Dis tinet

boundary

C=:J Barren

o Halophobous -..._ITTTfFTITTTl Freshwater o Indifferent -- lll.J..lL:J..ll LJ. Halophilous --� Brackish

o Mesohalobous ----� Marine

• Polyhalobous--- .

Fig. 13. Litho- and diatom stratigraphy of basin Sl , Skipsforddal, Vanna, showing the position of the isolation contact.

Basin S2, Skipsfjorddal, Vanna, 22.3 m a.s.l.

This 150 m diameter, 1-1.5 m deep, boulder-strewn, morainic basin Iies within the inferred tidal zone of the Main shoreline. A 0.7 m sediment cores shows a V-III. facies sequence (cf. Fig. 4). No radiocarbon dating was made.

Unit A (facies V) - O.l m subrounded, sandy gravel containing a sparse freshwater diatom flora.

Unit B (/acustrine facies Ill) - 0.6 m gyttja/plant detritus containing lenses of fine sand and scattered pebbles. A 2 cm thick layer of black jelly-like gyttja occurs at the

NORSK GEOLOGISK TIDSSKRIFT 73 (I993) Marine-lacustrine stratigraphy at Lyngen and Vanna, Troms 191

base. Diatoms in the ana1ysed lower 20 cm of the unit comprise freshwater species, except for a single brackish species.

Iso/ation. - Unit B is clearly lacustrine whereas unit A may represent littoral sediment. The abrupt facies transition suggests the presence of a hiatus representing the period during which this shallow basin became isolated and before organic lacustrine deposition became established (see discussion for basin S4). The sand lenses and scattered pebbles in unit B are probably of windblown and/or ice-rafted origin.

Basin S3, Skipsfjordda/, Vanna, 25.3 m a.s.l.

This l m deep, bog-enclosed basin is situated centrally on the flat floor of the valley. It contains more than 1.6 m of sand (facies V) which is laminated with organic material in its upper part and overlain by 0.3 m of gyttja (facies Ill). The lithology, and a freshwater diatom flora, suggest a purely fluvial/lacustrine origin for these sediments.

Basin S4, Skipsfjorddal, Vanna, 46.3 m a.s.l.

This 100 x 200 m diameter, 2 m deep basin consists of a littoral-ridge dammed lake situated on the side of the valley at the marine limit. The ridge consists partly of rounded, littoral cobbles and boulders, and partly of bouldery diamicton of presumed iceberg-rafted or sea-ice rafted origin. A 2.5 m long sediment core contained a VII-Ill facies sequence (cf. Fig. 4).

Unit A (facies V) - 0.14 m relatively poorly sorted, predominantly sandy silt having a variable content of dispersed organic material and poorly preserved freshwater diatoms.

Unit B (facies Il)- 0.06 m laminated gyttja and fine sand containing dominantly freshwater diatoms.

Unit C (lacustrine facies Ill) - 2.5 m gyttja containing numerous, very thin, fine-sand laminae in the 1ower part, and a diatom flora similar to that in the underlying unit.

Palaeoenvironment. - The sediments are interpreted as having formed in a lacustrine environment in which early colluvial deposition of minerogenic sediment was later replaced by deposition of organic material. The transition (unit B) was dated to 8200 ± 160 BP. This date is much younger than the expected age close to the date of basin formation around the time of deglaciation at approximately 13000 B P. The pollen stratigraphy, however, suggests that the date is reliable and marks a period of increased vegetation growth and substrate stabilization of this northeast-facing slope, following a climatic amelioration (K.-D. Vorren pers. comm. 1993).

Basin VI (Litlevatn), Vannareid, Vanna, 24.8 m a.s.l.

This 250 m diameter, mostly shallow, up to 3.6 m deep basin Iies at a levet 10 m above the Main shoreline and 15 m below the marine limit. It Iies upvalley from and just 0.5 m above a much larger lake (Storvatn), near the head of the valley. The lake is fed by small streams and seepage. Two 2 m long cores from the lake showed a similar, compound I-II-V-II-III facies sequence (Fig. 14-16) which most likely represents a regressive sequence modified by climatic factors.

Unit A (marine facies l) - 0.55 m silty fine sand containing intermittent laminae of slightly coarser sand and, near the top, two thin beds of medium sand and gravelly sand, respectively. The lower part of the unit contains many well-preserved shells and fragments of Hiatella arctica and Mytilus edulis, including the periostracum of Mytilus. Unit A lacks diatoms. The coarser sandy layers near the top of the unit suggest shallowing-upward marine conditions and the influence of storms.

Unit B (transitional facies Il) - 0.17 m finding-upward unit of mainly finely laminated silty gyttjafplant detritus

4.0

4.5

5.0

5.5

GRA IN-SIZE DISTRIBUTION DIATOMS/ � �A LINITi

o 100% o 100 %

Fig. 14. Lithostratigraphy and diatom summary diagram for basin VI (Lake

Litlevatn), Vannareid, Vanna. The favoured interpretation of the sequence places

the isolation contact at the base of unit B and correlates units C and D with a

Y o unger Dryas lacustrine p hase. An alternative interpretation suggesting ingres

sion (shaded dashed triangle) and renewed isolation ( open dashed triangle), seems

less likely (see text). Diatom sampling interval and legend is given in Fig. 15.


o

r1 OD ODD DO O •

l l ' �

OD O O o

r � ,. �

o


o o

o 50% L..u...u..l

� � • • ..

•

� ·"''

Legend LITHOLOGY: DIATOMS:

og Plant detritus @] Scattered clasts

W Shells

� Laminated c=J Barren

� Gyttja

� Muddy gyttja l .i./ l Bioturbation

B Distinct boundary

G Gradational bound.

o Indifferent -[].l[]Jll!] Freshwater

• Mesohalobous -� Marine

I,::I:: :n Mud and sand Low diversity (c 3 species)

Fig. 15. Diatom diagram for basin VI (Lake Litlevatn), Vannareid, Va':lna (cf. Fig. 14).

and fine sand (Fig. 16). The lower boundary is gradational and the organic content increases upwards. At the top is a thin silt bed overlain by a thin bed of plant detritus containing mostly moss (Campyliun stel/atumf polygamum). The unit contains scattered, probably icerafted, sand and pebble clasts. A poor flora of freshwater diatoms dominated by Fragilaria spp. occurs in the upper half of the unit. A sample from the lower part contained resting spores ( cysts) of a marine dinoflagellate ('Hystrix'), (Vorren 1985).

The lamination and virtual absence of bioturbation, as well as the first appearance of freshwater diatoms in unit B, suggest that the basin had become isolated from the sea at this time. The unusually high content of minerogenic material in this unit compared with facies Il sediment in other, younger sequences, may reflect the Late Weichselian environment in which rates of subaerial

sediment transport were high and organic production low.

Unit C (laminat ed facies V) - 0.27 m finely, evenly laminated, sandy mud, being slightly coarser at the base (Fig. 16). The unit contrasts lithologically with the underlying unit but the boundary between the two does not appear to be erosional. Sporadic, thin ( < l mm), subvertical, pyritized tubes are interpreted as burrows. A sparse, partly corroded diatom flora occurs in the upper and lower parts of the unit. It consists of freshwater species, except for a single species identified as the mesohalobous Navicula cf. crucigera typica, which is relatively abundant near the top.

The sparse diatom flora in unit C does not allow a reliable environmental interpretation. The unit differs from normal transitional facies Il and lacustrine facies


Cf) UJ () <( u..

E

Fig. 16. X-radiographs from basin VI, Vannareid, showing well-laminated sediments (facies Il and V) in the transition zone between marine (unit A) and lacustrine (unit E) sediments. Laminated unit D (right-hand radiograpb) is particularly distinct. The apparent density difference between the two images is not directly comparable since different exposure times were used.

Ill in lacking organic materiaL It ditfers from marine facies I in having distinct lamination, and lacking strong bioturbation. The dominantly minerogenic lithology suggests either a marine or estuarine environment, or a climatic control on sediment supply to a lacustrine environment.

Unit D (transitional facies Il) - 0.09 m laminated gyttja containing several, very fine sand laminae. The organic

material consists of algal material and plant detritus containing well preserved leaves of Salix polaris. The unit contains a rich diatom flora comprising freshwater speeies. Both the relatively high organic content and the diatom flora indicate that unit D was deposited in a lacustrine environment. The presence of Salix suggests that a substantial vegetation cover existed at the time. The unit resembles transitional facies Il in other basins with regard to its laminated structure, but ditfers with regard to the absence of marine diatoms.

Unit E (/acustrine facies Ill) - ca. 3.2 m gyttjafplant detritus with scattered sand and pebble clasts and an increasing proportion of plant detritus, including Phragmites sp. , towards the top. The unit contains a diatom flora similar to that in the underlying unit and is clearly lacustrine in origin.

Isolation and palaeoenvironment. - The stratigraphy of basin VI indicates a transition from marine (unit A) to lacustrine (unit E) conditions, but the isolation contact is difficult to define precisely. Units B, C and D all show lamination, but they contain few diatoms and the sequence ditfers from that found in other basins. Initial isolation of the basin probably occurred during deposition of unit B as suggested by the increase in organic matter and first occurrence of freshwater diatoms. The overlying minerogenic-rich sequence ( units C and D) may be interpreted in two alternative ways: ( l) marine ingression and subsequent isolation , (2) climatically induced increase in sediment supply to an already isolated lacustrine basin. The evidence for a marine ingression is not compelling. It consists of sporadic bioturbation traces and a single diatom species, both of presumed marine origin. A climatic control on the sediment supply seenis feasible, however, in view of the Late Weichselian age of the sediments.

Radiocarbon dates obtained from shells at the base of unit A and from gyttja in units B and D, gave ages of 12 140 ± 300, Il 480 ± 290 and Il 140 ± 130 BP, respectively (Fig. 14). Pollen stratigraphic evidence from the core suggests that the gyttja dates are too old (K. -D. Vorren 1985 , pers. comm. 1993) . Unit C shows an Artemisia peak which is preceded and succeeded by an Oxyria peak in units B and D, respectively. Compared with regional evidence (Vorren 1978, 1985 : Fimreite 1980; Prentice 1981, 1982; Vorren et aL 1988; Alm 1990; Vorren et al. in press) this vegetation pattern suggests that unit C formed under arctic steppe conditions during the earl y part of the Y o unger Dryas Chronozone (ca. lO 500-11 000 BP), whereas units B and D formed under more humid and part1y milder conditions during Allerød and late Younger Dryas, respectively (K. -D. Vorren pers. comm. 1993). This correlation , if correct, implies that the older and younger gyttja dates are ca. 300 years and 600-700 years too old, respectively. For the older date, the age discrepancy could be largely explained by the marine reservoir etfect. For the younger date, it is


thought to be related to the presence, in the sample, of old resedimented organic matter derived from eroded soil and solifluction material, as reported elsewhere (Sutherland 1983; Vorren 1985) . The reinterpreted age of unit C corresponds well with a dimatic interpretation of the sequence, since the Younger Dryas dimatic fluctuation would be expected to cause a noticeable increase in the minerogenic-organic sediment ratio (cf. Svendsen & Mangerud 1987, 1990) , and such a change is not seen higher in the sequence (unit E. )

To condude, the compound sequence at basin V1 is considered to represent a simple regression, rather than transgression-regression. The shell date of 12 140 ± 300 BP provides a maximum age for basin isolation. The isolation contact near the base of unit B has an estimated age of between ca. Il 600 BP ( estimated from uncorrected radiocarbon date) and ca. Il 300 BP (pollen stratigraphic age).

Regarding the occurrence of Mytilus edulis in unit A, dated to 12 100 BP, this musse! was obviously living in the bay at the time, and is the oldest recorded postglacial occurrence of this circumpolar, relatively temperate (mid-arctic to boreal) species at this latitude. M. edulis has been found in earl y Bølling (ca. 12 400-12 700 BP) sediments from Hordaland in western Norway (Mangerud 1977) , but not from Late Weichselian (ca. 10 000-12 500 BP) sediments from inner (glacier-proximal) coastal areas of Troms (Andersen 1968) . Because larvae of M. edulis have a limited life span (Seed 1976), the occurrence of this mollusc at Vanna at this early date suggests the presence of a strong coastal current which could transport the larvae from more southerly locations. The source is likely to have been western Norway since much of the intervening coast of Nordland was glaciated at the time (Andersen 1975 , 1979; Andersen et al. 1981; Rasmussen 1981). The evidence from Vanna supports previous indications (Mangerud 1977; Vorren et al. 1978) that the Polar Front had a relatively northerly position (north of Troms) during the Bølling and Allerød Chronozones.

Sea-level displacement curves for Lyngen and Vanna

Construction

Sea-level displacement curves have been constructed for Lyngen and Vanna (Fig. 17) based on dated isolation contacts and other data. The curve for Vanna consists of separate halves (Vannareid and Skipsfjorddal) for which the altitude scale has been mutually adjusted, using the gradient of the Main shoreline (0 .9 mjkm), in order to make them broadly comparable.

The curves refer to high-tide leve! (ca. 1.5 m a. mean s. l. ). This corresponds approximately to the water plane at the time of isolation at the basin threshold, and to the approximate altitude of contemporaneous shore terraces.


Each curve has been drawn as a smooth interpolated fit to the data using a minimum of assumptions regarding its shape. The curves are based on the following evidence:

(l) Radiocarbon-dated stratigraphic sequences and isolation contacts in 6 out of 10 investigated raised basins (Table 1).

(2) A radiocarbon-dated palaeosol from Skipsfjorddal (Table 1). The sample (locality 'x', Figs. 2B, 3C) was taken from the lowermost of several, superimposed, palaeosol horizons in dunes covering beach ridges at 7. 1 m a. s. l. , just below the Tapes shoreline. The dated NaOH-soluble and insoluble fractions gave fairly similar results and probably provided a reliable minimum age for the beach ridges.

(3) The elevation of the Tapes shoreline, which is assumed to mark the peak of the TIM.

( 4) The elevation and inferred age of the Main shoreline. This shoreline corresponds with the Tromsø-Lyngen (Y o unger Dry as) moraines (Andersen 1968) but its exact age and genesis is uncertain. For present purposes, it is assumed to have an age of ca. 10 500 BP, although in inner areas dose to the Tromsø Lyngen moraines, an age doser to lO 300 BP may be more correct (Corner 1980) .

( 5 ) The altitude and estimated age of the marine limit at Vannareid. This is placed at approximately 40 m a. s. l. based on the elevation of the highest beach ridge at 39 m s. a. l. and Hansen's ( 1966) marine limit determination of 4 1-42 m a.s. l. lts maximum age corresponds to the date of general deglaciation in the area which, judging from regional data (Andersen 1968, 1979; Corner 1978; Vorren & Elvsborg 1979) probably occurred between 13 000 and 15 000 BP.

( 6) The gradient of the present rate of relative uplift which, according to reconstructed isobases (Sørensen et al. 1987) has a general (regional) rate of ca. l and 2 mmjyr at Vanna and Lyngen, respectively.

(7) The age and amplitude of the Tapes transgression at Vanna, derived from comparison with localities farther south in the region (between Tromsø and Lofoten) which have a similar position relative to the isobases (Hald & Vorren 1983; Møller 1984, 1987). An amplitude of 10 m and a starting and ending date of 8500 and 6000 BP, respectively, are presumed.

Discussion

Of the dated isolation contacts, five (Ll , L2 , L5, Sl, Vl) lie dose to expected values and appear to be relatively reliable. Two dated transitions (L4, S4) are dearly too young and represent lacustrine depositional phases. Inconsistencies appear in two basins (Ll, Vl) where more than one dating was made, and introduce a small degree of uncertainty; in both cases gyttja dates may be too old by several hundred years.


"C Q) �

co c c co > -

jLynge!!]_ Main

40_ Marine limit

.. .. 30- ··· .. ,

\ V1 * \?

shoreline . . . . . . . . . . . . . . . . . . . . . . .

....._S4

LEGEND - 14C-dating (±1o-), isolation contact

...... " " , lacustrine

...... " " , marine � " " , palaeosol

<> Undated syngressive sequence

r--60

r--50

r--40

r--30

co "C "C �

o ·----(/) o.

� en + c Q) C) c 3'

(/) co

20- \ . . Main · ..

\._ L5

\ -· - L4 -(/) co E shoreline ---"··· .. - \

\- ,.:s 7 _ --L3 Tapes

-......:::�.�

-...

_joreline r---20

E Q)

"C :::J -

10- . . . . . . . . . . .

-

.... ···· · ··· ... -Q)

"C :::J l Vannareid/ . . ··.

- 0- .. ... . .

/ S 1··...._-..:::::::.� Palaeosol

l Skipsfjorddal/ L�� --

r- 10 --

�-��-��-��-��-��-��==,r===��==T=I==�, -�,-��-�,-��o 14 13 12 11 10 9 8 7 6 5 4 3 2 1 o

14C-yrs B.P. x 1000 Fig. 17. Shoreline-displacement curves for Lyngen (Lenangsbotn-Jægervatn) and Vanna (Vannareid-Skipsfjorddal), based on dated isolation contacts in lake basin sediment cores, and other data. The curve refers to high-tide leve l ( threshold isolation level). Dashed and continuous parts of the curve indicate relative degree of uncertainty; dotted parts are interpolated or based on regional data. Question marks beside data points for basins V l and LI denote gyttja dates that appear to be too old.

The sea-level curves (Fig. 17) indicate a relatively rapid pre-Tapes (before 8500 BP) and relatively slow post-Tapes (after 6000 BP) rate of regression, in accordance with results from previous work in the region (Corner 1980; Hald & Vorren 1983; Møller 1984, 1987). A verage rates of regression for the two periods are of the order of 15 and 3 mm/yr at Lyngen and lO and 1. 5 mm/ yr at Vanna. Rates obtained using calibrated ages (Table l) are slightly ( 15%) lower.

The Tapes transgression appears on both sea-level curves, based on local data at Lyngen and regional data at Vanna. At Lyngen, mixed facies IV units occur in basins L2 and L3 at an elevation just below the Tapes shoreline. They belong to sequences interpreted as ingressive and ingressivejsyngressive, respectively, formed during the Tapes transgression. Comparing the sea level necessary for initial isolation of basin L2, with the TIM sea-level as indicated by the Tapes shoreline, indicates a minimum amplitude of 2-3 m for the Tapes transgression at this locality. The age of the TIM peak is estimated at ca. 7000 BP, based on bracketing pre-ingression and isolation dates from basin L2, of 7880 ± 100 and 6480 ± 90 BP, respectively.

Facies similar to facies IV sediments in basins L2, L3 and L4 at Lyngen, have been found in raised basins in

western Norway, where they are interpreted as tsunami deposits formed about 7000 BP (J. l. Svendsen, J. Mangerud & S. Bondevik pers. comm. 1993; cf. also Svendsen & Mangerud 1990). This hypothesis could provide an alternative interpretation of facies IV sediments at Lyngen and negate the need for a transgression to explain the sequences in basins L2 and L3. However, in the absence of evidence supporting the tsunami hypothesis, it is thought that a transgression best explains the stratigraphic sequences in basins L2 and L3 and their predictable relationship to the Tapes shoreline.

The age (ca. 7000 BP) indicated for the postulated TIM at Lyngen is somewhat older than that derived for more distal ( outer) areas in northern Norway, where an age close to 6000 BP is relatively well established (Møller 1984, 1986, 1987; Bergstrøm 1973). The age of the TTM at ioner areas is more uncertain, but appears to be older than 6000 BP at two localities where dates have been obtained; in northern Nordland and eastern Finnmark, respectively (Dahl 1968; Donner et al. 1977). These dates, together with the present date from Lyngen, suggest that the TTM is older in ioner areas than in outer areas (cf. Fig. 17). This is in accordance with previous geometric reconstructions of the Tapes shoreline complex in northern Norway as a curved, diachronous feature


(Tanner 1930; Marthinussen 1960) rather than a dorninantly synchronous shoreline (Møller 1987) . The evidence from Lyngen also suggests that the Tapes transgression in Troms reached well inland beyond the 20 m isobase, in accordance with previous indications from other parts of northern Norway that it reached the 25-30 m isobase (Tanner 1930; Donner et al. 1977; Møller 1987) . More dates are needed, however, before the age and geometry of the TTM and Tapes shoreline can be defined precisely.

The reconstruction of pre-Tapes sea-level change at Vanna is rather uncertain on account of the limited number of data points, which include derived ages for the marine limit, Main shoreline and Holocene regression minimum. The sequence in basin Vl is interpreted as a probable climate-influenced regressive sequence, rather than a transgressive-regressive sequence. A transgression at this level also seems unlikely considering the timing of possible causa) factors such as a glacier readvance (cf. Late Weichselian transgression in western Norway; Anundsen 1978, 1985 ; Kaland 1984; Krzywinski & Stahell 1984; Svendsen & Mangerud 1987, 1990) . For the period before 12 000 BP, following deglaciation, the sealeve) curve for Vanna indicates a relatively low rate of uplift, in accordance with previous tentative curves constructed for the outermost areas (Marthinussen 1962; Andersen 1968; Vorren et al. 1988) .

Conclusions

(l) A lithostratigraphic and dia tom study of co res from raised, postglacial, coastal basins situated between 2 .6 m and the marine limit in an inner (Lyngen) and outer (Vanna) area of Troms, northern Norway, provided reliable evidence of sea-level change in 6 out of lO cases. Dated isolation contacts range in age from ca. 800 to ca. l l 500 14C BP.

(2) Four major facies {l-IV) characteristic of depositional environments related to sea-level change are distinguished and form the basis for recognizing a variety of simple regressive, syngressive-regressive and compound transgressive-regressive sequences. The isolation contact is generally placed at the base of transitional laminated facies Il, interpreted as having formed, in most cases, during a meromictic phase of basin evolution following isolation from the sea.

(3) Climatic fluctuations during the Late Weichselian and Early Holocene appear to have influenced the pattern of deposition in two of the basins (S4, Vl).

( 4) Sea-level displacement curves are constructed for Lyngen and Vanna, based on radiocarbon-dated isolationjingression contacts, a dated palaeosol, and the elevationjestimated age of regionally prominent shorelines. The curves show a rapid ( l 0-15 mm/yr) pre-Tapes regression (before 8500 BP) and a slow ( 1.5-3 mmjyr) post-Tapes regression (after 6000 BP).


( 5) The Tapes transgression maximum is dated to ca. 7000 BP at Lyngen, based on bracketing dates of 7880 ± 100 and 6480 ± 90 BP from a basin (L2) lying just below the Tapes shoreline. The evidence suggests that the Tapes transgression amplitude was at least 2_:_3 m at Lyngen, that the transgression extended inland to at least the 25 m isobase, and that it peaked earlier in inner areas than in outer areas.

Acknowledgements. - The fieldwork and analyses were carried out in 1981 and 1982 as part of E.H's cand. real. thesis. We thank Bjørg Stabell, University of Oslo, for teaching one of us (E.H.) the fundamentals of diatom analysis and for help with identification. We also thank: Karl-Dag Vorren and Elsebeth Thomsen, University of Tromsø, for identifying plant remains and shell fragment taxa, respectively: Marit Bernsten, Geir Elvebakk, Geir B. Larssen, Roald Olsen, Hermod and Hilbert Thomassen, and Hans Vasseng for field assistance; Hilkka Falkseth, Frøydis Strand and Liss Olsen for drafting the figures; Gunvor Granaas for photographic reproduction; and Bjørg Stabell and John Inge Svendsen for critical review. Radiocarbon dating and calibration was carried out at the Radiocarbon Dating Laboratory in Trondheim. The work was financed by the University of Tromsø.

Manuscript received March 1993

References

Alm, T. 1990: Late Weichselian vegetation and terrrestrialflacustrine environments of Andøya, northern Norway - a paleoecological study. Unpublished thesis, University of Tromsø, 263 pp.

Andersen, B. G. 1968: Glacial Geology of western Troms, North Norway. Norges geologiske undersøkelse 256, 1-160.

Andersen, B. G. 1975: Glacial geology of northern Nordland, north Norway. Norges geologiske undersøkelse 320, 1-74.

Andersen, B. G. 1979: The delgaciation of Norway 15 000-10 000 BP. Boreas 8, 79-87.

Andersen, B. G., Bøen F., Nydal, R., Rasmussen, A. & Vallevik, P. N. 1981: Radiocarbon dates of marginal moraines in Nordland, North Norway. Geografiska Annaler 63(A}, 155-160.

Anderson, R. Y., Dean, W. E., Bradbury, J. P. & Love, D. 1985: Meromictic !akes and varved lake sediments in North America. US Geologica/ Survey Bulletin 1607, 1-19.

Anundsen, K. 1978: Marine transgression in Younger Dryas in Norway. Boreas 7, 49-60.

Anundsen, K. 1985: Changes in shore-level and ice-front position in Late Weichsel and Holocene, southern Norway. Norsk Geografisk Tidsskrift 39, 205-225.

Bergstrom, E. 1973: Den prerecente lokalglaciationens utbredningshistoria inom Skanderna. Naturgeografiska institutionen, University of Stockholm. Forskningsrapport 16, 212 pp.

Bøyum, A. 1970: Some physical and chemical properties of Jak es in north-eastern Norway. Schweizerische Zeitschrift for Hydrobio/ogie 32, 299-327.

Cleve-Euler, A. 1951-55: Die diatomeen von Schweden und Finland. Kung/. Svenska Vet. Akad. Hand/. Stockh. 4, ser. 1-5.

Corner, G. D. 1978: Deglaciation of Fugløy, Troms, North Norway. Norsk Geografisk Tidsskrift 32, 137-142.

Corner, G. D. 1980: Preboreal deglaciation chronology and marine limits of the Lyngen-Storfjord area, Troms, North Norway. Boreas 9, 239-249.

Dahl, R. 1968: Late-glacial accumulations, drainage and ice recession in the Narvik - Skjomen district, Norway. Norsk Geografisk Tidsskrift 22, 101-165.

Donner, J., Eronen, M. & Jungner, H. 1977: The dating of the Holocene relative sea-leve! changes in Finnmark, North Norway. Norsk Geografisk Tidsskrift 31, 103-128.

Fimreite, S. 1980 Vegetasjonshistoriske og paleolimnologiske undersøkelser i Tromsø, Nord-Norge fra Sen Weichsel og Holocen. Unpublished thesis, University of Tromsø, 179 pp.

Florin, M. B. 1982: Light microscopical studies of Cymbella diluviana (Krasske) Florin. In: Håkansson, H. & Gerlolf, J. (eds.): Diatomaceae Ill. Nova Nedwigia, 73.

Foged, N. 1978: Diatom analysis. The Archaeo/ogy of Svedbord, Denmark l , Odense.

NORSK GEOLOGISK TIDSSKRIFT 73 (I993) Marine-lacustrine stratigraphy at Lyngen and Vanna, Troms 197

Foged, N. 1982: Diatoms in Bornholm, Denmark. Bibl. phyco/ogica 59, Cramer, Vaduz.

Freiwald, A., Henrich, R., Schiifer, P. & Willkommen, H. 1991: The significance of high-boreat to subarctic maerl deposits in northern Norway to reconstruct Holocene climatic changes and sea levet oscillations. Facies 25, 315-340.

Gulliksen, S. 1980: lsotopic fractionation of Norwegian materials for radiocarbon dating. Radiocarbon 22, 980-986.

Hafsten, U. 1960: Pollen-analytic investigations in South Norway. Vegetation, climate, shore-line displacement, land occupation. In: Holtedahl, O. (ed.): Geology of Norway, Norges geologiske undersøkelse 208, 434-462.

Hafsten, U. 1983: Shore-level changes in South Norway during the last 13 000 years, traced by biostratigraphical methods and radiometric datings. Norsk Geografisk Tidsskrift 37, 63-79.

Hald, M. & Vorren T. O. 1983: A shore displacement curve from the Tromsø district, North Norway. Norsk Geologisk Tidsskrift 63, 103-110.

Hansen, H. P. 1966: Sein- og postglasiale havnivåer i Nord-Troms. Unpublished thesis, University of Oslo.

Haugane, E. 1984: Stratigrafiske undersøkelser av kystnære basseng og strandforskyvning i nord-Troms. Unpubtished thesis, University of Tromsø, 212 pp.

Hendey, N. l. 1964: An introductory account of the smatter algae of British coastal waters. Part V: Bacillariophyceae. Fishery lnvest. 4, 1-317.

Hustedt, F. 1930: Bacillariophyta (Diatomeae). In Pascher, A. (ed.): Die Siisswasser-F/ora Mitteleuropas JO, 466 pp.

Hustedt, F. 1957: Die diatomeenflora des Fluss-Systems der Weser im Gebiet der Hansestad! Bremen. Abh. Naturw. Ver. Bremem. 34, 181-440.

Kaland, P. E. 1984: Holocene shore displacement and shoretines in Hordaland, western Norway. Boreas l 3, 203-242.

Kaland, P. E., Krzywinski, K. & Stabell, B. 1984: Radiocarbon-dating of transitions between marine and lacustrine sediments and their relation to the development of takes. Boreas 13, 243-258.

Kjemperud, A. 1981: A shoreline displacement investigation from Frosta in Trondheimsfjorden, Nord-Trøndelag, Norway. Norsk Geologisk Tidsskrift 61, 1-15.

Kjemperud, A. 1986: Late Weichselian and Holocene shoretine displacement in the Trondheimsfjord area, central Norway. Boreas 15, 61-82.

Krzywinski, K. & Stabell, B. 1984: Late Weichselian sea levet changes at Sotra, Hordaland, western Norway. Boreas 13, 159-202.

Lie, S. E., Stabell, B. & Mangerud, J. 1983: Diatom stratigraphy related to Late Weichselian sea-levet changes in Sunnmøre, western Norway. Norges geologiske undersøkelse 380, 203-219.

Mangerud, J. 1977: Late Weichselian marine sediments containing shells, foraminifera, and pollen, at Ågotnes, western Norway. Norsk Geologisk Tidsskrift 57, 23-54.

Mangerud, J. & Gulliksen, S. 1975: Apparent radiocarbon ages of recent marine shells from Norway, Spitsbergen and Arctic Canada. Quaternary Research 5, 263-273.

Marthinussen, M. 1960: Coast- and fjord area of Finnmark, with remarks on some other districts. In: Holtedahl, O. (ed.): Geotogy of Norway. Norges geologiske undersøkelse 208, 416-429.

Marthinussen, M. 1962: 14C-datings referring to shorelines, transgressions and glaciat substages in northern Norway. Norges geologiske undersøkelse 215, 37-67.

Marthinussen, M. 1974: Contributions to the Quaternary geology of north-easternmost Norway and closely adjoining foreign territories. Norges geologiske undersøkelse 315, 1-157.

Møller, J. J. 1984: Holocene shore displacement at Nappstraumen, Lofoten, North Norway. Norsk Geologisk Tidsskrift 64, 1-5.

Møller, J. J. 1985: Coastal caves and their relation to early postglacial shore levels in Lofoten and Vesterålen, North Norway. Norges geologiske undersøkelse 400, 51-65.

Møller, J. J. 1986: Holocene transgression maximum about 6000 years BP at Ramså, Vesterålen, North Norway. Norsk Geologisk Tidsskrift 40, 77-84.

Møller, J. J. 1987: Shoreline relation and prehistoric settlement in northern Norway. Norsk Geologisk Tidsskrift 41, 45-60.

Møller, J. J. 1989: Geometric simulation and mapping of Holocene relative sea-levet changes in northern Norway. Journal ofCoastal Research 5, 403-417.

Møller, J. J. & Sollid, J. L. 1972: Deglaciation chronology of Lofoten-VesterålenOfoten, north Norway. Norsk Geografisk Tidsskrift 26, 101-133.

Nordgård, 0., Normann, U., Pettersen, F. & Skarberg, N. E. 1982: Hamviljødata fra nordnorske fjorder 1981. Tromura, Tromsø Museum.

Olsson, l. U. 1979: A warning against radiocarbon dating of samples containing little car bon. Boreas 8, 203-207.

Palmer, A. J. M. & Abbott, W. H. 1986: Diatoms as indicators of sea-level change. In: van de Plassche, O. (ed.): Sea-leve/ research: a manual for the col/ection and evaluation of data, 457-481, Geo Books, Norwich.

Prentice, H. 1981: A Late Weichselian and early Flandrian pollen diagram from Østervatnet, Varanger peninsula, NE Norway. Boreas 10, 53-70.

Prentice, H. 1982: Late Weichsetian and early Flandrian vegetational history of Varanger peninsula, northeast Norway. Boreas Il, 187-208.

Rassmussen, A. 1981: The deglaciation of the coastal area NW of Svartisen, Northern Norway. Norges geologiske undersøkelse 369, 1-31.

Seed, R 1976: Ecology. In: Bayne, B. L. (ed.): Marine mussels: their ecology and physio/ogy. Cambridge University Press.

Sollid, J. L., Andersen, S., Hamre, N. Kjeldsen 0., Salvigsen, 0., Sturød, S., Tveitå, T. & Wilhelmsen, A. 1973: Deglaciation of Finnmark, North Norway. Norsk Geografisk Tidsskrift 27, 233-325.

Stabell, B. 1980: Holocene shorelevel displacement in Telemark, southern Norway. Norsk Geologisk Tidsskrift, 60, 71-81.

Stabell, B. 1981: The diatom Fragilaria virescens var. subsalina. In: F/ori/egium Florirvis Dedicatum. Striae 14, 126-129.

Stuiver, M. & Reimer, P. J. 1986: A computer program for radiocarbon age catibration. Radiocarbon 28, 1022-1030.

Strøm K. M. 1936: Land-locked waters. Det norske videnskabers se/skabs skrifter, Mat. Nat. Kl. , 1-45.

Sutherland, D. G. 1983: The dating of former shorelines. In: Smith, D. E. & Dawson, A. G. (ed.): Shorelines and isostasy. Institute of British Geographers Special Pubtication 16, 129-157. Academic Press, London.

Svendsen, J. l. & Mangerud, J. 1987: Late Weichsetian and Holocene sea-leve( history for a cross-section of western Norway. Journal of Quaternary Science 2, 113-132.

Svendsen, J. l. & Mangerud, J. 1990: Sea-levet changes and pollen stratigraphy on the outer coast of Sunnmøre, western Norway. Norsk Geologisk Tidsskrift 70, 111-134.

Sørensen, R., Bakkelid, S. & Torp, B. 1987. Nasjona/atlas for Norge, Kartblad 2.3.3, /andhevning (land uplift). Statens kartverk, Norway.

Tanner, V. 1930: Studies over kvartiirsystemet i Fennoskandias nordliga delar, IV. Fennia 53, 1-594.

Vorren, K.-D. 1978: Late and Middle Weichselian stratigraphy of Andøya, north Norway. Boreas 7, 19-38.

Vorren, K.-D. 1985: Vegetasjonshistorien i gamle Helgøy Herred, Troms, NordNorge. Publikasjon nr. 9 fra Helgøprosjektet, University of Tromsø/NAVF. 93 pp.

Vorren, K.-D. & Moe, D. 1986: The early Holocene climate and sea-levet changes in Lofoten and Vesterålen, North Norway. Norsk Geologisk Tidsskrift 66, 135-143.

Vorren, K.-D., Alm, T., Fimreite, S., Mørkved, B. & Nilssen, E. Palaeoecological syntheses for the type region of Northem Norway and palaeoecological reference area of Vesterålen-South Troms (NIII). In: Berglund, B. E., Birks, H. J. B. & Ralsha-Jasiewiczowa, M. (eds.): Palaeoecological events in Europe during the last 15 ()()() years - patterns, processes and problems. Wiley & Sons, in press.

Vorren, T. 0., Strass, l. F. & Lind-Hansen, O. W. 1978: Late Quatemary sediments and stratigraphy on the continental shelf off Troms and west Finnmark, northem Norway. Quaternary Research JO, 340-365.

Vorren, T. O. & Elvsborg, A. 1979: Late Weichselian deglaciation and paleoenvironment of the shelf and coastal areas of Troms, north Norway - a review. Boreas 8, 247-253.

Vorren, T. 0., Vorren, K.-D., Alm, T., Gulliksen, S. & Løvlie, R. 1988: The last deglaciation (20 000 to Il 000 BP) on Andøya, Northem Norway. Boreas 17, 41-77.

Marine-lacustrine stratigraphy of raised coastal basins ... · (Ill) Lacustrine (gyttjajplant detritus), and (IV) Mixed (gyttja, mud and sand/gravel). Laminated transitional facies

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