9
Quaternary International, Vols 3/4, pp. 21-29, 1989. 1040-6182/89 $0.00 + .50 Printed in Great Britain. All rights reserved. © 1990 INQUA/Pergamon Press plc THE LAST INTERGLACIAL--GLACIAL CYCLE IN FENNOSCANDIA Bjcrn G. Andersen* and Jan Mangerudt *Department of Geology, University of Oslo, P.O. Box 1047, Blindern, 0316 Oslo 3, Norway "#Departmentof Geology, Section B, University of Bergen, Alldgt. 41, 5007 Bergen, Norway The climate and glacier fluctuations during the last interglacial-glacial cycle in Fennoscandia seem to correspond roughly in time with the climate fluctuations recorded in France-Germany-Holland. However, the climate in Fennoscandia was considerably colder, and the coldest phases are recorded as periods with glacier fluctuations. Admittedly, the exact age and amplitudes of some fluctuations are still much debated. INTRODUCTION An extensive review of the glacier fluctuations in Fennoscandia was recently presented by Mangerud (in press a, b), and the following includes an updated version of his glaciation curve (Fig. 6). The climatic changes during the last interglacial- glacial cycle in western Europe (France-Netherlands- North Germany) are well known on the basis of fairly continuous pollen records. However, in Fennoscandia most of the sediments from the periods before 18 ka BP were removed by the Late Weichselian ice sheet, and mostly short stratigraphic fragments are left. There- fore, a complete record for Fennoscandia must be based on correlation and dating of stratigraphic frag- ments from various parts of the glaciated area. Con- sidering the many problems involved, particularly the dating problems, it must be stressed that there are still many unsolved questions in this record. The following is an attempt to present a rough outline of both the climatic and the glacial fluctuations in Fennoscandia during the last interglacial-glacial cycle. Figure 1 shows simplified graphs of suggested climate fluctuations from south to north in western Europe, together with an oxygen isotope graph. Graph A is based on a continuous pollen record from Grand Pile in northern France (Woillard, 1978; Woillard and Mook, 1982). Graph B is based on several correlated pollen records from North Germany-South Denmark- Holland (Behre, 1989), and graph C is a composite record from Fennoscandia. There is a striking similarity between the three graphs. The climatic fluctuations seem to have been nearly contemporaneous and of about the same order of magnitude in the three regions. The question arises -- is it so simple that the climate fluctuations were about the same in the north and the south, except that all phases were colder in the north? The graph for Fennoscandia is based on both biostrati- graphy and lithostratigraphy, and till beds correspond with the coldest phases. Therefore, the graph (C) is also a rough record of the glacier fluctuations. Connect- ing the resemblance with the deep sea oxygen-isotope graph (D) is interesting, since that graph records the global changes in ice volume. Unfortunately our knowledge of the exact age of several glacial phases in graph C is problematic, as will be seen from the following review. For the parts older than 50 ka BP all three graphs for Europe are more or less dated by correlation with the isotope curve. Therefore the resemblance between the curves is partly a result of circular reasoning. The Eemian Many sites with interglacial deposits have been recorded in Fennoscandia, and most of them have been correlated with the Eemian Interglacial (Fig. 2). Notice that most of the sites are located in areas which lay either near the center or near the periphery of the last Fennoscandian ice sheet. Most deposits in the inter- medial areas were removed by glacial erosion. Charac- teristic for all interglacial sediments is their location below Weichselian deposits, usually basal tills. Both terrestrial and marine sediments, together with speleothems in caves have been found. They in general record climatic conditions at least as warm as the present, and in several cases clearly warmer than the Holocene climate. Therefore, they represent true interglacial deposits. But are they necessarily Eemian? At most localities the correlation with the Eemian is based on the pollen stratigraphy, and only at a few localities do independent dates exist. We will not discuss the many sites, but just mention that the N-S vegetation gradient was much the same during the Eemian as today. Pollen diagrams presented by Andersen (1965) from Denmark show that mixed oak forest dominated during the warmest phase. They correspond well with diagrams from Holland and North Germany (Menke and Tynni, 1984). In diagrams from northern Finland (Hirvas and Kujansuu, 1981) and northern Sweden (Lundqvist, 1971) a Boreal type forest dominated. Two sites in southwestern Norway are of particular interest since they contain both typical interglacial terrestrial pollen-flora and marine fauna successions, 21

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Page 1: The last interglacial-glacial cycle in fennoscandia

Quaternary International, Vols 3/4, pp. 21-29, 1989. 1040-6182/89 $0.00 + .50 Printed in Great Britain. All rights reserved. © 1990 INQUA/Pergamon Press plc

THE L A S T I N T E R G L A C I A L - - G L A C I A L C Y C L E IN F E N N O S C A N D I A

Bjc rn G. Andersen* and Jan Mange rud t *Department of Geology, University of Oslo, P.O. Box 1047, Blindern, 0316 Oslo 3, Norway "#Department of Geology, Section B, University of Bergen, Alldgt. 41, 5007 Bergen, Norway

The climate and glacier fluctuations during the last interglacial-glacial cycle in Fennoscandia seem to correspond roughly in time with the climate fluctuations recorded in France-Germany-Holland. However, the climate in Fennoscandia was considerably colder, and the coldest phases are recorded as periods with glacier fluctuations. Admittedly, the exact age and amplitudes of some fluctuations are still much debated.

INTRODUCTION

An extensive review of the glacier fluctuations in Fennoscandia was recently presented by Mangerud (in press a, b), and the following includes an updated version of his glaciation curve (Fig. 6).

The climatic changes during the last interglacial- glacial cycle in western Europe (France-Netherlands- North Germany) are well known on the basis of fairly continuous pollen records. However, in Fennoscandia most of the sediments from the periods before 18 ka BP were removed by the Late Weichselian ice sheet, and mostly short stratigraphic fragments are left. There- fore, a complete record for Fennoscandia must be based on correlation and dating of stratigraphic frag- ments from various parts of the glaciated area. Con- sidering the many problems involved, particularly the dating problems, it must be stressed that there are still many unsolved questions in this record. The following is an attempt to present a rough outline of both the climatic and the glacial fluctuations in Fennoscandia during the last interglacial-glacial cycle.

Figure 1 shows simplified graphs of suggested climate fluctuations from south to north in western Europe, together with an oxygen isotope graph. Graph A is based on a continuous pollen record from Grand Pile in northern France (Woillard, 1978; Woillard and Mook, 1982). Graph B is based on several correlated pollen records from North Germany-South Denmark- Holland (Behre, 1989), and graph C is a composite record from Fennoscandia. There is a striking similarity between the three graphs. The climatic fluctuations seem to have been nearly contemporaneous and of about the same order of magnitude in the three regions. The question arises - - is it so simple that the climate fluctuations were about the same in the north and the south, except that all phases were colder in the north? The graph for Fennoscandia is based on both biostrati- graphy and lithostratigraphy, and till beds correspond with the coldest phases. Therefore, the graph (C) is also a rough record of the glacier fluctuations. Connect- ing the resemblance with the deep sea oxygen-isotope

graph (D) is interesting, since that graph records the global changes in ice volume. Unfortunately our knowledge of the exact age of several glacial phases in graph C is problematic, as will be seen from the following review. For the parts older than 50 ka BP all three graphs for Europe are more or less dated by correlation with the isotope curve. Therefore the resemblance between the curves is partly a result of circular reasoning.

The Eemian Many sites with interglacial deposits have been

recorded in Fennoscandia, and most of them have been correlated with the Eemian Interglacial (Fig. 2). Notice that most of the sites are located in areas which lay either near the center or near the periphery of the last Fennoscandian ice sheet. Most deposits in the inter- medial areas were removed by glacial erosion. Charac- teristic for all interglacial sediments is their location below Weichselian deposits, usually basal tills. Both terrestrial and marine sediments, together with speleothems in caves have been found. They in general record climatic conditions at least as warm as the present, and in several cases clearly warmer than the Holocene climate. Therefore, they represent true interglacial deposits. But are they necessarily Eemian? At most localities the correlation with the Eemian is based on the pollen stratigraphy, and only at a few localities do independent dates exist.

We will not discuss the many sites, but just mention that the N-S vegetation gradient was much the same during the Eemian as today. Pollen diagrams presented by Andersen (1965) from Denmark show that mixed oak forest dominated during the warmest phase. They correspond well with diagrams from Holland and North Germany (Menke and Tynni, 1984). In diagrams from northern Finland (Hirvas and Kujansuu, 1981) and northern Sweden (Lundqvist, 1971) a Boreal type forest dominated.

Two sites in southwestern Norway are of particular interest since they contain both typical interglacial terrestrial pollen-flora and marine fauna successions,

21

Page 2: The last interglacial-glacial cycle in fennoscandia

22 B.G. Andersen and J. Mangerud

AGE Ka.B.P.

WARM u

10-

20-

30-

40-

50-

70-

80 - SI.

90- ST.

100- ~

110-

130

COOL COLD GLACIAL

FJUSANGER

YOUNGER DRYAS ALLEROD

HENGELO

T'ARENDO

J~rIMTLAND PERXPOHJOLA

DEEP SEA OXYGEN ISOTOPE

1

2

3

4

5b

5c

5e

FIG. 1. Climate fluctuations from south to north in western Europe (three left graphs). (A) Northern France (modified from Woiilard, 1978). (B) Northern Germany-Holland (modified from Behre, 1989). (C) Fennoscandia. This graph also represents glacier fluctuations. (D) Deep sea oxygen-isotope record (modified from Martinson et al., 1987). Notice that the graphs for Europe are made to present general trends, and the exact age and amplitudes of the fluctuations can be questioned.

and they are both dated by various methods to be Eemian. A site at Fj0sanger in Bergen (Fig. 3) was described by Mangerud et al. (1981). The other site lies at Be on KarmOy, to the south of Bergen, where both the fauna and flora stratigraphy correlate very well with Fj0sanger (Andersen etal., 1983; Sejrup, 1987). Subse- quent unpublished studies and dates (amino acid thermoluminescence and uranium series) of the de- posits at BO show that there is a complete interglacial succession which is no older than the Eemian (Fig. 4).

Early Weichselian (Isotope Substages 5a-5d) The location of most of the Early Weichselian sites

are shown in Fig. 5. Notice that their distribution has a somewhat similar pattern as the Eemian sites, and particularly many sites are located in northern Finland and northern Sweden. Observations carried out in northern Sweden lately (Lagerb/ick, 1988a, b; Lagerb/ick and Robertsson, 1988) show that surpris- ingly little glacial erosion took place in that area during the Late Weichselian.

On the maritime side of the Fennoscandian ice sheet (Fig. 6), the most important sites are the two just mentioned at Fjosanger and at B0 on KarmOy (see Figs 3 and 4).

On top of the Eemian deposits at Fj0sanger (Fig. 3) there is the following succession of Early Weichselian sediments: a glaciomarine silt (G); a Fana Interstadial gravel with a cool climate marine fauna and BOnes Till. At Be there is a hiatus separating an Eemian marine sand from a Torvastad Interstadial sand which has a mild climate marine fauna (Fig. 4). The interstadial sand is overlain by a Karm0y Stadial till which is correlated with Isotope Stage 4. Amino acid ratios suggest that the Fana Interstadial is slightly younger than the Eemian, and the Torvastad Interstadial is 'considerably' younger. Therefore the two interstadials are most likely of different ages (Fig. 6). The glaciomarine silt (G) and the Bones Till show that the mountain and fjord-districts of southwestern Norway were glaciated during two Early Weichselian stadials (Fig. 6).

The pattern on the eastern, continental side of the ice sheet seems to be about the same as the pattern on the western side. Until recently most of the interstadial deposits on the eastern side were correlated with the Per/ipohjola/J~imtland Interstadial, and Lundqvist (1986) made a reconstruction with only one major interstadial (Fig, 7). A birch forest in the north and some spruce and pine in the southern districts are

Page 3: The last interglacial-glacial cycle in fennoscandia

The Last Interglacial-Glacial Cycle in Fennoscandia 23

O

.'"". : .°

O

~ O '°°%

% %.

s9 X : m a r i n e r e c o r d

o : p o l l e n ,,

s : s p e l e o t h e m -

"%.

FIG. 2. Recorded interglacial deposits which are supposed to be of Eemian age. (F) Fjosanger. (B) Be.

m

10

5 .

.=S

F=Fana interst.

'avel H

sanger ian mian)

dis Till 0 lian)

Z <~ . _ 1

1.11

"i"

w

BO SW. NORWAY

C o r r e l a t i o n Units Litholog~ Isotopq

stage i • • .

~ ~ " L a t e HAUGE , " • *" W e i c h - SUND ' , " ,7". , 2

se l i an

& ~ , . &

, v . . . . . . . . - _ - . . . - . - _ -

B 0 : .... ~: .~. . 3 M i d d l e

.~;- ---- : : .,~ ,~ W e l c h -

• • • . A s e l i a n ° ° " ° .

TORVA- " " ' " 5a OdderA_C

D, VALDS- "~"?~'"?'{:"...... NES : : . .~.: 5e E a r n -

i .' :-.-~." '__~ ".." i an

. . . . . . . . 6 ~'--=!;.~n . . . . . . _%,

s i l t c l a y

t i l l t i l l hiatus

FIG. 3. Simplified lithostratigraphy for the Fjosanger site. From FIG. 4. The lithostratigraphy at BO on KarmOy Island. Based on Mangerud (in press), based on Mangerud et al. (1981). Andersen et al. (1983) and Skinnemoen (1989).

Page 4: The last interglacial-glacial cycle in fennoscandia

24 B.G. Andersen and J• Mangerud

0

..•., . :

/ /

, 0 6 / 0

:.- i i ' ,

...... :"... "'.'"'"" 0".::

: o 3 ; t ,, O : v O ~...

../

. :/ ) o ::i

0

(7 "•'. ,

: mar ine r eco rd

o " pol len ,,

s : speleothem ,,

/ ~ marg in of f ice sheets

FIG. 5. Localities with Early Weichselian deposits, and suggested margin of Isotope Substages 5d and 5b ice sheets. The presented ice margin is speculative. The Early Weichselian deposits generally include till beds combined with organical beds.

(D) DCsebacka near Gotenburg.

characteristic for this interstadial. However, more recent studies carried out in northern Sweden by Lagerb/ick and Robertsson (1988), show that there are two Early Weichselian interstadials. The oldest, with birch forest, was correlated with the Per~ipohjola/ J/imtland Interstadial, and the youngest, the T/irend¢ Interstadial with less birch, was supposed to represent Isotope Substage 5a (see review by Lagerb~ick, this volume)• The many radiocarbon dates which have been presented from the different localities of both inter- stadials, are a mixture of infinite and finite dates between 40 and 50 ka BP. However, all dates are supposed to represent minimum ages.

Figure 5 presents a rough reconstruction of the Early Weichselian ice sheets during Isotope Substages 5b and 5d. Till beds below, between and on top of the interstadial beds in northern Sweden and northern Finland show that this part of Fennoscandia was glaciated. A buried end moraine in northern Finland (Sutinen, 1984) supposedly represents the maximum extension of the ice sheet. The Isotope Substage 5d glaciomarine bed, and the Isotope Substage 5b till bed at Fj~sanger in Bergen show that the west coast of

Norway was ice covered or partly ice covered• Till beds at D0sebacka near Gotenburg in SW-Sweden, Hillefors (1974, 1986) and at Brummundal, to the north of Oslo in SE-Norway (Helle et al., 1981) are evidence of Early Weichselian glaciations. However, no evidence of corresponding ice cover has been found in southernmost Sweden and Denmark.

During the Early Weichselian interstadials the ice sheet disappeared, and only small ice caps and valley glaciers may have survived in the high mountains•

Middle Weichselian (Isotope Stages 4 and 3)

Isotope Stage 4 The diagram in Fig. 6 suggests an extensive glaciation

during Isotope Stage 4. On the western side of the ice sheet this reconstruction is based mainly on the presence of a distinctive till bed which represents the Karm~y Stadial at Karm~y (Fig. 4). The till bed lies between the Torvastad and the B~ Interstadial beds, which are dated by various methods to be 80-90 ka BP and 50-70 ka BP old respectively. Corresponding till beds were found at J~eren (Andersen et al., 1987) which

Page 5: The last interglacial-glacial cycle in fennoscandia

The Last Interglacial-Glacial Cycle in Fennoscandia 25

W e s t e r n ( m a r i t i m e ) s i d e o f t h e i ce s h e e t .

S h e l f C o a s t M o u n t a i n s

• w e s t eas t

® Y o u n g e r D r y a s ~

========================================================================================== ===================================

================================== Alesund ,J¢ ~.. . . . . . . . . . . . . . , : . ' . ' . ' . ' . ' - ' . ' - ' . ' . ' . :Denekamp

G S a n d n e s 9 r .'.'-'.'-'- -'~'*:.'.'. '. '. '.! )

"-[ . . . . . . . . . . . "-=-" "+:':':':':':';';';':" "':':'-'"'1 ==================================== S a n d n e $ ? , - . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . 'Moers-

K ~.:.:.:-:.:-:.:.:-:.:.:.:.:.: nO 'd Bo* :::::::::::::::::::::::::::::::::: /..:-1.:.:.:.:.1.1.:.1-:.1-:.1-:.:-: ®

:::::::::::::::::::::::::::::::::::::::::::::::::::::: t . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . • .'." ".'.'.'.'.'. K a r m e y .'. '. '. '.-.-.', '.-.',-.', '. '. '. '. '. ', '. ' ~:::::[:::::::::::::::::::::::::::::::::::::::::::::::::::::: t ......................./..............-.......................... • j ,:---..-.-.'.'.'.'.'.'.'.'.-.'.-.'.-.'.:.:.:.'.'.'.:.:.:.:.:.;.;.:.:.:.:

m o

M Tor v a s l a d ~ t

/ , . . . . ;- . . . . . . . . . . . . . . . . , = ........ . . . . . . . . . . . . . . . . . . . . . . . . j ; _ ®

t . - . . . - .Bones Till . . . . . . " . . ' . ~'~i "-" .... -'-'- ..... '"""'".',"': ':= =o

"-',L.: :.:.:-:

o~

m

o

"6

o o o

II

~, 1

Q.

g 4O

~ 3 ."2- 5(]

6C

4

5a .8(

5b .9(

5C !0

5d -11

E a s t e r n ( c o n t i n e n t a l ) s i d e o f t h e i ce s h e e t .

M o u n t a i n s F i n l a n d

w e s t / n o r t h

.o 0 o lil I ( ~ F l e s a n g e n a n - 5e 13(]

I I I ~ ) F a u n a s u g g e s t i n g c l i m a t e a s t o d a y , o r w a r m e r .

~. F a u n a w i t h A t l a n t i c C u r r e n t " g u i d e f b s s i l s " .

s o u t h

D a n e m a r k

".'.'.'.'.'.'.'.'.'-'.'".X.Z.'.Z.X.X.X.Z.~-','-'-'-'-'- . . . . . .

30 ". '. ' . ' . ' . '- '- ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' I :-:-:.~.~." :.:.:.:.:.:.:.1.:.:.:.:-:.'.:.:.:.1.'.:-:4 .:.?~.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.1 '.'." ;.k;-'.'.'.'.:.:.:.:.:.'.'-'.'.'.'.'.'.'.'.'.: • . - . ' . ' . . . ,'.'.'." . . . . . . ..........%......-.-.] . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' I " . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . ' . '4 -:-:.:-:.:.:.:.:.:.:.:.:.:.1.:.:.:.:.:.:.:.'.:.:.:.:.'i ::::::::::::::::::::::::::::::::::::::::::::::::::::::: :':.:-:.:.:.:.:.:.'.Z':-:':':.:-:.:.:':.:-:.:.:.:':'] .:-'.:-'.:.'.:.'.Z.'.:.'.:.'.Z-'-.-'-:.'.:.Z.'.:~ :.:.:.:.:.:.:.:.:.:.Z.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.T.~.-"3.7..t :::::::::::::::::::::::::::::::::::::::.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:~ ....-...............,.'.-.'.'.-.....................'.'.'.-...-.-.-.-.r

T~ i rendo O Desebacka 9

V~i lbackan / J a m l l a n d

. . . . . . . . . . . /

~ a l e n G u d b r a l l d s d a l e n 9 P d g r i m s l a d / J i m l l a n d

I e p s a n k u m p u a n d other Finnish siles

Leve~r~emi

FIG. 6. Schematic glaciation curves for the last interglacial/glacial cycle in Fennoscandia. Slightly modified from Mangerud (in press) where a complete reference list is given. Ages for the isotope-stage boundaries from Martinson et al. (1987).

suggest that the entire SW coast of Norway was glaciated during Isotope Stage 4. Sejrup (pers. commun.) has suggested that the ice sheet covered the northern part of the North Sea and merged with the British ice sheet during Isotope Stage 4 or 5. However, better evidence is needed to be sure about his reconstruction.

Problems relating to the Isotope Stage 4 glaciation are not less on the eastern side of the ice sheet. It is generally believed that the ice sheet covered much of Fennoscandia, but there are not many localities where Isotope Stage 4 glacial deposits have been clearly identified and dated. The best is probably DOsebacka in SW-Sweden (Hillefors, 1986). Petersen (1984) have observed a till of a possible Isotope Stage 4 age at Holmstrup in Denmark, and thermoluminescence dates of glacial deposits in NW-Denmark indicate that they could be of Isotope Stage 4 age (Kronborg, 1988). A fairly extensive ice sheet, at least in the Baltic Sea

area, including southern Denmark, agrees well with observations made in Poland (Mojski, 1985). In Fig. 8 we have suggested two (3) alternative extensions of the Isotope Stage 4 ice sheet both in the North Sea region and in the Baltic Sea region. At present it is difficult to decide which alternative is most correct.

Isotope Stage 3 (Fig. 9) On the west coast of Norway, there is good evidence

of a B~ Interstadial about 40--60 ka BP recorded at KarmCy (Fig. 4; Andersen et al., 1983; Sejrup 1989) and an Alesund Interstadial about 30 ka BP best dated in a cave near/~lesund (Larsen et al., 1987; Larsen and Mangerud, this volume). The faunas in both intersta- dials suggest cool climate conditions. New radiocarbon dates of deposits correlated with the Sandnes Intersta- dial (Feyling-Hanssen, 1971) on J~eren in SW-Norway (Fig. 6), suggest that this interstadial is older than previously assumed, and it could correspond with the

Page 6: The last interglacial-glacial cycle in fennoscandia

26 B.G. Andersen and J. Mangerud

t000 Ym

BP NORTH SWEDEN SOUTH SWEDEN CONTINENT _ I FINLAND NORWAY DE NMARK

t0

Y I~sebackQ- Eilesbo

GSta 8Iv

Gudbmndsdalen Denekarnp

He~jeto

Moershoofd

~0

6° t

Per~pohjokz O. DSsebacka - Etlesbo Odderade

Br6rup

Amersfoort

EEM

FIG. 7. Weichselian glacier fluctuations in Fennoscandia. From Lundqvist (1986).

BO Interstadiai or be somewhat younger (Andersen et al., in press). The Sandnes Interstadial deposits contain some glaciomarine beds and even till beds have been observed in the glaciomarine units which were corre- lated with the Sandnes Interstadial.

Several localities with Middle Weichselian marine deposits have been found in Denmark, the most famous being the Sk/irumhede. Lykke-Andersen (1987) presented a review of the stratigraphy where two, possibly three small Middle Weichselian climate fluctuations were recorded (Fig. 10). However, no Middle Weichselian tills have been found in Denmark or at the interstadial sites in southernmost Sweden. Till beds connected with the interstadial beds at D6sebacka near Gotenburg show that this area was ice-covered during the middle Weichselian stadials.

Within areas that were located below the central parts of the Fennoscandian ice sheet there are almost no interstadial deposits which have been referred to the Middle Weichselian (Fig. 9). The reason could be that central Fennoscandia was ice-covered during the entire Middle Weichselian, as suggested by many scientists. However , some finite Middle Weichselian radiocarbon

dates have been obtained, but they have been rejected as being contaminated. The main argument against a Middle Weichselian age has been that the dated deposits record forests, and as forest did not exist in North Germany after the Odderade, they could not have grown in Fennoscandia either. Eolian deposits from Gudbrandsdal Valley in central south Norway have been TL-dated to around 40 ka indicating that the area could have been deglaciated at that time (Bergersen, 1989). If that date is correct, then much of Fennoscandia must have been deglaciated. This possi- bility was indicated by Lundqvist (1986; Fig. 7).

Late Weichselian (Isotope Stage 2) A review of the extent of, and the retreat of the ice

sheet was presented by Lundqvist (1986). However, Isotope Stage 2 is beyond the scope of this paper.

REFERENCES

Andersen, B.G., Sejrup, H.P. and Kirkhus, O. (1983). Eemian and Weichselian deposits at BO on KarmOy, SW Norway: A preli- minary report. Norges Geologiske Undersckelse, 380, 189-201.

/

Page 7: The last interglacial-glacial cycle in fennoscandia

The Last Interglacial-Glacial Cycle in Fennoseandia 27

I i I:

/ /

, i

S f • J ' j ~

• /

N ~ v f ! ~ . S

/ /

f _

f

%

I

! /

/ / t

A l t e r n a t i v e 1

s o ~

o s J I ! 2

e e ~

• recorded glacial depos i t s

FIG. 8. Isotope Stage 4 ice margin (three alternatives) and glacial deposits that are correlated with Isotope Stage 4. (J) J~eren. (H) Holmstrup. (D) Desebacka. (B) Be on Karmey. (A,) A.lesund.

Andersen, B.G., Wangen, O.P. and Ostmo, S.R. (1987). Quater- nary geology of Ja~ren and adjacent areas, southwestern Norway. Norges Geologiske Undersekelse, Bulletin, 411, 1-55.

Andersen, B.G., Bakken, K., Dale, B., Fugelli, E., Henningsmoen, K., H~egh, H.I., Nagy, J., Read, A. and Telleman, H. (inpress): Weischselian stratigraphy at Oppstad, Hegemork and Foss- Eikjeland, J~eren, SW-Norway. Striae, 34.

Andersen, S.T. (1965). Interglasialer og interstadialer i Danmarks kvartaer. Meddeleser Dansk Geologisk Forening, 15, 486-506.

Behre, K.E. (1989). Biostratigraphy of the last glacial period in Europe. Quaternary Science Reviews, 8, 25-44.

Bergersen, O.F. (1989). Was central Scandinavia deglaciated around 40,000 years before present? Terra Abstracts, 1(1), 63-64.

Feyling-Hanssen, R.F. (1971). Weichselian interstadial foraminifera from the Sandnes-J~eren area. Bulletin of the Geological Society of Denmark, 21, 72-116.

Helle, M., Senstegaard, E., Coope, R.G. and Rye, N. (1981). Early Weichselian peat at Brumunddal, southeastern Norway. Boreas, 10, 369-379.

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Page 8: The last interglacial-glacial cycle in fennoscandia

28 B.G. Andersen and J. Mangerud

d.

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/ /

/ 0

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e.~

/

J- / S .."

. , ° .

°,

. o ' ° . :

m ~

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' °

11

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U

°o~ °

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¢.

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%.

x : m a r i n e r e c o r d

o : p o ] l e n ,,

$ : s p e l e o t h e m ,,

C : c a v e °,

e : e o l i a n "

/ ~ m a r g i n o f i c e s h e e t

FIG. 9. Suggested maximum extension of the Isotope Stage 3 ice sheet, and localities with Isotope Stage 3 deposits. (C) Alesund. (J) Jaeren. (S) Sk~rumhede.

northern Europe, and its correlation with the deep sea isotope stratigraphy. Manuscript submitted to University of Minnesota Press, May 1988.

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Page 9: The last interglacial-glacial cycle in fennoscandia

The Last Interglacial-Glacial Cycle in Fennoscandia 29

FORAMINIFERAL ASSEMBLAGE

ZONES

MACROFOSSIL ZONES AND SUBZONES

D

Ka. CHRONO- ZONES ~ B.P.

N.labra- I doricom' Macoma

I.norcrossi calcarea

]] E.ask., N.orbic.

~_ CC.ren., I.nor. Porl- E.albium- landia

]~ bilicum arctica Balanus B.rnarginala crenat.

~r E.excav. N,orbic.

~ ] / g n I.norc., I.isL Turr. erosa

E.mar., E.gert. Abra nilida

Elphidium ge~hi Upper

Turritella Nonion terebra depressu- lum

Lower B.marginata Turritella Q.padana terebra

Ep.vitrea Nuculana pern. N.labrador. N.minuta

\ DENEKAMP -- 30

I HENGELO

3 - 40 IAL

- 5 0 MOERSHOOFD

. . . . . . IAL 4 - 70

ODDERADE? a _ 80

I b - 9 0 5 BRONUP?

I C --100

AMERSFORT? d -110

- 120 EEMIAN 5e

~ '~STADIAL -- 130 6

/

FIG. 10. Marine stratigraphy in Denmark, modified from a section of a larger compilation presented by Lykke-Andersen (1987). The curve is a simplified temperature curve. Notice that it shows no Early Weichselian interstadials.