Brage NP

Nøst, Ole Anders

Kart over Antarktis med isbremmene markert i mørk blå, is som ligger på land i hvit og 
hav i lys blå farge.
Isbremmer i 
Dronning Maud Land
Omtrent 10 % av landområdene i Antarktis er isbremmer, dvs. isbreer som 
flyter på havet. I Antarktis er det ingen elver, men store mengder ferskvann 
renner ut i havet når undersiden av isbremmene smelter. Nyere forsknings-
resultater viser at den største ferskvannstilførselen til havet rundt Antarktis 
kommer fra isbremmene langs kysten av Dronning Maud Land.
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Dronning Maud
Land
Weddell Sea
0º East Grennwich30º West Grennwich 30º
60º
90º
80
º
70
º
60
º
0 1000 km
Scale at 70º South
Fimbulisen
Kaldt hav og sjøis
Isbremmene består av mellom 100 og 2000 meter tykk is, og ferskvann 
fra smelting på undersiden av isbremmene er svært viktig for havsirku-
lasjonen og isdekket rundt Antarktis. Ferskvannet som renner ut i havet 
danner et lett overflatelag med ferskt og kaldt vann. Dette overflatelaget 
isolerer for varme nedenfra og gjør det mulig å danne sjøis. På den 
andre siden av kloden er det ferskvann fra de store elvene i Sibir og 
Alaska som danner overflatelaget. Uten dette ville isdekket i Arktis vært 
betydelig mindre enn det er i dag, og dyreliv og klima ville hatt helt andre 
betingelser. 
Det spesielle med havområdene langs kysten av det norske kravområ-
det i Antarktis, er den smale kontinentalsokkelen. Kontinentalsokkelen 
er grunn, og vannet på sokkelen blir avkjølt fra overflate til bunn mye 
raskere enn over dyphavet. Foran de store isbremmene i Weddellhavet 
og Rosshavet (Filchner-Ronne og Ross) ligger det flere hundre kilo-
meter med kontinentalsokkel, og temperaturen i vannet som omgir 
isbremmene ligger nær frysepunktet, noe som gir lav smelting. 
Fimbulisen 
Isbremmene langs Dronning Maud Land flyter flere steder utover dypt 
vann. Havdypet under den nordligste delen av Fimbulisen er nesten 
3000 meter. Her er isen mye mer utsatt for smelting da disse isbremm-
ene har kontakt med vann som har temperaturer 2-3 grader over fryse-
punktet. 
Fimbulisen er, til tross for sin noe beskjedne størrelse, den isbremmen i 
Antarktis som tilførerer havet mest ferskvann. Estimater fra forsknings-
modeller tyder på at mengden ferskvann fra Fimbulisen kan sammen-
lignes med vannføringen i en av de store sibirske elvene som renner ut
i Polhavet. Dette ferskvannet har stor betydning for utbredelsen og tyk-
kelsen av isdekket i Weddellhavet og for dannelsen av bunnvann. 
Forskning på isbremmer 
Fimbulisen har inntil ganske nylig blitt ansett som en liten og ganske 
ubetydelig isbrem, og prosessene som styrer sirkulasjon og smelting un-
der Fimbulisen er derfor lite kjent. I løpet av de siste årene har derimot 
interessen for Fimbulisen økt betydelig også internasjonalt. Havet spiller 
en viktig rolle i klimautviklingen, og det er stort behov for å bedre forstå 
prosessene både i sør og i nord. 
Smeltingen på undersiden av en isbrem er avhenging av sirkulasjonen av 
havvann under isbremmen. For å si noe om dette er vi i første omgang 
nødt til å skaffe informasjon om havdypet under bremmen. Istykkelsen 
og havdypet under Fimbulisen ble kartlagt av forskere fra Norsk 
Polarinstitutt under Norwegian Antarctic Research Expedition (NARE) 
2000/2001. Dette datasettet har åpnet for muligheten til å modellere 
69.6S
70,0S
70,4S
70,8S
71,2S
71,6S
3W  2W  1W  0W  1E  2E  3E  4E  5E  6E
1200
1120 
1040
960 
880 
800 
720
640 
560
480
400
320
240
160
80
0
69,4S
69,8S
70,2S
70,6S
71,2S
71,4S
3W  2W  1W  0W  1E  2E  3E  4E  5E  6E
10
13
12
11
10
9
8
7
6
5
4
3
2
1
Tekst og figurer: Ole Anders Nøst, nøst@npolar.no. Design: J. Roald
Tykkelsen av Fimbulisen i meter.
Havdypet under Fimbulisen i meter. Isfronten er markert med en svart linje. Is som 
ligger på grunn er grå.
Havsirkulasjon på 450 meters dyp under Fimbulisen fra en numerisk havmodell. Pilene 
viser sirkulasjonens retning og fargene viser strømhastigheter i cm/s.
Modellert smelting under Fimbulisen i cm/år.
   2oW    0
o     2oE    4oE    6oE 
 20’ 
  71
oS 
 40’ 
 20’ 
  70
oS 
 40’ 
 100 150 200 250 300 350 400 450 500 550
15
00
20
00
   2oW    0
o     2oE    4oE    6oE 
 20’ 
  71
oS 
 40’ 
 20’ 
  70
oS 
 40’ 
 0 100 200 300 400 500 600 700 800 900 1000 1100
strømningene og smeltingen under Fimbulisen i detalj. Forskere fra 
British Antarctic Survey ønsker å sende en liten u-båt, ustyrt med 
avanserte instrumenter, inn under Fimbulisen i 2005, noe som er 
mulig fordi man nå kjenner topografien under Fimbulisen.
Nye muligheter for klimaforskning
Til tross for at isbremmene i Dronning Maud Land er av stor betydning 
for ferskvannstilførselen til havet rundt Antarktis, støtter foreløpig ingen 
av estimatene som er gjort av smeltingen seg på feltbaserte målepro-
grammer. Dette er derfor det neste steget for å finne ut mer om betyd-
ningen av isbremmene i Dronning Maud Land. Fimbulisen ligger bare 
noen timers kjøring med snøskuter fra den norske forskningsstasjonen 
Troll, og med den nye landingsstripen og helårsstasjonen – som begge 
åpnet i februar 2005 – har forskerne en unik mulighet til å utforske 
isbremmene langs kysten av Dronning Maud Land. 


Norwegian

Isbremmer i Dronning Maud Land

Dallmann, Winfried

Elvevold, Synnøve

Geokart : geologisk kartlegging i de norske polarområdene : Svalbard, Jan Mayen, Dronning Maud Land

Trollposten 2/2007

Rotschky, Gerit

Holmlund, Per

Isaksson, Elisabeth

Mulvaney, Robert

Oerter, Hans

van den Broeke, Michiel

Winther, Jan-Gunnar

English

A new surface accumulation map for western Dronning Maud Land, Antarctica, from interpolation of point measurements

Kohler, Jack

Antarctica is well known as the coldest place on 
Earth, but it is also surprisingly wet. Whereas 
the upper part of the ice is cold, geothermal 
heat and the insulating effect of the overlying 
ice combine towards its base to bring extensive 
areas of ice at the bed to its melting point. In 
the most extreme cases, lakes form beneath the 
ice sheet. In the past 20 years more than 150 
such subglacial lakes have been discovered; 
Lake Vostok, at 15,690 km2 about three-quar-
ters the size of Wales, is the largest and best 
known1. As satellites provide better coverage 
and higher-resolution imagery of the Antarctic 
ice sheet, more and more such lakes are being 
found. On page 904 of this issue, Bell et al.2 
present satellite and ground data that reveal 
four additional lakes in Dronning Maud Land 
(sometimes referred to in English as Queen 
Maud Land), East Antarctica. These lakes are 
remarkable not only for their size, but also for 
their location, which is just where the flow of 
the ice sheet begins to accelerate. 
Investigations of the base of the Antarctic 
ice sheet began in the 1960s, when glaciolo-
gists used ground-based and airborne radars 
to map the ice’s thickness. Ice is transparent to 
radar over a wide range of frequencies, so the 
boundary between ice and bedrock is readily 
detected, even through several kilometres of 
ice. Water reflects radar energy more strongly 
than rock, making it easy to identify those parts 
of the bed that are wet. Early on, very bright 
radar reflections delineating a relatively flat 
boundary were recognized as the distinctive 
signature of subglacial lakes. The largest sub-
glacial lakes can also be detected using remote 
sensing: the surface topography above lakes is 
unusually flat (Fig. 1).
Subglacial lakes were initially thought to be 
essentially stagnant, with water moving into 
or out of them at a trickle. But our view of the 
Antarctic basal drainage system has changed 
profoundly in light of recent observations. 
First, satellite radar altimetry data from East 
Antarctica revealed that the ice surface had 
dropped suddenly in one area while simulta-
neously rising at another location hundreds 
of kilometres away3,4. This drainage event, in 
which large amounts of water had flowed from 
one subglacial lake to another, occurred over 
the relatively short period of about 16 months. 
Laser altimetry data from the West Antarctic 
ice streams have since exposed a rich variety of 
lake drainage events, a veritable roiling of the 
ice surface up and down as water is squeezed 
from one part of the ice stream to another5.
Bell et al.2 supply the latest evidence for a 
link between subglacial water and the dynam-
ics of the ice sheet above. The four subglacial 
lakes that they have discovered are in the drain-
age basin of the Recovery Glacier ice stream, 
which empties into the Filchner Ice Shelf off 
Antarctica at a longitude of about 30° W. These 
Recovery lakes are not only located in a part of 
the continent with relatively few known lakes, 
but they are also very large; two are exceeded in 
size only by Lake Vostok. What is most interest-
ing about the Recovery lakes, however, is that 
they sit at the upstream end of one of the largest 
of the ice streams that drain the interior ice of 
the high polar plateau, just where ice velocities 
start to increase. Upstream of the lakes, the ice 
sheet moves at a leisurely 2–3 metres per year; 
downstream of the lakes it suddenly flows at 
about 50 m yr1 towards the Filchner Ice Shelf, 
and eventually into the Weddell Sea. 
So how exactly does water underneath an 
ice sheet affect ice dynamics? As ice flows over 
a lake, the friction at its base vanishes and its 
speed increases (see Fig. 1). Furthermore, the 
freezing of lake water on the underside of the 
ice sheet adds thermal energy to the basal ice. 
This prevents the ice from freezing onto the 
bedrock when it hits the ground again, and also 
allows faster flow, as warm ice is much softer 
than cold ice. Nevertheless, for most of the sub-
glacial lakes discovered so far, the surrounding 
ice apparently buttresses the ice over the lake 
and prevents faster flow. Bell et al. suggest that 
the location of the Recovery lakes at the onset 
of a fast-flowing ice stream provides the first 
evidence that subglacial hydrology could be 
responsible for the initiation of an ice stream, 
Ice sheet
Lake
Transmitted wave
Received wave
Bedrock
Radar vehicle
Satellite
GLACIOLOGY 
Lubricating lakes
Jack Kohler
More than 150 subglacial lakes have been discovered beneath the Antarctic 
ice sheet. The four most recent additions, found right at the start of fast 
flow in a large ice stream, suggest that the lakes influence ice dynamics.
Figure 1 | Slippery slope. The relative strength of reflection of ground-based radar distinguishes 
between bedrock and water at the base of an ice sheet, and the characteristic flat area in the ice 
surface above a subglacial lake can be detected by satellite-based surface observations. Using satellite 
measurements, Bell et al.2 find four subglacial lakes right at the onset of fast ice flow at the Recovery 
Glacier ice stream in Dronning Maud Land, Antarctica. They propose that the freezing of lake water 
to the base of the ice sheet (pink area), together with water spilling over from the lake and scouring the 
bedrock, could reduce friction and help speed up ice flow towards the sea.
Young Drive South, Los Angeles, California 
90095-7088, USA. 
e-mail: csabatti@mednet.ucla.edu
1. Sladek, R. et al. Nature 445, 881–885 (2007).
2. Grant, S. F. A. et al. Nature Genet. 38, 320–323 (2006). 
3. Kubo, M. et al. Nature Genet. 39, 212–217 (2007).
4. Hampe, J. et al. Nature Genet. 39, 207–211 (2007).
5. Klein, R. J. et al. Science 308, 385–389 (2005).
6. Maraganore, D. M. et al. Am. J. Hum. Genet. 77, 685–693 
(2005).
7. DeWan, A. et al. Science 314, 989–992 (2006). 
8. Duerr, R. H. et al. Science 314, 1461–1463 (2006).
9. The International HapMap Consortium Nature 437, 
1299–1320 (2005).
10. Cardon, L. R. Science 314, 1403–1405 (2006).
11. Service, S. K. et al. Nature Genet. 38, 556–560 (2006).
830
NATURE|Vol 445|22 February 2007NEWS & VIEWS
Figure 2 | Scenes from above the shores of the Recovery lakes. The 1965–66 US–UK South Pole–
Queen Maud Land traverse, showing a Sno-Cat tractor and, in the background, a ‘rolly’ tyre set 
containing fuel, and the ice-sounding radar antennae. The tractor is just crossing a crevasse at the edge 
of the Recovery ice stream, near where Bell et al.2 have now discovered four subglacial lakes.
either by changing the ice sheet’s basal thermal 
regime or by introducing water into the path 
of the ice stream through periodic drainage 
events.
If this proves to be the case, it would sub-
stantially change our understanding of the 
effect of subglacial lakes on ice-sheet stabil-
ity. It indicates that basal hydrology needs 
to be accounted for in numerical models of 
ice-sheet motion because it has the potential 
to rapidly induce fast flow. The recent sudden 
acceleration of ice streams in Greenland6,7, and 
its resultant effect on the mass balance of the 
Greenland ice sheet8, underscores the impor-
tance of understanding the dynamics of ice-
sheet response to climatic change.
Might the geographical coincidence of the 
Recovery lakes and the start of fast flow be just 
that, a coincidence? So far we have not seen 
any other large subglacial lakes at the heads of 
ice streams. But Antarctica remains one of the 
most poorly mapped parts of our planet — we 
know more about the surface of the dark side 
of the Moon than we do about the bedrock or 
even the surface topography of Antarctica. 
Antarctica’s surface is being mapped at ever 
higher resolution with remote-sensing satel-
lites such as NASA’s ICESat or the planned 
European Space Agency mission CryoSat-2, 
but radar imaging of the bedrock is not keep-
ing pace. Proposed missions to put ice-sound-
ing radar instruments on board a satellite, with 
the goal of mapping the bed in Greenland and 
Antarctica, have yet to be approved. For now, 
continued airborne and ground-based geo-
physical exploration is the only way forward 
for imaging the ice sheet’s base. 
During the forthcoming International Polar 
Year, a number of land traverses and aerial 
campaigns are planned for Antarctica. In 
2008, a Norwegian–US traverse will survey the 
Recovery lakes area. This was last visited by the 
US–UK traverse from the South Pole to Dron-
ning Maud Land in 1965–66. Interestingly, that 
early expedition, which was equipped with one 
of the first radars, also crossed over the lakes 
discovered by Bell and colleagues (Fig. 2). The 
radar equipment was relatively primitive and 
used only intermittently, so the lakes were not 
identified in the field. But a logbook duly noted 
that Gordon de Q. Robin, then head of the 
Scott Polar Research Institute in Cambridge, 
UK, and one of the pioneers of radar glaciol-
ogy, had suggested the existence of a “…pos-
sible melt-layer at the bottom of ice cap”. 
The implications of this early prediction for 
ice flow are just starting to be appreciated, as 
Bell et al.2 make the link between subglacial 
lakes and the onset of one of the largest ice 
streams in Antarctica. ■ 
Jack Kohler is at the Norwegian Polar Institute, 
Polar Environmental Centre, N-9296 Tromsø, 
Norway.
e-mail: jack.kohler@npolar.no
1. Kapitsa, A. P., Ridley, J. K., Robin, G. de Q., Siegert, M. J. & 
Zotikov, I. A. Nature 381, 684–686 (1996).
2. Bell, R. E., Studinger, M., Shuman, C. A., Fahnestock, M. A. 
& Joughin, I. Nature 445, 904–907 (2007).
3. Clarke, G. K. C. Nature 440, 1000–1001 (2006).
4. Wingham, D. J., Siegert, M. J., Shepherd, A. & Muir, A. S. 
Nature 440, 1033–1036 (2006).
5. Fricker, H. A., Scambos, T., Bindschadler, R. & Padman, L. 
Science doi:101126/science.1136897 (2007).
6. Joughin, I., Abdalati, W. & Fahnestock, M. Nature 432, 
608–610 (2004).
7. Luckman, A., Murray, T., de Lange, R. & Hanna, E. Geophys. 
Res. Lett. 33, L03503 (2006).
8. Zwally, J. et al. Eos Trans. AGU 87, Fall Meet. Suppl., Abstr. 
C14B-03 (2006).
PHYSICAL CHEMISTRY
Oil on troubled waters
David Chandler
The nature of the boundary between water and oil is crucial to many 
nanometre-scale assembly processes, including protein folding. But until 
now, what the interface really looks like remained in dispute.
At the boundary between liquid water and water 
vapour, an interface forms that is marked by an 
area of lower-than-average density. The same 
sort of ‘depletion layer’ also occurs when water 
comes into contact with a sufficiently large 
hydrophobic surface — oil, in the most notori-
ous instance, and various other organic mole-
cules. According to theory, this happens because 
hydrophobic surfaces provide no opportunity 
for water molecules to establish their usual 
hydrogen bonds. Without this adhesive force, 
the molecules move away from the surface to 
seek such bonds in the bulk of the liquid. 
As lucid as this explanation might seem, 
experimental confirmation has so far been sur-
prisingly elusive. But at last two independent 
groups of researchers — Poynor et al.1, writing 
in Physical Review Letters, and Mezger et al.2, 
writing in Proceedings of the National Acad-
emy of Sciences — provide experimental con-
firmation of a depletion layer at the interface 
between water and a hydrophobic surface. And 
calculations of the molecular dynamics of water 
confined by two surfaces with nanometre-
scale patterns of hydrophobic and hydrophilic 
regions, described by Giovambattista et al.3 in 
the Journal of Physical Chemistry C, provide 
further grist to the mill.
The prediction that liquid water borders 
with oil in the same way it does with vapour 
was first made more than 30 years ago4. Since 
then, the idea has been bolstered by further 
theoretical analysis5, and has helped in under-
standing the forces that stabilize the assembly 
of hydrophobic molecules, among them the 
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NATURE|Vol 445|22 February 2007 NEWS & VIEWS


Lubricating lakes

Miljeteig, Cecilie

Strøm, Hallvard

Gavrilo, Maria

Skåre, Janneche Utne

Jenssen, Bjørn Munro

Gabrielsen, Geir Wing

Organohalogens and mercury in ivory gull eggs

von Quillfeldt, Cecilie H.

Økosystembasert forvaltning av Barentshavet og havområdene utenfor Lofoten : rapport fra Faglig forum til den interdepartementale styringsgruppen for forvaltningsplanen

Blomeier, Dierk

Ohta, Yoshihide

[Svalbards geologi] - japansk tekst

GEOLOGY OF THE LAND AND SEA AREAS OF NORTHERN EUROPE SPECIAL PUBLICATION 10 -  87
Tectonic setting
The archipelago of Svalbard forms the 
emergent northwestern corner of the 
Barents Sea Shelf, which was uplifted by 
Late Mesozoic and Cenozoic crustal move-
ments. The area provides a splendid insight 
into the varied geological structure and 
geo-historical development of the north-
western Barents Sea since the Palaeo-
proterozoic. The geological record ranges 
from possi ble Archaean to Recent and 
shows a multi-oro genic development with 
prominent tectonic events of Grenvillian 
(Late Mesoproterozoic), Cale donian (Or-
do vician-Silurian), Ellesmerian or Sval-
bard ian (Late Devonian), Variscan (Middle 
Carbo niferous) and Alpidic (Early Tertiary) 
age. 
North of Svalbard, 50-100 km from the 
shore, a steep passive continental margin 
with slopes up to 10° (average 4°) forms 
the boundary with the Eurasian Basin of 
the Arctic Ocean. Offshore to the west of 
Svalbard, a 40-80 km-wide shelf separates 
the coast of the main island, Spitsbergen, 
from a structurally complex oceanic area, 
an active mid-ocean ridge, the Knipovich 
Ridge. The central part of this ridge is a 
spreading axis which is segmented by a 
transform fault system, the Spitsbergen 
Fracture Zone in the north, and the Molloy 
Fracture Zone in the south. 
The northwestern shelf corner borders the 
Yermak Plateau, the northern part of which 
may be all that remains of an Early Tertiary 
hot spot. Late Cretaceous thermal uplift, 
Early Tertiary shoulder uplift along the 
rifted margin of the developing Arctic 
Ocean, and subsequent transform move-
ments in a periodically transpressive re-
gime along the western margin may all 
have their share in explaining the uplift of 
the archipelago and especially of its west-
ernmost and northernmost parts. 
Pre-Old Red Sandstone basement
The pre-Old Red succession (key map 11, 
10) is exposed in the west and north of the 
archipelago. U-Pb zircon isotopic age de-
terminations have revealed relict elements 
of several Precambrian events (1800-1700 
Ma, 1400 Ma and two or three older ones), 
the Grenvillian tectonothermal event 
(1000-950 Ma) and the Timanian 
(Baikalian) movements (650-600 Ma). 
These events are followed by two phases of 
Caledonian folding and thrusting, includ-
ing evidence for an oceanic suture zone in 
the western province (Fig. 1). 
The pre-Old Red is subdivided into three 
different tectonostratigraphic basement 
provinces, whose structure, sedimentary 
record and tectonothermal evolution differ 
from each other. All of these consist mainly 
of metamorphosed supracrustals (327, 
326), whose lower structural levels were 
granitised and migmatised during several 
of the tectonometamorphic events in the 
two northern provinces (410). Their juxta-
position occurred probably during the 
Caledonian period, though no consensus 
about the mechanisms involved yet exists. 
Geology of Svalbard
WINFRIED K. DALLMANN
Norwegian Polar Institute, Polarmiljøsenteret , 9296 Tromsø, Norway. 
E-mail: winfried.dallmann@npolar.no
Fig. 1. Interlayered eclogite and blueschist 
in the high-pressure metamorphic, 
Vestgötabreen Complex, Motalafjella, wes-
tern Spitsbergen. The formation of the 
complex was related to subduction along 
an orogenic suture zone during an Early 
Caledonian metamorphic event in 
Ordovician time. Photo: Synnøve Elvevold.
88  -  SPECIAL PUBLICATION 10 GEOLOGY OF THE LAND AND SEA AREAS OF NORTHERN EUROPE
oped along older tectonic lines. With wan-
ing tectonic movements in later 
Carboniferous time, most of Svalbard de-
veloped into a carbonate platform (Fig. 3) 
with episodes of evaporite formation 
(middle part of 140). These conditions 
lasted through the Early Permian, while 
the later part of the Permian experienced 
renewed clastic influx and a subse quent 
hiatus at the era boundary (upper part of 
140). The latest Permian is represented by 
a hiatus throughout Svalbard.
Late Palaeozoic sedimentation in the 
Svalbard-Barents Sea area was continuous 
with that in the Wandel Sea Basin in north-
eastern Greenland, a site at that time situ-
ated not farther than maybe 100 km from 
what is now the western coast of Svalbard. 
Mesozoic. The Mesozoic stratigraphic 
record consists of re peated clastic sedi-
mentary successions, mainly Triassic-Early 
Jurassic, delta-related coastal and shallow-
marine, shelf sediments (105, part of 103) 
and Mid Jurassic to earliest Cretaceous 
deeper shelf sediments (88, part of 103), 
and again Early Cretaceous shallow shelf/
delta deposits (86). The source area of the 
sediments was mainly situated to the west, 
and later also to the north, while the basin 
opened towards the present Barents Sea. 
This view is consistent with the less com-
plete Mesozoic sections in the Wandel Sea 
Basin of NE Greenland (not seen on the 
map). Early Jurassic block fault ing and de-
velopment of sedimentary basins during 
the Cretaceous in the Wandel Sea Basin are 
explained by the Mesozoic onset of trans-
form faulting between Greenland and the 
Barents Sea. In Svalbard, no such tectonics 
are seen, and the en tire Upper Cretaceous 
is lacking due to an over all uplift, with 
highest uplift rates in the northwest.
The first sign of break-up between 
Greenland and Europe and the opening of 
the Arctic and North Atlantic oceans re-
corded in Svalbard is the intrusion of dol-
erites (102) from the latest Jurassic through 
the Early Cretaceous. They occur most 
commonly as sills in Carboniferous 
through to Jurassic strata (progressively 
younger to the east) (Fig. 3). On Kong 
Karls Land, in eastern Svalbard, basaltic la-
vas (within 88) were extruded during the 
later part of the Early Cretaceous. They be-
long to a larger volcanic province (81) that 
also includes large parts of the Barents Sea 
After the Middle Silurian, however, 
Svalbard formed part of the ‘Old Red 
Continent’. During the Silurian and earli-
est Devonian, Caledonian granites (194) 
and, exceptionally, gabbros (239) intruded 
the basement rocks. A Caledonian angular 
unconformity of Late Silurian age is well 
developed across Svalbard (Fig. 2).
Devonian and younger rocks 
Old Red Sandstone (Devonian). During 
the Devonian period, Svalbard experienced 
the deposition of a vast thickness of Old 
Red molasse sediments (177, 175, 170) that 
are mainly preserved in a downfaulted 
crustal block in northern Svalbard between 
Precambrian basement terranes. The main 
tectonic overprint and tectonic style of this 
graben system is related to a Late Devonian 
culmination of tectonism, the ‘Svalbardian 
Phase’, which resulted in contractional 
movements predominantly in northern 
Svalbard. This phase of deformation is ge-
netically related to the Ellesmerian-North 
Greenland Fold Belt in the Canadian Arctic 
and northern Greenland.
Late Palaeozoic. During the Carboniferous 
period, Svalbard developed from a site of 
fault-block tectonism with differential sed-
imentation to a stable shelf that experi-
enced overall subsidence (except for south-
ern Spitsbergen) (147, 140). The main 
fault-block movements occurred in the 
Bashkirian and Moscovian, resulting in a 
new constellation of troughs, mainly half-
grabens, with a pre- to syntectonic sedi-
mentary (lower part of 140) record devel-
Fig. 2. Caledonian angular unconformity 
between inverted, Early Palaeozoic limesto-
nes (Arkfjellet unit: brownish rocks in left 
foreground) and red and yellowish-brown, 
Devonian sandstones. A dark-purple 
weathering horizon is developed directly 
below the contact. Kneikfjellet, Sørkapp 
Land, southern Spitsbergen. Photo: Winfried 
Dallmann.
Fig. 3. Upper Carboniferous platform carbo-
nate rocks of the Wordiekammen 
Formation (light) intruded by a thick, 
strongly jointed, Mesozoic dolerite sill. 
Nannafjellet, Lomfjordhalvøya, northeastern 
Spitsbergen. Photo: Christian Scheibner.
GeoloGy of the land and sea areas of northern europe special publication 10 -  89
rocks. Quaternary volcanic centres of off-
ridge alkali basalts (B) are situated on old 
fracture zones; their age is probably be-
tween 700,000 and 100,000 years. Thermal 
springs in several places in northwestern 
and southern Spitsbergen indicate contin-
uously high geo thermal gradients along 
the Tertiary fold-and-thrust belt.
Selected literature for further reading
Aga, O. J. & Worsley, D. 1986: The geological history 
of Svalbard. Evolution of an Arctic archipelago. 
Den norske stats oljeselskap a.s, Stavanger, 
121 pp.
Dallmann, W. K. (ed). 1999: Lithostratigraphic lexi-
con of Svalbard. Upper Palaeozoic to 
Quaternary bedrock. Review and recommen-
dations for nomenclature use. Committee on 
the Stratigraphy of Svalbard. Norsk 
Polarinstitutt, 320 pp.
Harland, W. B. 1997: The geology of Svalbard. 
Geological Society of London Memoir 17, 
          521 pp.
Hjelle A. 1993: Svalbards geologi (Norwegian 
language edition). Polarhåndbok No.6, Norsk 
Polarinstitutt, Oslo, 163 pp.
Hjelle, A. 1993: Geology of Svalbard (English lan-
guage edition). Polarhåndbok No. 7, Norsk 
Polarinstitutt, Oslo, 163 pp.
and Franz Joseph Land (Zemlja Frantsa 
Iosifa).
Tertiary.  The opening of the Arctic and 
North Atlantic oceans caused a tectonic 
overprint in western Svalbard during the 
Palaeocene and Eocene. Tectonism was re-
lated to a transform fault system between 
the Greenland and Barents shelves, the 
Spitsbergen Fracture Zone, offshore to the 
west of Svalbard. Despite this dextral trans-
form plate setting, the developing Tertiary 
fold-thrust belt consists mainly of conver-
gent struc tures. This led to a decoupling 
model, meaning that strike-slip and con-
vergent movements may be localised in 
different deformation zones. An alternative 
– and mechanically more easily under-
standable – model makes plate motions 
between Greenland and Ellesmere Island 
responsible for the convergent deforma-
tion, which would thus be unrelated to the 
Arctic-North Atlantic transform displace-
ment. 
The western part of the fold-thrust belt 
was uplifted and eroded down to 
Precambrian strata, which were thrust 
ENE-ward onto the simultaneously devel-
oping, depositional foreland basin (Central 
Tertiary Basin). Thrust movements were 
transferred to the east ahead of the fold 
belt along high-level detachments within 
the cover sediments and interfered with 
basement-involved fault zones farther east 
(Billefjorden and Lomfjorden fault zones). 
The stratigraphical record of Tertiary ba-
sins is entirely clastic, with intervals of 
coal-bearing successions (72, 68) that have 
been worked for almost a century (Fig. 4). 
During the later stages of fold belt devel-
opment (Eocene-Oligocene), minor sedi-
mentary basins, especially the 
Forlandsundet Basin with a clastic sedi-
mentary fill (54), developed in the west of 
Svalbard. Their structural record contains 
components of strike-slip. The latest tec-
tonic overprint involved faulting associated 
with a post-Eocene, E-W extensional re-
gime throughout western Svalbard, in con-
nection with the development of a passive 
continental margin to the west. 
Tertiary and Quaternary volcanic activity. 
Volcanic activity of both Tertiary and 
Quaternary age occurred in NW Spits-
bergen. Plateau basalts of Miocene to 
Pliocene age (transitional olivine basalts, 
53) overlie Devonian and Precambrian 
Fig. 4. Basal part of the Tertiary succession 
of the Central Tertiary Basin, Spitsbergen. 
The sandstone unit in the upper part of the 
photo is the Endalen Member of the 
Firkanten Formation. The underlying 
Todalen Member is largely covered by 
scree. The coal seams of the Todalen 
Member are still worked in Longyearbyen, 
Sveagruva and Barentsburg. Here, however, 
in Sverdrupbyen, Longyeardalen, central 
Spitsbergen, we see the abandoned coal 
mine ‘Nye Gruve 1’, which was worked 
during the period 1939–1958. 
Photo: Winfried Dallmann. 


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