VII 
det løse slam?) Vi skulde derfor antage, at det kun er 
det øverste bundlag, som er bleven afflødt. 
Dr. Jensen antager, at sedimentærdannelsen paa de 
store haydyb foregaar overmaade langsomt, idet han støtter 
sig til John Murrays iagttagelser fra Challengerexpeditio- 
nen. De arktiske have frembyder imidlertid ikke de samme 
fysikalske forholde som de store verdenshaye. Enhver, der 
har bereist de arktiske egne, vil have seet, at isen fører 
adskillig slam med sig. Pa Nordhavsexpeditionen saaes 
oftere mere eller mindre skidden is og de samme iagttagel- 
ser gjorde Nansen i Danmarksstrædet. 
Konservator Kolthoff fortæller i ,Ur Djurens Lif* 
(vol. 2, p. 457), at tre klapmyds (cystophora cristata), 
som bley skudt paa en plads, hvor havet var mellem 2 
og 3 tusen meter dybt, havde lerslam i maven. To af 
dem havde maven fuld deraf. Dette slam maa dyrene 
have slikket i sig ude paa drivisen, thi det er utænkeligt, 
at de kunde dykke ned til bunden paa et saadant dyb: 
Heller ikke er det tænkeligt, at de kan have faaet det * 
sig inde ved land, da dette var for langt fjernet og denne 
sælart desuden holder til ude paa drivisen mellem Spits- 
bergen, Jan Mayen og Grønland og kun sjelden træffes 
den under land eller i fjordene. 
Tager vi for os Schmelcks arbeide over havbundens 
afleirninger*), vil vi finde, at der var sand og smaasten 1 
bundprøyerne fra en hel del dybyandsstationer fra Spits. 
bergen nedover mod Island og paa vedføiede kart har v 
afsat sydgrænsen for disse stationer. Som det vil sees 
falder den paa en paafaldende maade sammen med grænsen 
for isens smeltebælte. I bundprøverne fra stationerne nord 
for denne linie var der sand og grus, syd for linien fandtes 
derimod kun lerslam. Først fra stationerne ind under 
kystbankerne gjentinder vi igjen grus og sand. Af disse 
stationer med sand i bundprøverne ligger station 240 og 
245 indenfor Ingolfexpeditionens undersøgelsesfelt. 
En ganske interessant bekræftelse paa det rige ma- 
teriale, sam isen maa sprede oyer sit smeltefelt, fik vi ved 
at faa anledning til at se en planktonprøve som kandidat 
Wollebæk havde taget under et toet med ,,Heimdal* vaaren 
1900 i nærheden af iskanten paa 70° 24’ N. Br., 420 29’ 
Ø. Le. Dybde 50 fy. Planktonproven toges midtvands 
paa 25 fr. I denne fandtes en paafaldende mængde sand- 
korn samt ikke saa faa smaa skalrester. Alt dette synes 
paa det bestemteste at vise, at sedimentærdannelsen i de 
Jensen antager at trawlen kan trænge indtil 2 fod (62 em.) ned 
i bunden. Saa svagt, trawlnettet paa Nordhavsexpeditionens var 
belastet, holder vi dette for usandsynlig. 
2?) Nordhavs Exp., Kemi. 
the soft mud!, We should therefore suppose that it is 
only the uppermost layer of the bottom that has been 
skimmed, 
Dr. Jensen assumes that the formation of sediment 
in the great ocean depths takes place exceedingly slowly, 
supporting his assumption on John Murray’s observations 
on the Challenger Expedition. The arctic seas, how- 
ever, do not present the same physical conditions as the 
large oceans. Eyery one who has travelled in the arctic 
regions will have seen that the ice carries a consider- 
able quantity of mud with it. Ice that was more or less 
dirty was frequently seen on the North Atlantic Ex- 
pedition, and Nansen observed the same thing in Denmark 
Strait. 
Curator Kolthoff, in his ‘Ur Djurens Lif’ (vol. II, 
p. 497) relates that three hooded seals (Cystophora eri- 
stata) that were shot in a place where the sea was be- 
tween two and three thousand metres deep, had clayey 
mud in their stomach, two of them being quite filled 
with it. The animals must have licked up this mud 
out on the drift-ice, for it is impossible to imagine that 
they could dive down to the bottom at such a depth. 
Nor is it likely that they can have swallowed it on shore, 
as this was too remote; and moreover this species of seal 
lives out on the drift-ice between Spitsbergen, Jan Mayen, 
and Greenland, and is rarely found near the shores or in 
the fjords. 
If we look at Schmelck’s report on the ,,Oceanic 
Deposits”), we find that there were sand and small stones 
in the bottom-samples from a number of deep-water sta- 
tions, from Spitsbergen southwards towards Iceland. In 
the accompanying map, have marked the southern 
limit of these stations. It will be seen that this coin- 
cides in a remarkable manner with the limit for the melt- 
ing of the ice. In the bottom-samples from the stations 
north and west of this line, there was sand and gravel; 
south and east of it, on the other hand, there was only 
clayey mud. It is only at the stations in under the coast- 
banks that we once more find gravel and sand. Among 
the stations with sand in their bottom-samples, Stations 
240 & 243 are within the field of the investigations of 
the Ingolf Expedition. 
We had a most. interesting proof of the abundance 
of matter that the ice must scatter over its melting area, 
seeing a plankton-sample taken by Hr. Wollebæk 
during a cruise with the ‘Heimdal’ in the spring of 
1900, near the edge of the drift-ice in 709 24’ N. Lat. 
and 42° 29’ E. Long., depth 50 fathoms. The plankton- 
sample was taken in midwater at 25 fathoms. A remarkable 
number of sand particles were found in this sample, and 
not a few small fragments of shell. All this goes most 
we 
in 
Jensen assumes that the trawl can penetrate as much as 2 
feet (62 cm.) into the bottom. So lightly was the trawl-net on 
the North Atlantic Expedition loaded, that we consider this im- 
probable. 
2) North Atlantic Expedition, Chemistry. 
4 
