65 



Jernoxydul og Jernoxyd er bestemt ligesom ved de 

 foregaaende Slainarter. 



Det vil fremgaa af Tabellen, at Biloculinlerets Kalk- 

 gehalt differerer meget paa de forskjellige Punkter af Hav- 

 bunden. Ved paa Kartet at opstillc Tallene lor Kalk- 

 mængden vil man imidlertid finde. at en tydelig Lovmæssig- 

 hed er raadende med Hensyn til Kalkens Fordeling i Bilo- 

 culinleret. idet visse Partier af dette skarpt adskiller sig 

 fra hinanden i denne Retning. 



Vestenfor den Kurve, der paa Kartet er betegnet 

 med 15°/ CaCOa, tinder vi saaledes et meget kalkfattigt 

 Ler. 



Her fandtes i 7 Bundprøver fra 5.7 pGt. til 12.2 pCt. 

 kulsur Kalk og som Middeltal 8.8 pCt. I det store Parti 

 af Biloculinleret søndenfor og østenfor Kurven 15 % 

 CaC0 3 linder vi en langt bøiere Kalkgehalt. Denne fand- 

 tes ber ved 22 Bestemmelser at ligge imellem 21 og -fu 

 pCt.; Middeltallet var 30 pCt. 



Kurven 45% GaCO., betegner den mest kalkrige Del 

 af Biloculinleret. Kalkgehalten i 4 Bundprøver var her 

 fra 45.8 pCt. til 5G.2 pCt.. Middel 52.4 pCt. 



Den mærkelig ringe Kalkgehalt i Biloculinleret vesten- 

 for Kurven 15% CaCO. s synes at staa i Samklang med de 

 zoologiske Observationer. At dømme efter det forboldsvis 

 ringe Udbytte, der blev indvundet ved Skrabningerne paa 

 denne Del af Havbunden. skulde man tro, at Dyrelivet ber 

 stod tilbage i kvantitativ Udvikling. Derimod syntes Slam- 

 met ber at indeholde mange Stene. der vanskeliggjorde 

 Skrabningerne og paa et Sted (Stat. 350) rimeligvis var 

 Aarsag i. at Trawlen gik tabt. 



Denne Afleiring af Stene maa skyldes den drivende 

 Is, bvis Virkninger vistnok i særlig Grad er fremtredende 

 i dette udprægede polare Parti af Havet. Maaske kan 

 denne Tilforsel af grovere Materiale være Grunden til. at 

 de ovenomtalte Bundprøver fra Stat, 301, 302 og 306 ikke 

 befmder sig i den samme finkornige Tilstand som de øvrige 

 fra den sydligere Del af Biloculinleret. 



De Tal, der udtrykker det brune Lers Oxydations- 

 grad, ligger paa faa Undtagelser nær imellem 3 og 4 (Middel 

 af samtlige Bestemmelser: 3.0). Til yderligere Karakteri- 

 stik af det eiendommelige kalkfattige Parti af Biloculinleret 

 fortjener det imidlertid at nævnes. at Bundproverne herfra 

 gjennemsnitlig syntes at være noget bøiere oxyderet end de 

 øvrige. I de 8 Bundprøver vestenfor Kurven 15%CaC0 3 

 fandtes nemlig som Middeltal for Lerets Oxydationsgrad : 

 3.4; i den øvrige Del af det brune Ler: 2.7. 



From tbis Table. the amount of lime present in Bilo- 

 culina clay appears to vary considerably in different parts 

 of the ocean-bed. If we set down on the map the figures 

 denoting the proportion of lime. a manifest regularity will, 

 however, be found to characterize the distribution of tbat 

 constituent in Biloculina clay, with regard to wbicb certain 

 surface-layers of the deposit differ widely from one another. 



Tims, for instance, west of the curve 15" CaC0 3 

 we meet with a clay in wbicb the proportion of lime is 

 exceedingly small. 



In 7 samples of the bottom brougbt up here, I de- 

 termined from 5.7 per cent to 12.2 per cent of carbonate 

 of lime, the average amount being 8.8 per cent. The ex- 

 tensive surface-layer of Biloculina clay stretcbing south and 

 east of the curve 15%CaC0 3 was found to contain a much 

 larger proportion of lime. The amount of tbis constituent, as 

 sbown by 22 determinations, ranged from 21 per cent to 

 4u per cent. averaging 30 per cent. 



The curve 45°/ CaC0 3 indicates the section of the sea- 

 bed witbin wbicb the greatest quantity of lime has been found 

 in Biloculina clay. The proportion in 4 samples varied 

 between 45.8 per cent and 56.2 per cent. the average amount 

 being 52.4 per cent. 



The remarkably low amount of lime, present in Bilo- 

 culina clay west of the curve 15% CaG0 3 , may in part, 

 it would seem. be explained by the results of the zoological 

 observations. To judge from the comparatively meagre 

 yield of dredgings in tbis part of the ocean-basin. the 

 quantitative development of animal life would not ap- 

 pear to be large. Meanwbile, numbers of large stones — 

 a serious impediment to successful dredging — were, on 

 the otber band, apparently imbedded in the deposit. and 

 the loss of the trawl — at Station 350 — must in all 

 probability be ascribed to their presence there. 



Tbis distribution of stones is obviously to a great ex- 

 tent the work of drift-ice in tbis peculiarly Polar tract of 

 the ocean. Maybe, this addition of coarser material will serve 

 to account for the deposit brougbt up at Stations 301, 302. and 

 306 baving been much less finely granulated than were the 

 samples of Biloculina clay from more southerly localities. 



The figures expressing the oxidation of the brown 

 clay lie, with very few exceptions. between 3 and 4 (the 

 mean for all sucb determinations was 3.0). As a further 

 characteristic of tbat deposit west of the curve 15% CaG0 3 , 

 where it contains so small an amount of lime, I may mention 

 tbat. as a rule, the samples would appear to have been 

 more bighly oxidized than was the case with those from 

 any other part of the sea-bed. For the 8 samples of brown 

 clay brought up west of the curve 15%CaC0 3 , I found the 

 mean degree of oxidation to be 3.4; elsewbere it was 2.7. 



Den norske Nordhavsexpedition. Sehmelek : Cliemi. 



