.. Rhabdammina-Ler" effcer en Foraminifer, som ofte fore- 

 kommer paa denne I>el af Havbunden. 



liuudt omkrint;' den vulkanske Jan .Maven bestaar 

 Bnndens Afleiringer af el graasort fint Sand eller Sandler, 

 der indeliolder talrige Brudstykker af den basaltiske Lavas 

 Mineraler. 



Éxpeditionens Dybdemaalinger langs [slands Østkyst 

 viste, at Bunden her var af en noget aligeartet Beskaffen- 

 hed. Selv paa de større Dyb (indtil 84-1 Favne) stødte 

 Loddet flere Gange mod Sten og kom o.p aden nogen Bund- 

 prøve. Ved de nordlige Stationer paa denne Rute fandtes 

 et mørkgraat Ler. paa de sydlige syntes Sand og Sten at 

 \ ære fremherskende. 



Etter disse forelobige Meddelelser vil jeg nu give en 

 ordnet Fortegnelse over det foreliggende Materiale, i hvil- 

 ken man vil tinde en kortfattet Beskrivelse af Bundprøvér- 

 nesUdseende og Art. Hvad der i det foregaaende er sagt 

 om Slamarternes Udbredelse belyses nøiere af det vedføiede 

 Kart. som i det tblgende skal nærmere forklares Slam- 

 arterne er paa dette Kart betegnet hver med sin naturlige 

 Farve. Foråt faa disse i Overensstemmelse med Virkelig- 

 heden har jeg ladet dem kopiere efter et Originalkart. 

 malet med pulveriserede Bundprøver, udrorte i Grummivand. 



De Stene, der fandtes i Bundprøverne. hvilke likeledes 

 er medtaget i- tblgende Fortegnelse, kunde naturligvis blot 

 være af en ringe Størrelse. Hvor der paa Havbunden laa 

 Stene. der var større end Aabnfngen af Jernrøret, hvormed 

 Bundprøverne optoges, maatte dette ialmindelighed komme 

 tomt op. og i Loddejournalen noteredes i saailanne Tilfælde: 

 haard Bund, eller: Fjeld. Den sidste Benævnelse er dog 

 ved senere Overveielse blevet afskaffet. da den lettelig kan 

 lede til en Begrebsforvirring, forsaavidt som den fører 

 Tanken hen paa større sammenhængende Stenmasser, hvis 

 Nærværelse naturligvis ikke kan bevises derved, at .Jern- 

 roret kommer tomt op. Jeg har i dette Tilladde benyttet 

 Ddtrvkket : Stenbund. 



De fleste af de Bundprøver, der er optagne paa Kyst- 

 bankerne indenfor det graa Lers Omraade, indeholder Stene 

 i vexlende Mængde og af forskjellig Størrelse. Mangengang 

 udgjorde disse en væsentlig Del af Bundprøven, saaat denne 

 i tørret Tilstand lignede et Konglomerat. 



I Bundprøverne fra Biloculinleret fandtes ogsaa af 

 og til enkelte Stene. især i den nordlige Del af Havet. 



De større Stene. der optoges med Skrå ben eller Traw- 

 len. blev ialmindelighed bestemte ombord af Hr. Professor 

 Mohn, der velvillig har overladt mig sine Optegnelser; en 

 Del blev forst efter Hjemkomsten undersøgt. 



Jeg vil her paa Forhaand gjøre opmærksom paa. at 



This deposil our naturalists haye termed "Rbabdammina 

 Clay," after a genus of Foraminifera whicb ofteo abounds 

 in that part of the ocean-bed. 



Off tbe volcanic island of .lau Maven, the surface- 

 laver of the bottom consists of a tine. dark-grey sand, or 

 sabulous clay. contaiuing numerous particles of basaltic lava. 



The soundings tåken along tin- east co.ist of Iceland 

 show the bottom to be somewhat variable in character 

 tbrougbout that locality. Even in the greater depths (as 

 far down as S44 fatboms, for instance) the lead repeatedly 

 struck against rock or stone, and ca me up with the tube 

 empty. At the northern Stations in this tract we found a 

 bottom of dark-grey clay. whereas at the southern, sand 

 arid stone would seem to predominate. 



1 will now. after the above preliminary observations, 

 give a List of the samples collected on the North-Atlantic 

 Expedition. along with a brief description of their nature 

 and appearance. What has already been stated concerning 

 the distribution of the oceanic deposits treated of in this 

 Memoir. the acfcømpanying map, of which a detailed expla- 

 nation will aftenvards be given, more fullv eliicidates. In 

 this Map each section has the colour ort mill// distinguishing 

 flir ilepusif it represents. That the different colours might 

 be as true as possible to nature. I bad them copied from 

 au original map coloured with pulverized samples of the 

 bottom dissolved in gum-water. 



The pebbles found in the samples of the bottom 

 and included in the following List. could .be naturally 

 hut of- tritiing magnitude. If. in the locality wbere a 

 sounding vas tåken, the sea-bed was covered with stones 

 larger than the opening of the iron tube with which the 

 samples of the bottom were collected. the apparatus would 

 as a genera] rule come up empty. in which case -hard 

 bottom" or -rock" was entered in the sounding-journal. 

 The term rock. however. I have seen tit. after mature con- 

 sideration. to reject, since it might verv naturally give rise 

 to misunderstanding, and be tåken to signify a connected 

 mass of stone. whose existence there is of course nothiug 

 whatever to prove in the fact of the tube coming up •with- 

 out a sample of the bottom. The expression -bottom stouy" 

 is therefore substituted for -rock", as less liable to rnis- 

 coustruction. 



^lost of the samples collected on the coastal banks, 

 where a grev clay predominates, contained pebbles varying 

 in number and magnitude. Frequently huleed they con- 

 stituted the principal part of the sample, which. when dry. 

 resembled conglomerate in appearance. 



A few pebbles occurred too in the samples of Bilo- 

 culiha clay. more especially those from the northern part 

 of the ocean-tract explofed. 



The larger stones brotight up in the drédge or trawl 

 were as a rule determined on board by Professor Mohn. 

 who has kindly jtlaced his memoranda at my service: some 

 few however weré not examined till after the return of the 

 Expedition. 



With regard to my determination of the pebbles ' 



