44 



tioner (omkring den 38te Længdegrad), hvor det fremtræ- 

 der som et ensartet, temmelig fint Slam af en eiendommelig ^ 

 mørkgrøn Farve, Elter Tørring opnaar det kun en ube- 

 tydelig Fasthed eller Sammerihængskraft og kan mellem 

 Fingrene knuses, til et Pulver, der er at føle paa som et 

 meget fint Sand. 



Under Mikroskopet viser det sig for en væsentlig 

 Del at beståa af smaa Kvartskorn. der i Almindelighed er 

 temmelig skarpkantede. 



Af Dyrelevninger indebolder Slammet kun faa. Al- 

 mindeligst tinder man Kor af Annelider (udelukkende Spio- 

 chetopterus), Kiselspikuler af Svampe og Skaller af Slægten 

 Astarté; formlen den omtalte Foraminifer • Ehdbdamrnina, 

 der synes at være meget almindelig. 



Det fremgaar af Bundprøverne fra Expeditionens øst- 

 ligste Stationer, at Rhabdammina-Leret ber er af en ringe 

 Mægtighed, da jeg nemlig paa flere Steder bar fundet et 

 underliggende Lag af morkgraat. finkornigt og mindre sand- 

 Koldigt Ler. 



Paa de vestligere Stationer taber Rhabdammina-Leret 

 lidt etter lidt sine karakteristiske Egenskaber: det bliver 

 mere plastisk og Farven mindre udpræget grønlig, ligesom 

 bell.er ikke nogen Lagdannelse viser sig i Bundprøverne — 

 indtil vi i Syd for Beeren Eiland (under 20— 25" 0. L.) 

 gjenfinder det graa Ler. Nordenom denne gaar Rbab- 

 dammina-Leret længere ud i Havet i vestlig Retning og 

 naar ber op til Spidsbergens Sydkyst.' 



I kemisk Retning udmærker det grønlige Ler sig ved 

 sin store Kiselsyremængde og ved den mindre oxyderte 

 Tilstand, hvori det beånder sig. Jeg bar troet at iagttage, 

 at flere af Bundprøverne, ved at henligge i Luften (paa 

 Laboratoriet)', forandrer sit Udseende. og i en enkelt har 

 jeg ad kemisk Vei konstateret, at den i pulveriseret Til- 

 stand etter nogen Tids Forløb har tiltaget i Jernoxydgehalt, 

 idet Farven samtidig er blevet brunlig. I Bundproven fra 

 Station 264 fandt jeg nemlig i det saltsure Udtræk ved 

 den første Analyse: 2.48 pCt. FeO og blot U.24 pCt. 

 Fe..( ».,.- et balvt Aar senere erholdt jeg derimod: l.OOpCt. 

 FeO og 1.39 pCt. 1-V,0 3 . 



Da jeg bar kontrolleret den sidste Bestemmelse og 

 heller ikke har nogen Grund til at tvivle paa Rigtigheden 

 af den første, synes dette mig at være et Fænomen, der er 

 vel værd at lægge Mærke til. 



I Rhabdammina-Leret har je^ udført fuldstændigc 

 Analyser af to Bundprøver fra Expeditionens østligste Rute, 



1 Rundt em Beeren Biland vil man paa Korte! finde el aabenl 

 r nu. Her bar Expeditionen foretaget tiere Dybdemaalinger, der 

 viser, al Bunden ikki li sr dybere end 100 Favne. Da Lodde! 



aæsten altid stødte i I Sten. Iilev inevn Uiiinl|intve. njitajfi-t. 



Den amlede .Ternmeengde er bestemt med Kamæleon efter 

 Redukti id Zink, 



extreme eastern section of the tract (near the 38tb parallel 

 of latitude), where this deposit occurs as a homogeneous, 

 comparatively fine mud of a peculiar dark-green colour. 

 Friable when dried, it possesses very little cohesive power, . 

 admitting of being crushed between the fingers to powdér, 

 which has a gritty feel, like fine sand. 



Examined under the microscope, it is minute. and, as. a 

 . rule. comparatively sharp-édgéd particles of quartz are found 

 to form its chief constituent. 



Of animal remains this deposit contains but few. 

 Those most frequently met with are tubes of Annelids (ex- 

 clusively SpiochdojÉerus), siliceous spicules of sponges, 

 and shells of the genus Astarte, as also of the previously 

 mentioned Foraminifer ' Mhahdctm/mina,, which would appear 

 to be comparatively numerous. 



The deposit brougbt up at the most easterly of the 



. observing-stations shows the siirface-layer of Rbabdammina 



clay in that locality to be of trilling thickness; several of 



the samples bad an under layer of dark-grey. finely granu- 



lated, and somewhat sabulous clay. 



Throughout the western part of the tract, the Rbab- 

 dammina clay gradually loses its distinctive features, be- 

 coniing more plastic in substance and in colour less cbarac- 

 teristically green, with no appearance of stratification in 

 the samples, - - till. south of Beeren Eiland (long. 20° to 

 25° E.) we again meet with the grev clay. North of that 

 island, the Rbabdammina clay extends farther seaward, 

 reaching up to the south coast of Spitzbergen. 1 



Regarded chemically. the chief characteristics of this 

 greenish clay are its large proportion of silica and the 

 slight extent to whicb it is oxidized. On exposure to 

 atmospheric influénce (in the laboratory). several of the 

 samples underwent. I feel pretty sure. a change of aspect; 

 and in one. which had been pulyerized and allowed to 

 stand over for some time, I pro ved by direct analysis an 

 increase in the amount of oxide of iron: its colour. too, 

 had become brownish.- Again. in the sample brougbt up 

 at Station 264. I found in the hydrocbloric acid decoction 

 as the result of a first analysis. 2.48 per cent of FeO and 

 only 0.24 per cent of Fe L ,<> :! ; 2 but six montbs later the 

 proportion determined was 1:00 per cent of FeO and 1.39 

 per cent of Fe_»0.j. 



Having tested the results of the latter analysis and 

 seeing no reason to doubt the accuracy of the first, I call 

 attention to this phenomenon as one that should, I think. 

 by no means pass disregarded. 



Of the Rbabdammina clay met with on the eastern 

 ronte of the Expedition, I have suhmitted to rigorous ana- 



' Elound the shorrs et' Hecivii Kilanil a blank space has been 

 left in the map; Frem several soundings tåken bere at 'different 

 ] u ii ut s. the deptL was found not te oxeeed 10.0fathoms; and the lead 

 having almosl invariablj struck .ej.imsi rock ei- stoiie, ne sample of 

 the bottom could of course he obtained. 



The total amount ol' Lron was determined with permanganate 



el' potash, after ilesoxiilation witli zinc. 



