Nr. 6] KVARTÆR-STUDIER I TRONDHJEMSFELTET 157 



at iaktta tre utprægede linjesæt; ofte sees kun to, til sine lider 

 ogsaa en flerhet af mindre skarpt fremtrædende linjer. Klippe- 

 terrasser og almindelige terrasser gaar mangesteds umiddelbart 

 over i hverandre; foran sækkedale og botner sees ofte som ter- 

 rasser utformede moræner. 



Archirald Geikie sier ogsaa, at »there are in Scotland three 

 strandlines so conspicuous and so persistent that attention may 

 be contined to Ihem. From what has been tåken to be their 

 average height above mean sea-level or Ordnance-datum, they are 

 known respectively as the 100-foot, the 50-foot, and the 25-foot 

 beaches« (The Quart. Journ. Geol. Soc. London, Vol. 60 (1904), 

 pag. XC). 



Med hensyn til bevægelser i jordskorpen, «crust of the earth« 

 (Davis: Physical Geography, 1900, pag. 91) uttaler Davis: »there 

 can be no question that such movements have repeatedly tåken 

 place, and that they are even no w in slow progress << (L. c. pag. 92). 



SuESS indtok et særegent standpunkt til spørsmaalet om den 

 relative forbindelse mellem hævning og sænkning af land og hav, 

 saaledes som vi kan læse i hans af handling »Ueber die vermeint- 

 lichen såcularen Schwankungen einzelner Theile der Erdober- 

 flåche« (Verh. d. k. k. geol. Reichsanstalt, 1880, nr. 11, pag. 171 

 flg.), hvor han ganske neutralt kun taler om »Verschiebungen 

 der Strandiinie« og indfører betegnelserne positive & negative 

 forskyvninger (L. c. pag. 173). Slutresultatet af Suess' under- 

 søkelser resumerer han selv i følgende: »Wir werden uns ent- 

 schliessen mussen, auch die letzte Form der Erhebungstheorie, 

 die Doctrin von den sacularen Schwankungen der Continente, 

 zu verlassen« (L. c. pag. 180). Der er en mulighet for, at Suess 

 har virket tilbake ikke saa ganske lite paa enkeltes opfatning af 

 forholdene selv i vort land; thi det lyder ganske besynderlig, naar 

 Karl Pettersen i sin af handling om »The slow secular Rise 

 or Fall of Continental Masses« (The GeoL Magazine, London, 

 D. 2, V. 6, 1879, pag. 298—304) sier: »the opinions of Mr. Bravais 

 are founded on erroneous suppositions, and that his conclusions 

 must be kept, at least for the present, apart from the range of 

 positive facts« (L. c. pag. 301). Gilrert sier, at »the minute 

 elements of orographic displacement are often paroxysmal, but 

 so far as observation informs us, the general progress of such 

 changes is slow and gradual« (U. S. Geol. Surv., V. Ann. Rep. 

 1883—84, pag. 123). 



Jamieson var af den anskuelse, at »the weight of the great 

 glacier had caused a depression of the northern region on which 

 it lay, and that afterwards, when the ice melted, the land, being 

 relieved from its load, gradually rose again, so that the old beach, 

 which was formerly horizontal, now presents an upward slope 



