Nr. 6] KVARTÆR-STUDIER I TKONDHJEMSFELTET 



kede bassiner i den i^anile (lalhuiul er el kaiakleiislisk Tælles- 

 træk for dem begge. 



Vi bliver her nodl lil al se rænomenel paa samine inaale 

 som de amerikanske geologer allerede lor længe siden har fundet 

 forholdet at være saavel paa Amerikas oslkysl som |)aa vest 

 kysten: »The suhmaiine conlinualions of Ihe channels of the 

 St. Lawrence, Hudson, Deleware, Suscpiehanna, and Mississippi 

 rivers are cited as |)roof thai the Atlantic coast of North America 

 was uplifted during the Pliocene period, attaining, probably in 

 the early part of the Quarternary, an altilude of 2,000 to ;},000 

 feet above its present hight. Its northern coasts were also up 

 lifted, as shown by liords. The elevation of British (^olumbia. 

 according to Dr. G. M. Dawson, was al least 9(»0 feet. Thai il 

 mav have greatly exceeded this amount, is indicated by the 

 submerged channels discovered on the coast of California by 

 Prof. (ii:ouc.K D.wmsoN of the U. S. Coast Survey. Nol less Ihan 

 twenty of Ihese sunken liords have been found belween Cd\)e 

 Mendocino and San Diego, wilhin a distance of aboul 700 miles, 

 some of them reaching deplhs of 2,000 to 2,500 feet. Like the 

 Hudson submarine channel and fiord. Ihese have all the distinc 

 tive features of subaerial erosion, and they are regarded by Prof. 

 Lk Conti-; as decisive evidence thai this part of the continenlal 

 plateau has been greatly uplifted, similarly wilh its easlern 

 portion and probably al the same time. The submarine channels 

 of California, however, are nol conlinualions of the present rivers, 

 and none exist opposite to San Francisco and Ihe (iolden (late. 

 Prof. Li-: (>onti-; Ibercfore suggesls thai the diainage of the greal 

 valley of (>alilbrnia during Pliocene time piobably passed inlo 

 the sea farther south by a deeply submerged channel wbich is 

 traced bv soundings in the Monterev liav (The American (ieo- 

 logisl. Vol. \'III (ISDl), pag. 541. 



VA'lvv dybdeforholdene at domme synes det meget sandsynlig 

 al landet, paa den lid i\vn store, gamle Trondbjenisdal l)le\ 

 ulfoiMnel, slod omkring :'.i>ii in. hoiere end nu; som \\ ser stem 

 mer delle ganske godt med angivelsen fra Hiilish Columbia. \'i 

 skal ikke ved denne anledning fordyjx' <»s i hypotheser med 

 hensyn lil det mulige tidspunkt for demie proi'es, men \i kan 

 v;ere uu'gel tilfreds nu'd, al del ialfald er lykkedes al l'remlinde 

 et karakteristisk Ira-k, der tillaler at skimle en forbindi-lse mel 

 lem vorl onnaade oi; andre, dei- gra-nsci- lil samme hav. De bas 

 siner, vi linder i denne ^anile dals hund. og deres beliggeidiel 

 viser os imidlertid, al en anden, exogen kraft her, likesom i den 

 nuva-rende Trondbjenisljord, har g,i<)rl sig i merkbar grad g^jel 

 deude \ cd siden al' de lo ovenfor na'vnte 



Soni en krall af den ait kjender vi for liden kun den glaciale, 



