KiC) 1'. A. ØYEN [1914 



First Period of Valley Glacialion, 



Second Period of Valley Glaciation, 



Fonnation of Terrace-steps. 

 Og her nttaler han ganske liketil: Periodic changes of climate 

 in post Glacial time hrought aboul minor stages of alluviation 

 and degradation Nvith the prodnction of the present terrace-steps, 

 gorges, and ravines« (Drysdali:: Geology of Franklin Mining 

 Camp, British Columbia, 1915, pag. 18). Og samme forsker 

 uttaler videre: Without further climatic variations there would 

 be a single cycle of degradation and no terraces except those 

 due lo the normal sidewise swinging of Ihe streams. This is 

 nol the case in the Franklin dislricl, for periodic changes of 

 climate in post-Crlacial time have broughl aboul minor stages of 

 alluviation and degradation. Such climatic oscillations are in- 

 ferred on accounl of the presence on bolh sides of the Franklin 

 valley, near ils junction with the main Ketlle valley, of a series 

 of lerrace stej)s^ (L. c. pag. 26j. Del har sin store interesse her, 

 i motsælning til den tidligere efter Upham anførte opfatning, og- 

 saa fra amerikansk side at finde uttryk for en mere med nyere 

 europæiske oi)fatningpr samstemmende anskuelse, hvilket vi jo 

 ogsaa ganske natm-lig maalte vente, naar vi erindrer, at allerede 

 for omkring en menneskealder siden gjorde Salisbury opmerksom 

 paa den store likhel mellem de til Meck lenbur gi an i Europa 

 og til Wisconsin i America svarende endemorænelandskaper i 

 en afhandling: Terminal Moraines in Northern Germany< (Ame- 

 rican .lourn. Sci., Vol. Ho, 188S, pag. 401 — ^407^ Dette har da 

 ogsaa senere og i mere ulvidel form fundet uttryk i Llvkrett's 

 afhandling: Comparison of North American and European glacial 

 deposils (Zeitschr. fiir Gletsherkunde, B. IV, 1910, pag. 304 flg.), 

 hvor han behandler the fourth drift . For os har det i denne 

 forbindelse en speciel interesse, at Levlrett ved hin anledning 

 kommer til del resultal, at the moraines of the Wisconsin drift 

 admit of grouping in a way thai suggest sladia similar to those 

 described by Penck and Bruckner in the Alpine region. East 

 group consisls of a bulky outer moraine which seems to be 

 merely recessional and to indicale no readvance of the ice border. 

 The bulky outer moraine of the group, however, is Ihoughl lo 

 indicale a readvance of more or less consequence, for il is nol 

 entirely concenlric ^vilh the moraines oulside of il« (L. c. pag. 306). 

 Særlig bør vi her merke os Leverett's uttalelse: It can scarcely 

 be decided in the present state of investigation whelher the groups 

 of moraines in the Wisconsin drift of America correlale with the 

 several sladia in the Alpine region, but il certainly is a sugges- 

 live feature of resemblance (L. c. pag. 306). I umiddelbar til- 

 slutning hertil har det derfor ogsaa sin store interesse at minde 



