272 



Proceedings of the Boyal Physical Society. 



the valley expands without interruption towards the sea. 

 The former he views as beaches of lakes, which burst their 

 barriers from time to time ; the latter, existing only below 

 his " marine limit " of about 600 feet, beyond which the 



Fig. 4. 



Terraces — Norway. (Kjerulf, Om Skuringsmserker, etc., p. 51.) 

 F, Flat, levelled-out by river near S^, the sea; B, Submerged Bank in 

 which these flats may terminate ; T, Raised Terrace, due to the formation 

 of a similar Flat and Bank at a former sea-level, S^; S^, S^, sudden step 

 of upheaval necessary to its preservation ; I, shows Terrace-making to be 

 prevented by gradual elevation — F being converted into an incline, and B 

 kept at the foreshore. 



plentiful remains of marine exuvice abruptly cease, consist 

 of steps marking the retirement of the sea, to steep 

 submerged margins of which the terrace-fronts correspond.* 



CI. 



Fig. 5. 



Section of Valley, showing probable lodgment of gravelly debris between 

 a glacier and the side of a valley, afterwards falling into terraces. 



Gl, Glacier in retreat ; T, T, Terraces (Jamieson, Quart. Jour. Geol. Soc, 

 1874, p. 333). 



Mr Jamieson, of Ellon, has suggested yet another mode of 

 terrace-formation, and appears willing to apply it not only 

 to high-lying terraces in Highland glens, but to such terraces 



* Om Skuringsmaerker, Glacial Formationen, og Terrasser, 1871, p. 51. 

 Kjerulf s views are widely accepted in Norway (Reusch, "Traek af Havets 

 Virkninger paa Norges Vest Kyst " — Nyt. Mag. for Videnskaberne, 1876). 

 Petersen, however, finds evidence that the sea did not always retire in steps 

 ("Terrasser," etc., Tromso, 1880); and Guma^lius proves that terraces may 

 be of unlike heights on the opposite sides of dales. The latter believes that 

 the Norse terraces answer to the Swedish asar (Karnes), and were formed 

 under the sea (Gumaelius, " Rullstengrus, Terrasser, etc." — Geologiska 

 Foreningens i Stockholm Forhandlingar, 1880, p. 184). 



