﻿682 SUMMARY OF THE CONTENTS. 



Pp. 73—79. The Time of the Deposition of the Yoldia Clay. 



In this chapter it is stated that the older yoldia clay of the 

 Kristiania region has never been found inside the ra; being 

 situated inimediately oirtside the ra, it must have been deposited 

 during the formation of the ra itself ; the yoldia clay at a greater 

 distance from the ra must have been deposited at a somewhat 

 earlier time. 



As the yoldia clay at a greater distance from the ra (on 

 the sea-bottom or along the shore) occurs below, or only a few 

 metres above, the sea-level, while the yoldia clay on the side 

 of the ra itself, on the contrary, is found up to 40 — 50 metres 

 above the present sea-level, vve must conclude that the Kristiania 

 region at the beginning of the deposition of the yoldia clay (at 

 some earlier time than the ra-station of the ice-border) must 

 have been situated higher than it is at present, and that then, 

 during the retreat of the ice-front to the ra-station, and further 

 during the formation of the ra, it must have been continually 

 sinking, — from about 50 m. oi- more above to about 70 — 75 

 m. heloiv the present sea-level. Even during this time of the 

 ra-station, the climate must have been changed, as is proved 

 by the circumstance, that the great form of portlandia arctica 

 and some of its companions vvere already on the retreat from 

 the south coast of Norway. 



Pp. 79 — 85 contain a comparison between the yoldia clay 

 of the Kristiania region and the corresponding yoldia clays from 

 the west coast of Sweden and from Vendsyssel in Jutland. 



Pp. 86 — 100. A Discussion on the Level of the Kristiania 

 Region during the Time of the Great Ice-Sheet. The occur- 

 rence at great depths of the Norwegian Sea of the high-arctic 

 fossil shallow-water mollusca of the yoldia-fauna (p. 88, list of 

 fossils from the dredgings during the Norwegian North Atlantic 

 Expedition near Spitzbergen by H. Friele; p. 89, list of fossils 

 from the Danish Ingolf Expedition between Iceland and Jan 

 Mayen; by Ad. S. Jensen) is explained by the hypothesis, that 



