I916. No. 10. THE LOWER CAMBRIAN HOLMIA FAUNA. I03 



Quartz sandstone is only a faciès of the upper light sparagmite. Even in 

 the Mjesen district it also to some extent passes into pure sparagmitic rocks. 

 I refer to K. O. Bjorlykke's ^ large work, but especially to the work of 

 W. Werenskjold ■-, that appeared in 1911, and dealt with Søndre Fron. 

 W. Werenskjold's large section from Sendre Fron to Snødalvolden is ol 

 great interest in this connection, since it shows the whole series of beds 

 from the archaeic rocks to the Phyllite formation. 



As far as concerns the Mjesen district, too, V. M. Goldschmidt also 

 admits that the original sequence has possibl}' been of a different character 

 than that usually believed, a fact that as is known O. E. Schiøtz and later 

 on also Rothpletz ^ have emphasized. It would also appear to be reaso- 

 nable a priori to assume that the facies alterations in these districts have 

 played an important part. 



In our opinion it therefore appears natural not to place any limit ot 

 formation between the Sparagmite formation and our fossil-bearing Lower 

 Cambrian deposits. The latter directly succeeded the underl3'ing huge 

 coarse clastic formations, although in such a manner that there was a 

 transition — presumably in the sandstone shales — from continental to 

 marine facies. 



We therefore regard the whole Sparagmite formation as 

 Lower Cambrian. This assumption is supported by the admirable 

 investigations lately carried out. particularly those of Ch. L. Walcott-*, with 

 respect to the Cambrian strata and their fauna in America. Through these 

 works we have optained an entirely new view of the Cambrian, both with 

 respect to the sedimentary and the faunistic evolution. It is found that the 

 Lower Cambrian where it is richly developed exhibits a hitherto inconcei- 

 vable immensity, and a long faunistic evolution. 



In Waucoba Springs Section' in the Inyo Range (California), for in- 

 stance, he discovered the older part of the Lower Cambrian with dimen- 

 sions of no less than about 1700 m., although the lower limits cannot be 

 seen. We there find the oldest fauna, the Xez'adia-ia.uua. 



Farther to the north, in British Columbia, we have the wonderful 

 Mount Bosworth Section, that extends from the Lower Cambrian up to the 



1 Centrale Norges fjeldb\'gning (Norges Geol. Unders. No. 39. 1905). 



- Sondre Fron (Norges Geol. Unders. No. 60, 1911I. 



^ Meine Beobacht. über d. Sparagmit u. Birikalk am Mjösen in Norwegen (Sitzungb. 



Kgl. Bayr. Akad. d. Wiss. 19101. 

 ■* I refer to Walcott's series "Cambrian Geology and Paleontology" in the Smithsox. 



Misc. Coll. 

 5 Ch. Walcott, Cambrian Sections of the Cordilleran area (Smitson Misc. Coll. Vol. 53, 1908). 



