OLAF HOLTEDAHL. 



[SEC. ARCT. EXP. FRAM 



other similar structures have been called Cryplozoon by American geo- 

 logists, and which are extremely common in the dolomites and limestones 

 of the Upper Cambrian and Lower Beekmantown in the Appalachian 

 Valley, as well as in New York. I will not here go into the question 

 of the nature of this structure, as the matter will, in the near future, be 

 treated by the present author in a paper dealing with the geology of 

 Finmarken in Northern Norway, where similar structures in dolomites 

 are very common. The structures called Cryptozoon in America are of 

 rather different types, as some show laminae throughout the rock, as in 

 the specimen from Havnefjord, while others show more isolated, single 

 ,,specimens" with structureless rock in intervals between the concen- 

 trically built convex elevations. The Crypt ozoon proliferum HALL from the 

 Knox dolomite, illustrated by STOSE in his paper on n The Sedimentary 

 rocks of South Mountain, Pennsylvania" 1 p. 217, fig. 3, is remarkably 

 similar to the specimen from Ellesmereland. An interesting feature in 

 the latter is the existence of oolitic structure in some places, between 

 the laminae, a feature also known from localities in Pennsylvania. 



In this connection also the presence of very considerable quantities 

 of limestone-conglomerates, certainly intraformational, in the basal 

 portion of the Ellesmereland sedimentary series, is of considerable inteiest, 

 since similar conglomerates are predominant rocks in the Upper Cambrian 

 series of the Appalachian Valley (Conococheaque) as well as in the Beek- 

 mantown. 



The petrographical likeness between the basal paleozoic sedimentary 

 series of Ellesmereland and the Ozarkian deposits of the Appalachian 

 Valley strongly indicates an open oceanic connection between the two 

 regions at the time in question. The stratigraphic conditions in the far 

 north also seem to be very similar to what is known from the Saratoga 

 district in New York, where, resting on the Pre-Cambrian we find a not 

 thick sandstone bed on which lie Cryptozoon-bea.ring limestones and 

 dolomites of Upper Cambrian age. 2 



The fact that 200 km. to the south of Ellesmereland, on the south 

 side of North Devon, Silurian (Niagaran) limestone is found only some 

 tens of meters above the Pre-Cambrian, probably means that dry land 

 existed there in Cambro-Ordovician time, although it cannot be considered 

 impossible that sediments corresponding to a part of that time have been 

 deposited but later on removed by erosion. 



1 Journal of Geology, 14, 1906. 



2 See GUSHING and RUEDEMANN: Geology of Saratoga springs and Vicinity" in 

 Bulletin 169, New York State Museum, 1914. 



