No. XV. GEOLOGY. &29 



Silurian Limestones. — Mural cliffs of limestone, with 

 conglomerate at the base, rise to ;i heighl <>i* more than 1000 

 feet on the east coast of Bache Island. These beds al the 

 south end of Bache Island, as viewed from Buchanan Strait, 

 appear to rest on syenitic and granitoid rocks, and dip gently 

 to the N.N.W. as far as Victoria Head, where a landing was 

 effected and some fossils obtained : the mural cliffs, forming 

 the northern shore of the island, consist of this formation, and 

 correspond in direction to the strike of the strata. 



The limestones of Norman Loekyer Island, lat. 79° 52' N., 

 at the mouth of Franklin Pierce Bay, dip at a high angle to 

 the north. The south side of the island is a steep bluff rising 

 to 600 feet, glaciated at the top, in a north and south direc- 

 tion. To the north is a low shelving shore ; and between the 

 island and the mainland there is a fault bringing in the 

 basement conglomerate beds of Bache Island. It is well seen 

 at Cape Prescott, in Allman and Dobbin Bays, Cape Louis 

 Napoleon, and Hayes Point, as are the limestones, by which 

 it is overlaid. 



A north-east anticlinal passing through Cape Hilgard 

 probably brings in older Silurian rocks, as some of the fossils 

 from this locality have been determined by Mr. Etheridge to 

 be Lower Silurian forms : Maclurea magna, Recept acuities 

 occidentalism R. arctica, Eth. Several of these types appear 

 to have been previously brought from the Parry Archipelago, 

 where there is probably an unbroken sequence from the 

 Lower Silurian, through the Upper Silurian into the Devo- 

 nian, without any physical break. 



The Cape Hilgard conglomerate appears to correspond in 

 time and position to the red sandstone and coarse grit under- 

 lying the Silurian limestones of North Somerset, which are 

 described as like those found between Wolstenholme and 

 Whale Sounds, West Greenland. Whether the Lower Silurian 

 horizon is that portion of the section lying between the lime- 

 stones and the conglomerate or grit bed, has not been clearly 

 made out either in Grinnell Land or in the Arctic Archi- 

 pelago ; but this view is strongly supported by the fact that 



