" 



^ 



I 



n' 



I 



PBB-OARBONIPEROUS PLANTS. 7 



of exploration, wo took with us a largo boat and two boatmen, so that 

 we could secure abundant ond large specimens, and could take time to 

 work out the connections of the plants in the beds in which they Ho, points of 

 the utmost importance in the study of fossil plants. 



The Gaspd sandstones have been fully described by Sir W. E. Logan, 

 in his Report on the Geology of Canada, 1863. lie there assigns to them 

 a thickness of 7036 feet, and shows that they rest conformably on the 

 Upper Silurian limestones of the Lower Ilelderberg Group (Ludlow), and 

 are in their turn overlaid unconformably by the conglomerates which form 

 the base of the Carboniferous rocks of New Brunswick. I shall add here 

 merely a few remarks on points in their physical character connected with 

 the occurrence of plants in them. 



In my recent visit I obtained specimens of Prototaxitea Logani and 

 other characteristic plants from the base of the Sandstones at Little Gasp(j. 

 This fact, along with the occurrence, as stated in my paper of 1863, of 

 rhizomes of Psilophyton preserving their scalariform structure, in the 

 upper part of the Marine Upper Silurian limestones, * proves the Flora of 

 the Devonian rocks to have had its beginning at least in the previous 

 geological period, and to characterize the lower as well as the upper beds 

 of the Devonian series. In this connection I may state that, from their 

 marine fossils, as well as their stratigraphical arrangement. Sir W. E. 

 Logan and Mr. Billings regard the lower portions of the Gasp^ Sand- 

 stones as the equivalents of the Oriskany sandstone of New York. On 

 the other hand the great thickness of this formation, the absence of Lower 

 Devonian fossils from its upper part, and the resemblance of the upper 

 beds to those of the newer members of the Devonian elsewhere, render it pro- 

 bable that the Gasp^ Sandstones, though deficient in the calcareous mem- 

 bers of the system seen farther to the westward, represent the whole of 

 the Devonian period. 



The Gaspd sandstones, as their name imports, are predominantly aren 

 aceous, and often coarsely so, the sandstones being frequently composed 

 of large grains and studded with quartz pebbles. Gray and buif are prevar 

 lent colours, but red beds also occur, more especially in the upper portion. 

 There are also interstratified shaly beds, sometimes occurring in groups of 

 considerable thickness, and associated with fine-grained and laminated 

 argillaceous sandstone, the whole having in many places the lithological 

 aspect of the coal-measures. At one place, near the middle of the series, 

 there is a bed of coal from one inch to three inches in thickness, associated 

 with highly bituminous shales abounding in remains of plants, and also 



* The marine fossils of these beds have been determined by Mr. Billings. They are Upper 

 Silurian with an intermixture of Lower Devonian in the upp p^t 



* 



&«MUkilMUUMHIkMliflL 



