30 



PEKEALLOW AND DAWSON 



2. — Geological Relations. 



North of G-aspé Bay, the Silurian limestones extend into the promontory of Cape 

 Gaspé, with dips to the south-west. These beds, which attain a thickness of about 2,000 

 feet, hold numerous marine fossils, which in the upper part are those elsewhere 

 characteristic of the Lower Helderberg series. Near Little Gaspé they are conformably 

 overlaid by sandstones and shales, which in some places hold Rensellaria ovoides and 

 other species found in the Oriskany of the west, and in which are also found the fucoids 

 known as Spirophyton. These beds are the lowest in the great Erian or Devonian series of 

 Gaspé Bay, which, according to Logan's measurements, is more than "T.OOO feet in thick- 

 ness. Arranged in a synclinal form, they occupy both sides of the bay. 



Fki. 3. — Section showing position of a prostrate trunk of Nematophyton, 

 (a) on an underclay, {h) filled with Psilophyton— Gaspé. 



A few fossil plants, mostly fiicoids, occur in the Silurian limestones, but in one bed, 

 not far above the base of the series, are fragments of rhizomata of Psilophyton in some of 

 which the scalariform tissue of the axis is well preserved. In the overlying sandstones, 

 fragments of plants are abtindant, and in the lowest beds in Little Gaspé Cove, I observed 

 two great stumps of Nematophyton with their roots spreading in the sandstone, while in 

 the vicinity of this place there are underclays filled with rhizomata of Psilophyton, and 

 extensive fields of these plants in situ. The following extracts from my notes of 1869 

 farther ilhtstrate the structure of the Gaspé sandstones : — 



" The Gaspé sandstones, as their name imports, are predominantly arenaceous, and 

 often coarsely so, the sandstones being frequently composed of large grains and studded 

 with quartz pebbles. Gray and buff are prevalent 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 argillaceoiis 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 containing fragments of crustaceans and fishes 

 [Plerygotus, Ctenacanthus ? etc). The beds connected with this coal are grey sandstones 

 and grey and dark shales, much resembling those of the ordinary coal formation. The 

 coal is shining and laminated, and both its roof and floor consist of laminated bituminous 

 shale with fragments of Psilophyton. It has no true under-clay, and has been, I believe, 

 a peaty mass of rhizomes of Psilophyton. It occurs near Tar Point, on the south side of 

 Gaspé Bay, a place so named from the occurrence of a thick dyke of trap holding 

 petroleum in its cavities. The coal is of considerable horizontal extent, as in its line of 



