212 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



From this section, I think it is quite clear that the limestone and 

 gypsum, dipping under the millstone grit of Boulardrie, emerge 

 again, the former on the east, and the latter on the west side of 

 the ship entrance, where we find this rock resting upon the con- 

 glomerate of Red Head. Crossing the promontory of Red Head, 

 the gypsum is again seen on the east side of Baddeck Harbour, 

 dipping apparently under the sandstone beds on the opposite shore. 

 Further up the lakes, especially on the peninsula formed by 

 Patrick's Channel and the river Denny, the gypsiferous strata 

 spread out in every direction, sweeping round the bases of the 

 lofty hills of the conglomerate, which constitute such prominent 

 objects in the scenery of the lakes. These hills rise to the height 

 of 400 or 500 feet, the strata of conglomerate being highly in- 

 clined, whilst the limestone and gypsum which occupy the lower 

 ground, rarely rise 100 feet above the level of the lakes. 



Salt springs are frequent in the gypsum districts ; but the 

 brine is generally weak, seldom yielding more than 7 per cent, 

 of salt. Gypsum is also found on the shores of Aspey Bay, in 

 the neighbourhood of igneous rocks, on the shores of St. Ann's 

 Harbour, on the south side of Lennox's Passage, and at Plaister 

 Cove in the Gut of Canso. 



Underlying the gypsum and shales of the last -mentioned locality, 

 we find an extensive belt of coarse conglomerate, which probably 

 crosses the river "Inhabitants," and unites with the conglomerates 

 of the river Denny and Ogomah Basin. In the opposite direction, 

 it crosses the Gut of Canso, being separated from the igneous 

 rocks of Cape Porcupine by a series of altered shales and grits 

 of the greywacke formation ; and it continues thence to the head 

 of Chedabucto Bay. 



Between Miray Bay and Louisbourg, the country is chiefly 

 occupied by strata of fine-grained conglomerates, passing down- 

 wards into slates, and upwards, near their junction with the car- 

 boniferous limestone, into compact brown sandstones and hard red 

 shales, analogous to the greywacke system of Europe. From 

 Scatari Island towards Gabarus Bay, these rocks occasionally as- 

 sume a crystalline texture, owing apparently to the presence of 

 long ridges of greenstone trap interposed between the strata, which 

 are generally vertical, or nearly so. 



These parallel ridges of greenstone rise sometimes to a height 

 of 20 to 30 feet above the general surface, and are frequently not 

 more than 100 yards distant from one another ; although it must 

 be observed, that large areas of altered strata are met with where 

 none of these trap rocks are visible on the surface. On the south 

 shore of the Little Bras d'Or, similar strata of greywacke with 

 altered rocks are also met with ; but in this instance, the red 

 granite which breaks through the limestone at George's River 

 has changed the red shales and sandstones of the upper part of 

 the greywacke series, and at the same time converted the limestone 

 into white marble ; the following is a section of the strata : — 



