Dr. Gesner on the Geology of Nova Scotia, 149 



not appear to fill rents, but form regular parts of the stratified series, 

 sometimes alternating with limestone and shale. 



The author concludes by describing a newer and unconformable 

 red sandstone, without fossils, which is seen to rest on the edges of 

 the carboniferous strata on the Salmon river, six miles above Truro. 



" A Geological Map of Nova Scotia, with an accompanying 

 Memoir," by Abraham Gesner, M.D., F.G.S., was presented to the 

 Society. 



The surface of the province of Nova Scotia is for the most part 

 very uneven, much of it being traversed from south-west to north- 

 east by long parallel ridges of rock. The height of the hills seldom 

 exceeds 800 feet. The geology, as represented in Dr. Gesner's map, 

 is as follows : — 



1. Granitic rocks. — The south-eastern coast of the peninsula pre- 

 sents an almost continual, though narrow band of granite, syenite, 

 and other granitic rocks. A second band of very unequal breadth 

 commences about the middle of the south-west coast of the penin- 

 sula, and ends near the course of the Ohio river. A third appears 

 in the isthmus forming the Cobequial mountain, a narrow ridge 

 extending from east to west. The granitic rocks of the province 

 frequently send off dykes and veins into the stratified rocks incum- 

 bent on them. 



2. Stratified non-fossiliferous rocks. — A belt consisting of mica- 

 slate, hornblende slate, chlorite slate, greywacke slate, greywacke 

 and quartz rock, intervenes between the first and second of the above- 

 mentioned granitic bands. It is in the district occupied by these 

 older schistose rocks that the long parallel ridges, running from 

 south-west to north-east, are most clearly exhibited. 



3. Silurian group. — The stratified non-fossiliferous rocks are suc- 

 ceeded by stratified fossiliferous clay slate, greywacke, and grey- 

 wacke slate. Fossils of a Silurian character occur in the latter. The 

 lowermost of these deposits, where they have ceased to afford organic 

 remains, may be regarded as Cambrian. A complete zone of Silurian 

 beds encircles and immediately covers the Cobequial granitic range. 

 The non-fossiliferous slates and the Silurian beds of the province 

 agree in the circumstance, that their strata dip away from the ad- 

 jacent ridges of granitic rock at angles of high elevation. 



4. Old red sandstone, or Devonian group. — Above the Silurian beds 

 there occurs, in several parts of the province, a bright red micaceous 

 sandstone or conglomerate, accompanied by thin beds of red shale 

 and marly clay, and in some places containing seams of fibrous gyp- 

 sum. Hitherto no organic remains have been found in it. At Advo- 

 cate Harbour and on tlie Moose River this sandstone is seen lying 

 unconformably beneath the coal-measures. At the latter locality the 

 sandstone dips W. 21°, and the coal-measures dip N.N.E. 60°. It 

 is from a joint consideration of the mineral character of this forma- 

 tion, and its relative position as compared with the coal-measures, 

 that the author has regarded it as the equivalent of the old red sand- 

 stone. 



5. Coal-measures. — Unless the calcareous deposits of the districts 



