PROCEEDINGS 



OF 



THE GEOLOGICAL SOCIETY OP LONDON. 



1827—1828. No. 5. 



1827. Dec. 7. — John Braddick, Esq. of Boughton -Mount near 

 Maidstone ; G. W. Featherstonhaugh, Esq. of Duanesburgh, New 

 York ; Arthur Kett Barclay, Esq, of Grosvenor Place, London ; and 

 Lord Francis Leveson Gower, of Albemarle Street, were elected 

 Fellows of the Society. 



A paper was read, " On the Geology of Quebec and its Vicinity, 

 by J. T. Bigsby, M.D. F.L.S. G.S." &c. &c. 



The author, who acknowledges the assistance he has derived from 

 the manuscripts of Lieut. Skene, R. E., first describes the tract, on 

 the eastern termination of which the city of Quebec is situated, as an 

 oblong ridge of about seven miles and a half in length, and in aver- 

 age width about one mile and a half ; subsiding on the north-west, 

 by steep and rocky slopes, into rich meadows ; whilst on the south- 

 east it advances in the form of cliffs towards the northern bank of 

 the St. Lawrence. 



Several rivers traverse the district above mentioned, nearly from 

 north to south, of which the most considerable are the St. Charles 

 and the Montmorenci. On the southern bank of the St. Lawrence, 

 Point Levi is the most conspicuous promontory ; and to the west of 

 it, the country is intersected by several streams running from south to 

 north. 



The districts above mentioned are partially covered with boulders 

 of gneiss, granite, syenite, and labrador felspar ; the greatest quan- 

 tities of which are found on and near Cape Diamond, Point Levi, 

 and Point Montmorenci ; whilst occasional deposits of clay, grave), 

 and sand, including organic remains, the author supposes to be of di- 

 luvial origin, — and not produced by the operation of any existing 

 watercourses. 



The rocks of this region repose upon each other in the following- 

 descending order: — 1st. A slaty series, composed of shale and grau- 

 wacke, occasionally passing into a brown limestone, and alternating 

 with calcareous conglomerate in beds, some of which are charged 

 with fossils. — 2nd. A conchiferous brown and black limestone, some- 

 times based upon a calcareous conglomerate. — 3rd. Gneiss. The 

 author's chief reason for considering the slaty-series as superior to the 

 limestone, is, that the latter is in some situations in immediate con- 

 tact with gneiss ; while in others it passes into beds of the first series 

 above mentioned j the conglomerates of which contain organic re- 

 mains derived from the conchiferous limestone. 



1 . The slaty-series occupies the whole of the southern shore of the 



