GEOLOGICAL AREAS OF CANADA. 101 



and in many places they are penetrated by trap dykes. They rest 

 unconformably on strata of the Gaspe-Sandstone series. The forma- 

 tion is seen principally on the eastern coast of Gasp^ and on the 

 opposite Island of Bonaventure, and still more prominently along 

 the coast of the Bay of Chaleurs, where its average thickness was 

 estimated by Sir William Logan, at no less than 3,000 feet. 



The more important of the eruptive rocks occurring within the 

 district, comprise : — (i.) The trachytic mountains of Brome and 

 Shefford, agreeing in character with most of the eruptive mountains 

 of the Upper St. Lawrence district, and belonging to the same linear 

 series ; (ii.) the granites of the Great and Little Megantic Moun- 

 tains, and other granitic masses around Lake St. Francis, with those 

 of Winslow, Hereford, Stanstead, Weedon, and other portions of the 

 Eastern Townships' area ; and (iii.), various trappean exposures of 

 Eastern Gaspe and the Bay of Chaleurs. Most of these latter occur 

 as interpenetrating and^overlying dykes ; but at some spots, trappean 

 (or trachytic'?) masses form mountains of high elevation, as seen 

 in the " Conical Mountain " of the Cascapedia, and in others of 

 similar character in the covmtry between the Matapedia and the 

 Restigouche. 



The third series of formations referred to as occurring within the 

 Appalachian district, consist of Post-Cainozoic deposits. These com- 

 px'ise : — (i.) Beds of auriferous gravel and magnetic sand ; (ii.) boul- 

 der-clays, or drift deposits, proper ; (iii.) beds of Leda clay and Saxi- 

 cava sand; and (iv.) sundry superficial deposits of comparatively 

 recent origin. The drift clays in many parts of the Eastern Town- 

 ships and adjacent areas, are underlaid by (and also partially mixed 

 with) layers of gravel and black magnetic sand containing, very 

 generally, fine grains, and occasionally small nuggets, of free gold. 

 These auriferous deposits have been recognized in the beds of most of 

 the streams and rivers which flow through this section of the Pro- 

 vince, and especially in the St. Francis, Chaudifere, Famine, Riviere 

 des Plantes, Etchemin, Gilbert, Metgermet, and Pdvi^re du Loup. 

 The Leda clay and Saxicava sand deposits are lai^gely displayed on 

 the Trois Pistoles, Cacouna, Riviere du Loup, Ste. Anne, Matanne, 

 Metis, and other livers. On the Metis (in Gaspe) a bed of Saxicava 

 sand occurs at an elevation of 245 feet above the present sea level. 

 The more superficial deposits of the district include the bog iron ores 

 of Stanbridge, Farnham, Simpson, Ascot, Stanstead, Ireland, St. 



