PAET Of THE PEOYINCE OF QUEBEC. Ill 



The upper part of the section is furnished by a belt of black shales and limestones often 

 graphitic, which are fonnd at Faruham West and Centre, and which contains graptolites 

 and other forms which indicate a Trenton horizon. 



This last series of Faruham is worthy of a brief description, since upon these or their 

 equivalents elsewhere, much of the confusion regarding the stratigraphy of the Quebec 

 group depended. From Faruham Centre they can be traced northward continuously for 

 many miles and are there found to be the equivalents of the black graphitic slates and lime- 

 stones of Richmond, Melbourne, Danville, Arthabaska, etc. The structure of this division 

 at Richmond and Melbourne is much more obscure than at Farnham, though recent 

 researches have shewn these also to be fossiliterous and to be of Trenton age ; but at Mel- 

 bourne and Danville, several heavy faults and probably overthrusts have brought the lime- 

 stone into an apparently underlying position to the crystalline schists and other rocks for- 

 merly reg-arded as the Sillery division of the Quebec group. They here have the structure 

 of an anticlinal and were for many years regarded as the lowest members of that group, 

 although the contained fos.sils in the beds at Faruham, seemed to be opposed to this view.' 

 The occurrence of these limestones further to the north, near Arthabaska, in their proper 

 position, resting upon the crystalline schists on the one hand and, upon the Sillery red 

 and green shale.s on the other, showed that these must be considered newer, especially 

 when, from the same black beds, characteristic Trenton fossils were obtained. This view, 

 which was expressed in 1877 by Dr. Selwyn, has since been amply confirmed by the 

 writer, not only for the district north of Richmond but in that of Farnham, where the 

 regular stratigraphical position of these limestones and shales as the upper members of 

 the Chazy Trenton formation is clearly established. 



The stratigraphy of the Levis beds was rendered still more confused by the fact that 

 of the large collections of fossils which were obtained in 185*7-00, part were taken from 

 the pebbles of the conglomerates and part from the paste, the separation of which was 

 not carefully attended to, while a further element of confusion resulted from the obtaining 

 of a great number from a large but loose boulder of conglomerate, supposed at the time 

 to be from one of the conglomerate ridges of the vicinity, but which may have been 

 derived from belts of an entirely distinct horizon at no great distance. Hence the inevit- 

 able result followed of a commingling of forms of Potsdam and Calciferous ages appar- 

 ently from the same formation. The faulted and overturned condition of the strata from 

 which the fossils were obtained, and the consequent uncertainty of the true relation of the 

 several divisions rendered the question still more complicated. 



A comparison of the Levis roclis with those of the north extremity of Newfoundland, 

 while serving to show that these there occur, in character precisely similar to what is seen 

 in the province of Quebec, is of very little assistance in the matter of understanding the 

 complicated structure of the group. It is evident from the sections furnished of that 

 locality that the same errors of stratigraphy affect their value unfavourably, w^hich Ibr 

 many years rendered the stnicture nearer home unintelligible. It is believed, however, 

 that a careful reexamination of the Newfoundland sections, in view of the new light 

 obtained as to the structure of the group, would be of great value in completing the 

 portions of the sequence iipward from the Laurentian, which have been apparently faulted 

 out in the sections presented along the River St. Lawrence. 



'GeoL Can.' 1863, pp. 239-40. 



