CHARACTERISTICS OF EXPOSURES EXAMINED. 193 



Newfoundland.^ During the summer of 1889 I had an opportunity to 

 examine the sections of the Ordovician and Cambrian rocks in the 

 vicinity of Quebec, and I was very much impressed b}^ the mode of occur- 

 rence of the limestone conglomerates. The lowest bed of conglomerate 

 occurs in the Sillery shales, on the south shore of the Saint Lawrence 

 below Levis, and on the south shore of the island of Orleans. The lime- 

 stone bowlders show transportation, and are mingled with pebbles of 

 quartz, sandstone, et cetera. The Olenellus fauna occurs abundantly in 

 the fragments of limestone, but the source of the limestone is unknown. 

 It is, however, of Cambrian age, and it has been redeposited about 1,500 

 feet from the summit of the series of shales, sandstones, et cetera, that 

 are referred to the Cambrian.f 



The lower bed of limestone conglomerate at Point Levis occurs near 

 the base of the Ordovician, in the Point Levis shale. It is made up of 

 large and small bowlders of limestone, carrying the Upper Cambrian 

 fauna, that are embedded in the limestone matrix in which occurs the 

 typical Calciferous fauna. The matrix is a hard, gray, impure limestone 

 which forms solid layers that were traced for over 500 feet on the strike. 

 As in the case of the limestone bowlders carrying the Olenellus fauna, 

 the origin of the bowldiu-s carrying the Upper Cambrian fauna is un- 

 known, as no beds of limestone of a similar character have been found 

 in the Sillery shales upon which the Ordovician shales and interbedded 

 conglomerate rest. The matrix of the conglomerate proves the forma- 

 tion to be of lower Ordovician age. In a bed of limestone fifty feet higher 

 up in the section I found additional species of the Calciferous fauna, and 

 in a bed of limestone conglomerate above this the fossils in the bowlders 

 and in the matrix as well are of Calciferous age. In a search of two days 

 I failed to find a Cambrian fossil at this horizon, although such an occur- 

 rence might be anticipated from the occurrence of the older limestones 

 in the conglomerates beneath. This second band of conglomerate in the 

 Levis series appears to be a true intra-formational conglomerate. The 

 limestone conglomerates embedded in the shales and shaly limestones 

 beneath the city of Quebec are of much less stratigraphic importance 

 than are those at Point Levis ; but the same conditions of deposition 

 appear to have existed during the formation of these rocks of middle 

 Ordovician (Chazy-Trenton) time. 



Vermont and New York Localities. — In the passage beds between the 

 Cambrian and Ordovician east of Highgate springs, Franklin county, 

 Vermont, layers of limestone conglomerate occur, some of the fragments 

 of which carry the lower Ordovician fauna. The horizon of the con- 



* Geology of Canada, 1863, pp. 227, 260-261. 

 t Am. Jour. Sci., vol. xxxiv, 1890, pp. 112-113. 



