gy of Portion <>f Proriitci of Quebi L18 



the city of Quebec and northwest side of the Island of Orleans. 

 The contained fauna is of Trenton-Utica age. 



From the Cape Rouge section and the strata on the south 

 Bide of the St. Lawrence, Dr. Ells concludes that the evidence 

 afforded bv the Btratigraphy and the graptolites, determined by 

 Professor Lapworth, is sufficient to refer the Sillery rocks of 

 1. 2, 3 and 4 of the section, to the Cambrian system, and the 

 is beds (5) to the Lower Ordovician. 



The thickness of the Sillery and Levis rocks are not given ; 



but Dr. Eils told me that the measurements given by Logan 



were as nearly correct as could be determined. These were 



"i feet for'the Levis shales and 5000 to 6000 feet for the 



Sillery series as now known. * 



The OboltUa jpretiosa ranges through from 1500 to 2000 feet 

 of the CFpper Sillery, and the lower conglomerate, of 2, occurs 

 in the lower portion of this series. The Cape Hosier Dictyo- 

 nema socidU zone is regarded as the lowest of the graptolitic 

 zones, and to indicate the horizon of the Tremadoc terrane of 

 Great Britain. The ('ape Rosier beds are referred to the 

 Upper Cambrian by Professor Lapworth and Dr. Ells, but 

 with our present knowledge of the Cambrian in America, I 

 would refer them to the Lower Ordovician or to the Lower 

 Calciferous. The occurrence of the typical Calciferous fauna 

 within one hundred (100) feet of the base of the Levis series, 

 at St. Joseph de Levis, points very strongly to considering the 

 graptolitic fauna of the Tapper Sillery to be of Calciferous age, 

 if a comparison is made with the Phillipsburgh section. 



Dr. Ells refers the Sillery series to the Cambrian and in this 

 I mainly agree with him, except that the upper portion is evi- 

 dently a passage series between the Cambrian and Ordovician. 

 On lithologic and stratigraphic evidence the line would be drawn 

 at the summit of the red shales. On paleontologic evidence, 

 a- furnished by the graptolites, I would include the upper 

 portion of the Sillery red, and green beds in the Ordovician, 

 as I think they are above the typical Potsdam zone of America. 



It will be recalled that Dr. Ells stated that the Sillery beds 

 rested unconformable* upon the slates, quartzites, etc., which 

 he refers to the Lower Cambrian. He mentions that, in this 

 lower series, beds of gray subcrystalline limestone occur. It 

 may be that we here have the source from which the lime- 

 stone conglomerate of the Sillery was derived, which contains 

 the Olenellus fauna. This would be in accordance witli the 

 mode of occurrence of the Olenellus or Lower Cambrian fauna 

 to the southward, in Vermont and eastern Kcw York. 



Dr. Ells's conclusion as to the value of the term " Quebec 



* This transfers a considerable portion of the strata originally referred to the 

 Levis to the Sillery. 



