114 C. D. Waleott— Review of Br. E. W. Ells' s Report, etc. 



Group" in geologic nomenclature has already been quoted, 

 ante p. 105. After an examination of the typical area, in com- 

 pany with Drs. Selwyn and Ells, and with the latter, the Sutton 

 Mountain anticlinal and superjacent volcanic rocks and so- 

 called Lower Cambrian rocks, I agree with the conclusions 

 given, and think that the term " Quebec Group " had best be 

 dropped from geologic nomenclature To the one who would 

 use the term I will ask, to which of the following groups would 

 you apply it ? 



1. The Trenton-Utica strata of the Citadel Hill of the city 

 of Quebec? 



2. The Lower Ordovician strata of the Levis Terrane ? 



3. The Upper and Middle (?) Cambrian strata of the Sillery 

 Terrane ? 



4. The Lower Cambrian strata flanking the Sutton Mountain 

 range? or, 



5 The pre-Cambrian post-Laurentian strata of the Sutton 

 Mountain anticlinal ? 



Until it is determined which of the above shall receive the 

 name, it appears best not to use it indiscriminately. 



Dr. Ells's suggestion to use the name " Levis " for the local 

 development of the Calciferous terrane about Quebec, and the 

 name*" Sillery " for the passage beds and Cambrian strata of 

 the St. Lawrence valley, in the viciinity of Quebec, is an 

 admirable one and worthy of imitation by those geologists 

 interested in the advance of geology in America 



Pre- Cambrian. — The crystalline schists of the Sutton Moun- 

 tain anticlinal and its northeasterly extension are unconform- 

 ably subjacent to the overlapping slates and quartzites of the 

 supposed Lower Cambrian, and form the oldest known rock 

 series in the district. Dr. Ells describes their geologic distri- 

 bution, and the character of the micaceous, chloritic and talcose 

 schists, as found in several sections crossing the anticlinal. 



Under the head of " Crystalline and Igneous Bocks," p. 93K, 

 intrusive granite and diorite are described. The diorite forms 

 a chain of hills that extend from the Vermont boundary, 

 near Lake Memphremagog, to north of the Chaudiere river. 

 The diorites are closely associated with the serpentines and all 

 are referred to the Cambrian system. The areas of serpentine 

 are quite large and of great economic importance, owing to the 

 numerous veins of asbestus found in them, especially in the 

 townships of Thetford, Coleraine and Ireland. A short de- 

 scription of the mines is given, with the product of several 

 of the larger ones (pp. 106K-112K). A short description of 

 the economic minerals notes the presence of gold on the Chau- 

 diere river and the exploration for it ; also the indications and 

 mining of copper, and the occurrence of iron ores, soapstone, 

 limestone and building stones. 



