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THE OTTAWA NATURALIST 



VOL. XXIV. OTTAWA, FEBRUARY, 1911 No. 11 



PRELIMINARY NOTES ON THE "CHAZY" FORMATION 

 IN THE VICINITY OF OTTAWA.* 



By Percy E. Raymond. 



The strata which He between the Beekmantown and the 

 Black River in the Ottawa Valley have been referred to the 

 the Chazy, principally on account of their stratigraphic position. 

 Their character and distribution have been described in the 

 "Geology of Canada," 1863, pp. 123-130, and in more detail by 

 Dr. Ells in reports accompanying the various maps covering the 

 region. 



The fauna of this formation is unlike the fauna of the typical 

 Chazy of the Champlain Valley in New York and Vermont, and 

 its extension in Canada, and the writer has recently begun some 

 studies at various places between Ottawa and Montreal, with the 

 hope of finding the reason for this change. The present paper is 

 a preliminary one, prepared for the purpose of showing the 

 lithological characters and the range of the principal fossils in 

 the formation near Ottawa. 



Since the first description of the formation two members 

 have been defined. The lower portion consists of sandstone and 

 shale, and the upper portion of limestone. The two members 

 have been mapped separately by Dr. Ells, and their distribution 

 in the vicinity of Ottawa is well shown on his map of the region. 

 At the base of the formation are layers of coarse-grained conglo- 

 merates and sometimes arkose, lying on the fine-grained dolo- 

 mites of the Beekmantown. The top of the formation does not 

 appear to have been definitely defined, but it would seem from 

 the maps and descriptions that all the limestone up to the black, 

 lumpy, cephalopod-bearing beds of the Black River were in- 

 cluded in the Chazy. 



In the vicinity of Ottawa both the sandstone and limestone 

 are fairly well exposed, but no one. exposure presents a good 



Published by permission of the Director of the Geological Survey of Canada. 



