456 K. W. ELLS — STRATIGRAPHY 01 THE "QUEBEC GROUP. 



feet, and in which was comprised a considerable variety of sediments. Some 

 of these contained an abundance of fossils, while others were comparatively 

 barren of organic remains. The lowest portion was supposed to consist of 

 greenish shales, mostly calcareous and magnesian, l>nt having interstratified 

 beds of purple color. These graduated upwards into grayish argillaceous 

 -hales and limestone conglomerates, with which were closely associated 

 bands of dolomitic Limestone and olive-green slates, the latter containing 

 glauconite. In the upper part of the section, beds of gray sandstone and 

 grittv conglomerate occurred together with others largely composed of j»<1>- 

 bles of limestone in a gritty or sandy paste. The upper members consisted 

 chiefly of dark gray and green Blates with quartzites, which were interstrati- 

 fied with a Beries of red and green Bhales, the latter containing fossils, among 

 which were recognized two Bpecies of LingtUa and an Obolella presumably 

 pretiosa. Some doubt, however, existed as to the true ascending sequence 

 of these several divisions, owing to the fact that of the Obolelln found in the 



en slates several allied species were also recognized in the Potsdam for- 

 mation elsewhere, as well as in what had been regarded as the Calciferous 

 of New York. 



Succeeding the red and green shales, which for the time at least were re- 

 garded as constituting the upper portion of the Levis formations, came a 

 series of greenish gray sandstones of peculiar aspect, with shales of various 

 colors — red, green, gray, and black — having an estimated thickness of li.ooo 



feet. These composed the Sillery division, and were then held to constitute 



the upper portion of the Quebec group. 



In 1864 the Levis formation was again divided into two parts, of which 

 the upper, comprising a thickness of :5,74<> feet, was separated under the head 

 of the Lauzon. This embraced the hulk of the olive-green and red shales 

 with their associated sandstone- and quartzites, the sequence in ascending 

 order now being L<'vis, Lauzou, and Sillery. In the report of the Geologi- 

 cal Survey of Canada for 1866 the Levis or lower division was said to be 

 distinguished by it- generally black or dark color, and was stated to contain 

 nearly all t he fossils found in the group, and from the evidence of these fossils 

 the geological position of the base of this division was held to be about the 

 summit of the Calciferous. The middle division, or Lauzon, was marked 

 by a predominance of green and purple -hade-, the fossils found being only 

 three -the two species of LingtUa and the Obolella already noted — which oc- 

 curred near it- BUpposed Summit. It was, however, further distinguished by 



the presence of two magnesian hand-, one at the base and the other near the 

 top, both characterized in what was regarded as it- metamorphic equivalent 

 by the presence of metallic ore-. The upper, or Sillery, in its unaltered con- 

 dition consisted of the green Bandstones with their associated shale-, which 

 in their altered Btate were Bupposed to form the series of highly crystalline 



