19161 The Ottawa Naturalist. 59 



a diameter of six feet. Regarding the origin of the coarse in- 

 traformational conglomerates, Walcott writes (op.cit. p. 39: 

 "The relation of the bedded limestone to the subjacent con- 

 glomerates proves that the calcareous mud which was subse- 

 quently consolidated into the limestones solidified soon after 

 position. This is shown by the presence of limestone with 

 sharp, clear-cut edges. The presence of the conglomerates above 

 the limestone beds, from some portion of which they were de- 

 rived, leads one to believe that the sea-bed was raised in rid] 

 or domes above sea-level, and thus subjected to the action of 

 sea-shore ice, if present and aerial agents of erosion * * *." 

 The mode of occurrence of the lders, especially those in 



the limestone at Stone's Quarry, leads to the hypothesis that 

 they may have been dropped upon the sea-bed from floating 

 ice. No other explanation occurs to me that will account for 

 the placing of them upon the sea-bed, so as to not disturb to 

 any marked degree the sediment then accumulating 



Mixed Conglomerates. 



A very interesting type of conglomerate which might be 

 classified under B, I, 1, is that described by Raymond (14) 

 from the Levis. The Levis formation consists mostly of 



shale, with zones of hard blue and light grey limestone, and 

 thick and thin beds of limestone conglomerate. Neither the 

 top nor bottom of the formation is known. * * * Very 

 fossiliferous pebbles have been found in the conglomerates- 

 in the Levis, and the fossils show them to be . derived 

 from strata of three geological ages. The pebbles are: 1st, 

 Lower Cambrian; 2nd, Upper Cambrian or Lower Ordovician; 

 3rd, Beekmantown. Besides the limestone pebbles there are 

 many of igneous rocks and quartzites, but they do not form 

 nearly so large a proportion of the conglomerates as do 

 those composed of limestone. These conglomerates also con- 

 tain pebbles of the red and green shale, and sandstone of the 

 Sillery, thus proving that the Sillery is older than the Levis, while 

 the presence of Beekmantown fossils in both pebbles and matrix 

 of the conglomerates shows that the Levis is of the same age 

 as the Beekmantown at Phillipsburg, Quebec." According to 

 Walcott's definition these may not be considered as intraform- 

 ational conglomerates, since the majority of the pebbles are 

 apparently not derived from the strictly subjacent zones of the 

 same formation. Since such a type is not interformational, and 

 since it is intraformational in all other respects, except for the 

 fact that its pebbles are not derived from the same formation, 

 it is believed best to provisionally classify it under B, I, 1. In 

 short, this type of clastic does not postulate any such condition 



