DIFFICILTIKS OK PROFESSOR WRIGHT's INTERPRETATION 249 



ent position in this way, for he refers later to the great masses of chalk 

 in Sweden, one of them 3 miles long, 1,000 feet wide, and 100 or 200 feet 

 thick, shifted by the ice and now inclosed above and below by glacial 

 materials. 



Tertiary beds have not yet been found in Ontario from which the warm- 

 climate fossils of the interglacial could be derived, and in any case it is 

 incredible that the 100 square miles of fossiliferous deposits should not 

 somewhere show evidence of the strange history they are supposed to have 

 passed through. The interglacial leaves and shells, all whole and sound, 

 could not have survived the Moel Tryfaen experience, in which the great 

 majority of the shells were broken ; and Professor Wright will hardly 

 suggest that a sheet of sand and clay 100 square miles in area could be 

 transported bodily for an unknown distance to be laid gently on the lower 

 bed of boulder-clay. The immense disturbance must somewhere have left 

 its marks. 



Even if this extraordinary theory were accepted the real difficulty has 

 not been touched, for it has been shown that the warm-climate beds are 

 buried conformably by the later Scarboro beds. If the Don ])eds were 

 shifted bodily, they could hardly be laid down so evenly that the delta 

 clavs and sands of the Scarboi'O stage should not show some unconformity. 

 If it be suggested that the whole series, including both Don and Scarboro 

 beds, was shifted together, the difficulty of transport is still further in- 

 creased, since the Scarboro beds have a width of 35 miles as compared 

 with the 13 miles of the Don beds, and the area of flat, undisturbed clay 

 and sand to be transported is increased to probably 150 or 1?5 square 

 miles. 



However, it is prol)able that Professor Wright had no such thought in 

 mind, since in his concluding statements he suggests that the Keewatin 

 (rlacier extended in the vicinity of Toronto into a region "occupied by 

 some species of piants and iininials which now exist only at a considerable 

 distance to the south. At that time the lower Don beds were fomied. 

 Later the Labrador rilacier pushed outward as the Keewatin Glacier re- 

 ceded. . . . During this advance over the deserted Keewatin deposits 

 in the vicinity of Toronto, the Scarboro beds, overlying the Don beds, 

 were deposited and some of the fossil plants and animals native to the 

 lower beds were incorporated into the lower portions of the upper beds." 



How this is to be reconciled with the drainage of the interglacial waters 

 to a depth below that of Tjakc Ontario, as ])roved by the Dutch Church 

 Valley, at Scarboro is iuird to see. This interglacial valley, a mile wide 

 and 166 feet deep, could not have been carved while the Labrador ice- 



XXIX — Bri.i,. Gkou Soc, .V.m., Vol,. 20, lOH 



