THE TORONTO FORMATION. J 89 



by streams prior to the Bloomington substage of glaciation to nearly as 

 marked a degree as the channeling below the level of the loess effected in 

 the Peorian stage of deglaciation. There was also a marked increase in the 

 stream gradients, the Bloomington drift sheet being accompanied by a much 

 more vigorous gravel outwash than that which accompanies the Shelby- 

 ville sheet, In the writer's opinion it is Questionable if the interval between 

 the Iowan and early Wisconsin invasions covers more than a small fraction 

 of the time occupied by those between the Iowan and lllinoian and between 

 the lllinoian and Kansan. The union of the several lines of evidence just 

 cited would seem to support the view that it is longer than the interglacial 

 substages of the Wisconsin. The view of a brief interval between the 

 Iowan and Wisconsin, however, meets a strong objection in the supposed 

 attendant deposits at Toronto. 



THE TORONTO FORMATION. 



Turning to the Toronto formation it is found that a fossiliferous silt 

 occupying a horizon between bowldery glacial clays has a fauna and flora 

 which denote a climate fully as mild as that which at present characterizes 

 that region. 1 In discussing this formation Dr. A. P. Coleman remarks that 

 unless the Labrador gathering ground is shown to have stood much higher 

 than at present, it can scarcely be supposed that a widespread sheet of ice 

 was maintained there while oaks and maples and pawpaws flourished on 

 the land and Mississippi unios in the waters, within 400 to 500 miles to the 

 southwest. In the absence of any evidence of such uplift, he concludes that 

 the ice fields were completely melted during this interglacial epoch. 



The extent of deglaciation suggested by these beds, so far as space is 

 concerned, can scarcely be supposed to have been exceeded either by the 

 Sangamon or the Yarmouth stage of deglaciation. The Toronto beds con- 

 stitute probably the most decisive evidence yet brought forward in support 

 of an extensive deglaciation within the Glacial period. The time involved 

 may reasonably be supposed to cover a portion of the Glacial period by no 

 means small. Its rank should be as high as that of any of the interglacial 



v i vifr tle o= r ^ Pti ° nS by Dr ' A ' P - C ° leman aDd Pr0f - D - P " P<^"°w: Am. Geologist, Feb , 1894^ 

 Vol. XIII, pp. 85-9o. See also additional interpretation by Dr. Coleman : Jour. Geol., Vol III p„ 274 

 6J.2-645. For description of fossiliferous beds at Scarborough Heights and other localities near 

 loronto, by Dr. George J. Hinde, see Jour. Canadian Inst , April, 1877. 



