ON THE STONE AGE. 71 



the red gravel to a period when the ice had its greatest extension, and when there was 

 considerable local depression of the laud. " During this period of greatest ice-extension 

 and depression, the Philadelphia Red Gravel and Brick Clay were deposited by the ice- 

 laden Hoods which annually poured down the valley in the summer season. As the ice 

 retreated towards the headwaters of the valley, the period was marked also by a reëleva- 

 tion of the land to about its present height, when the later deposits of gravel at Trenton 

 took place. Dr. Abbott's discoveries at Trenton prove the presence of man on the con- 

 tinent at that stage of the Glacial epoch. Mr. Cresson's discoveries prove the presence of 

 man at a far earlier stage. How much earlier will depend upon our interpretation of the 

 general facts bearing on the question of the duality of the Glacial epoch " ' — a branch of 

 the enquiry which it is not necessary to discuss here. It is sufficient to note that this 

 argillite — an altogether inferior material to the flint, or hornstone of later tool-makers; — 

 appears, thus far, to be a characteristic feature of American palaeolithic art. The locality 

 of the native rock is still undetermined ; but implements fashioned of it have been 

 found in great mimbers along the escarpments facing the river Dehuvare. Prof. Shaler 

 describes the material as a curious granular argillite, the like of which, he says, " I do 

 not know in place." Should the native rock be hereafter identified, with traces of the 

 manufactured celts in its vicinity, it may help to throw light on the age and history of 

 the primitive American implement-makers. 



The flint of the cretaceous deposits does not occur in America. True chalk is all but 

 unknown among the cretaceous strata of this continent, although it has been found in 

 the form of a somewhat extensive bed in Western Kansas. In Texas, the cretaceous lime- 

 stones contain in places hornstone nodules distributed through them, like the flint nodules 

 in the upper chalk beds of Europe. But though, so far, differing in origin, the hornstone 

 and flint are practically identical ; and the chert, or hornstone, which abounds in the 

 chert-layers of the corniferous formation, of common occurrence in Canada, is simply a 

 variety of flint, consisting essentially, like the substance to which that name is specific- 

 ally applied, of amorphous silica, and with a similar cleavage. This Devonian formation 

 is made up chiefly of limestone strata, parted in many places by layers of chert which 

 vary in thickness from htilf an inch to three or four inches. The limestones are more or 

 less bituminous, and frequently contain chert nodules. Most of their fossils are silicified. 

 The formation underlies a considerable portion of south-w^estern Ontario. Outcrops occur 

 at Port Dover, Port Colborne, Kincardine, Woodstock, St. Mary's aud other localities. At 

 a point which I have explored more than once near Port Dover, implements occur in con- 

 siderable numbers, along with fractured or imperfect specimens, mingled with flakes and 

 chippings, evidently indicative of a spot where their manufacture was carried on. At 

 this, and some others of the localities here named, Canadian flint pits may be looked for. 

 Among other objects illustrative of primitive native arts in the museum of the University 

 of Toronto, is a block of flint or brown cherl, from which flakes have been struck off for 

 the use of the native arrow-maker. This flint-core was found in a field on Paisley Block, 

 in Guelph Township, along with a large flake, a scraper, and fourteen arrow-heads of 

 various sizes, all made from the same material. Alongside of them lay a flint hammer- 

 stone bearing marks of long use. All of thoie objects are now in the Toronto museum, 



' Palaeolithic Man in Eastern and Central North America, pp. 152, 153. 



