26 



There are in some places many concretions of brown iron 

 ore, once no doubt, siderite. 



Toward the bottom of the sand and immediately above 

 the clay there is often a thick bed of coarse peaty materials, 

 including many chips of wood and bark and bits of branches. 

 The trees recognized are Larix Americana and Abies bal- 

 samea. A few small shell-fish are found also, Sphcenum 

 rhomboideum, S. fabale, Limucea sp., Planorbis sp. and 

 Valvata tricarinata. 



The sand extends for five miles along the cliffs and has 

 been found in ravines several miles north of the shore. 



The Scarboro interglacial beds were formed in a 

 northern bay of an interglacial lake, which reached at least 

 ten miles inland from the present shore. They are delta 

 deposits laid down by a great river coming from the 

 Georgian bay region, draining the basins of the present 

 upper lakes, and they began with a water level somewhat 

 below that of lake Ontario. 



Above the second till sheet there is stratified clay and 

 sand, followed by a third sheet of till, and in the highest 

 part of the cliffs a fourth and a fifth sheet of boulder clay 

 have been found with intervening stratified sands and clays. 

 There were three well-defined recessions of the ice during 

 which lake deposits having thicknesses of from 25 to 36 

 feet were deposited. How long these later interglacial 

 periods lasted is unknown. No important erosion intervals 

 are known in connection with them, and except for a few 

 small shells in one of the beds they are without fossils ; so 

 that they seem to have been of much less importance than 

 the Toronto interglacial period. 



The total thickness of these upper glacial and inter- 

 glacial deposits at the highest point of the Scarboro sec- 

 tion is 203 feet. 



The magnificent Scarboro section may be seen to the 

 best advantage by taking a King street car as far east as 

 possible and then walking eastwards along the shore. This, 

 however, demands a good deal of time, and the highest and 

 most interesting parts of the section may be seen more expe- 

 ditiously by taking a King street car to the Woodbine and 

 there transferring to a suburban car running along King- 

 ston road. This ascends the sandy slopes of the long spit 

 which enclosed the ancient Don bay of lake Iroquois, and 

 then runs for two miles east along the old gravel bar, which 



