316 Tertiary. 



face, making a total section of clay and gravel of 49 feet, Unio circulus, 

 IT. gibbosus, and valves of a Cyclas were found in the upper bed of 

 gravel, and a deer's bone was said to have been found also. Between 

 the gravel and the overlying 10 feet of clay, a thin layer of impure 

 mineral pitch, or half dried peti-oleum, intervenes, inclosing leaves of 

 land plants, and occasionally insects. Fresh-water shells occur in the 

 clay on the Detroit river. At Niagara Falls the Silurian limestone is 

 covered by 120 feet of sandy loam, holding striated pebbles and small 

 bowlders, and containing near the middle the shells of a species of 

 Cyclas. It is overlaid by fifteen feet of thinly bedded, reddish-brown 

 claj^, containing similar pebbles and angular fragments. This deposit, 

 whose summit is 60 feet above the level of Lake Erie, forms a bank 

 which continues up to Chippawa. Valves of the Cyclas occur in the 

 upper cla}^ in calcareous nodules, at a railway cut betweu Kingston 

 and the Grand Trunk nftilway station, and leaves of a plant resembling 

 Vaccinium occur in a laminated brownish clay at Newborough, At 

 the upper termination of the town plat, on the right bank of the 

 Goulais river, there is a deposit of the roots and limbs of trees, im- 

 bedded in a bluish scaly material, apparently a mass of compressed 

 leaves and moss, which rests upon a bed of clay, and is overlaid by a 

 mixture of clay and sand; the whole, with a stratum of sand at the top, 

 constitutes a bank of from 20 to 24 feet high. The bed of vegetable 

 matter, which is from one to three feet thick, and about ten feet over 

 the river at the western end of the exposure, dips gently and evenly up 

 the stream; while a thin bed of reddish clay, intervening between the 

 overlying arenaceous cla}^ and the stratum of sand which forms the 

 surface, seems to be perfectly horizontal. On the south side of Lake 

 Superior, between White-fish Point and the Painted Rocks, a great 

 deposit of sand, interstratified with gravel, is spread over the surface 

 of the country. At the Grand Sable, a short distance west from the 

 Grand Marais, it rises here and there almost verticallj^ from the lake 

 to a height of 300 feet. A bed of vegetable matter occurs below 

 a laj^er of mixed sand and clay, and beneath this hill of sand and 

 gravel, which contains Thuya occidentalis, Betula paperacea, and 

 populus balsamifera. 



Behind the Sault Ste Marie, a terrace, varying in its height, but 

 averaging perhaps 150 feet above Lake Superior, and often composed 

 of clay in red and drab layers, stretches from the Laurentide hills 

 southward toward the St. Mary river. About a mile below, and again 

 about four miles above the foot of the Sault, this terrace comes near 



