148 ROYAL SOCIETY OF CANADA 
reached at a depth of 1160 feet, from the summit of the first stratum of 
Lorraine shales struck; whilst at Swansea, on the east side of the Hum- 
ber river, and about three-quarters of a mile north of the lake shore, 
1138 feet of Palaeozoic sediments had to be traversed before reaching the 
Archean crystalline limestone rock. 
At Clarkson’s on Lake Ontario, about 18 miles west of Toronto, the 
Archean or granite rock was struck at a depth of 1457 feet. The fol- 
lowing is an estimate of the thickness of the geological formations 
traversed by the drill at Clarkson’s :—Pleistocene: 4 feet; Lorraine: 650 
to 700 feet; Utica: 100 feet; Trenton: 550 feet; Black River: 160 feet; 
Archean: indefinite thickness. In connection with the various forma- 
tions underlying the city of Toronto comprised in the accompanying 
synoptical tables, reference made to the occurrence of pre-Lorraine for- 
mations must be taken to indicate the presence of these formations about 
Toronto, not as outcrops which may be visited and examined in the field, 
but as subjacent formations which compose the earth’s crust in that por- 
tion of the province of Ontario. 
A number of practical tests have been made to ascertain the possible 
occurrence of natural gas, petroleum and salt, in paying quantities for 
economic purposes, but so far these have for the most part proved . 
rather barren of good results. Weak indications of the occurrence of 
gas at various depths in the shale and limestones underlying Toronto, 
have been met at various depths. At Mimico, for instance, three flows 
of gas were met at 425, 575 and 1052 feet respectively ; whilst at 
Clarkson’s the first gas was struck in the Trenton limestone at a depth 
of 1238 feet, the best gas at 1307 feet. Soft and brackish water was 
found in the first 200 feet from the surface. So far as known the deep 
wells about Toronto have not yielded an abundant flow of fresh water. 
THE LAURENTIAN OR ARCHZAN. 
As above mentioned, the crystalline limestones were struck in the 
deep well at Swansea, Ontario Bolt Works, Toronto. The presence of 
these limestones, beneath the stratified sediments of the paleeozoic must 
indicate the occurrence of one of those numerous bands of crystalline 
limestones, which are so frequently met with in Eastern Ontario, or 
Western Quebec, in the great complex or Canadian protaxis and are 
usually referred to an upper series—the Grenvillian or Grenville 
formation. 
The record of the boring at Clarkson’s, eighteen miles west of 
Toronto, gave 11 feet of “ granite rock ” which for the most part proved 
to contain orthoclase felspar, mica, and what appears to be garnet. 
In the deep well at Copeland’s Brewery, Toronto, “ granite” is 

