358 T. S. Hunt on the Geology of Southwestern Ontario, 
outcrop of this formation, crossing the Niagara river, enters 
Ontario. ee 
At Tilsonburg, ninety miles west from Buffalo, borings have 
shown the existence of the Corniferous limestone — Oe 
pure limestones, were met with to the depth of 854 bat 
50° of the salometer, The well was then abandoned. bie 
here a boring traversing 854 feet of solid strata, from wh 
was, probably, near the summit of the Corniferous, Salins 
reaching the marls which form the lower part of the 5au™ 
formation. hal ae 
Ina boring at London, where the presence of the rer’ 
the Hamilton was marked by about twenty feet of ST tile 
including a band of black pyroschist, overlying the wh 
rous, 600 feet of hard rock were passed through before depth 
soft esian marls, which were penetrated to the cepr 
seventy-five feet. Specimens of the borin 
oe a another near by, carried 300 feet pe the to 
orniferous, show that pure limestones are int . pure 
the dolomites to a de r of 400 feet. At Tilsonburg a pur 
Heetate he met with at 524 feet oe the iy 2 . 
t St. y's, 700 feet, and at Oil Springs 2 & 
595 feet of i : trated, 
last, soft 
