368 J. Gibson—Salt deposits of Ontario. 
(4.) Chert or siliceous stone, containing variable quantities ot 
TORRONE iis ciccu «OR Saws Fecuge Laden 
(5.) Stratified limestone, uppermost 4 feet tolerably pure, the 
rest containing variable quantities of silica and magnesia. 
From 780 to 810 feet from the surface the rock approaches i 
1 
REE a on oo hy bene oan dee eck eee 
(6.) Shales intercalated with thin beds of clay,.------------ 80 
a7.) Wryeraiine OrOWh HmcsOnG, ke ee 25 
(8.) Brown and white magnesian limestone, alternating with 
beds of shale and gypsum, ote 4) 
(9.) Blue clay intercalated with gypsum,..-__.-.---..----- 45 
(10.) Cellular limestone, shale, and gypsum, --.------------- 26 
Bae DPR WBN a os dle Kiss Une eee 15 
(12.). Shale, gypsum, and. rock salt,,..4...2...-..+.<.-2-+6 14 
present existence of water in them. Crystals of calespar occur- 
red at the depth of 400 feet, and at 780 feet crystals of selenite 
(CaSO*+2H?0). At 952 feet a bed of compact gypsum sev- 
eral feet in thickness was encountered, and at 1,005 feet a layer 
of pure alabaster. 
Before reaching the salt horizon a sudden transition from 
fresh water to strong brine was observed, at about 1,100 feet 
from the surface. Such an occurrence may be explained by 
the hypothesis, that an impermeable argillaceous shale com- 
pletely excluded the fresh water of the upper layers of lime- 
stone from the lower saliferous rocks. 
Finally, it may be mentioned that the prevalence of vast 
quantities of gypsum and salt in a mixed state naturally sug- 
gests the utility of a shaft, by which not only could ge roc 
salt be obtained, but also the combined gypsum and salt for 
agricultural purposes. 
8. Coleman and Gowinlock’s well, Seaforth. Feet. 
i) Srenve Sid, pd claw, 25 
(2.) Stratified dark-gray limestone, ........-.------ ------ 
—(3.) — oc ginieas limestone, followed by 2 very hard 
y che 
ana 
200 
