WAVERLY GROUP. 'jj 



Port Huron. Mr. Thompson sunk two artesian wells at White 

 Rock — one to the depth of 555 feet, the other to 700. In both, 

 blue shales, alternating with arenaceous layers containing much 

 iron pyrites, extended to the depth of about 450 feet below the 

 surface, when a porous gray sand rock was struck, saturated with 

 a strong and very pure salt brine. The thickness of the sand 

 rock was about lOO feet, and below it blue shales were found again, 

 which were penetrated to a depth of 50 feet. Mr. Thompson had 

 saved specimens of his deeper drill hole, representing almost every 

 interval of 5 feet, which he kindly presented to me, and by which 

 I could form a more correct idea of the character of the rock beds 

 than could be obtained from any descriptive record. 



Of other deep borings made within the district under considera- 

 tion, I may mention the salt well at New River, only two miles 

 south of the grindstone quarries, bored to a depth of 1029 feet. 



It begins in the grindstone, which is there 15 feet in thickness, 

 underlaid by soft blue shales 30 feet thick ; to them follow alter- 

 nately shale and sand-rock ledges to the depth of 800 feet. There, 

 as the record says, a rotten, bad-smelling, soft rock was penetrated, 

 and then 100 feet of a porous, coarse-grained, whitish sand rock 

 was found, saturated with brine, below which the boring was con- 

 tinued for a few feet into blue shales. Salt brine was already found 

 at a depth of 90 feet below the surface, but it continued to increase 

 in strength as a greater depth was reached. In the sand rock at 

 the bottom of the well, it has a strength of 85 salinometer degrees. 



At Port Austin, one of the oldest salt wells was bored to a 

 depth of 1200 feet, but the boring record has been lost. Lately, 

 Mr. Skene made a new boring to the depth of 1225 feet in a 

 locality one mile west of the village and about 200 yards from the 

 shore line of the bay. The boring, after the penetration of a few feet 

 of drift, begins in the conglomerate band of the grindstone series, 

 following which are greenish-blue micaceous, fine-grained sand-rock 

 ledges. Another conglomerate bed is found 125 feet below the sur- 

 face, and from that a strong current of sweet water rises to the sur- 

 face. From there to 163 feet are arenaceous shales; at 204 feet is a 

 gray sandstone, and the first signs of brine were observed at from 

 204 to 3 1 5 feet, shales with arenaceous seams occur at 3 1 7 feet, and a 

 conglomeratic sand rock 20 feet thick. There was a strong discharge 

 of sweet water from the bore hole, from 336 to 1 100 feet (764 feet). 



