COAL MEASURES. I41 



In Saginaw Bay district, thin coal seams were frequently found 

 in boring for salt, and several experimental borings in search 

 of coal were made in the district a good many years ago, but no 

 sufficient inducements for coal-mining could be discovered. During 

 the last few years the report of the discovery of rich beds of can- 

 nel coal in the valley of Rifle River has caused great excitement, 

 not only in Saginaw district, which is specially interested in such a 

 discovery, but throughout the whole State. In order to ascertain 

 the actual state of the case, I examined the Rifle River district 

 with particular care, and give here a brief statement of the observa- 

 tions made. 



The first explorations for coal on Rifle River were induced by 

 some pieces of cannel coal found in the bed of the river by a 

 settler living close by it. Some gentlemen of Bay City, hearing of 

 the fact, began to examine the surroundings of the locality indi- 

 cated to them, and after experimenting awhile, succeeded in' 

 finding, at a depth of only 18 feet below the surface, a deposit of 

 black shales and cannel coal, the latter, according to their reports, 

 having a thickness of 7 feet. They sunk a shaft to the depth 

 of 27 feet ; the upper 14 feet of the excavation were loose drift 

 masses ; under them, seemingly, a three-foot ledge of a hard, cal- 

 careous sand rock was found ; then came a hard black slate a few 

 feet in thickness, the lower 7 feet in the shaft being thought to be 

 all cannel coal. When I visited the spot, the shaft was full of 

 water, and I could not ascertain the facts as accurately as would 

 have been desirable ; but from the examination of the material 

 taken out of the shaft, which was all there yet with the exception 

 of a few barrels of coal taken away, I came to the following con- 

 clusions : That the sand rock next under the drift and above the 

 black slate was not a ledge in its natural position, but a large 

 boulder of the arenaceous beds of the lower horizon of the subcar- 

 bonif erous limestones, the same rock which forms the cliffs on Point 

 aux Grees ; that the remainder of the excavation went through a 

 deposit of a black, highly bituminous slate, 10 feet in thickness. 

 Three feet of, these slates were considered as such, and the rest were 

 taken for cannel coal ; but I rather think the proportion is invert- 

 ed. The true cannel coal in the promiscuous mass thrown out 

 from the shaft was the smaller part of the whole, and even admitting 



