STATE GEOLOGIST. 9? 



linear surveyors. Mr. Wm. B. Hess, of Kast Saginaw, has in 

 his 6ustody maps and notes of resurveys, copies of which I had 

 hoped to procure, but the limited means at my disposal have 

 not been sufficient to enable me to incur the expense of copy- 

 ing them In the mean time there is little doubt that the rocks 

 of the Michigan Salt Group outcrop in a broad belt arching 

 northward from Tawas Bay through Ogemaw, Boscommon, 

 Missaukee, Wexford, Lake and Newaygo counties. The inter- 

 ests of the State demand that explorations be made across. this 

 region at as early a day as possible. If the indications observ- 

 ed, be found verified, this resource will prove of incalculable 

 value to the central counties of the peninsula, at present cut 

 off from all ready communication with other parts of the State. 

 On the east side of Saginaw Bay some clays were seen at the 

 mouth of Pigeon river, in Huron county, which very much re- 

 semble those of the Salt Group ; and as this is about the place 

 for the formation to strike the main land again, after crossing 

 the bay, there are reasons for undertaking some more thorough 

 explorations in 'that vicinity. Indications also exist of the 

 occurrence of the formation in Tuscola county. It is likely, 

 however, that the group thins out toward the south and nearly 

 disappears through Lapeer, Oakland, Washtenaw, Jackson and 

 Eaton counties, thus furnishing another illustration of the 

 thickening of our formations toward the north. The salt springs 

 at Saline, in Washtenaw county, and at various points in Jack- 

 son, may possibly issue from the attenuated representative of 

 the group; but I am more inclined to think that these waters, 

 like similar ones in Branch, Oakland, and the northern part of 

 Huron county, are supplied by the various formations outcrop- 

 ing at these localities. Borings for salt have shown the Napo- 

 leon and Marshall sandstones to be saliferous, while at Saginaw, 

 water from the coal measures stood at 1° of the Salometer in 

 the upper part, and increased to 14" before reaching the Parma 

 Sandstone. It is important to bear in. mind that the occurrence 

 of a brine spring proves nothing more than that there is salt 

 somewhere in the State. 

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