212 BULLETIN 109, UNITED STATES NATIONAL MUSEUM. 



IT. DEVONIAN SYSTEM. 



5. Jlarsball series (Hillsdale, Jonesville, Marshall, Battle Creek, Holland, 

 Point aux Barques, etc.). 



(a) Marshall sandstone. 



(6) Sh.ily micaceous siuidstone. 



6. Shale, abounding in kidney iron ore. 



7. Monroe limestone. 



An interpretation was now for the first time placed on the facts 

 obtained in tlie State salt well and Lyon's well at Grand Eapids. 

 As this report announced : 



The State well commenced in the lower part of the Gypseous series. It struck 

 the Napoleon series at 61 feet, the l^larshnll series at 1S4 feet, and the shale 

 series at 343 feet, which it penetrated 130 feet. The boring at Lyon's well 

 commenced in the Carboniferous limestone, which was here 19 feet thick. It 

 struck the Gypseous series at 20 feet, the Napoleon series at 191 feet, the Mar- 

 shall series at 309 feet, the shale series at 448 feet, and continued in this 214 feet 

 The borins; at Saginaw, after passing through a great thickness of alluvial and 

 diluvial materials, struck upon the Woodville sandstone at 92 feet, the shales, 

 etc., of the coal measures, at 171 feet the Parma sandstone at 294 feet, the Car- 

 boniferous limestone at 390 feet, the gypseous series at 404 feet, and the Na- 

 poleon series at 033 feet. 



Judging from the experience at Grand Rapids and from my observations on 

 the outcrops of the lower rocks, you will next find 250 to 300 feet of arenaceous 

 rocks and then over 200 feet of shales. You will not discover as strong brine 

 at any point lower than this which will overflow at the top. We nmst, prob- 

 ably, content ourselves in this State with raising the salt water by pumps. 

 * * * I believe * * ♦ t^jg gxiperior strength of your brine, the ';ompara- 

 tive cheapness of fuel, and yoiu- location upon navigable waters which stretch 

 many hundred miles in every quarter to the we.st of your meridian, as well as to 

 the east of it, will enable you to compete with any other source of supply to the 

 Northwestern States. 



In a report to the governor on the operations and results of the j'ear 

 1859 the State geologist, under date of April 9, 18G0, embodied an ex- 

 hibit of the stratigraphical structure of the Lower Peninsula substan- 

 tially identical with that already cited. For that reason it is not 

 necessary to reproduce it here. The same interpretation was put upon 

 the geology of the salt wells. It will be understood, therefore, that 

 the order of stratigraphical successions first formulated in February, 

 18G0, and standing materially unchanged to the present time, was the 

 result of studies made in 1859. It was not yet, however, fully under- 

 stood that the salt group, on account of its shaly constitution, could 

 not hold supplies of brine within itself, but the underlying Napoleon 

 and Mnr-hall sandstones must serve as reservoirs of the brine. That 

 conception, however, was foreshadoAved, since in his report to the East 

 Saginaw Salt Manufacturing Company, the State geologist, speak- 

 ing of the arenaceous rocks and shales beneath the bottom of the well, 



