STATE GEOLOGIST. 15 



village. Following up the creek for two and a half miles the 

 land is found to rise rapidly, and the banks of the creek are in 

 some places sixty to eighty feet high. The elevation here rises 

 up into the group next above. 



At the light house, one mile easE of Willaw Creek, the fol- 

 lowing section is seen: 



9 Shale, with interlaminations of sandstone 12 ft. 



8. Sandstone, bluish, fine, 2 ft. 



"I. Arenaceous shale, 2 ft. 



6. Sandstone, bluish, hard, concretionary, 2 ft. 



5. Shale, very persistent, 3 in. 



4. Sandstone, calcareous, hard, highly fossiliferous; con- 

 tains Relzia, Merista, Gomphoceras (?) Glymenia, Rhyn- 

 chonella, a Spirifer resembling 8. mucronatus and S. 

 medialis, but distinct from both, and a large Leptss- 

 noid shell, 2f inches across the hinge line, 2 ft. 



3. Shale 2 ft. 



2. Sandstone, hard, pyritiferous, very persistent, l|in. 



1. Shale, 12 ft. 



The hard, projecting, pyritous layer, (2) affords an excellent 

 opportunity for measuring the dip of the formation, which wa3 

 found to bo one and a half degrees toward the south-west. 



A short distance west of the light house occurs the most 

 extensive dislocation seen south of Mackinac. In the neigh- 

 borhood of the disturbance, on each side, the strata exhibit 

 short undulations, which finally become an actual break, and 

 downthrow of five or six feet. Indications of a sliding move- 

 ment are seen in the vicinity, and the whole effect is such as 

 might be produced by a lateral pressure from the west. 



The gritstones of Lake Huron are destined to play an im- 

 portant part in the economical geology of the Lower Peninsula. 

 The principal quarry owned by Johnson, Pier and Wallace 

 (sec. 30, T. 19 N., 14 E.) is now worked over an area of 

 little more than four by twelve rods. Two hundred tons of 

 grindstones were taken out during 1859, and I was informed 

 1 y the foreman that he expected to manufacture five hundred 

 tons during 1860. Several stones have been finished, weighing- 

 a ton each, and one which weighed three tons. These facts 



