358 



Its course is south-west through a corner of the town of Livonia, en- 

 tering Plyinouth between sections 12 anJ 13, passing a little to the east 

 of Plyiiioulh corners; thence through section 3:5 into town of Canton, 

 which it leaves on section 30. As but a small portion of this ridge is 

 found in Wayne county, a particular description is deferred to a future 

 report. 



BOULDERS. 



No part of the county can be denominated stony. Imbedded in 

 the clays, and occasionally found grouped upon the surface, are water- 

 worn boulders or fragments ot the jiriinary rocks, A species of leddish 

 granite predominates, occuring frequently of more than a ton weight. 

 Boulders are found in great numbers in the town of Plymouth, a large 

 proportion being of fossiliferous limerock. Limestone boulders are also 

 numerous in the bed of Huron river, sometimes of large size. Occa- 

 sional banks of c <bble stones were found heaped along its sides, of a 

 size suitable for paving. 



An interestintr locality of boulder rocks was met with at Rawson's 

 mills, town of Van Biiren, An excavation in the river bank had ex- 

 posed a bed of limestone and clay s!a'e rocks, thickly deposited near 

 the water's edge, to the depth of several feet. The slates were often of 

 two to three feet diameter, of dark color, fissile, and containing iron 

 pyrites. 



MARSHES OR WET PRAIRIES, 



Comprise extensive tracts; they are of generally similar character, 

 being low portions of the sandy openings that have been subjected to 

 an overflow of water for a sufficient |)eriod to allow a deposition of muck 

 or ]>eat from vegetable decomposition. This peat supports a growth of 

 wild grass, destined to a<ld annually to its accumulation. Thus what 

 were pond^^, become by this jirocess extensive beds of vegetable soil, 

 varying in humidity with the seasons. These beds have a depth of 

 from one to six feet, and upwads. 



Indications are apparent whioh prove that very many, at least, of 

 these peat marshes ha<l their origin in the labors of the beaver, aided 

 by the natural conformation of the surface. They occupy gently rolling 

 tracts, in which ridges of sandy "openings" and detached prominences 

 or inlands ot the same are intersected by long bands of marsh. Nearly 



