3l5 



tion. The outer range, commencing at the south-east corner of town 

 of Whiteford, forms there a ridge or step, having a rise above the gene- 

 ral surface of 15 feet in a breadth of 2 miles. It passes thence in a 

 nearly north-east course to Brest, occasioning those intermediate hil- 

 locks or protrusions of rock Avhich occupy areas of from one half to 

 two square miles. At Stony Point it comes out upon the Lake in the 

 ledge before mentioned, and still further on in the same direction makes 

 its appearance on the islands at the mouth of Detroit Straits and the 

 neighboring shores. 



The second range, from the town of Whiteford, where it apparently 

 approaches the range first mentioned, passes through the northern part 

 of the town of Ida, in a nearly direct line to Flat Rock. 



West of this range, rock again appears on the Macon river, in the 

 reservation, and in the Raisin, at Dundee. 



From all the data that could be obtained, the deposit of blue marly 

 clay in the intervals between these ranges, does not exceed in thickness 

 20 feet. Upon this rests a brown or yellow clay, similar to that which 

 overlies the blue in Wayne county.* It has a thickness of 3 to 10 

 feet. This clay constitutes the basis of more than three -fourths of the 

 soil of the timbered lands. Sand loams occasionally alternate with it, 

 and in the town of Milan a rich black sand loam constitutes three-fourths 

 of the soil. 



The sand of the openings and plains has a depth probably not ex- 

 ceeding 10 feet on the general level. Its surface is slightly undulating, 

 and in a few instances considerable ridges rise abruptly. One of these 

 was observed bounding the heavily timbered lands of the town of 

 Erie, succeeded by others having no uniform direction, and varying in 

 height from 6 to 1 5 feet ; wet, grassy swales intervening. I traced one 

 of them for a mile in a northerly direction. A sand ridge borders the 

 prairies in the southwest corner of Ida. It continues for half a mile in 

 a northeast course, attaining to 15 feet in altitude, with the breadth of 

 100, and terminates by a sudden descent. Similar ridges may be ob- 

 served on the plains near Sandy creek, town of Raisinville. 



•An analysts of lOOgrains of these clays showed: Upper Clay. Loteer Clay. 



Silicious matter, 925 23 00 



Alumina, 67.25 4400 



C«rb. Lime, 2350 31.16 



Iron, 00 1.84 



lOUOO 100.00 



