380 



may be seen to be corcposed of well formed quartz crystals. Where 

 not discolored by oxides of iron, it is of a pare white. 



Associated with this stratum is a gray silicious limestone, which is 

 fossiliferous. 



A similar sandrock appears in the bed of the Raisin, at low water 

 mart, section 29, town of Raisinville, where it forms a ledge of a foot 

 in thickness. Some portions are beautifully white, and are nearly pure 

 silex. It breaks easily, and is inclined to disintegrate. It has not been 

 used, except as a scouring sand. 



Near the west line of section 1 9, rock appears at the surface, and has 

 been quarried superficially. It is a silicious limerock, of dark color, and 

 when quarried, moist and soft, and may be dressed with ease to any re- 

 quired form. Owing to its want of compactness, it may be doubted 

 whether it would be permanent exposed to the action of the atmos- 

 phere. It has been employed as a building material at Monroe. 



Opposite Lawrence's mill, a smooth ledge of limerock forms the bed 

 of the Raisin, and a quarry has been opened on the upland several 

 rods south from the river. The latter furnishes a silicious limestone, va- 

 rying in color from alight to a dark mixed gray. 



In a south-west direction from the above, in town of Ida, rock is found 

 at the surface, over a small area, on section 4. A superficial stratum 

 only has been quarried, of a foot thick, which is said to afford superior 

 lime. 



On section !6 a silicious limerock appears in the bank of a small 

 pond, and has been opened to depth of 4 feet. It removes readily in 

 slabs three feet in length, with thickness of four to six inches. Color 

 light yellowish gray. 



A vesicular limerock forms the bank at the head of Ottawa Lake, 

 town of Whiteford. It alfords excellent lime. 



A compact limerock also appears in an inlet at the foot of Ottawa 

 Lake, and has been quarried for lime. Portions are silicious. Consid- 

 erable calcareous spar is contained. 



West of the range just described, limerock makes its appearance on 

 the Macon river just above its mouth, and forms its bed for a mile. It 

 has been quarried extensively, but the excavations have not penetrated 

 below the first solid layer, a depth of eighteen inches. It is mostly of 

 a dark gray color, sparry, approaching a crystalline texture, and abounds 



