291 



may be tolerably well adapted for a hydraulic lime. Should this cou- 

 elusion be verified by trial in a larger way, this stone will prove of very 

 great importance to the State. For this purpose, the dark blue, and 

 the vesiculated or oolitic strata will probably be found best adapted, and 

 in making the experiment, these should be separated and admitted into 

 the kiln without intermixture of other portions. 



Ornamented limestone. — Some of the strata at these quarries, are of 

 dark color, and finely veined like mai-ble ; they receive a good pohsh, 

 and were the beauty of the material better known, would, no doubt, be 

 extensively used for chimney slabs and other ornamental purposes. 



Sand for Glass. — I would again refer to the singular purity and 

 value of the bed of white sand, occasioned by the disintegration of the 

 very friable, siliceous limestone which is included in the intermediate 

 portion of this series of limerocks, and which baa been noticed in for- 

 mer reports. This bed is mostly pure silex, and under the microscope, 

 will be seen to consist of perfect quartz crystals, free from any foreign 

 or coloring materials. No sand in the State is so well adapted to the 

 manufacture of glass, and for this purpose it may well be considered 

 unrivalled. Viewing the wants of the State, in this respect, and the 

 eligible situation of this material, six miles from the city of Monroe, 

 this subject is strongly recommended to the enterprise of our citizens. 



II, KIDNEY IRON FORMATION. 



In passing west from Monroe county, no rock is met with through 

 the whole of Lenawee, it being completely overlaid and concealed by 

 diluvium, and those thick bt ds of clay, which in part cover the rock in 

 Monroe county, and over nearly the whole of Wayne, to a depth of 

 more than 1((0 feet. These blue and yellow clays are presumed to be 

 analagous to those which cover the limerock of the adjoining States, 

 and which have been designated by Dr. Hildreth, of Ohio, as "semi- 

 tertiary deposits," They are found almost universally to envelope the 

 limerock in this State, as far as to the commencement of the sandstone 

 series. The gi-eat accumulation of all these several deposits may be 

 conceived, when it is stated that a rise of 200 feet is attained, after 

 leaving the limerock in Monroe county, before rock in place is again 

 discoverable. 



The clay of the kidney iron formation, is fii-st met with at the very 

 southern extremity of the coal basin, in Hillsdale county, town seven 



