Geology and Mineralogy. 245 



Bieler's quarry in Cedar County, Iowa, was analyzed by Miss 

 Herrinton. 



CaC0 3 ._ 58-2 per cent 



MgC0 3 "_ 39-5 



Fe 2 3 and Al 2 O s 0-9 " 



Si0 2 _ 1-2 



99-8 " 

 This is not a true dolomite but more nearly approaches it than 

 the rock described in 1. 



(3.) The Gower stage as defined by Professor Norton includes 

 two distinct lithological types : a hard crystalline rock used 

 extensively for lime and hitherto known as the Le Claire lime- 

 stone ; and a granular evenly-bedded rock which furnishes the 

 best building stone in the State. This was, until recently, desig- 

 nated as the Anamosa beds, which have usually been assigned 

 rank as a distinct geological formation ; but the Iowa Geological 

 Survey, in its recent reports, has taken them to be but a litho- 

 logical phase of one formation. The name Gower has been 

 assigned them from the township in Cedar County in which the 

 important Bieler quarries are situated. Both types of rock are 

 found in the Bieler quarries. The following specimen of the 

 granular laminated building stone was analyzed by Miss Her- 

 rinton. It varies only slightly from a true dolomite. 



CaC0 3 56-4 per cent 



MoC0 3 42-6 " 



Fe a O, and A1 9 0, 0*7 



Si0 2 _. ._ 0-i 



100-1 " 



(4.) Specimen of the Gower phase taken from the Mount Vernon 

 quarry. It was analyzed by Mr. E. A. Rayner. 



CaC0 3 54-02 per cent 



MgC0 3 44-73 



Fe 2 3 and A1 2 3 0-61 



Si0 2 0-29 



99-65 " 

 The rock is nearly a typical dolomite. 



(5.) The rock at the Palisades, on the Cedar River, six miles 

 distant from Mount Vernon, is similar in composition to the 

 Mount Vernon rock. It is stratified but not granular. Building 

 stone occupies layers adjacent to others which are burned for 

 lime. The specimen was analyzed by Mr. G. R. Greaves. 



CaC0 3 53'64 per cent 



MgC0 3 43-89 



Fe 2 0andAl 2 3 __ 052 



SiU 2 1-98 



10003 " 



