PLATE VI. 



PHOTOMICROGRAPHS OF LIMESTONE AND MARBLES. 



A. Limestone from Wauwatosa, Wis., showing the evenly granular character of a compact lime- 

 stone. After Buckley. 



B. Marble from Cockeysville, Md. After Diller. 



C. Carrara marble after haying been slowly deformed during 124 days at a temperature of 300° C. 

 The calcite has yielded by gliding. After Adams. 



I). Carrara marble deformed at 400° C. The slide shows a uniform mosaic of somewhat flattened 

 grains free from all fracturing or cataclastic structure. After Adams. 



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