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Indiana University Studies 



seam marks the line between a distinctly laminated stratum 

 and one showing little lamination. This is best miderstood 

 from a study of Fig". 23. Here the horizontal lamination of 

 the upper stratum is distinctly continued into the downward- 

 penetrating columns. The laminae are sharply cut off at the 

 edges of a column, but are continued in the next downward- 

 pointing one. There is no evidence of distortion or disturb- 

 ance of the lamination, either within the columns, or above 

 them. At the ends of the upward-pointing columns, the 

 laminae, instead of bending around the convex ends, retain 



Fig. 23. — Semi-diagrammatic sketch, shoving the relat^'on of 

 stylolites to the lamination of the rock. Note that the 

 distinct laminae of the upper layer are undisturbed, both 

 above the upward-penetrating columns, and within the 

 dovaiward-pointing ones. The laminae are not bent 

 around the ends of the columns, but are actually hollowed 

 out. Note the darker laminae. 



undisturbed their parallel, horizontal position, the rock having 

 been actually hollowed out. 



More striking yet is this observation of undisturbed lam- 

 ination as seen where a stylolite-parting occurs between a 

 cross-bedded and a horizontally bedded stratum. The most 

 distinct example was observed by the writer at a quarry of 

 J. Hoadley and Sons Co., Stinesville district (see Fig. 24). 

 Here the overlying bed is distinctly cross-bedded, and the 

 lower one clearly horizontally laminated. Very pronounced 

 is the continuation of the angular lamination from the upper 



