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Indiana University Studies 



stratum into the downward-pointing penetrations, and the 

 presence of horizontal lamination in the adjacent, upward- 

 projecting- columns. 



Often dark laminae stand out very clearly in the stratifi- 

 cation. Where penetrated by stylolites, they are missing (see 

 Figs. 23 and 24). Under the pressure theory one should ex- 

 pect to find them displaced above or below the ends of the 

 penetrating columns. Such is not the case. How could the 

 various, above-described laminated conditions have been re- 

 tained, had the sediments been "differentially compressed in 

 a plastic state"? The rock materials have been actually re- 





















V J 







Fig. 25. — Diagram of a small stylolite-seam partially eradi- 

 cated by the penetration of upward-pointing columns of 

 a large stylolite-seam. Mitchell limestone. One-third 

 natural size. 



moved, and the two beds have been ''dovetailed" into each 

 other. 



Analogous to this observation of the removal of the 

 laminae of the one bed into which the columns of the opposite 

 have penetrated, are numerous examples of small stylolite- 

 seams which have been penetrated and removed by larger 

 stylolites. Figure 25 is a case where a small, once-continuous 

 stylolitic suture, following the lamination of the rock, occurs 

 now only in the do\^Ti ward-projecting columns, being sharply 

 cut off and absent in the rock of the upward-pointing parts. 

 Under the pressure theory, should not one expect to find it 

 displaced in the rock above the columns? 



