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Indiana University Studies 



partings are sometimes several square rods in area. Some 

 partings are so small, however, as to have an area of only 

 a few square feet. Single, isolated stylolites are never found. 

 They occur only as a series of alternating columns making up 

 a stylolite-parting. 



Stylolite-seams run most commonly in a horizontal direc- 

 tion, or nearly so, and parallel with the lines of stratification. 

 Occasionally they have been observed running obliquely and 

 even perpendicularly (see Fig. 17). They are also known to 



Fig. 6. — Stylolite-surface in the Mitchell limestone, showing 

 the thin deposit of black residual clay. The white spaces 

 result from broken-off stylolites, and show the irregular 

 outline of the columns. 



cross one another. The chief characteristics of the stylolites 

 are the same regardless of the direction of the seam. 



Stylolite-partings are often very numerous and close to- 

 gether (see Figs. 16 and 32). In a single, thin stratum, there 

 have been observed as many as a dozen or more lying directly 

 one above the other with only a few inches of stone separating 

 them. They have also been observed to lie one upon another 

 and even to penetrate one another. In some stylolite-bearing 

 strata, however, the partings are very rare and far apart. 



