CHAPTER XIV 
STRATIFICATION 
Nature of Stratification. —If we examine a series of 
rocks that have been formed in the sea, such as any 
section of sedimentary strata, we find them arranged 
in layers. Upon looking closely we are able to dis- 
cover both small (Fig. 149) and large layers (Figs. 148 
and 167), just as if a series of books were placed in 
a pile. Each book, it may be, is different from every 
other, and the covers differ from the leaves. Hach 
of the larger divisions of the rock, which might be 
likened ‘to the book itself, would be called a bed or 
stratum (Fig. 148), and the small layers comparable 
to the leaves, would be named lamine (Fig. 149). The 
larger layers, or strata, would be found to differ from 
one another considerably. We might even discover 
a bed of shale resting upon a bed of limestone, and 
above this a sandstone or even a conglomerate; but 
the lamine differ less markedly, and may all be of 
one kind (such as shale, etc.). 
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