A PECULIAR CLEAVAGE STRUCTURE 559 



The rocks here strike N. 20-25° W., though the general strike 

 of the region is to the east of north. Like the rocks at Elhjay 

 depot, the country rock here may be classed as a feldspathic 

 mica schist, in which there are secondary feldspar phenocrysts, 

 badly weathered. The rock probably was arkose originally. As at 

 Ellijay depot, there are associated quartz veins which here however 

 postdate the metamorphic processes which produced the pebble- 

 like structure, as the vein material does not show any particular tend- 

 ency to break into lenses as at Ellijay depot. The phenocrysts of 

 feldspar already referred to have probably formed since the crushing 

 took place, as during their development they have pushed away the 

 surrounding matrix which now curves about them. This latter 

 hypothesis to the writer is a more plausible assumption than that the 

 crushing processes have failed to affect them, for there is no reason to 

 suppose that they would resist the crushing action more effectively 

 than quartz. The joint planes in the rock cut squarely across the 

 pebble-like quartzes and are therefore in part at least of later origin. 

 The broadest band in which quartz lenses appear is fully 15 feet thick. 

 A short distance farther up the hill are two thinner bands showing the 

 phenomenon equally well with the 15-foot band, and the intermediate 

 beds exhibit it, though less perfectly. Such highly metamorphosed 

 bands are fairly common in this general region and good examples 

 have been observed and specimens showing the structure collected 

 north of the head of Kells Creek within the Ellijay area. 



It is not so easy here to disprove the former existence of original 

 true quartz pebbles and no attempt will be made to do this. It will 

 simply be pointed out that the similarity of the occurrences to that 

 near Ellijay depot is noteworthy, and that, as in the latter case, another 

 hypothesis for the origin of the quartz masses is not only possible but 

 probable. 



DETAILED DESCRIPTIONS 



It was thought that a study of thin sections of the rock showing 

 the pebble structure might throw some light on the origin of the 

 phenomenon. The results, however, are somewhat inconclusive. 

 The sections of the "pebbles" do show evidence of profound crushing, 

 but then either crushed true pebbles or vein material would exhibit 

 similar features in thin sections. Instead of the crystalline outlines 



