296 VAN HISE—METAMORPHISM OF ROCKS AND ROCK FLOWAGE. 
Granulation.—W here the movements result in granulation this exposes 
large surfaces to the action of the contained water. The dissolving power 
of water when not nearly saturated is almost directly in proportion to 
the area upon which it can act. If the grains of a rock be broken by 
granulation into particles having radii .1 of those of the original grains, 
each small grain will have .001 the volume of an original grain, and the 
total surfaces of the fewer original grains will be to the total surfaces of 
the more numerous grains as 1:10. If the granulation goes so far as to 
give the granules radii averaging only .01 of that of the original grains, 
each small grain will have .0O0001 of the volume of the original grains, 
and the total surfaces for the original grains will be to the total surfaces 
of the granules as 1:100. his last is not an extreme case, for in the 
Original Laurentian district of Canada, described by Adams,* the ratios 
between the diameter of the granules and original particles must be at 
Jeast 1 : 100. 
In different cases the average degree of granulation varies greatly. 
The amount of granulation depends upon the size of the particles and 
upon the mineral character of the particles. At a stage when the 
smaller mineral particles are granulated throughout, the larger mineral 
particles may have only a narrow outer zone affected. In a more ad- 
vanced stage the larger particles may be broken throughout, and in cases 
of extreme deformation the largest pebbles or boulders in sedimentary 
formations may be mashed into thin layers not recognizable as clastic 
fragments, each being composed of a multitude of individual particles. 
Also it is well known that some minerals may be much more readily 
granulated than others. As acommon case, may be mentioned quartz 
and feldspar. In many rocks in which the former mineral is largely 
granulated the latter mineral is little affected. 
Recrystallization.—FKacts of recrystallization.—One might perhaps ex- 
pect from the foregoing that the more profound the kneading the finer 
would be the granulation of the altered rock, but this is not the case. 
Many of the most profoundly altered rocks, instead of being extremely 
fine grained, are somewhat coarsely crystalline. 
This anomaly was long a puzzle to me. In examining the mashed 
rocks I found that under certain conditions the more profound the mash- 
ing the finer the granulation ; but in tracing the process to the extreme 
of granulation I found there was always a limit beyond which the par- 
ticles did not become more finely granulated. On the contrary, at a 
certain stage a reverse tendency appeared, and the particles instead of 
* Report on the geology of a portion of the Laurentian area lying to the north of the island of 
Montreal, by F. D. Adams: Ann. Rept. Geol. Survey of Canada, vol. viii, part J, 1896, p. 108, pl. 
vii, fig. C. 
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