DEPTH OF ZONE OF FLOW IN THE EARTH’S CRUST 109 
crust—will retain its form and will not flow into holes traversing 
it even when submitted for months to a pressure three times as 
great as would suffice to crush it instantly under the ordinary con- 
ditions obtaining at the surface of the earth. 
SABIE. — 
SHOWING THE EFFECTS PRODUCED WHEN COLUMNS OF SOLENHOFEN LIMESTONE—AT 
THE ORDINARY TEMPERATURE—ARE SUBMITTED TO PRESSURES EXISTING 
AT SUCCESSIVE DEPTHS WITHIN THE EARTH’S CRUST 
= epee below A ; 
No. of Tessure Kilos. per urtace of the uration 
Bees ee | co caut | Seton, || ote, peu 
Pressure 
ACs sass 96,000 6,750 15 miles 24 mos. No movement of 
any kind. 
(See Plate I, Fig. a) 
BOOMs ate 128,000 9,000 20 miles 23 mos. Transverse hole 
smaller. 
Vertical hole partly 
filled. 
(See Plate I, Fig. d) 
BO 2A iiecan 193,000 13,570 30 miles 7 hrs. Transverse hole 
unaltered. 
Vertical hole partly 
filled. 
520m eras 200,000 14,060 31 miles Sy illieg Transverse hole 
flattened. 
Vertical hole most- 
ly filled. 
(See Plate I, Fig. 6) 
Shoe areas 257,000 18,070 40 miles 7 hrs. Transverse hole 
flattened. 
Vertical hole most- 
s ly filled. 
(See Plate I, Fig. c) 
The movement noted in the cases of experiments 520 and 8535 
representing depths of 31 and 40 miles—seems to be of the nature 
of flow, so far as it affects the transverse holes, these holes becom- 
ing flattened. But as shown in the descriptions of Plates I and II, 
the movement takes place by the development of minute fractures 
along the course of the vertical holes, small fragments of the rock 
becoming detached from the walls. The author desires to express 
his thanks to Dr. J. A. Bancroft of McGill University, to whom 
he is indebted for the photographs from which these prints were 
taken. 
