QUARRIES IN WALDO COUNTY. 
Test of Mount Waldo granite. 
155 
Number of test. 
Direction of pressure. 
Specific 
gravity. 
First 
crack. 
Total 
pressure 
applied. 
Ultimate 
strength 
per 
square 
inch. 
1 1055 
At 90° to rift 
2. 637 
2. 655 
2.662 
2. 649 
Pounds. 
120, 000 
123, 300 
107, 400 
112,600 
Pounds. 
128,400 
132,500 
122, 600 
117,900 
Pounds. 
31 , 782 
11056 
do 
32, 635 
11057. 
Parallel to rift 
do 
30, 197 
29, 183 
11058... 
The quarry, opened before 1851, measures 800 feet from north to 
south by 400 feet from east to west and from 10 to 30 feet in depth. 
There is no drainage problem nor stripping. 
Rock structure: There is a vertical dike of the coarser and lighter 
granite (specimen 53, b) 200 feet or more wide, having a course N. 
20° W., with the darker granite (specimen 53, a) on both sides of it, 
the relations indicating vertical flow structure. The longer axes of 
Fig. 35. — Structure at the Mount Waldo quarry, Frankfort. 
many of the feldspars lie about north-south. The sheets, from 8 
inches to 8 feet thick and lenticular, dip 10° E. The joint courses are 
shown in fig. 35. There is only one joint of A. Joint B recurs at 
[intervals of 40 feet ; C at intervals of 20 to 40 feet or more. The rift 
ps horizontal and the grain vertical, trending N. 85° W. The granite 
is under compressive strain from east-northeast to west-southwest, 
causing north-northwest to south-southeast vertical fissures the entire 
length of the quarry. This Assuring has occurred in summer time 
and has been accompanied by an explosive noise. The sheets are very 
free from sap. Knots are exceptional, but one near the junction of the 
fine and medium granites measures 6 feet by 3 feet and consists of a 
medium gray apiite, with porphyritic whitish twinned feldspars up 
to three-fourths inch in length and biotite scales up to one-twentieth 
inch. 
