234 
‘‘QUICKSAND PocKETS” IN THE ‘‘BLuE CLAy” oF SoutH BEND. By W. M. 
WHITTEN. 
The public water supply of South Bend comes from artesian wells 
driven to a water-bearing gravel 60 to 80 feet below the surface of the 
St. Joseph River. In this gravel the water is under a pressure sufficient 
to raise it about 25 feet above the river. 
The impervious stratum which confines this water is locally known as 
blue clay. This deposit is from 13 to 50 feet in thickness, and the territory 
in which wells can be obtained which flow at approximately the same 
level, indicates that it is several miles in extent. 
Between the blue clay stratum and the water-bearing gravel is a 
deposit of what is locally known as quicksand, which varies in depth from 
10 to 40 feet. 
Throughout the deposit of blue clay, distributed somewhat like boul- 
ders im the drift, are numerous masses of the quicksand, which are locally 
oe 
known as “quicksand pockets.” These are of all shapes and vary in size 
from a few cubic inches to many cubic yards. 
The record of borings of well No. 21 shows the following strata: 
SSE 0 hee Si ADs fried eg lee ois A SR arn ee aA DS SNe Me 1 PES A ri 20 feet. 
ESM EICLA YY: eck ok ep Oi ies aicivele lab alele ee bin beets > nee terete 31 feet. 
CUTITER SANG to hiletortiere atte. ciel ele sitetks ode Nedite ot taenstan othe tations 24 feet. 
TEV OLS 0 ate ce aheasenen ar oke eet a) oo erst ala Ae ha oes eee eine ere 16 feet. 
