238 
These facts seem to indicate that these masses of sand have been 
gathered up from the underlying strata and raised partly or wholly 
through the clay to the positions in which they were found. If so, the same 
force might be invoked to fill the “pockets” in the “blue clay” at South 
Bend with the quicksand underlying that deposit. 
It is difficult, however, to conceive of these detached bodies of sand 
retaining their distinctive character and a compact form while being trans- 
ferred from the underlying strata to the positions in which they were 
found, unless they were solidly frozen during the process, for otherwise 
they would have lost their identity and simply become mixed with the 
clay. The best explanation of these facts that I can think of is to assume 
that during a retreat of the ice the sand deposit has been uncovered and 
solidly frozen, and in that state has been overridden by the re-advancing 
ice, at the base of which the clay was transported, and that frozen frag- 
ments of sand have been detached from the main body of that deposit and 
raised to the position in which they were found, in the same manner that 
fragments of rock, over which glaciers move, are said to become detached 
and raised by the movement of the ice. 
Some plausibility is given to the above assumption by a study of the 
following section of a sewer trench excavated on Leland avenue, South 
Bend, in 1894. The trench runs north and south: 
ONY 
6SSSSSSS 
A—Shows surface soil, sand and gravel. 
B—Clay deposit from 1] to 4 feet thick, unstratified. 
C—Fine sand, containing distinct horizontal stratifications or markings, g, g, 9, g, Which 
are faulted at H, K, Land N. 
o, 0, o—Are dyke-like masses of clay extending down from the main body of clay into the 
stratified sand a distance of from 4 to 8 feet. 
