536 ARCHEOLOGICAL INVESTIGATIONS—II [ETH. ANN. 44 
chert; nor to a few of the very long, slender implements, or cere- 
monials, occasionally found, which were brought from some other 
region. 
One feature is reported here that has not been observed at any 
other flint quarry, though it has been noticed in mines of other 
material. This is aboriginal tunneling. Some years ago prospectors 
for lead reported that in sinking a shaft from the top of a flint- 
capped ridge they struck a drift at a depth of 30 feet. Again, when 
a macadamized road was under construction near High Ridge, ballast 
was hauled from the refuse about the old pits. In one of these the 
workmen, when near the bottom of loose débris, uncovered the mouth 
of a tunnel leading into the hill. It is possible that these were natural 
caves or crevices; but in each case the workmen were very positive 
in their assertion that the drift or tunnel so found was artificial, 
but that they were afraid to explore it. No one now can point out the 
exact location of either tunnel, as the entrances are obliterated by 
talus which has worked downward from the slopes above them. 
Furnt 1n Potk Country, Mo. 
Mr. George C. Swallow, former State geologist of Missouri, says 
in the First and Second Annual Reports of the Survey that the lme- 
stone at Crescent (Jefferson County), Mo., reappears in Polk County. 
He also describes some aboriginal chert quarries or “ old diggings ” 
on the S. 1% of the NW. 1 sec. 34, T. 34, R. 22 W., near the Pomme 
de Terre River. This would be 6 or 8 miles northeast of Bolivar, 
the county seat. 
While the stratified limestones of the two regions he names may 
be of the same geological age, the chert deposits are very different 
in appearance, structure, and manner of occurrence. At Crescent 
the stone is regularly stratified, of great thickness, with no inter- 
seams of other rock. It lies entirely above the limestone which 
forms the bulk of the hill, is an original sea-water deposit, not due 
to replacement or substitution, and contains no nodules except now 
and then a small one due to a slight change in the nature of the 
general structure. At the Pomme de Terre, on the contrary, the 
chert occurs in nodules or concretions of various sizes, imbedded in 
the limestone; and with the disintegration, solution, and removal of 
the latter, is left in the residual clay, unchanged except for weath- 
ering. The depth of such alteration on the nodules is governed by 
several causes, such as the slightly different composition and in- 
clusions of the stone, the character of the soil as regards density, 
porosity, presence of organic matter and acids, the size of the 
nodules, and the depth to which they are imbedded in the clay. 
