90 University Geological Survey of Kansas. 
the valley in North Empire attracted a large number of work- 
men who produced a large quantity of ore in a very short 
time. ‘To the south of this valley is the main Empire City 
hill which carries limestone in places and elsewhere is almost 
entirely flint. To the north is a hill which develops into a 
broad upland stretching away to the north with almost un- 
broken continuity to the Gracie Clark mine, an area more 
than a mile away. ‘The structure in the North Empire valley 
is quite varied. In some places the flint rock is moderately 
well bedded, as is so well shown in certain parts of the Little 
Coon mine. Elsewhere the ground is very open, water 
abundant, and excessive timbering is necessary. Probably 
more timbering per square acre was required in this place 
than anywhere in the vicinity of Galena outside of Bonanza. 
Concretionary masses are not so abundant here as in the first 
two places named, but they are frequently found, and that 
most generally on the borders. 
There is a certain relation between these flint areas and 
surface features. The comparatively narrow bodies of flint 
which grade into limestone on either side, as has already 
been explained, almost invariably occupy the low ground of 
ravines and creeks. The largest hills and the largest bodies 
of broad uplands usually are limestone. It would seem that 
in some way the dissolving power of ground water was more 
active along creek valleys than elsewhere and that the loca- 
tions of creeks have been determined to a great measure by 
such dissolving and settling. In this way underground open- 
ings were produced, a necessary prerequisite for ore accumula- 
tion. Where comparatively large areas are composed entirely 
of flint rock a smaller mass of limestone existed for solution, 
and consequently a lesser amount of contraction resulted 
therefrom. Such large flint bodies occupy uplands and high 
ground somewhat similar to the way large limestone bodies 
do. Whether or not this explanation is correct, it is a mat- 
ter of observation throughout the Galena district, and to a 
great extent throughout the entire Joplin area, that creeks 
flow over flint rock more or less disarranged from the re- 
moval of limestone from between the flint masses. This is 
further evidenced from the notion mining men have of where 
