108 University Geological Survey of Kansas. 
bin. Its scarcity is well represented by the fact that the 
miners have no name for it and do not know what it is. Its 
presence is so unusual that when found it is looked upon as 
acuriosity that is scarcely worth investigation. Copper pyrite 
is also found in many places throughout the Galena district, 
and with equal frequency in the Joplin district. It has been 
deposited recently and is found in beautiful tetrahedral crys- 
tals built upon blende, flint rock, and other materials. 
For a more complete discussion of all the minerals of the 
Galena district and their paragenesis, that is, the order of 
their formation in time, reference should be made to Doctor 
Rogers’s paper, part III of this volume. 
How Ores Occur. 
Lead ores and zine ores are so intimately associated 
throughout the entire mining district that a discussion of 
mode of occurrence of one must necessarily be a discussion of 
mode of occurrence of the other. In general, lead ores are 
found closer to the surface than zinc ores. But this rule has 
sO many exceptions it is hardly worth stating. Lead ore has 
been found at the bottom of the very deepest shafts in Galena. 
On the Kirby land just south of the Mastin the deepest shaft 
that has ever been sunk for zinc ore found lead ore intimately 
associated with it. Likewise, the deepest shaft on the South 
Side land found lead ore at the very bottom, and that, too, 
in comparative abundance. Zinc ore, likewise, is found at 
great depths and also at the very surface. In a good many 
places, particularly in the vicinity of Cave Springs, and on 
land belonging to the Illinois Lead and Zinc Company in 
section 27 southwest of Galena, zinc blende is found almost at 
the very surface. Some years ago mining was carried on in 
the Cave Springs vicinity by general open work from the 
surface down, and the familiar expression ‘‘from the grass 
roots down’’ literally expressed the position of the ores. Yet 
it is doubtless true in general that the great bulk of lead ore 
occurs closer to the surface than zinc ore. 
The two ores are intimately associated throughout the en- 
tire mining district. It is very unusual to find a mine pro- 
ducing one without the other. It is still more unusual to 
