Hawortu. | Detailed Geology. 87 
that their contact is an indefinite line. A little farther down 
stream the contact seems to be more definite, and different 
parties have explained this by assuming that a fault exists 
here trending northwest and southeast which brought the 
flint immediately adjacent the limestone. By gradually trac- 
ing the line between the two it is found that it swings around 
to the right, crossing the Brinkerhoff addition to Galena and 
bearing up stream along Short creek, making a line so sinu- 
ous and with such short curves that probably no one would 
call it a fault line. 
The large fissures filled with shale, already described, and 
many hundreds of smaller fissures clearly due to earth move- 
ments, are so common and have such positions that the 
probabilities are strongly in favor of many vertical displace- 
ments. And yet it must be contended that such displacements 
are not very great; how great has not yet been determined. 
An interesting and important line of evidence comes from 
the coal regions to the northwest. Here we have well strati- 
fied rock and interbedded coal seams which make splendid 
markers, so that any and all vertical displacements can be 
measured with a high degree of accuracy. The coal in Chero- 
kee and Crawford counties in the vicinity of Weir City, Pitts- 
burg, Cherokee and Scammon is badly cut up by fissures with 
a trend approximately parallel to the periphery of the Ozark 
dome. These fissures constitute the ‘‘ horsebacks”’ or “‘ faults’’ 
of the miners, and have been studied in connection with the pre- 
paration of our volume III, ‘‘Special Report on Coal.’’ Doc- 
tor Crane has illustrated the conditions of these horsebacks 
by various figures published in that report, and has shown 
that they were produced after the coal became completely 
solidified, that they were quite variable in character, and still 
farther, that very rarely was there any vertical displacement 
on either side of the fissure. The maximum vertical dis- 
placement known in the entire coal mining region is only 
about eight feet. Doctor Crane further shows that such 
horsebacks, although so abundant in Cherokee and Crawford 
counties, gradually disappear to the northwest and in this 
form are unknown in the mines of Leavenworth and Osage 
counties, leaving no room for reasonable doubt that they were 
