320 Carboniferous Formation of Pennsylvania — Wasmuth. 
characters have been crossed by the Williamstown tunnel. In 
the northern part of the tunnel for a distance of about 1,500 
feet the strata are fractured and confusedly distorted, as in the 
Panther Creek region. The disturbances are not represented 
on the public maps (Report of Mine Inspectors), which indicates 
that no importance has been given to them, but tijeir results 
will be developed very soon in the workings to be opened 
below the present deepest level and in the new shaft in Bear 
valley. 
Longitudinal faulting has 'been met with in several other 
mines in the western portion of the southern coal field. There 
are also numerous lines of ''shaftings," a great many of which 
have proven the existence of coal without contributing greatly 
to the knowledge of structural geology, but some of the lines 
indicate great disturbances of the strata. 
One peculiar feature of longitudinal faults is that the flexures 
of the coal are contracted and bent more or less toward the 
fracture on the strike as well as on the dip, as illustrated in 
fig. 9, which might be explained as consequences of the pro- 
digious oblique force of the sliding strata on the foot wall 
of the fault, the weight of over-lying measures and resistance 
of the under-lying strata. Horizontal sections, constructed in 
different elevations as indicated in fig. 9, always will show 
similar shapes. This feature is most distinct in the very hard 
strata of the anthracite region, but where softer measures are 
involved, the fracture is wide and represents a mass of broken 
strata similar to that exposed by the fault in Otto colliery and 
in a shaft in the Panther Creek region. It is obvious that 
longitudinal faults create a doubling of the strata of more or 
less extent, and it is therefore certain that many estimates of 
