530 Butts — Geologic Section of Blair and 



where a fault is plainly exposed in a cut immediately east 

 of the station. The fault plane here dips east at about 

 15°, the beds of the over thrust mass being parallel to 

 the fault plane and those below the fault being overturned 

 with an east dip of 40°. The overthrust mass is Warrior 

 limestone and the overridden beds are Carlim limestone. 

 This fault is shown in fig. 1. The position of this fault 

 or faulted zone is plainly indicated by the sharp bend or 

 offset in Canoe Mountain, about 8 miles a little southwest 

 of Birmingham and by the fault offsetting Bald Eagle 

 Mountain 5 miles northeast of Tyrone. A number of 

 other strike faults were discovered showing that this 

 region has been faulted in a manner similar to the south- 

 ern Appalachian region. 



The classification followed in this paper differs from the 

 usual classification in the following particulars : The Loy- 

 alhanna limestone is placed in the Mauch Chunk instead 

 of in the Pocono, because the author believes that the 

 Loyalhanna is probably the same as the Trough Creek 

 limestone of I. C. White at the base of the Mauch Chunk 

 in the Broad Top Mountain syncline, in Huntingdon 

 County. The Burgoon sandstone, which forms the upper 

 part of the Pocono, is believed to be of Keokuk or upper 

 Fort Payne age, whereas the Loyalhanna is believed to be 

 of Warsaw age, a belief founded on the existence of a 

 similar cross-bedded limestone of probable Warsaw age, 

 in a similar stratigraphic position just above the Fort 

 Payne chert at the head of Sequatchie Valley, in eastern 

 Tennessee. If the Loyalhanna is thus of Warsaw age it 

 should, in the author's opinion, be classed with the beds 

 overlying the Pocono. 



The Pennsylvanian and Mississippian are recognized 

 as systems, instead of series in the Carboniferous. 



The Ordovician- Silurian boundary is placed at the base 

 of the Oswego sandstone, in which the practice of the New 

 York State Survey is followed. It seems reasonable to 

 assume that the deposition of this sandstone was the 

 result of crustal movements such as are regarded as 

 initiating new periods of geologic time. 



The only other important deviation from prevailing 

 usage is the recognition of the Canadian and Ozarkian 

 systems, in which, of course, the writer follows Ulrich. 

 The writer is satisfied that there are sufficient grounds 



