ye 
im 
O« 
225 [Claypole, 
1883.] 
The north side is occupied by the Hamilton sandstone, through which 
the fault here cuts obliquely and the throw having increased it causes a 
lateral displacement of nearly a mile, through which the road passes from 
the Lower to the Upper shale without crossing any Sandstone ridge. 
Entering Centre township, the fault passes along the strata as they rise 
to the Crawley arch, leaving the synclinal west end of Mahanoy ridge 
separated from the anticlinal east end of Crawley hill. The latter is so far 
eroded as to expose the Hamilton Lower shale for more than two miles 
from Little Germany. 
The throw is greatest near the watershed on the township line, where 
the lower part of the Lower Hamilton shale is brought up against the 
Upper Hamilton shale and may be estimated thus : 
Upper Hamilton, SHals COMDL) seu te tise cuss tc cscs. 150 feet. 
Hamilton BAMdstOnes bus ceners ee ti gst eae Ve Ae hur 
Lower Hamilton shale (part)....... ek 4h eh Wibod 400 * 
1150 
But as the beds dip at about 45°, the actual vertical displacement is more, 
being in proportion to the sine of the angle of dip. This will give 1600 
feet. The Little Germany fault extends into Centre township almost to 
Bloomfield, gradually dying out. But it may be traced by a slight valley, 
and by the increased thickness of the Hamilton Upper shale, as far at 
least as the residence of Mr. William Brunner. Its total length is about 
four and a half miles. 
INTERMEDIATE FAULT. 
Yet further in this connection, a third fault of small dimensions passes 
between the two above described. Manifesting itself near the house of 
Mr, George Meck, it causes a repetition of the Hamilton sandstone, bringing 
the middle and upper beds to the surface after they have dipped south from 
the Crawley anticline, 
This fault is of no great extent, apparently disappearing in a mile and a 
half. Nor is its throw more than about 200 or 300 feet. But it makes a 
distinct short ridge of Hamilton sandstone, and a deep intervening valley 
between it and Crawley hill. 
Ne Bye consequence of the discovery of this third dislocation, a slight 
Correction is rendered necessary on the map representing the eastern end 
of the Perry County fault. The middle one of the three short anticlines 
there represented, is the small ridge thrown up by the third fault, and is 
therefore monoclinal, with south-east dip, and not anticlinal in structure. 
PROC. AMER, PHILOS. 800. xxt. 114, 20. PRINTED NOVEMBER 2, 1883. 
