210 ¥* REPORT OF PROGRESS. E. W. CLAY POLE. 



The Little Germany fault. 



This fault, of which an account will be found in the re- 

 port on Spring township, enters Centre at the southwest 

 just where it cuts through the topmost beds of the Hamil- 

 ton sandstone. The lateral displacement here is about a 

 mile, and through the gap thus left in the eastern rampart 

 of Little Germany, passes the road to New Bloomfield. At 

 this point the Lower Hamilton shales of the eroded Craw- 

 ley anticline abut against the Genessee or probably against 

 the Portage shales of the south slope of Mahanoy ridge. 

 Consequently the throw of the fault is here at its maximum. 

 We may form an approximation to its extent from the fol- 

 lowing figures which represent the thickness of the several 

 groups as nearly as I have been able to determine them : 



Portage, part, 50 feet. 



Genessee, 200 " 



Hamilton upper shale, , . 300 " 



Hamilton sandstone, 600 " 



Hamilton lower shale, part, 100 " 



Total throw, 1250 " 



This is little, compared with the throw of the Perry 

 county fault a mile further south, but is yet sufficient to 

 produce important changes in the geology of the county. 



From this point the fault continues northeastward and 

 about a mile from the township line the disjointed edge of 

 the Hamilton sandstone is seen rising on the south of the 

 road. Soon afterwards the Hamilton upper shales showing 

 the Tropidoleptus bed appear in the road, and at the fork 

 to Perry furnace the throw of the fault has become quite 

 insignificant. It may however be traced for nearly half a 

 mile farther. The Tropidoleptus shale crops out at the 

 residence of Mr. Wm. Brunnerand then follow, descending, 

 the Genessee shales, thus indicating very closely the place 

 of the fault. It is here indicated by a depression which, 

 enlarging to the southwest, becomes the valley along which 

 we have, in imagination, been traveling from Little Ger- 

 many. 



