3. CENTRE TOWNSHIP. F*. 207 



difficulty up the valley to the western line of the town- 

 ship. 



Numerous other exposures of tlie.se shales occur in the 

 township. For instance, southwest of Bloomfield, along the 

 road to Little Germany, again on the branch road to Perry 

 furnace, on the land of Mr. George McKeeand Mr. S. Brown, 

 and Mr. William Brunner. in the field adjoining whose 

 brickyard they were exposed in digging some ditches, and 

 showed the fossils very much crushed and distorted. 



The Genessee shale. 



This shale makes no conspicuous displays, and being 

 destitute of fossils, can only be recognized by its position. 

 Its dark thin layers can be seen along the road on the south 

 side of Mahanoy ridge, but they crop out nowhere else. 



The Portage shale. 



Though these beds should occur in several places in the 

 valley between Mahanoy ridge, and Dick's hill, and Iron 

 ridge, yet I have not recognized them anywhere except near 

 the house of Mr. S. Brown, where they crop out at the road- 

 side and contain their characteristic fossils, details concern- 

 ing which may be found in the proceedings of the American 

 Philosophical Society for 1883, and will be given in the 

 volume on the palaeontology. 



The Chemung group. 



Rocks of the Chemung group occupy all the middle of 

 the valley south of Mahanoy ridge and extend to the foot 

 of Iron ridge and Dick's hill where they are cut off by the 

 Perry county fault. Fen- the most part they dip steeply to 

 the south but the extension of the Perry furnace anticline 

 along the valley reduces and reverses the dip so that no 

 measurements minutely accurate can be made of their thick- 

 ness. They are fossiliferous in many places, but there are 

 few good exposures and the surface shows the usual rounded 

 hills that mark the Chemung areas in the county. The 

 passage from the Portage to the Chemung is well shown at 



