THE DEVONIAN SECTION NEAR ALTOONA, PA. 



62' 



these rocks practically to the top. Fig. 5 is a photograph of the 

 shale in this exposure. West of the above-mentioned exposure is 

 a concealed space of 630 feet, to the point where Twenty-first Street 

 intersects the track. At this point is the beginning of an outcrop 

 of rocks bearing a Nunda fanua throughout. At the intersection of 

 Fourteenth Street and Thirteenth Avenue in Altoona the Genesee 

 shale is exposed with overlying shale identical in character and fos- 

 sils with that at the base of the outcrop beginning on the railroad 





-■al^■^mrfSi^>^^ -ry .*,.^i 



fe^ajJL^h- J^-^^ 



Fig. 5 



track at Twenty-first Street, as mentioned above. At the above- 

 described street intersection the Genesee shale is at least 80 feet 

 thick, and the strike of the rocks is such as to carry it through the 

 concealed space along the railroad already described. The thick- 

 ness of rocks in this space is about 140 feet, and deducting 80 feet 

 leaves 50 feet of Hamilton rocks at the bottom of the concealed space. 

 This would extend the Hamilton formation 230 feet beyond the 

 western end of the first cut west of Altoona Station, so that its top 

 would lie about 2,600 feet west of the Logan Hotel along the track. 



