LIST OF PAGE PLATES. 



Page. 



1. Map of No. IV mountains, 6 



2. Fall of the Susquehanna river, 18 



3. Geological structure, Figs. 1, 2, 3, 4, 30 



4. Six cross sections of the great arch, 32 



5. Table of formations, 34 



6. Four figures of the Perry county fault, 82 



7. Maps and sections of the fault, 84 



8. Ore and coal sections, 92 



8(b). Section of tunnel mine, fossil ore, 112 



9. Map of Buffalo township and section A B, . . . 146 



10. Map of Carroll township, 156 



11. Local map and cross section A B, 158 



12. Map of Centre township, 168 



13. Cross section A B, 170 



14. Cross section CD, 172 



15. Local map and small section, 174 



16. Four small sections, 176 



17. Local map and small sections, 178 



18. Map of Greenwood township and two sections, . . 212 



19. Cross section A B, 214 



20. Map of Howe township and section A B, ... 222 



21. Columnar section in Jackson township, 228 



22. Map of Juniata township and section A B, ... 236 



23. Map of Liverpool township and section A B, . . 240 



24. Local map and sections, Madison township, . . . 246 



25. Two sections, 248 



26. Two quarry sections, . . 250 



27. Centre mills section, 252 



28. Map of Miller township and section A B, . . . . 264 



29. Map of Oliver township and section A B, . , 274 



(xxi F2.) 



