36 F\ REPORT OF PROGRESS. E. W. CLATPOLE. 



ancient ocean of North America. The lowest is the first 

 deposited — the oldest — and the others were laid down suc- 

 cessively above it. 



The uppermost formations, Nos. XII and XIII, have been, 

 in the course of ages, swept away from Perry count}', but 

 remain in the counties east of the Susquehanna river. 



The lowermost formations, No. I and most of No. II, are 

 everywhere buried underground in Perry county, but come 

 to the surface in Cumberland and Franklin counties. 



Table of PalcBozoic rocks, with their thicknesses as ex- 

 posed in Perry and bordering counties. 



No. Name. Thickness. Composition. 



i . ( XIII. Coal Measures, .... 2o00' Sandstone, shale, and coal. 



© s j XII. Pottsville, .... 1000' Pebbles and sandstone. 



XI. Mauch Chunk, . . . 2500' Red shale. 



O ^> ( X. Pocouo, 2000' Gray sandstone. 



IX. Catskill, 6000' Red sandstone and shale. 



, Chemung, 3000' Olive sandstone and shale. 



I Portage, 200' Shale. 



s { , TTTT Genessee, 200' Dark shale. 



VIII. J 



j Hamilton, 1500 Shale and sandstone. 



I Marcellus, 200' Dark shale and limestone. 



I (Upper Helderberg, absent.) 



VII \ (Cauda-galli, . . . absent.) 



f Oriskany, .... 25' Sandstone. 



Lower Helderberg, . 200' Limestone and shale. 



Onondaga, 1600' Shale. 



Clinton, 800' Red sandstone and green shale. 



Medina, 1500' Sandstone and shales. 



Oneida, 500' Conglomerate and sandstone. 



Hudson River, . . . . 1000' Slates and shales. 



Utica, 500' Dark shales. 



Trenton, . 500' ^ 



Chazy, . . . . . . ) 5000 , > Limestone. 



Calciferous, .... J ) 



Potsdam, 2000' Sandstone and slate. 



. 1 



VI. 







V. 

 IV. 



1 

 1 



. < 



III. 



{ 







■^ 8 







; C < 





( 



•^ ~^ 1 



II. 







I 



Cambrian. I 





Total, 32725' 



All the formations vary greatly in thickness in different 

 counties, and even indifferent parts of a county; and in 

 some places were not deposited at all ; so that the thicknesses 

 assigned to them in the table must not be taken as exactly 

 correct, but only as general indications. No. I, for example, 

 veral thousand feet thick in the mountains south of 



