15. SPRING TOWNSHIP. F\ 337 



it passes. The overlying red shale is not yet eroded deeply 

 enough to expose it anywhere else in the township. See 

 report on Tyrone township. 



The Lower Helderberg limestone, No. VI. 



This limestone forms an exceedingly intricate line or 

 rather many lines of the outcrop in the township. A nar- 

 row strip of it occupies the northern edge, the township line 

 running along the ridge. Its beds dip to the N. N. W. un- 

 der the Oriskany sandstone, which, together with the flint 

 beds, caps the hill north of Elliotsburg. 



The next outcrop of this limestone is on the hill south of 

 Elliotsburg, where it spreads over a large extent of county. 

 The details of its structure must be sought on the geologi- 

 cal map of the township given herewith. It forms the high 

 round ridge called Bell's hill, and is intersected by two lines 

 of Oriskany sandstone as is uniformly the case in all broad 

 exposures of this thin linestone in the county. 



The position of the outcrop of this limestone can be readily 

 traced on the geological map. It zigzags back and forth 

 from E. N. E. to W. S.W., completely crossing the county 

 several times and at last leaving it near the S. E. corner 

 where it is becoming thin and is on the point of disappear- 

 ing. 



The lime shales are shown on Sherman's creek near the 

 Falling Spring and again near Mr. F. Gibson's in an old 

 abandoned quarry. In the former the Stromatopora bed is 

 well shown and forms a complete band in the rock. 



Garbef s Quarry section. 



Rubbly shaly limestone, 5' 0" 



Coral bed, Stromatopora, <fec, ... 5' 0'' 



Rubbly limestone with crinoid stems and Rhynchonella for- 



mosa, ... 12' 0" 



Solid dark blue limestone with Beyrichia notata, 8' 0" 



Dip 20° S. 30° E. 



The top beds of this quarry lie about 300 feet horizontally, 

 100 feet vertically from the outcrop of the Oriskany sand- 

 stone which here shows itself in place. 

 22 F\ 



