25. 



S feet, 



24. 



2 feet. 



23. 



6 in. 



22. 



5* ft. 



21. 



10 in. 



20. 



15 in. 



19. 



10 in. 



18. 



8 in. 



Ziegler — Siliceous Oolites of Central Pennsylvania. Ill 



26 .3 feet. Dense gray limestone, carrying five distinct 

 bands of siliceous oolite. The oolites are small. 

 Dense, gray, slialy, and laminated limestone. 

 Oolitic limestone of mottled appearance. 

 Layer of siliceous oolite. 



Dense, black, shaly limestone, interbedded with 

 gray, crystalline, dolomitic limestone. 

 Dark blue, dense l.s. in upper part with white, 

 oolitic chart concretions. 



Dense, black crystalline l.s. with chert concre- 

 tions, oolitic in thin sections. 

 Dark blue, dense l.s. with gray chert concretions. 

 Siliceous oolite, made up of white quartz spherules 

 with a calcareous cement, acting as a matrix of 

 pebbles, of dense gray l.s. and of pure white 

 sandstone at base. 



17. 8 feet. Alternating, very dense, dark, and light gray, lam- 

 inated limestone, with occasional chert nodules. 



16. 3 in. Black, oolitic chert. 



15. 18 in. Black, coarsely crystalline, l.s., with vugs, and 

 small calcite seams. 



14. 2 feet. Dense, gray, dolomitic limestone, with conchoidal 

 fracture. 



13. 2^ ft. Mottled shaly limestone. 



12. 3^ ft. Dense, finely banded, light gray, dolomitic lime- 

 stone. 



11. 3 feet. Dark bine, oolitic, finely laminated limestone, 

 containing in its lower portion pebbles of the un- 

 derlying light gray limestone. The line on con- 

 tact is irregular. 



10. 5 feet. Light gray, dolomitic limestone with conchoidal 



fracture. 

 9. 4 feet. As above, but blocky, and smooth breaking. 

 8. 2 feet. Dense, black limestone. 



1. 6 feet. Dark gray, crystalline limestone with chert con- 



cretions. At top a breccia of limestone fragments 

 cemented by well-crystallized calcite, probably a 

 collapsed cave. 



6. 3 in. White-grained, black, siliceous oolite carrying 

 enclosed dense, black chert concretions which are 

 oolitic under crossed nicols. 



5. 16 in. Dense, gray limestone. 



4. 10 in. Light gray, siliceous oolite, carrying also frag- 

 ments of an older, darker oolite-horizon as pebbles. 



3. 6 feet. Dense, graj^, slightly crystalline limestone and 

 dolomite. 



2. V-g- ft. Covered. 



1. 4 feet. Light gray limestone with irregular and angular 

 pieces of oolitic chert. 



Total, 139 ft. 3 in. 



Am. Jour. Sci.— Fourth Series, Vol. XXXIV, No. 200.— August, 1912. 

 9 



