CAMBRO-ORDOVICIAN LIMESTONES 705 



mantown occurs on Licking Creek near its mouth. Unfortunately the 

 upper part of the formation is not exposed in the creek bank and is 

 complicated by folding. The section measured by Mr. Ulrich and 

 the writer is as follows: 



Beekmantown Section, near Mouth of Licking Creek. 



Interbedded pure and magnesian limestones of Stones River type. 



340 feet. Light gray finely laminated magnesian limestone and white dolomite, 

 with cherts of rosette type at the top. 



140 feet. Dark and light, coarse dolomite. 



Rocks here folded and largely covered; contains white domolite, dark- 

 blue oolitic limestone, and dark coarse dolomite with yellow blocky 

 sandstone fragments and rosette cherts. Exact continuity indeter- 

 minable, but the previous beds are apparently repeated by folding. 



350 feet. Interbedded pure and magnesian limestones, with beds of coarse dark 

 dolomite, and in the lower part beds of "edgewise" conglomerate; 

 at base contains Gasteropods, Cephalopods, and Trilobites. 



1 70 feet. Largely finely banded magnesian limestone with few pure limestones. 

 Contains fine conglomerate beds and Gasteropods. 



130 feet. Largely dolomite, some coarse and dark. Large scoriaceous black 

 chert and coarse sandstone at the base. 



290 feet. Chiefly dolomite, coarse and dark in upper part, with occasional pure 

 fossiliferous limestone. Bed of granular limestone with numerous 

 Ophileta and pinkish fine-grained limestone near middle, crossbedded 

 banded limestone at base locally unconformable on underlying beds. 

 65 feet. Fine-grained limestone seamed with calcite and dolomite beds, with 

 flinty chert containing Cryptozoan at the base. 



130 feet. Partly covered. Lower part pure dark limestone with few beds of 

 finely laminated magnesian limestone and fine white oolite near base. 

 Small rough chert with casts of crystal at the base. 



165 feet. Light-blue limestone with fine contorted sandy laminae that weather 

 in relief. Contains fine dark conglomerate with red limestone 

 pebbles and fragments of Trilobites. 



530 feet. Purer fine even-grain limestone with few sandy partings. 



Sandy laminated limestone, much contorted, of the Conococheague 

 formation. 



2,310 feet, total. 



The details of the sections in the two areas are quite unlike. 

 Whereas beds of pure limestone and marble are common and chert 

 infrequent in the Chambersburg section, the reverse is true in the 

 Licking Creek section. The pure limestones have been extensively 



