BEEKMANTOWN AND CHAZY FORMATIONS OF CHAMPLAIN BASIN 4OI 



FEET 



6 Impure limestone, abounding in Orthis ^ 10 



7 Measures concealed 25 



8 Massive, gray limestone, largely made up of crinoidal re- 



mains, having red spots in a stratum about 10 feet from 

 the top; abounding near the middle of the strata with 

 gastropods. Bellerophon, Raphistoma, Metoptoma, A s a- 

 phus margin alis, Sten opera fibrosa, Bol- 

 boporites a m erica n us, Retepora gracilis. 50 



310 



GROUP B 



1 Thick bedded, nodular, dark colored limestone, containing 



M a c 1 u r e a magna 50 



2 Massive, pure limestone, gray, fine grained, often oolitic, 



abounding in crinoidal remains and Stenopora 

 fibrosa 20 



3 Massive, bluish black, tolerably pure, nodular limestone, 



containing M a c 1 u r e a magna and masses of black 



chert 45 



4 Similar to no. 3, but containing in addition to Maclurea, 



various species of Orthoceras and large masses of Stroma- 

 tocerium go 



5 Less massive limestones, quite impure and often disintegrated 



into nodules as though shaly 60 



265 



GROUP C 



1 Dark, iron gray, dolomite, weathering yellowish i 



2 Blue, compact, fine grained, pure, limestone, containing fine 



lines of calcite 6 



3 Dove colored, compact, brittle, perfectly pure limestone con- 



taining small nodules of calcite 5 



4 Iron gray dolomite 3^2 



5 Like no. 3, only containing larger nodules of calcspar 4Vi 



6 Dark gray, fine grained compact limestone somewhat impure, 



having a mottled aspect when weathered, containing sev- 

 eral undetermined species of Murchisonia, Orthoceras and 

 usually enveloped in Strephochetus 2 



7 Iron gray dolomite i 



8 Blackish, impure limestone, abounding in R h y n c h o n e 1 1 a 



plena 3^K- 



9 Dark or light gray, massive coarsely granular limestone, 



mostly made up of crinoidal fragments which are some- 

 times red, containing Rhynchonella 265^2 



10 Same as no. 8 3^ 



1 1 Measures concealed 7 



12 Tough, impure dolomite 8 



13 Concealed 24 



157 

 Total thickness of A, B and C 732 



