136 



NEW YORK STATE MUSEUM 



or Glens Falls limestone in the Sprakers and Canajoharie sections^^ 

 affords evidence of a direct nature as to the Trenton age of the 

 Canajoharie shale. 



The Utica shale, like the Canajoharie and Snake Hill shales, car- 

 ries mixed graptolite and nongraptolite faunas. 



Summarizing these correlations of the graptolite facies with the 

 littoral facies we get the following table of approximate correlations : 



Correlation Table 



Graptolite facies 

 Utica shale 

 Canajoharie shale 



Magog, Van Schaick Island, etc. shale 

 Upper Normanskill shale 

 Lower Normanskill shale 

 Upper Deep Kill (zone of Diplo- 



graptus dentatus) 

 Lower and middle Deep Kill shale 

 Schaghticoke shale 



Littoral facies 

 Utica shale 

 Trenton limestone 



Glens Falls and Amsterdam limestone 

 Lowville and Leray limestone 

 Upper Chazy limestone 

 Lower and middle Chazy limestone 

 Beekmantown limestone and dolo- 

 mite 

 Basal Beekmantown dolomite 



DIAGRAM OF GRAPTOLITE ZONES OF ORDOVICIAN OF NEW YORK 



Upoer Mohawk valley 

 20 Z. of Glossogr. quadr. typ: i ■=■ 

 19 Z. of Climac. typic. pos teru s) 

 i8 Z. of Climac. pygmaen s 

 17 Z. of DicranogT. nicholsonil 



i6 Z. of Climacogr. typical 



14 Z. of Lasiogr. eucharis 



Trenton 



Black River 



Chazy 



Lower Mohawk and Hudson valleys 

 Atwater Creek shale 

 Deer River shale 



Utica shale 



Canajoharie shale 



Magog shale 

 Normanskill shale 



13 Z. of Glossogr. quadrimucr. cornutus 

 12 Z. of Diplogr. amplexicaulis 



11 Z. of Mesogr. mohawkensis 



10 Z. of Cryptogr. tricornis insectiform i s 

 9 Z. of Corynoides gracilis 



8 Z. of Nemagr. gracilis 



7 Z. of Diplogr. dentatus etc. 



c Subz. of Trigonogr. ensiformis 

 b Subz. of Phyllogr. angustifolius 

 a Subz. of Climacogr. pungens 



Canadian 

 (Beekmantown) 



6 Z. of Didymogr. bifidus 



b Subz. of Didymogr. similis 



a Subz. of Goniogr. geometricns 



S Z. of Didymograptus 



b Subz. of Didymogr. extensus 



a Subz. of Didymogr. nitidus 



4 Z. of Phyllograptus typus etc. 



3 Z. of Clonogr. flexilis, Tetragi. 



2 Z. of Staurogr. dichotomus 



I Z. of Dictyonema flabelliforme 



Ozarkian 



Cambrian 



> Deep Kill shale 



Schaghticoke 

 shale 



' See Ruedemann, op. cit, 1912, p. 22, 



