163 The Lower Devonian Deposits of Maryland 



Oriskany Formation 

 Shriver Chert Member 

 Yellow shale with chert. 



Heldebbekg Fobmation 



Vertical Total 



New Scotland Member thickness vertical 



feet thickness 



Residual clay after limestone filled with white blocky chert 

 containing numerous fossils 12.0 293.1 



Goeymans Member 



Hard, blue-gray, mottled and fine black-speckled limestone 

 full of fossil fragments 8.5 281.1 



Eeyser Member 



Somewhat lamellar limestone with argillaceous and purer, 

 fossiliferous, subcrystalline bands. Lioclema subramosum and 

 Strophonella sp., 270.6 66.0 272.6 



Coarsely cobbly to irregular lamellar impure limestone with 

 purer fossiliferous bands. Schuchertella prolifica, Meristella 

 pranuntia and Lioclema subramosum occur throughout; Pho- 

 lidops ovata, Tentaculites gyracanthus, 263.1, 259.1; Stropho- 

 nella leavenworthana. 263.1; Batostomella interporosa, Vnci- 

 nulus keyserensis, 241.3 26.0 266.6 



Very shaly, platy limestone full of Tentaculites gyracanthus, 

 Meristella sp., Uncinulus keyserensis ? and bryozoa, 236.6 ver- 

 tically 3.0 240.6 



Shaly, cobbly limestone, solid when fresh. Lioclema subra- 

 mosum and Orthopora rhombifera, 234.4; Tentaculites gyra- 

 canthus, Meristella sp., Uncinulus keyserensis, 231 7.0 237.6 



Very shaly, cobbly limestone. Tentaculites gyracanthus (a), 

 Uncinulus keyserensis {el), Meristella sp., cf. Dalmanella con- 

 cinna. and Eridotrypa parvulipora, 230 2.5 230.6 



Dark gray-blue limestone, coarsely cobbly, Rensselcria 

 mutabilis (a), R. mutabilis var., Whitfieldia sp., and Tentacu- 

 lites gyracanthus, 227.5; Uncinulus keyserensis ?, Meristella sp., 

 Uncinulus nucleolatus, 225.3 , 10.0 228.1 



Cobbly limestone with surface full of Tentaculites gyra- 

 canthus, Eridotrypa parvulipora, and Batostomella interporosa . 2.0 218.1 



Cobbly limestone containing reef of Stromatoporoids, Lep- 

 t(ena rhomboidalis, Eridotrypa parvulipora, and Lioclema subra- 

 mosum (a.); Tentaculites gyracanthus, Uncinulus nucleolatus. . 2.0 216.1 



Coarse cobbly argillaceous limestone. Atrypa reticularis (a), 

 Leptwna rhomboidalis. Merista typa 3.0 214.1 



Cobbly limestone. Leptana rhomboidalis abundant through- 

 out. Stropheodonta bipartita, 210.2; Dalmanella concinna (a), 



