Mauylanu Geological Survey 139 



The Stromatopora bed occurs near the middle of the section and just 

 beneath it Cladopora reciilineaia is found in great profusion. Fossils 

 are very numerous in the upper part of the section, including Chonetes 

 jerseyensis, Dalmanella concinna, Stropheodonta bipartita, and Camaro- 

 tcechia litchfieldensis, all of wliich are characteristic of the lower part of 

 the Keyser member. 



Helderberg Formation 



Vertical Total 

 Keyser Member thicknesa vertical 



feet thickness 



Concealed. 



Thin-bedded shaly limestone 10.0 118.4 



Massive nodular limestone 4.0 108.4 



Axis of syncline on bed of track. 



Thin-bedded shaly limestone with some thicker beds con- 

 taining Batostomella interporosa, Fenestella cumberlandica, 

 Fistuliporella marylandica, Orthopora rhombifera, Rhyncho- 

 spira forniosa, Stropheodonta bipartita, Chonetes jerseyensis 

 (aa), Schuchertella deckerensis, Camarotwchia litchfieldensis, 

 Favosites sp., Dalmanella concinna, Stropheodonta sp., Uncin- 



ulus convexorus 10.0 104.4 



Massive crinoidal limestone 1.6 94.4 



Calcareous shale with some bands of limestone containing 

 Batostomella interporosa, Eridotrypa parvulipora, Lioclema 

 subramosum, Schuchertella sp., Rhynchonella litchfieldensis, 



Niicleospira swartzi 6.0 92.8 



Massive nodular limestone 6.5 86.8 



Shaly nodular limestone containing Atrypa reticularis 11.4 80.3 



Massive crystalline dark limestone 8.0 68.9 



Stromatopora bed. Syringostroma barretti, Aulopora schuch- 



erti 5.0 60.9 



Massive nodular limestone abounding in Cladopora rectili- 

 neata in upper 2.7 feet. In this unit occur Favosites pyriformis, 

 Cladopora rectilineata, Bryozoa, Stropheodonta bipartita (c) 



XJncinulus convexorus 16.0 55.9 



Dark crystalline limestone 2.3 39.9 



Massive nodular limestone, containing Batostomella inter- 

 porosa, Stropheodonta sp., Dalmanella concinna, Nucleospira 



sivartzi 25.0 37.6 



Dark banded arenaceous limestone 1.6 12.6 



Thin-bedded nodular limestone slightly cherty 3.5 11.0 



Thin-bedded nodular limestone. Much chert in upper 2 feet. 

 Fenestella cumberlandica, Schuchertella sp., crinoids 7.5 7.5 



Thickness of Keyser member exposed 118.4 



