142 The Lower Devoxiax Deposits of Maeyland 



The section begins at the base of the Eomney shale, 100 feet south of the 

 fork in the road, one road leading north to Cresaptown and the other 

 northwest to Keyser. The Keyser limestone lies immediately beneath the 

 Romney shale. 



Helderberg Formation 



Horizontal Vertical Total 

 Kpiivpr MpmTipr distance thickness vertical 



jyeyser memoer ^^^^ ^^^^ thickness 



Dark blue limestone. The upper portion filled with 

 Favosites helderierguc var. pnecedens and crinoids. . . 590.0 41.0 173.9 



Ravine running east and west 



Concealed 470.0 6.9 132.9 



The section now follows along the strike of the rock. 

 The following fossils were found, mostly loose: Favo- 

 sites helderbergiw var. prwcedens (aa), crinoids (aa), 

 hryozoa (aa), Cladopora rectilineata, Atrypa reticu- 

 laris (aa), Gypidula coeymanensis var. prognostica 

 (c), Lepta-na rhomboidalis (r), 'Nucleospira swartzi 

 ic), Camarotoechia litchfieldensis (c), Calymene s]?. . . 430.0 .... .... 



Largely concealed. Heavy-bedded dark blue lime- 

 stone is exposed at the top and the bottom of this 

 unit. Calymene camerata was found loose at the top. 

 Ten feet below the top were found loose crinoids (a), 

 Atrypa reticularis (a), Stenochisma deckerensis (c), 

 S^tropheodonta (cf.) bipartita. Schuchertena decke- 

 rensis (c) 30.0 19.2 126.0 



The beds were measured in vertical thickness only 

 from here to the bottom of the section. 



Solid blue-gray limestone containing some crinoids 4.0 106.8 



Arenaceous thin-bedded gray limestone containing 

 at top a crinoid bed about 3 feet thick. Crinoids also 

 occur throughout the whole unit though not as abund- 

 antly as in this bed. At the bottom occur Thamniscus 

 regularis (a), Orthopora rhombifera (a), Favosites 

 pyriformis. Cladopora rectilineata (aa), Atrypa reticu- 

 laris (aa), Dalmanella concinna (c), Meristella sp., 

 Camarotachia litchfleldensis (c), CamarotcccMa lamel- 

 lata (r), Rhynchospira (cf.) globosa, Schuchertella 

 deckerensis (r), Vncinulus convexorus (c) 12.4 102.8 



Heavy-bedded gray limestone containing crinoids. 

 Thin-bedded towards the top. At the bottom occur 

 Dalmanella concinna (c) , Camarotachia lainellata (t) 4.5 90.4 



Mostly concealed 7.0 85.9 



Massive dark blue limestone. At the bottom occur 

 corals, Camarotwchia litchfleldensis (c), StropJieo- 

 donta sp., Tentaculites gyracanthus (r) 10.0 78.9 



