Maryland Geological Survey 157 



following fossils have been identified from the lower beds of the Keyser 

 member : 



Corals. Spirlfer octocostatus. 



Crinolds. Spirifer vanuxemi. 



Atrypa reticularis. Uncinulus convexorus. 



Dalmanella concinna. Uncinulus nucleolatus var. angulatus 



Merista typa. Wilsonia globosa. 



Stenochisma formosa. Actinoptera communis. 



Camarotoechia lamellata. Platyostoma niagarense. 



Camarotoechia litchfieldensis. Orthoceras multiannulatum. 



Spirifer modestus. 



XII. Section on National Road West of Flintstone 

 This section is exposed along the ISTational Eoad on the east side and 

 near the top of Martin Mountain, 3^ miles west of Flintstone. It begins 

 at the base of the Helderberg about 175 feet west of the sharp turn of the 

 road to the southwest, ^ mile east of the summit. The lower nodular beds 

 are exposed in a small quarry by the road and the yellow " gravel " formed 

 by the weathering of the Oriskany chert is seen in excavations a short 

 distance above the top of the section. 



Helderbeeg Formatiox 



Horizontal Vertical Total 

 Keyser Member distance thickness vertical 



feet feet thickness 



Massive dark blue limestone. N. 33° E. 87° W 289.0 8.0 232.0 



Concealed 279.0 37.0 224.0 



Thin-bedded limestone with thin beds of chert. N. 

 34° E. 75° W 233.0 12.0 187.0 



Massive nodular dark blue limestone with thin 

 sheets of calcite along bedding planes. The top of the 

 Gypidula coeymanensis var. prognostica zone is 3 feet 

 vertically below top of unit, extending 2 feet down- 

 ward. This species being abundant in lower half of the 

 zone. N. 34° E. 75° W 218.0 28.0 175.0 



Concealed 183.0 9.0 147.0 



Massive nodular dark blue limestone 172.0 16.0 138.0 



Massive gray nodular limestone weathering thin- 

 bedded and shaly in places. Crinoid stems very abund- 

 ant. N. 33° E. 87° W 152.0 29.0 122.0 



Massive nodular blue limestone weathering thin- 

 bedded in places. At top occur Batostomella inter- 

 porella, Eridotrypa parvulipora 116.0 93.0 93.0 



Thickness of Keyser member exposed 232.0 



ToNOLowAY Formation 



Blue limestone, not nodular 3.3 



Concealed. Fissile platy limestone exposed at places. 



