158 The Lower Devoxiax Deposits of Maryland 



About one-half mile northeast of Breakneck Eoad, on the east side of 

 Breakneck Hill southwest of the preceding station, there is an exposure 

 of Helderberg rocks. The following Lower Keyser fossils were found in 

 the talus : Choneles jersey ensis, Rliipidomella emarginata, Spirifer vanu- 

 xemi, S. modestus, Stropheodonta hipartUa. 



XIII. Section at Flintstone 



The best exposure of the Keyser in this region occurs at Flintstone. 

 The Tonoloway and Lower Keyser are exposed at the south side of the 

 creek in the rear of the Methodist Church at the east end of the village. 

 A massive bed of stromatoporoids outcrops on the north side of the creek. 

 Three hundred feet west of this bed occurs the first exposure in the bluff 

 on the south side of the creek carrying OypiduJa coeymanensis var. prog- 

 nostica. Below this zone the section is largely concealed for a distance 

 which includes about 50 feet of the vertical thickness of the beds. In the 

 next 20 feet the following characteristic Lower Keyser fossils were found, 

 the species being those which usually occur in the basal part of the member 

 only: DalmaneUa concinna, Cladopora rectilineata, Chonetes jerseyensis, 

 Spirifer modestus. The lower part of the section is heavy-bedded to 

 massive and contains only a scant fauna. The contact of the Helderberg 

 and Tonoloway formations is seen in the bed of the creek at low water. 



The section begins at the base of the massive Stromatopora beds of the 

 Keyser, 7 feet in vertical thickness, which is exposed on the north side of 

 Flintstone Creek near a spring at the east end of the village, and extends 

 to the west. 



Heldeebekg Forjiation 



Horizontal Vertical Total 

 Kpiiopr Mpmhpr distance thickness vertical 



Keyser memocr ^^^^ j^^^ thickness 

 Concealed. 

 Stromatopora bed at top on north side of creek 871.0 



Direction N. 58° W. 



Massive, nodular, blue-gray limestone. N. 58° W. 

 Gypidula coeymanensis var. prognostica (aa) 10.2 172.9 



Massive, hard, blue limestone 3.0 162.7 



Concealed, with occasional outcrops of nodular lime- 

 stone. N. 40° E. 20° E 571.0 45.4 159.7 



