Maryland Geological Survey 183 



Oriskany Foemation 



Vertical Total 



Ridgely Sandstone Member thickness vertical 



feet thickness 

 Chiefly dark gray, massive, arenaceous limestone. In the 

 upper portion Anoplotheca flal)ellites (aa), Spirifer arenosus 

 (a), S. murchisoni (a), Stropheodonta magnifl-ca (a), and 

 Hipparionyx proxivius (a) occur. In the lower portion Spirifer 

 intermedius (aa), S. cumherlandiw (aa), Anoplotheca flaielUtcs 

 (aa), A. flmbriata (a), Chonostrophia complanata (rr), and 

 AnopUa nucleata (c) 130.0 246.0 



Shriver Chert Member 



Bluish-black cherty to dark gray arenaceous limestones, 

 heavy-bedded above, passing below into thinner beds. In the 

 upper portion Spirifer tribulis (r), S. paucicostatus (r), Ano- 

 plotheca flabellites (aa) occur. In the lower portion Anoplo- 

 theca flabellites (a) occurs IIG.O IIG.O 



IV. Sections near Ridgely 



At Miller's Station, about 1 mile south of Ridgely Station, on the West 

 Virginia Central Eailroad, there is a considerable talus from the Oriskany 

 cliffs above. The rock has disintegrated and many fossils can be collected, 

 especially the strophemenoid shells that are very scarce at the other 

 Oriskany collecting grounds. Some blocks of the Helderberg also are in 

 the talus slope, but they can be easily distinguished. The following 

 species were obtained from the Ridgely member of the Oriskany : Spirifer 

 arenosus (aa), S. cumherlandice (r), S. angularis (a), Meristella lata 

 (rr), RensselcBria marylandica (r), Beachia suessana (aa), Anoplotheca 

 flabellites (c), A. flmhriata (r), Eatonia pecularis (r), PleihorJiyncha 

 speciosa (r), Leptcena rkomhoidalis (r), Stropheodonta magnifica (c), 

 S. magniventra (r), Chonostrophia complanata (c), Chonctes rowei (r), 

 Dalmanella planiconvexa (r), Orhiciiloidea ampla (rr), Megamhonia 

 lamellosa (rr), Megamhonia sp. (rr), Avicula recticosta (rr), A. textilis 

 var. arenaria (r), A. textilis (?) (r), Platyceras magnificum (c), Dia^ 

 phorostoma ventricosum (c), Ho malonotus major {xv) , H . vanuxemi (rr). 



Ridgely at the north end of Knobly Mountain is perhaps the most satis- 

 factory collecting ground for Oriskany fossils about Cumberland. At this 

 point 50 or 75 feet of the upper part of the Oriskany is exposed. On the 

 right side of the railroad track before one reaches the railroad station. 



