90 



The Lower Devonian Deposits of Maryland 



Xi 



s "S 



§ ^ 



Thin to medium-bedded gray limestone with fine 

 brown lines, nearly unfossiliferous, Leper- 



ditia altoidcs 17.3 281.0 



Compact gray limestone, thin bedded 3.4 263.7 



Gray crystalline limestone 0.8 260.8 



Heavy-bedded gray limestone with many trans- 

 verse calcite seams Spirifer vanuxemi prog- 



nosticus 29.2 259.5 



Shaly limestone containing fossiliferous crystal- 

 line layers. Weathers more easily than ad- 

 joining units Tentaculites gyracanthus. 

 Schuchertella proliflca. Meristella prwnuntia. 7.2 230.3 

 Thin-bedded gray limestone Tentaculites gyra- 

 canthus 10.6 223.1 



Heavy-bedded, dark blue limestone, bottom foot 



argillaceous Rensselaria mutabilis 25.7 212.5 



Massive bed of dark blue limestone spotted with 



crinoids and corals preserved in calcite 16.6 186.8 



Heavy-bedded, dark blue limestone, gray and 



crystalline toward the top 26.0 170.2 



Dark blue limestone heavy-bedded below, be- 

 coming thin bedded toward top 9.0 144.2 



A solid heavy bed of blue limestone Oypidula 



coeymanensis var. prognostica (aa) 2.0 135.2 



Heavy-bedded, dark blue limestone Camarocr- 



inus stellatus 5.6 133.2 



Thin, irregularly bedded, dark blue limestone. . . 6.6 127.6 

 Thin, irregularly bedded, dark blue limestone. . . 13.6 121.6 

 Heavy-bedded, blue limestone. The cystid zone. 18.0 108.0 



Heavy-bedded, dark blue limestone 24.0 90.0 



Heavy-bedded, dark blue limestone 27.0 66.0 



Very massive, hard, dark nodular limestone 20.3 39.0 



Dark, thin-bedded very nodular limestone 3.1 18.7 



Nodular limestone, with some chert 15.6 15.6 



Oriskany Formation ' 



introductory 



The name Oriskany sandstone was applied by Hall '' to the friable white 

 sandstone at Oriskany Palls, N. Y., and was generally adopted by geolo- 

 gists. In 1899, Clarke and Sehuchert included all the various exact and 

 inexact local developments of Oriskany equivalents under the serial term 



Contributed by R. B. Rowe, Charles Schuchert, and Charles K. Swartz. 

 ■' 3d Ann. Rept. N. Y. Geol. Survey, 1839, pp. 308, 309. 



