GEOLOGY OF THE GENEVA-OVID QUADRANGLES 



I I 



are n os us, S. murchisoni, Chonostrophia com- 

 planata, Rensselaeri ovides, etc.) . A thin stratum 

 of this sandstone is exposed in the bed of Flint creek at Phelps, 

 and at Buffalo the loose sands of Oriskany time sifted into fissures 

 in the Cobleskill limestone, producing small sand " dikes." 



Onondaga limestone 



This appellation was first used by James Hall in the third 

 annual report of the Fourth Geological District for 1838, page 309, 

 and applied to " the gray crinoidal or Onondaga limestone which 

 follows the Oriskany sandstone and is well characterized and dis- 

 tinguished from any other by its peculiar gray or grayish blue color 

 and compact crystalline structure. Sometimes layers of chert or 

 hornstone are interspersed between those of the limestone ; and 

 some of those contain much of that mineral while in others it occurs 

 only in small nodules. When the lower layers abound in chert they 

 contain few or no fossils while those containing little of it are full 

 of them.'; 



The upper beds are described on page 310 as the " Seneca lime- 

 stone " which " succeeds the Onondaga and in some instances alter- 

 nates with it. It is recognized by its darker blue color, fine texture 

 and homogeneous structure. Like the Onondaga it contains much 

 chert or hornstone." 



Vanuxem, in the report on the third district for that year, page 

 274, describes the lower beds as the " gray sparry crinoidal lime- 

 stone " and says, " This limestone is but a thin mass of from 8 to 

 12 feet in thickness " and on page 275 he speaks of the upper beds 

 as " Seneca limestone. This rests upon layers of cornitiferous." 



In 1824 Prof. Amos Eaton in A Geological and Agricultural 

 Survey of the District Adjoining the Erie Canal introduced the 

 name Cornitiferous lini crock for a formation which evidently in- 

 cludes both the Onondaga and the Seneca limestones. He repeated 

 his definition with the addition of other localities in his Geological 

 Nomenclature for North America, 1828, page 25, and in the first edi- 

 tion of his Geological Text Book, 1830, page 42. Pie changed the 

 name to Cornifcrous limestone in the American Journal of Science 

 for 1839. 



In the Final Report on the Fourth Geological District, 1843 Pro- 

 fessor Hall redescribes the Onondaga as " included in the Cornifer- 

 ous limerock by Professor Eaton" and applies the term " Cornif- 

 erous limestone " as equivalent to the " upper part of the Cornif- 

 erous limerock of Eaton, Seneca limestone of the annual reports." 



