I 



GEOLOGY OF THE. GENEVA-OVID QUADRANGLES 1 5 



these basal beds there occurs the 2 foot stratum known to geologists 

 as the Agoniatite limestone which extends to the western part of 

 the State and is readily distinguished by its peculiar character and 

 fossils. 



The shales intervening between the Onondaga limestone and 

 Agoniatite limestone become more calcareous westward from Mar- 

 cellus and at Union Springs are mostly dark impure bituminous 

 limestone, more or less shaly. On this quadrangle and in Ontario 

 and Livingston counties they are still more calcareous and lighter 

 colored and in the western part of the state are so far assimilated 

 to the Onondaga limestone as to be not separable from that 

 formation. 



Above the Agoniatite limestone a row of large spherical concre- 

 tions and a few thin calcareous flags are the only variations in the 

 bed of densely black shale up to the horizon of the Stafford lime- 

 stone. The Marcellus black shale has a thickness of 45 feet on the 

 Geneva quadrangle. It is exposed along the bed of a small stream 

 that crosses the Romulus road 2 miles south of Waterloo; in the 

 bed of Kendig creek and on the east shore of Seneca lake south 

 of the outlet; also, slightly in the road a mile west of Canoga spring. 



The following is a list of the more common fossils of the Mar- 

 cellus black shale : 



Orthoceras subulatum Hall C. mucronatus Hall 



Styliolina fissiirella (Hall) Strophalosia truncata Hall 



Pleurotomaria rugulata Hall Liorhynchus limitare (Vamtxem) 



Nuculites oblongatus Conrad L. multicosta Hall 

 Chonetes lepidus Hall 



Cardiff shale 



In the absence of the Stafford limestone on this quadrangle, the 

 Cardiff shale here succeeds directly the Marcellus shale as above 

 described and is equivalent to the " Upper shale of Marcellus " of 

 Vanuxem for which the name here used was substituted in New 

 York State Museum bulletin 63,, 1904, from its abundant exposure 

 in the vicinity of Cardiff, Onondaga co. 



As compared with the shale below the Stafford limestone the 

 Cardiff shale is more argillaceous and fissile and gradually passes 

 from black to an olive or dark slate color. 



At the base of the formation a band of calcareous shale 2 feet 

 thick in the horizon of the Stafford limestone is lighter colored and 

 more fossiliferous than the succeeding beds, which are mostly dark 

 and bituminous. In the upper part there are thin lentils of lime- 



