336 G. H. CHADAVICK STRATIGRAPHY OF NEW YORK CLINTON 



Bear Creek shale 4 inches?. See discussion beyond. 



Martville? (Otsquago?) sandstone 2 feet? Somewhat reddish color. 



Maplewood shale Absent (hiatus). . . 21 feet at Rochester. 



Oneida conglomerate* Entered? (6") "White sandstone." 



( * In the western sections the Thorold sandstone occupies a similar position 

 beneath the Maplewood gi'een shale.) 



Too much emphasis can not be placed on the significance, for purposes 

 of classification, of the hiatuses in this, the thickest Clinton section in 

 New York. The}^ accord with gaps already recognized in the previous 

 sections. 



Special attention should be called to the presence here, but with greatly 

 reduced thickness, of the Eochester shale, 20 miles to the east of its last 

 known outcrop and apparently without noteworthy change in character. 

 These facts point to its total extinction within a few miles to the east- 

 ward. But beneath this sh^le, separated from it by a limestone that 

 Hartnagel clearly considered the top of the Clinton (see 9:25) is the 

 60 -foot shale mass carrying the first of the economically important sand- 

 stone intercalations of the Clinton that occur in outcrop at several points 

 along the south side of Oneida Lake east and west of this well (1: 89), 

 becoming of increasing importance eastward (1:87). This mass we 

 believe to be identical with the shale division seen at Phoenix (11 : 57-58), 

 with its large element of Eochester shale fossils. In the six feet of cri- 

 noidal ore-bearing limestone below these 60 feet of beds we recognize the 

 first definite presence of the upper (fossil or ''red flux") ore of the Clmton 

 district, while in the thin ore above them we see, with Yanuxem (1 : 88), 

 the equivalent not only of Donnelly's ore (9 : 26), but also of that over 

 Tipple's quarry, near Verona (1 : 87-88). 



For the Verona region Professor Fairchild's field copy of the topo- 

 graphic map with his memoranda of outcrops has aided greatly. The 

 vertical adjustment of the partial well section and the important ex- 

 posures have been arrived at by computations of altitude and dip that 

 would be wearisome here, but which seemed to clear away the problems 

 of correlation between Lakeport and Clinton as soon as they were plotted 

 on the chart. The limestone members are now all shale, identifiable only 

 by their attendant ore bodies; but Vanuxem's correlation of the layers 

 above the Verona ore bed with those exposed in the village of Martville 

 and "in contact with the ore at Wolcott furnace'^ (1 : 87) on the basis of 

 the guide fossil "Retepora clintoni" (HalPs "Fenestella priscaf') is 

 amply confirmed by the stratigraphy. So also is Hartnagel's seemingly 

 contradictory assertion (9: 26) that the Verona fossil ore ''occupies the 

 same relative horizon in the formation as the Clinton oolitic bed." In 



