STRATIGRAPHIC RELATIONS OF THE OXEIDA CONGLOMERATE 37 



the Medina is but a few feet above the lake at Wolcott, this 

 locality probably represents the most westward extension of 

 what may be regarded as the Oneida conglomerate. 



Champlainic and the Ontaric or Upper Siluric contact 



In all the recent publications on geology, the Oneida conglom- 

 erate when considered apart from the Medina is made the base 

 of the Ontaric division. The Oswego sandstone which has been 

 considered the westward extension of the Oneida has also been 

 generally regarded as belonging to the Ontaric. From the con- 

 siderations which have been stated, it follows that if we regard 

 the Oneida as the base of the Ontaric, the lower red Medina and 

 the Oswego sandstone- must be considered as belonging to the 

 Champlainic, or else the base of the Ontaric must be placed lower 

 than the Oneida conglomerate. 



It is not the purpose of the writer to here state just where the 

 line between the Champlainic and Ontaric divisions should be 

 drawn, but rather to state some of the factors which must be 

 considered in the final solution of the problem. 



In comparing the results of the early geologists, it should be 

 remembered that Hall and Emmons included the Oneida con- 

 glomerate as the highest member of the Champlainic system 

 and the Medina sandstone as the base of the Ontaric. Vanuxem 

 on the other hand regarded the Oneida as abo\~e the Medina and 

 made the gray Oswego sandstone, which is below the red Medina, 

 the base of the Ontaric. 



The later works of- Hall show that he finally included the 

 Oneida as the base of the Ontaric, but always held that the 

 Oneida was below the Medina. 



From Oneida county eastward, the Oneida conglomerate rests 

 on the Champlainic strata and represents the base of the Ontaric as 

 at present defined, only in the sense that it is the lowest Ontaric 

 formation present. In a like manner the higher Ontaric formations 

 rest on the Champlainic strata, the farther east we go, and at 

 Becraft mountain, the Manlius, the highest member of the 

 Ontaric, rests on unconformable Champlainic strata. 



The passage of the Lorraine into the Oswego sandstone can 

 be observed in Oswego county and has been described by 

 Vanuxem. 1 It is then evident that we have no unconformity 

 between the Lorraine and the members of the Medina formation 

 in Oswego county. 



Of the condition in Pennsylvania, Stevenson 2 states, " the 



JGeol. N. Y. 3d Dist. 1843. p. 67. 



^eol. of Bedford and Fulton Counties. 1882. p. 92. 



