MEDINA FORMATION 287 



a follower. Then, too, he was the first American to lay down in writing 

 the rule as to how formation names should be proposed (see quotation in 

 Part II), and as he then said nothing about priority, and as this second 

 rule was not formulated even by the biologists until 1844, we may over- 

 look his neglect in accepting Conrad^s term. To do otherwise now would 

 bring on more confusion than clarity, because in 1842 and 1843 Vanuxem 

 and Hall both used the same name, Niagara, for a group term of wide 

 acceptance at present to embrace the Rochester shale and Lockport lime- 

 stone. 



Further, the term Cayuga sandstone (Vanuxem, 1839) is older than 

 the accepted Oneida conglomerate (Vanuxem, 1840) and even than the 

 Medina of Hall, and Oswego sandstone (Vanuxem, 1839) could well 

 have been made to serve the place now taken by Queenston (Grabau, 

 1908). Most of these terms are, however, still of use to express local 

 facies differences, but for time terms we should now disregard the rules 

 and use here the younger names, Queenston and Medina. The ^%ray 

 band" of Eaton, at the top of the Medina, is now known as the Thorold 

 member,^^ while the basal white sandstone along the Niagara River is 

 well named Whirlpool sandstone.^'' It will be shown that the latter is a 

 member, not of the Medina, but of the Cataract formation, a series of 

 calcareous sediments that in passing southeastward through Ontario 

 gradually merges into a part of the sandy and fossiliferous Medina. 



The Medina is typically developed along Oak Orchard Creek, which 

 runs through the town of Medina. Here the formation is about 60 feet 

 thick; it is described in detail in the second part of this paper. This 

 thickness and the physical characters are about the same all the way 

 from Rochester, which is 40 miles east of Medina, to Niagara Falls, an 

 additional distance of 35 miles. At the last named place, however, the 

 Cataract formation, 54 feet in thickness, is wedged underneath the upper 

 Medina, consisting of the basal Whirlpool sandstone 22 feet thick, fol- 

 lowed above by 32 feet of green shales, with a little of impure magnesian 

 limestone. In all the sections from Niagara Falls eastward to Rochester 

 there is a basal white, more or less coarse sandstone; but as it is clearly 

 tangential in space and time, it is wrong to call it at all these places the 

 Whirlpool sandstone. Certainly east of Lockport none of the basal sand- 

 stones hold the time of that along the Niagara River. From Niagara 

 Falls northwestward the Whirlpool sandstone is far less or almost not at 

 all tangential in time, and the name can be applied, without doing vio- 

 lence to correlation, to the basal sandstones in all of these sections. 



" Kindle and Taylor : Op. cit. 



Grabau : Bull. Geol. Soc. Am., vol, 24, 1913, p. 460. Here Thorold quartzite. 

 " Grabau : Jour. Geol., vol. 17, 1909, p. 238. 



