340 G. H. CHADAVICK STRATIGRAPHY OF XEW YORK CLINTON 



The rest of the Tisdale section (9 : 27; 3:16) appears simple. Under 

 the gra}^ band are two feet of shale (which may be a misprint, since Hall 

 (3 : 16) gives "thickness?''), then "red sandstone with a sparkling grain" 

 (1: 81), together with gray sandstone, shale, and iron ore, about 20 feet. 

 Since the upper ore bed is kno^^l to come as far east as Steeles Creek 

 (1: 82) or within five miles, meantime becoming oolitic, there seems no 

 reason for not treating these beds as the middle ore-bearing portion of 

 the Clinton region (see 9: 42). The coarse, friable mixture of sand and 

 hematite (9 : 47) at this level becomes more marked (1 : 80-81) at Yan- 

 hornsville (spelled "'Yanhornesville'' on the topographic map and in 9 : 

 28), near the eastern limit of the group, but just how much it represents 

 of the Yerona-Kjrkland span at Clinton is unknown. The three lower 

 strata are clearly the Sauquoit beds in their triple aspect, the middle 

 sandstone being the beds of the Blackstone quarry here become heavily 

 cross-bedded (1:82), and thus passing eastward into the cross-bedded 

 red laminated sandstone of the Otsquago Creek below Yanhornsville (1: 

 80, 81; 9: 28), which may just possibly become the "coarse (red 3: 15) 

 sandstone with much iron ore" next below the Camillus shale at Salt 

 Springville (9: 28), the last Clinton exposure, though this sounds more 

 like the Yanhornsville bed. 



The Oneida conglomerate lies beneath in all these localities ( 1 : 80-82 ; 

 3:15-16; 9:27-28), but from its erratic thinning and rethickening it 

 appears likely that some portion of the basal Clinton shale may be merged 

 with it at the east. It must not be forgotten that Yanuxem (1 : 75) con- 

 sidered the Oneida "a part of the Clinton group," separated, he says, for 

 convenience. V^^e would reverse this statement and consider the unfos- 

 siliferous part of the basal shale below the Otsquago-Martville as a part 

 of the Oneida in its broader application, including, it would seem, the 

 Thorold and Maplewood of western New York, but not any part of the 

 true red Medina. The belief that Upper Medina strata existed in these 

 eastern sections above the Oneida conglomerate (see 7 : plate 2, and Sci- 

 ence, new series, volume 28 (1908) : 347) undoubtedly grew out of the 

 presence here of the cross-bedded and normally red Otsquago sandstone; 

 but as the red color of this fades away westward, while the ^ledina dark- 

 ens in coming east, they grow more and more unlike as they approach the 

 common meeting-point, and so can have little in common. The evidence 

 in hand favors the conclusion of Yanuxem (1:75-78) and Hartnagel 

 (7: 36) that the Oneida is "never far below the base of the Clinton" and 

 is closely connected with its basal shale. 



