1006 



NEW YORK STATE MUSEUM 



JW' 



" Twin Hogsbaeks " to the Lower falls. It is seen also in the 

 lower part of the Wolf creek ravine. 



Fossils are very rare in it, but a few of the common Portage 

 forms occur in the soft shales. 



G-ardeau shales and flags. The layer of compact blue sand- 

 stone, 1 foot, 3 inches thick, that forms the " Table rock " at 



the mouth of Wolf creek ravine, is the 

 same stratum as the " Table rock " at 

 the crest of the Lower Portage on the 

 Genesee river. 



Above this mass lie 15 feet of soft 

 light and dark shales and thin flags, at 

 the top of which is the hard even sand- 

 stone, 12 inches thick, that forms the 

 crest of the low cascade at the head of 

 the Plume. Fossils are quite common in 

 the soft light shales between the two 

 sandstone layers. 



There are 49 feet of strata, mostly 

 shales, between " Table rock " and the 

 horizon of the bottom of the Middle falls, 

 and 113 feet in the face of the Middle 

 falls, in which there is a much larger 



/£ 



/; 



//' 



17 



Mm 



5 

 r.ui 



7' 



sandstone 



flags and 

 dark blue 

 shale 



flags 



dark shale 

 flags 



blue and 

 black shale 



soft light 

 shale 



sandy shale 



with 



concretions 



soft blue 

 shale 



proportion of sandy layers. 



Fallen blocks of the sandstones from 

 the vertical cliffs at and below the falls 

 are almost entirely barren, but Aulopora 

 and a few brachiopods, of species com- 

 mon in this horizon farther east, were 

 found, but these probably came from 

 some of the sandy layers above. 



There are 19 feet of flags and shales 

 exposed between the top of the Middle 

 and the horizon of the bottom of the 

 Upper falls. 



Fossils are quite common in a few of the soft layers of shale 

 or shaly sandstone exposed between the Middle and Upper 

 falls and to the base of the heavy sandstones above the Upper 

 falls. They all belong to the Portage fauna, no brachiopods 



4.'£iSiS 





light and 

 dark shales 



sandstone 



shale 

 black shale 



sandy shale 



Fig. 5 Section in the ra- 

 vine at Wiscoy. Station 15 



