REPORT OF THE STATE PALEONTOLOGIST 1902 



1005 



The latter include 661 feet of strata exposed along that part 

 of the river formerly in the Gardeau Indian reservation and to 

 the top of the Upper falls at Portageville. 



Hatch flags and sands. Above the Rhinestreet shales are light 

 and dark shales, 88 feet, in layers of varying thickness from a 

 fraction of an inch to several feet, and with a few thin flags of fine 

 blue sandstone distributed at irregular intervals. A row of 

 symmetric concretions, from 1 foot to 1J feet in diameter lies 

 at the base of this subdivision, and many others of various sizes 

 and shapes are scattered through it and serve to distinguish it 

 from the overlying beds. Fossils are rare except in a few of the 

 lighter layers, but the beds are more fossiliferous toward the 

 east. 



Above there is a band of flaggy sandstones, 6 feet thick, ex- 

 posed for several miles in the cliffs on the east side of Smoky 

 hollow and the Gardeau flats. It comes down to the river 

 level opposite the " Five Corners road," 1 mile north of St 

 Helena. At this point the cliff above the flaggy band shows 115 feet 

 of shale m which no sandstones appear except about 10 feet of 

 thin flags. A large proportion of this shale is dark and slaty, 

 and the remainder is quite ferriferous, consequently the general 

 aspect of the weathered face is very dark, almost black, and 

 rusty. Fossils are almost entirely absent. 



In the escarpment at the east end of the St Helena bridge 60 

 feet of these shales are exposed and are overlain by 25 feet of 

 flags and soft sandstones that are separated from each other by 

 thin layers of hard blue shale. 



This arenaceous bed is thicker and proportionately sandier 

 toward the east. In the Dansville, Springwater and the Naples 

 valleys it contains fossil sponges, and at the last place many 

 brachiopods and other fossils, and marks the upper limit of the 

 normal Portage fauna, and is there known as the Grimes 

 sandstone. 



At the mouth of Wolf creek this bed is overlain by shales and 

 flags 110 feet thick, in which dark or black shales still pre- 

 dominate. It is exposed in the rock wall beneath the " Table 

 rock " above the mouth of Wolf creek near the south road from 

 St Helena to Castile, and in The gorge southward between the 



