REPORT OF THE STATE PALEONTOLOGIST 1901 625 



Litbologically and stratij»i'apliically the 000 feet of strata be- 

 tween the Grimes sandstones and the High Point sandstones 

 can be correlated only with that part of the Portage section 

 termed Gardeau, but paleontologically they bear no trace of 

 the Portage or Naples fauna and on the other hand an abundant 

 presentation of the Chemung fauna with tlie exception of a few 

 feet of deposits at the base of the Grimes sandstones which repre- 

 sents an outrunner from the Ithaca fauna farther east. 



At the top of these beds the proportion of arenaceous matter 

 increases gradually and a band of heavy sandstones occurs in a 

 stratigraphic position corresponding to that of the Portage sand- 

 stones at Portageville. The outcroppings of these sandstones 

 about Naples are found at or near the tops of the hills in the 

 vicinity and 000 to 1000 feet above the valley. 



As the exposures are isolated from each other, and not ex- 

 tensive, none having been found that present an entire section of 

 the formation, accurate measurement of the strata composing 

 it is not practicable, but the heavy layers of sandstone are promi- 

 nent in the bedding for 150 to 200 feet, closely I'esembling the 

 Portageville rocks, but more frequent.y separated by beds of 

 shale. The largest and most favorable exposure is in the cliff 

 at High Point 2 miles west of Naples, at the elevation of 1700' to 

 1800' A. T., where about 75 feet of the sandstones and shaly part- 

 ings appear in j^lace in the escarpment and large blocks are scat- 

 tered over the immense talus. 



Situated about the middle of the section exposed is a calcareous 

 lens 5 feet thick ^t the center, and 25 rods in breadth, composed 

 almost entirely of fossils, of which 33 species have been identi- 

 fied (United States geological survey, P>ulletin 10), 21 being 

 brachiopods, none of which so far as known have been found in 

 the Portage section on tlie Gen(Asee river, nor below the Grimes 

 sandstones in the Naples section. This constitutes the interest- 

 ing High Point fauna which has been elsewhere described and 

 shown to carry a marked representation of species present in the 

 upper Devonic faunas of Iowa. 



