GEOLOGY OF THE HONEOYE-WAYLAND QUADRANGLES Ij 



two miles north oi Hemlock village, and in the ravine on the west 

 side of Gonesus lake near Eagle point. 



GENUNDEWA LIMESTONE 



This designation has been appHed to a band of thin impure lime- 

 stones separated by partings of a few inches or feet of black shale, 

 the whole having a total thickness of six to eight feet. 



Some of the Hmestone layers are very uneven and somewhat 

 nodular, while others are even and compact; one of the latter, 

 twelve to fourteen inches thick, has been utilized to a limited extent 

 for building purposes. 



The limestones are composed principally of the minute shells of 

 the pteropod Styliolina fissurella Hall and the forma- 

 tion was formerly known as the *' Styliola band." These shells give 

 the limestone a sandy appearance after long exposure. This forma- 

 tion is exposed in two ravines two miles northeast of Honeoye 

 and in the bed of Whetstone brook two miles northwest of 

 Honeoye. It may be seen in a gully near the first bridge over the 

 Hemlock outlet below Hemlock village, and in a larger ravine half 

 a mile farther north. It appears fifty feet above the lake level 

 in the ravine near Eagle point, Conesus lake. 



Fossils are abundant in this formation, and the fauna is of pecu- 

 liar interest owing to the appearance of many forms not known to 

 occur in the rocks below. 



A list of fossils numbering forty-eight species, obtained from 

 the Genundewa strata, may be found in State Museum Bulletin 63. 



WEST RIVER DARK SHALE 



Succeeding the Genundewa limestones there are 65 to 75 feet 

 of dark gray shale in which there are interstratified beds of black 

 shale one to three feet thick, at intervals of three to eight feet, 

 which, in walls of ravines, give this formation a broadly banded 

 appearance. Calcareous concretions are common; some of these 

 are septaria and have been known under the names " petrified tur- 

 tles," '' niggerheads " and others of similar character. A few 

 thin flags of calcareous sandstone also occur. 



At the top the passage to the succeeding black Middlesex shale 

 is through several alternations of dark and black shale in a few 

 feet. 



The West River shales are exposed along Whetstone creek two 

 miles northwest of Honeoye; in all the large ravines toward the 



