1892.] PROSSER — THE GENESEE SECTION. 89 



NO. OF DESCRIPTION OF 



SAMPLE. DEPTH. SAMPLE. : 



4. 200'. Mostly light gray limestone and chert ; some of the 



dark gray chips. 



5. 250'. Drab colored limestone, moderate effervescence in 



cold HCl ; lithologic character quite different from 

 No. 4. Waterlime or upper Onondaga Salt group. (') 



6. 3oo'. Dark gra}' chips which effervesce very slowly in cold 



HCl, increased by heating, leaves large residue. 



7. 35°'- Dark gray, somewhat calcareous chips. Effervescence 



increased by heating. 



8. 400'. Ditto, only rather more calcareous. 



9. 450'. Dark gray to slightly greenish-gray argillaceous shales. 



Slightly calcareous. 



10. 550'. Dark gray chips, about the same as No. 8, more cal- 



careous than No. 9. 



11. 600'. (irayish. somewhat calcareous chips mixed with 



crystals of rock salt. Mr. Dodgson reported about 

 15' of salt. 



12. 650'. Greenish-gray shale, some very slightly pinkish. No 



effervescence in cold HCl. Mr. Dodgson reported 

 red shale at about 650', but only 6'-8' in thickness 

 with indications of salt. 



13. 700'. Cireenish-gray with some slightly purplish chips. Some 



effervescence in cold HCl. Fragments of gypsum. 



14. 750'. Dark gray limestone, effervescence moderately strong 



in cold HCl, after a few minutes. Some of the chips 

 show spots of resinous lustre as was described by 

 Professor Hall in 1843. ('"') 

 Ditto, nearly all the chips have a resinous lustre. {') 

 Dull gray to drab chips which are very fine. 

 About the same as No. 16. 



(i.) It is difficult in well samples to decide where the Upper Helderberg stops and the Onondaga 

 Salt group commences (see Harris, Amer. Geol., Vol. VII, p. 170) ; but of these samples No. 4 is 

 characteristic of the Upper Helderbergand No. 5 of the upper Onondaga Salt group. 



(2.) Geol. of N. Y., Pt. IV, p. 85. 



(3.) Sample No. 14, is a dark gray limestone which seems to be near the character of the Niag- 

 ara ; but No. t5, which is not quite so dark in color, must be Niagara. Prof. Hall says : " The litho- 

 logical characters alone of the two upper divisions [of the Niagara! are everywhere sufficient to dis- 

 tinguish this part of the rock from all other limestones in the State ; these are, its brittle nature, the 

 glistening surface of the minute crystalline laminae of which the mass is composed, and its harsh or 

 apparently siliceous character" (Geol. N. V., Pt. IV, p. 87). In No. 15 is a large chip on which the 

 glistening lamina; are very conspicuous, they are also noticeable on the largest chips of IS'o. 14. 



