114 C. S. PROSSER — DEVONIAN AND SILURIAN ROCKS. 



Lorraine shales " (Agri. N. Y., pp. 125, 120). Vanuxem reported the 

 Oneida conglomerate in Herkimer to he "from 15 to 25 feet thick ; " 

 while in a gulley southeast of Utica "it appears to present its maximum 

 thickness of ahout 35 feet" (Geol. N. Y., pt. iii, p. 76). Dana stated the 

 thickness of the Oneida conglomerate to be " 100 to 120 feet in Oneida 

 county, New York " (Manual Geol., p. 218), and, further, "the Oneida 

 conglomerate is the surface rock in Oneida and Oswego counties, New- 

 York. It is here 20 to 120 feet thick, but thins out to the eastward in 

 Herkimer county " (ibid., p. 220). He evidently used the terms Oneida 

 conglomerate and Oswego sandstone as synonymous, and gave the thick- 

 ness of the Oswego sandstone for that of the Oneida conglomerate. 



N. — Above the Utica shale, on the south branch of Sandy creek, Jef- 

 ferson county, New York, a locality not far west of the line of this section, 

 Mr YValcott measured 600 feet of shales and sandstones belonging to the 

 Lorraine stage iBull. Geol. Soc. Am., vol. 1, April, 1890, pp. 348, 349). 

 On the " diagram " for the Lorraine section Mr Walcott gave 180 feet as 

 Utica, then 100 feet of shale and calcareous sandstone, with 720 feet of 

 the Lorraine above (ibid., p. 350). Furthermore, Mr Walcott has stated : 

 "The data obtained in the study of the strata of the Hudson terrane 

 enables me to state that that terrane has a thickness of over 6,000 feet in 

 the valley of the Hudson" (Ninth Ann. Rep. U. S. Geol. Surv., pp. 116, 

 117). Vanuxem wrote: "In Schoharie county the Hudson group is 

 undisturbed and unaltered, and its maximum thickness is not less than 

 700 feet" (Geol. N. Y., pt. iii, p. 61). Mather concluded: " In the val- 

 leys of Norman's kill, the Mohawk river and the Schoharie kill, they 

 [Hudson] are beautifully exposed to view. . . . No actual meas- 

 urements of these strata have been made, but it is estimated that they 

 have a thickness of from 500 to 800 feet " (Geol. N. Y., pt. i, 1843, p. 369). 

 Ashburner described the Knowersville well, in Guilderland township, 

 Albany county, seventeen miles from Albany, which began 595 feet below 

 the top of the Hudson and reached the Trenton at a depth of 2,880 feet. 

 Consequently the Hudson group and Utica shale, if the latter be repre- 

 sented in this well, have a combined thickness of 3,475 feet (Trans. Am. 

 Inst. Min. Eng., vol. xvi, pp. 951, 952). Professor Hall gave it as from 

 800 to 1,000 feet thick in central and northwestern New York (Gd >1 . Surv. 

 N. Y., Paleontology, vol. iii, pt. i, text, p. 20, foot note). Professor Em- 

 mons reported the entire thickness of the Lorraine shales at the northern 

 termination of the Helderberg range as "not less than 700 feet" (Agri. 

 N. Y., p. 125). 



O. — Mr Walcott measured ISO feet of "dark bituminous shale in bands, 

 alternating with a smoother lead-colored shale," along the south branch 

 of Sandy creek, Jefferson county, New York, which was "characterized 

 by the fauna of the Utica shale*' (Bull. Geol. Soc. Am., vol. i. p. 318). 



