~~ 
Trans. N. VY. Ac. Scz. = D0 Dec. 12, 
composed of lapilli of soft cottony pumice, others are finer, grey, red, 
white, etc., and contain the trunks of coniferous trees, and in some in- 
stances are pierced with holes which represent the stems of upright 
plants, thickets of which were buried by the descending showers or 
rapidly accumulating sediment of volcanic ash. Here the source of the 
materials is to be sought in the line of great volcanic vents which 
crown the summit of the Cascade Mountains, and from which, at inter- 
vals, were emitted either floods of lava, poured down on to the plain 
along the eastern border of the range, or showers of ashes which, 
borne inland by the prevailing westerly winds, fell on forest, savannah 
and lake, temporarily destroying animal and vegetable life, and form- 
ing, when falling or washed into water basins, strata which alternate 
with fossil-beds, the accumulations of quieter times. In other places 
these tufaceous deposits were washed from all the highlands into the 
valleys, forming local masses of considerable thickness without the 
intercalated beds mentioned above. 
The accompanying section, copied from my report on the Geology of 
Northern California and Oregon (Pacific R. R. Report, Vol VI, 
Geology, p. 47), will itlustrate the deposition of these tufaceous rocks 
in the lake basins where they are interstratified with the fossiliferous 
beds. 
Dec. 12, 1881. 
SECTION OF GEOLOGY. 
The President, Dr. J. S. NEwBerry, in the Chair. 
Forty one persons present. 
Mr. N. L. Brirron presented 
“*‘ ADDITIONAL NOTES ON THE GEOLOGY OF STATEN ISLAND.”* 
Two wells have recently been sunk to a considerable depth on Staten 
Island, in the vicinity of Stapleton. One of these is on the property of 
Mr. J. J. Cisco, near the summit of the Serpentine hills; the section 
as given by the Superintendent of the Pierce Well-boring Co., who 
sank it, is as follows : 
Glacial triftst4 080%: .. 4s CREE & hi dietles eae > eee 50 feet. 
Sompstame sk esse’ +\sccfe cents piss bid ak eine tore 150 feet. 
The well is six inches in diameter, and sufficient water was obtained 
to make it a success. 
The other well is at the pump-house of Bischoff’s Brewery, some 
500 feet east of the most eastern serpentine outcrop at the foot of the 
* These notes are supplementary to the paper on this subject read by Mr. Britton on 
April 4, 1881. (Ann. N. Y. Ac. Sci., II, 16r.) 
