422 The American (Jealofjisl.. June, 1897 
The Cretaceous clay marl exposures at Cliffwood, N. J., Arthur Hol- 
lic-k. Trans. N. Y. Acad. Sci., vol. 16, pp. 124-136, pis. 11-14, March 26. 
1897. 
Report on the country between Athabasca lake and Churchill river, 
J. B. Tyrrell and D. B. Dowling. Geol. Surv. of Canada, Ann. Rept., 
vol. 8, pt. D. 120 pp., 3 pis., 1 map, 1896. 
COPxRESPONDENCE. 
A COMPLETE OIL WELL BECOED.* Geologists have long desired a care- 
ful and accurate measurement of the rocks passed through by the bor-- 
ings for oil in southwestern Pennsylvania. Mr. Carbel, during the life 
of the Second Geological Survey of Pennsylvania, had several careful 
records kept of the borings in Clarion and adjoining counties, but as 
the strata dip to the southwest, and thicken somewhat, it was very de- 
sirable to have a new-standard for comparison in southern Pennsyl- 
vania. 
The writer happily found in Mr. T. J. Vandergrift of Jamestown, N. 
Y., a successful oil operator of many years experience, the right man to 
undertake the work, purely as a labor of love in the interest of geology. 
The well in question was drilled by the Woodland Oil Co., of which 
Mr. Vandergrift is president, on the S. B. Phillips' farm, in the famous 
McDonald field, near the line between Allegheny and Washington coun- 
ties, about 20 miles southwest from Pittsburg. 
The main producing rock of this region is the lowest memVjer of the 
Venango Oil Sand group, or what is known as the fifth oil sand. This 
rock, it will be remembered, has yielded petroleum in greater quantity 
than any other horizon yet found on the American continent, fince 
some of the wells of the McDonald region produced oil, for a phort time, 
at the rate of 15,000 barrels daily. 
It is no slight task to keep one of these deep well records with the 
necessary care, since to bo reliable a sample of the drillings mvist be 
washed, dried and properly labeled every time the tools are withdrawn 
from the hole. Then, too, as rope measurements are not reliable to 
within ten to fifteen feet, steel line measurements must be taken fre- 
quently, and all these things were done in the present instance, so that 
the 2,342 feet of strata penetrated from 86 feet above the Pittsburgh 
coal down to seven feet below the bottom of the fifth oil sand, is repre- 
sented by 570 samples of drillings, and 55 steel line measurements, from 
which data a very complete account of all the intervening, beds can be 
obtained, for all of which geologists are certainly under great obligations 
to Mr. Vandei'grift. 
The writer will publish the log of the well in the exact language of 
the party .keeping the same, and also a condensed record in more strictly 
geological terms. I. C. White. 
♦Abstract of a paper read at wiuter (1896) meeting G. S. A. 
