Bulletin 23. Potash in the Greensands of NJ, 1923 - State of New ...

36 POTAS_ I_ THE GREEIVSANDS OF NEW JERSEY.
of the State Survey, will be of interest to any company that proposes
commercial development of the greensands:
The town supply of Woodstown, Salem County, is drawn in part from six wells
near the bank of the creek at an elevation of about 20 feet _nd varying from 136 to
149 feet in depth. The average flow of each well from the top of the casing, 1 foot abox e
the surface, is about 60 gallons per minute; temperature 58 °. The wells draw from
the Mount Laurel-Wenonah sands, which were water-bearing h'om 60 to H_ feet
below sea level. A seventh well at this point was prospected to 776 feet. Waterbearlilg
sands were found at the top of the Magothy-Raritan formation from 27G to 319
feet below sea level and also near the bottom of the series at 756 feet below sea le_ el.
Between these two horizons an alternating series of sands and white and red clays
was found, all of which apparently belong to the Raritan and Magothy formations,
which here have a thickness of ,180 feet, _vfith base not reached. The water at 2_6
feet (276 feet below sea level_ rose within 14 feet of the surface, and that from 776
feet (756 feet below sea levell within 18 feet. In 1915 a new well was driven to a depth
of 3,t0 feet, which drew upon the upper horizon in the Magothy-Raritan at 310 feet.
The yieht of this deep well on pumping is 300 gallons per minute, and it has therefore
proved an important addition to the town supply.
Available records of the 340-foot well diffcr somewhat, but the following,
taken from a letter in the files of the State Geological Survev,
cheeks fairly well with the samples now preserved at the pumping
station and kindly shown to the writer by Mr. Oren Conover, city
engineer.
Record of _zell of Boro_lgh of ll'ood, stou_ at loclilit!/ 18.
[Elevati_n, about 20 feet; depth, 340 feet. HlLhi_ & Ilolli_tshvad, drillers.}
Thick- Depth. Formati(m.
/less.
1
Meadow mud and gravel ..........................
Quaternary.
Limestone ................................
Green marl ................................. 40
25
65
Villeellto'_;ll.
_[ornerst owil _llld
Chocolate
Gray sal]d, marl, wa cr hard be.r ............................ ng ................... I0 I
_5 75 Navcsink.
1,50 Mount Do.
Laurel and W_
ilOll_h.
Black elaymarl .............. 160 , 310 Marshalltown to M_,rchaiit
viIh_ ?
White sarld and gravel .............................. 30 ] 3441 Magolh_ ?
The samples of material below the marl show some variation from
the description in the above record. Samples taken at depths of 185
and 210 feet show a fine-textured micaceous gray clayey sand, containing
small pebbles and fragments of shell. These represent the
Englishtown sand, which was not utilized. The entire thickness of
greensand marl is present, for both shell beds appear to have been
penetrated, as indicated by the samples.
2'ln'ee wells have been drilled for the Ice & Cold Storage Co., one
block north of the depot, at an elevation of 50 feet (locality 19).
The writer is indebted to Dr. Twitchell for the following description:
Two of the wells have a diameter of 6 inches, the other of 4½ inches; the last and
one of the 6-inch wells are 160 feet deep and obtain water from the Mount Laurel-
Wenonah sands 50 to 110 feet below sea level--the same horizon which supplies the
NEW JERSEY GEOLOGICAL SURVEY