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

18 POTASH IN THE GREENSA_NTDS OF NEW ;YERSEY.
The labor of mixing and dividing large quantities of marl was obviated
by using a trough with an end gate for collecting the sludge, as shown
in Plate VII, B. The sludge in the trough was mixed thoroughly,
and a sufficient quantity ladled out to provide duplicate samples,
one of which was dried as above described and the other preserved in
a 4-ounce wide-mouthed bottle. If more than one troughful was
required for a given sample, proportionate amounts were preserved
from each troughful and were mixed and divided for the final sample.
This method was used at the other localities whenever sludging was
necessary, care being taken to keep the sludge as thick as possible
and to operate the sand bucket so as to take only material from the
bottom of the hole. "
Disadvantages of wet method.--The main disadvantage of the wet
method of collecting marl samples is that by loosening the marl some i
of the finer constituents are mingled with water, and the relative
proportions of coarse and fine materials are thereby slightly altered.
The coarse constituents of the marl are relatively heavy and settle
rapidly to the bottom of the trough, so that it is frequently difficult -
to get a uniform mixture. There is danger, too, of intermixture of
material from farther up the hole, but this may be obviated to a
considerable degree by suitable casing. J
As shown on pages 125-126, the finer constituents of the marl conrain
beds
potash
at the same
in amounts
place.
varying
Where
from
the potash
place to
content
place
of
and
the
in
fines
different
of a
i
given sample is less than that of the sample as a whole a loss of fines
in collection would mean some enrichment of the sample, or an undue
amount of fines collected would mean a corresponding impoverishment
of the sample.
Three pairs of samples, one of each pair taken by the auger or
core tool and the other by the wet method, at hole 8, at Sewell, show
that the wet samples ran lower in total potash than the others by
amounts ranging from 0.07 to 0.35 per cent, the average difference,
weighted according to the thicknesses represented by the samples,
being 0.285 per cent. As similar methods were followed at succeeding
holes it seems probable that these figures show the order of discrepancy
between the wet and auger or core-tool methods.
The lithologic character and potash content of the samples from :
Salem and Woodstown are comparable to similar features of samples
from other holes, so that there appears to have been no undue enrichment
or impoverishment of the samples from those localities on
account of fines.
The potash was determined throughout this investigation by the
• method outlined by Hicks and Bailey. a
* Hicks_ W. B._ and Bailey t R. K,, Methods o f analysis o f greens_d: U. S. Geol. Survey Bull. fifO, pp.
51-58_ 1918.
NEW JERSEY GEOLOGICAL SURVEY
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