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

GLAUCONITE*BEARING AxeD ASSOCIATED FORMATgO_TS. _}
curved surfaces of fracture. Some 95 species of marine fossils have
been recognized, and these are more closely related to the Magothy
species than to those of the underlying Merchantville. The beds
are conformable with those above and below. They represent the
upper part of the "CS"osswicks clay" of Clark and are part of Cook's
"Clay-Marl series." The formation is one of the five formations of
the Matawan group.
EnglishtowT_ sand.--The Englistltown is a conspicuous bed of white
or yellow quartz sand, slightly mieaceous and sparingly glauconitic.
Locally it has been cemented in part by iron oxide into massive
stone. South of Woodbury, in Gloucester County, it contains local
heds of clay that are utilized for making brick. In Monmouth
County and to some extent farther south the Englishtown sand is
an important water-bearing bed. It decreases in thickness from 100
feet near Atlantic Highlands to less than 20 feet in the southern part
of the State. It represents the lower part of the "Hazlet sands"
of Clark and forms part of Cook's "Clay-Marl series." It was formerly
called tile "Columbus sand" and is one of the formations of
5he Matawan group. It is not known to contain fossils.
Marshalltown formatio*l. The Marsha]Ito_m formation ranges
from a black sandy clay to a clayey greensand marl. Locally it
contains many fossils, its characteristic species being in part recurrent
forms from the Merchantville and in part forms that occur in a higher
formation, though absent or inconspicuous in immediately succeeding
beds. The formation is 30 to 35 feet thick. It is a portion of the
"laminated sands" that formed the upper part of the "Clay-Marl
series" of Cook, although in the southwestern part of the State he
referred these beds to the Navesink marl. It was included in Clark's
"Hazlet sands" and is one of the formations of the Matawan group.
In parts of Burlington and Camden counties beds of clay in the Marshalltown
formation are used for the manufacture of brick. The
grcensand of the formation is locally abundant and has been dug fox'
fertilizer.
Wenonah and Mount Laurel sands.--Above the Marshalltown
formation there is a considerable thickness of sand regarding which
there has been some difference of opinion. The terms Wenonah and
Mount Laurel have both been applied to it in whole or in part. The
sand is of rather uniform character, though the lower part (Wenonah)
is generally a fine micaceous sand, and the upper part (Mount Laurel)
is coarser and contains considerable glaucolfite. These sands conrain
considerable water in the southern and central parts of the State,
where they are about 80 feet thick, but toward the northeast they
decrcasc both in thickness and in permeability.
88625°--22--2
NEW JERSEY GEOLOGICAL SURVEY