NJDEP - NJGS - First Annual Report of the Geological Survey of the ...

66htindrcd feet at Red Bank, and in the lffevisinks iit is equally ..thick. Whenever this sand has any degree of firmness it isfull of the impressions and casts of shells and ,other fossils.The lower part of this bed is a very friable sand i towards itsupper part a gi'cenish clay is found mixed with the sand, givingto it a good degree of firmness; the rock at Tinton Falls is anoxampte of this. The.uppar part of this bed, from four to sixfeet,'is a l_yer of greenish indurated clay, in some places hardenwagh to be called a rock. It slakes on exposure to theweather. No marl grains are found in it; but i_ is called.marl 'by rainy farmers, and is profitably used as such ....The _econd bed of marl is not so extensively developed in• this part of the country as the first elan; though it' is considerablythicker. Its several layers may be described as fol -_. lows :--1. A layer of marl containing but very f_w fossils; itslower part almost clean grains; clay is mixed With.the grainsin the'upper part, in many localities. The colo_.ofthe grainsin this layer, and indeed in the whole bed, isl green with ashade-of yellow, unlike those in the first bed_ in which thecolor is green, with a shade of black or dark blue. I have notin any place in this part of'the county found the layer workedmore than fourteen.feet, though I believe it to be much thicker.In the pits of Mr. Imlay, on Crosswicks Greek, a short distancebelow lqew Egypt, it is nearly twenty-five feet.2. 2k layer of from ten to fourteen feet of marl, with nu- ".merous shells. A streak in'the uppcr part of tt_is, for two orthree feet, is almost solid with shells of the T erebratula hat.lani;'and another layer near the bottom of it is cqually solidwith shells of the Gryphaea convexa. This layer graduallyloses its marl grains, at the upper part; and runs into3. 2k layer of broken shells with more or less sand.intermixed,and containing scarcely any marl grain_.. The color ofthis marl is yellow or g_ay. In the neighborhood of'Eatontownit is called yellow _narl.. No localities have been visitedin Eastern Monmouth where it has been penetrated more thanfourteen feet, but, near Salem it has been opened for more thantwenty feet.NEW JERSEY GEOLOGICAL SURVEY