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with lignite at Bordentovvn landing and below, is the lower bed . 

 of the nnarl formation, and identical with the astringent blue clay 

 bed beneath the true marl or greensand at the base of Nevesink 

 Hills and elsewhere in Monmouth county, and throughout a great 

 portion of the whole marl region. 



SfieUtown. — Howard's marl is near this place on the south side 

 of Crosswick's creek, and presents both the true marl stratum and 

 the astringent clay. The marl is dark, friable, smells of sulphur, 

 and is found to be very efficacious. The overlying lead-coloured 

 clay is somewhat micaceous, and contains a trivial quantity of 

 the greensand, being in all respects like the underlying bed which 

 shows itself at Wall's mill near Burlington. It resembles very 

 much the character of the bed where it caps the marl at Cross- 

 wick's and in the neighbourhood. 



On the road from Shelltown to James S. Lawrence's, which is 

 one mile southwest from Varmington, the same overlying bed is 

 exposed in numerous places in the banks of the meadows. 



All these cases are adduced to show that the true marl over- 

 lies and alternates with the dark astringent clay along nearly the 

 whole northwestern edge of the marl tract, as, for example, near 

 Burlington and Camden. 



Fine exposures of the marl offer themselves to view in the 

 vicinity of the residence of Mr. Lawrence. The soil itself is a 

 brown ferruginous loam, being a portion of a narrow tract of 

 red clayey soil, which extends a considerable distance northeast 

 and southwest, passing by Arneystown, and exibiting wherever 

 it is seen, every evidence, from its texture and the minute water- 

 worn grains of quartz, of its having resulted from the breaking 

 up of an overlying stratum of brown sandstone. In some of 

 Mr. Lawrence's fields, it contains a very sensible quantity of the 

 green granules. The upper part of the marl stratum here differs 

 materially in aspect from the lower. For a thickness of several 

 feet, it is little else than a mass of decomposed shells almost inva- 

 riably in the state of casts, the shells replaced by oxide of iron. 

 An inconsiderable proportion of the green grains is mingled with 

 a yellowish white pasty matter, which is a mixture principally of 

 sulphate and carbonate of lime, derived no doubt from the shells, 

 and which imparts many valuable qualities to the marl. 



The lower stratum is a mass of dark greensand, in which we 



