Of the Pond Marl connected with the Limestone, Formation 11. 



At several places in the limestone districts of the Kittatinny 

 valley, we meet with a material which is identical with the Lahe 

 Marl of Europe, occurring around the shores and in the beds of 

 small lakes or ponds, and throughout some of the swampy mea- 

 dows of Sussex and Warren counties. This useful deposit is only 

 found where the water is copiously impregnated with the carbon- 

 ate of lime, and hence it occurs only within, or immediately adja- 

 cent to, extensive limestone strata. It would seem to owe its 

 production, in part, to a chemical precipitation from the water; 

 in part, to the decay of myriads of small testaceous animals, of the 

 species usually found inhabiting calcareous waters, which, secre- 

 ting the carbonate of lime to supply the material of their shells, 

 generation after generation, accumulate it from the water in 

 great abundance. The ponds where this deposit occurs present 

 a rather singular aspect, being fringed with a broad white beach. 



Analysis of a Fresh Water Marl, from a pond four miles from 



JVewton. 



Description. — Light ash colour ; pulverulent. 



Composition. — In 100 parts : 



Carbonate of lime, - - 90*22 



Carbonate of magnesia, - 1'91 



Alumina and peroxide of iron, - 0*61 



Insoluble matter, - - 3-13 



Organic matter, moisture, and loss, 4- 13 



100-00 



In consequence of the peculiar appearance derived from this 

 deposit, two or three of the ponds containing it are called on the 

 map White Ponds; for instance, two ponds west of Pimple Hill, 

 in Sussex ; the more northern one being, however, incorrectly 

 so termed, as the marl is confined to the other. There is also 

 another pond about one mile north of Marksboro', in Warren. 

 These, however, are not the only depositories of this useful sub- 

 stance: I enumerate the following as its localities already ascer- 

 tained : White Pond, near Pimple Hill ; a pond near Brighton ; 

 Stickles Pond, two miles south of Newton ; a pond a mile and a 



8* 



