292 



The proportion of potash which this marl contains, by direct 

 analysis, is 9-5 per cent. 



Marl from the farm of Woodnut Petit, near Mannington 

 Hill, Salem county. 



Description. — Colour, light yellowish-green ; washed granules 

 dark-green, of medium size. 

 Composition. — In 100 parts: 



Greensand, ... 77-15 

 Clay, ... - 18-35 

 Quartzose sand, - - 4-50 



« 



10000 

 The proportion oi potash in this marl, deduced from that in the 

 greensand, is 8*8 per cent. 



I have thus brought my observations as far to the southwest 

 as any traces of the marl stratum show themselves. The chief 

 object of the numerous details here given is to furnish hints, 

 possibly of some future advantage to the several neighbourhoods 

 specified, and moreover to awaken in each district a spirit of 

 inquiry and experiment, which, should it ever be aroused to vi- 

 gorous activity, must sooner or later be productive of the greatest 

 benefits to the whole marl region, and to the Slate at large. 



CHAPTER II. 



DISTRICT SOUTHEAST OF THE MARL TRACT. 



The physical features of the extensive sandy plain which 

 reaches from the southeastern margin of the greensand, almost 

 to the seacoast, have already been described. It only remains 

 for me to detail a few points in its geology of a chiefly practical 

 bearing. These are some small tracts of tertiary calcareous marl, 

 its numerous deposits of bog iron ore, and the extensive stratum 

 o{ \\\\\iQ glass-malier''s sand, with which its surface is covered. 



