268 



felspar. It is very hard and durable, and shows no departure 

 from the horizontal position. 



On the top of Arney's Mount, there lies a pretty thick bed of 

 this sandstone; it is largely quarried, dipping very gently to the 

 east. This mount is distinctly visible from Mount Holly, from 

 which there is a rather extensive view. The whole surrounding 

 landscape is extremely flat, the eastern horizon, more especially, 

 being perfectly uniform. Marl occurs, near the surface of the 

 fields, to the southeast; its existence being shown by the water 

 oozing forth along the base of the hill or mount. 



Marl from the farm of Thomas Coats, half a mile southwest 

 of Juliustown, Burlington county. 



Description. — Colour, a very rich verdigris-green ; the washed 

 grains of a darker colour and very small. 

 Compositio7i. — In 100 parts: 



Greensand, ... 77-25 

 Clay, .... 12-75 

 Quartzose sand, - - 10-00 



10000 

 The proportion o{ potash in this marl, deduced from that in the 

 greensand, is 8-8 per cent. 



On the Assiscunk (Barker's branch) a little above Slabtown, 

 marl has recently been opened. It is not good, owing to its con- 

 taining too much of the ordinary impurities. The opening is on 

 the side of the road. It is said to contain fossils. 



Higher up, on the same branch, the marl seems to be consi- 

 derably better, yet it is too siliceous to be ranked as the best 

 kind. 



Burlington. — The nearest place to the river where marl occurs 

 in this vicinity, appears to be at the mill-pond near Wall's mill, 

 one mile south of the town. The pit is not deep, owing to the 

 stratum being wet. It is exposed in a spot where the dam some 

 time since gave way, and its top is very little below the level of 

 the original water course. The top of the stratum is covered by 

 a thin, hard, ferruginous crust. The marl is highly siHceous *and 



