No 9. 



Limestone of Mannington, Salem county, JV. J. 



279 



For the Farmers' Cabinet. 



Limestone of Mannington, Salem county, 



NeAV Jersey. 



On the farm where I reside, the stratum 

 is more than 25 feet thick at the point where 

 I have been digging, having penetrated that 

 far and found no bottom ; 15 feet of which 

 lie above spring water. The top of it lies 

 at various depths, from six inches to five 

 feet below the surface of the earth. 



At Aaron Lippincott's marl-pits, half a 

 mile N. W. from the abovementioned place, 

 the marl is overlaid by a thin vein of the 

 same stratum, not over three or four feet at 

 its greatest thickness; thus proving the dip 

 of the lime and marl towards the south-east, 

 as suggested by Professor Rogers, in his re- 

 port for the year 1640, a part of which for a 

 full description of said lime, I herewith 

 transcribe : 



" Geographical Extent. — The general 

 range of the stratum is from a point a little 

 north-east of Salem, past Woodstown, Mul- 

 lica-hill, Blackwoodtown, Vincentown, and 

 New Egypt, to Prospertown; beyond which, 

 I have been as yet unable to discover a trace 

 of it. But it is not to be inferred that it ex- 

 ists as a stratum of much extent or import- 

 ance, throughout all this long line. It has 

 hitherto been detected at distant points only, 

 and nowhere but in Salem county, does it 

 cover a wide area, or possess more than a 

 very insignificant thickness. It lies along 

 the south-eastern edge of the visible marl 

 tract, and if it dips at all, it is towards the 

 south-east, to underlie the ferruginous sands. 

 At its greatest width, four miles north-east 

 of Salem, it can be traced over a breadth of 

 three-fourths of a mile, its thickness in the 

 same neighbourhood, as proved by a well 

 sunk through it, is as great in one spot as 

 20 feet; though elsewhere in the same vi- 

 cinity, it is not more than six or eight. 



" Composition and aspect. — This rock is 

 usually a soft yellowish, or straw coloured 

 limestone, with a structure varying from 

 subchrystalline to coarsely granular. It is 

 often replete with organic remains, the dis- 

 integrated shells and corals, and other fos- 

 sils, composing a considerable portion of the 

 mass. Much of the rock contains impuri- 

 ties, as sand, clay, and oxide of iron ; and 

 its value as a limestone is very variable. 

 At times it is little else than a sandstone, in 

 which the sand is cemented together by a 

 trace of lime. It occurs with this character 

 in loose rounded masses, resting above the 

 marl at Woodstown. Again it exists as a 

 firm calcareous rock. This is its state in 

 some places near Salem, in Mannington 

 township. In the accompanying analysis, 



the composition of the leading varieties of 

 the rock may be accurately seen. This 

 limestone is nowhere to be found in thick 

 massive strata ; on the other hand, it occurs 

 only in thin horizontal beds, or irregular 

 layers, not more than four or six inches 

 thick, and commonly separated by a thin 

 parting of sand and carbonate of lime, in 

 small grains, to all appearance an inco- 

 hering mixture, of the same materials that 

 form the rock itself. The more calcareous 

 beds, have not unfrequently some resem- 

 blance to some of the thin oolitic strata of 

 England, in consequence chiefly of the 

 granular form of much of the carbonate of 

 lime ; together with the innumerable frag- 

 ments of fossils, which sometimes form al- 

 most half the mass. Unless attentively ob- 

 served, this rock will appear much more 

 sandy than it actually is, owing to some of 

 the carbonate of lime being in the shape of 

 small round yellow grains, like those of 

 sand. Occasionally, especially near the 

 bottom of the stratum, where it adjoins the 

 marl, it contains a sensible proportion of the 

 green grains, sometimes in such abundance 

 as to unfit it tor being burnt into lime, the 

 potash and other ingredients of the green 

 mineral, serving to vitrify it and form a kind 

 of slag. 



" On the farm of David Petit, in the vicinity 

 of Mannington Hill, the limestone displays 

 itself in considerable thickness, the layers 

 of the rock alternating with the calcareous 

 sand as described above. This locality is 

 about a mile and a quarter south-west from 

 the poor-house. 



" The following analysis exhibits the pro- 

 portion of carbonate of lime in the limestone 

 of this neighbourhood. 



Composition 100 parts: 



Carbonate of lime 77.P0 



Carbonate of magnesia, 1.20 



Alum and oxide of iron, 1.80 



Insoluble matter, .. 17.80 



Water, 1.12 



99.7-2 



"This stratum is destined to prove of sig- 

 nal service to all the region adjacent to it; 

 for lime is particularly useful upon lands 

 destitute of calcareous matter, like some of 

 the more sandy tracts of New Jersey. The 

 lime from this rock in Salem, is growing 

 rapidly into use. I would recommend — as 

 promising to prove highly beneficial — the 

 soft, friable, unconcreted parts of the stra- 

 tum, which lie between the solid layers, es- 

 pecially near the bottom of the formation. 

 Being already in a pulverulent state, and 

 composed chiefly of carbonate of lime, with 

 occasionally some of the grains of green 



