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mediate contiguity to the trap, but among the moderately altered 

 less heated rocks at a little distance, all go to indicate that a con- 

 siderable proportion at least of the metalliferous matter, especially 

 the carbonate, entered the strata in a gaseous or volatile condition, 

 and not that of igneous fusion. This latter was more probably 

 the state in which the metallic copper, such as occurs near New 

 Brunswick, and perhaps some of the less volatile ores of the mine 

 at Griggstown, were injected. 



In reference to the above speculation, it should be recollected 

 that the mass of the trap rock itself is not unfrequently seen to 

 contain both metallic copper, and its ores. 



ECOIVOMIC GEOLOGY OF THE RED SANDSTONE REGION, 



Several subjects have been already discussed, which from their 

 obviously practical importance, are entitled to a place in the eco- 

 nomic geology of the red sandstone region, but it was deemed 

 more expedient to introduce them in immediate connection with 

 the descriptive details which respectively suggested them. 



Thus, in the general description given of the several members 

 of the red shale and sandstone formation, mention was made in 

 every instance of the degree of adaption to useful purposes, such 

 as those of architecture, statuary, paving, &c. of each particular 

 belt of rock examined. A similar allusion was also made to the 

 uses of the calcareous conglomerate, its fitness for burning into 

 lime and for cutting as an ornamental marble being both alluded 

 to. Care was taken to point out the precise position and dimen- 

 sions of any thin beds of limestone found interstratified with the 

 red shale or sandstone, and suggestions offered concerning the 

 most suitable situations in which to seek for good and durable 

 building materials among the altered rocks contiguous to the belts 

 of trap. In like manner, in treating of the copper ores of the 

 formation, whatever was of a practical bearing was fully con- 

 sidered. 



I proceed to mention one or two other subjects of a somewhat 

 desultory nature, not yet adverted to, which appear to come 

 appropriately under this head. 



Peat. — In the meadows and low boggy grounds about Spring- 

 field, and also near Connecticut Farms, occur large quantities of 



