90 NOKTH-CAROLINA GEOLOGICAL SUEVEY. 



solidation was effected through the agency of soluble silica, 

 it has become a durable mass, and fit for being used in build- 

 ing. It has received the name of stone marl, which I propose 

 to speak of in the first place. 



62. Stone Marl. There are two varieties of stone marl, 

 both of which deserve a special notice. The first consists of 

 shells cemented strongly together, and which are usually from 

 one to one and a half inches across, and very uniform as to 

 size. They are very firmly cemented by silica, which seems 

 to have penetrated the shells more or less. This rock has 

 been employed for a long period for small mill stones. Its 

 valuable qualities consist in being easily wrought when first 

 removed from the quarry, but subsequently becomes very hard 

 and strong. Being made up of shells, it has a rough appear- 

 ance, even when cut evenly ; but this feature constitutes its 

 recommendation. For certain structures it is admirably adap- 

 ted. The enclosure of the cemetery in Newbern is made of 

 this rock, and the noble arches have an imposing effect. The 

 rock is very durable, as appears to be well sustained by the 

 rock itself, where it is exposed, or has been exposed for ages. 

 For rough work it may be used without dressing, but for 

 ornamental, if dressed properly, it is far superior to granite 

 for all structures, where the material should be indestructible. 

 It is adapted to the construction of dwellings, as the walls will 

 continue dry in wet weather. 



This rock underlies Newbern and the adjacent county. It 

 extends fifteen or twenty miles in a northeast and southwest 

 direction. In some places it reaches the surface ; in others 

 it is forty to fifty feet below. I regard it as one of the best 

 building materials in the State. 



The second variety is a granular cream colored rock, and 

 rather destitute of shells. It might be mistaken for an oolite. 

 The grain is uniform, and like the preceding is soft, when first 

 taken from the quarry, but becomes hard as any rock after an 

 exposure to the air for a few months. This rock is not dis- 

 posed to disintegrate, and hence in this respect is superior to 



granite. 



This granular variety occurs in "Wayne county. The rocks 



