84 NORTH-CAROLINA GEOLOGICAL SURVEY. 



FIG. 2. Soil. 1. Ten feet of 



^^T-T^v?. -. .'/ " yellow sand. 2. Four 



^ ~T feet of greenish clay. 



/_ _ 3. Six feet of shell marl. 



j $ M "'<$ ^3*0 3 4. Four feet of upper 



yrv~ ~ shell marl, containing 



^/ A- lignite and pyrites. 5. 



/**" p~~ Light gray sand, the 



j ^ thickness of which is 



undetermined, as it ex- 

 tends below the water of the Tar river, and does not become 

 visible at any other place in the vicinity. It is probably one 

 of the sand beds which seperate two of the adjacent beds of 

 green sand. But as it has not furnished fossils it cannot be 

 confidently maintained. It is, however, mineralogically, a 

 green sand. 



As all the beds of green sand are never exhibited at one 

 place, and as those which have been spoken of, except the 

 upper, on the Tar river, the thickness of this formation re- 

 mains undetermined. 



Wherever it occurs the country is comparatively low, and 

 at no point yet discovered has the base of the Blackrock mass 

 or lowest been sufficiently elevated to disclose, even approxi- 

 mately, its thickness. 



55. The bluffs which exhibit the tertiary and secondary 

 formations of the eastern counties are mostly upon the south- 

 side of the rivers and ravines. Some of these bluffs are high 

 and commanding, but they are never continuous for long dis- 

 tances. The green sand does not appear in any bluff above 

 Brown's landing. Indeed it disappears about three miles be- 

 low, and though this landing is high and bold, yet I am unable 

 to recognize a bed which can be referred to the upper part 

 of the secondary formation. 



At Brown's landing there are numerous distinct beds. In 

 arrangement they belong to two distinct dates : 1st, the upper 

 which is Miocene, and the lower which is probably Eocene. 

 These beds are exhibited in the following section : 



