16 Gold Region of North Carolina. 



idea, when we find them designated by this title. I am, for 

 my own part, becoming very sceptical on the subject of gen- 

 oral strata, and more and more inclined to believe that 

 causes similar perhaps, but not identical ; and limited in 

 their operations, have produced the rock formations of differ- 

 ent countries. If so, it will be vain to look for the different 

 members of an European series on this side of the Atlantic. 

 Every partof the crust of the globe will require a nomencla- 

 ture of its own, similar to that which Professor Eaton has 

 found it necessary to apply to the tract along the grand ca- 

 nal. But when entire kingdoms or continents, are brought 

 under review at once, we shall need a few great divisions, 

 answering somewhat the purpose of the classes and families 

 in botany and zoology, to designate the relations of extensive 

 series of strata to each other, and for answering this purpose 

 I do not see that any preferable to those that have been long 

 in use are likely to be immediately invented. 



If the class shall be retained, it does not appear that there 

 is any other to which these rocks can be so properly referred. 

 1. Because they lie adjacent to a formation itself apparently 

 one of the recent members of the primitive ; than which 

 they are more recent. 2. Because of their mineralogical 

 characters already mentioned. Indeed it is such a forma- 

 tion as this that I would select in preference to any other, to 

 stand as a type of the class. The absence of crystalline 

 mixed rocks, granite, gneiss and mica slate, and the pres- 

 ence of an earthy looking clay slate and of conglomerate al- 

 ternating with it, separate the formation by a wide remove 

 from the primitive, as does the absence of organic remains 

 from the secondary. At the same time, I believe it to be 

 very ancient. If the name of slate shall be thought safer and 

 more appropriate, no considerable objection can be raised. 

 It will be understood hereafter, that it is a slate alternating 

 with conglomerate rocks, and that though the greater part of 

 the strata of which it is composed are slaty, this is by no 

 means true of them all. 



Appearing as it does, on both sides of the old red sand- 

 stone, and with the same characters, at the Grassy Islands in 

 Richmond, and in the southern part of Montgomery, and on 

 the South Carolina line, it will not be doubted that it under- 

 lies that formation, at least in this part of its course, or that 

 after plunging under the sand, it is still the same slate that 

 presents itself on both sides of the Pedee, and in its bed at 



