162 Miscellaneous Notices, ^c. 



sen they will on account of their number be highly useful. I 

 do not perceive that American geologists are turning their at- 

 tention to the masses or formations which compose the primi- 

 tive class, and our country is the best for that purpose that has 

 been hitherto explored. From the resultof observations made 

 in the United States, from the upper part of New York to 

 Georgia, I have assigned no more than four masses or forma- 

 tions belonging to that class. They are the granite, gneiss, si- 

 enite, (includhig protogine or talcous gneiss) and clay slate. 

 All the other rocks were subordinate to one or more of these 

 four masses. These masses are arranged in parallel lines, 

 the first being nearest the ocean, the last farthest removed 

 from it; the geographic arrangement, as enumerated, ac- 

 cording with their supposed geological one. The granite 

 commences in Virginia, and runs through all the States 

 south of it. It contains within its range the shining clay slate 

 or schiste luisante of Brongniart, and the compact mass of 

 the same rock, which furnishes the gold of North Carolina. 

 The limestone of New York, Philadelphia and Baltimore, I 

 found was not a continuous mass ; though its direction is 

 uniform. I have walked round it in many places in North 

 Carolina, and in <South Carolina. It is generally encased in 

 talcous slate, or mica slate, and both are encompassed or en- 

 cased by the gneiss, being themselves also subordinates of 

 this great mass. Sienite with quartz, forms the rock of the 

 third range. This rock I have traced from the highlands 

 of New York, (North river,) to Pennsylvania ; there it begins 

 to be mixed with talc, which increases in going south, and 

 finally in Virginia and North Carolina, near the Georgia and 

 Tennessee boundaries, it is a well characterized protogine 

 o-neiss, resembling Jurine granite of that name; but with the 

 structure of gneiss. To this rock, alternating at the point of 

 contact, is referred the primitive clay slate, which alternates al- 

 so with the transition slate, which in the southern states, is per- 

 fectly analogous with the rocks containing the anthracite of 

 P».hode Island. I long ago intended to communicate to the 

 American Journal a paper upon the classification of the prim- 

 itive rocks, as well as the succeeding ones; but I found 

 some facts which tended to a more simple classification than 

 the one mentioned, and whilst seeking for others to direct 

 me to the point where to stop, I found myself preparing 

 to sail for Mexico. I have about one hundred observations 

 of the dip of the gneiss of the southern states, all which 

 are towards the east ; consequently this rock underlies the 



