334 Position of the Schistose Strata. 



remaining variations =0, and there will arise equations, which to- 

 gether with the equations of condition, will be sufficient to find the 

 place of the particle at any given time. 



Art. VIII. — All primitive general strata, below granular quartz, are 

 cotemporaneous and schistose ; by Prof. A. Eaton. 



PROF. SILLIMAN. 



I have received letters from several eminent geologists, since you 

 published my Geological Prodromus, all of which, express full satis- 

 faction on the subject of my five carboniferous formations, excepting 

 the primitive. The generous sentiments expressed on this subject, 

 especially by Dr. Morton, who is pleased to call it a reformation in 

 geology, with which he seems to be generally pleased,* induces me 

 to trouble you with a concise statement of facts relative to primitive 

 general strata. 



As consistency may be considered important, I will state, that in 

 the year 1818, 1 wrote an article, which is recorded in the MS. trans- 

 actions of the Troy Lyceum, in which I attempted to prove, that 

 there is not in New England, and probably not in North America, a 

 general stratum of Werner's crystalline granite. This being a ques- 

 tion in " matter of fact," no proof can be urged but that which is de- 

 rived from simple inspection. I have carefully examined most of the 

 territory of the Northern States, and have not been able to discover 

 crystalline granite, granitic hornblende rock, or any other rock, geol- 

 ogically below granular quartz, which is not schistose and carbonifer- 

 ous. The ranges of Spencer, and of Southampton, Mass. and of 

 the Highlands, N. Y. contain the most extensive alternating layers 

 or beds in the Northern States, of what has been called granite 

 by those who call the slaty kind gneiss. In all these locahties I can 

 see nothing more than subordinate strata, or beds, at most. 



Deducting crystalline granite and granitic hornblende rock including 

 porphyry, nothing is left but schistose (slaty,) rocks, containing plum- 

 bago. The primitive slates are the gneiss, (slaty granite,) the mica 

 slate, the hornblende slate, and the talcose slate. Plumbago (carbu- 

 ret of iron,) is found in all these rocks. It is true, that some of 



* Dr. Morton objects to my tertiary formation 



