AMERICAN GEOLOGY DECADE OF 1830—1839. 299 



line of contact between different formations. tw The deep bed of the 

 Hudson across the Highlands, however, may, without extravagance, 

 be ascribed to the fusion by volcanic heat which produced the basaltic 

 Palisades below the chasm. The same hypothesis may be well applied 

 to the channel of the Connecticut River north of the northern line of 

 Massachusetts, whence the volcanic lava flowed which now covers a 

 series of basaltic prominences which form the northern part of Long- 

 Island Sound. " And this as Late as L830-1832! Yet the Rensselaer 

 school, where Eaton was teaching, was, and continued to be for many 

 years, the chief training school for American geologists. Fortunately, 

 his students were taught to think and not to blindly follow. 



Eaton claimed at this date (1832) to have devoted more time and 

 labor to American geology than any other individual, and credits Gen. 

 Stephen Van Rensselaer with having furnished the necessary facilities. 

 ''I made the first attempt,* 1 he wrote, ''at a systematic arrangement 

 of American rock strata/' The various discoveries which he thought 

 might be claimed as having been made under the auspices above noted 

 are as follows: 



(1) That each of the classes of rocks always begins with a Carbonif- 

 erous slate and terminates with calcareous rocks, having a middle 

 formation of quartzose. 



(2) The discovery of ferriferous stratum containing argillaceous 

 iron ores, and which extends unbroken from near Utica to the extreme 

 termination of Lake Ontario, in Upper Canada. 



(3) That the bog-ore properly belongs to the Tertiary formation. 

 (•i) That talcose slate is the grand repository of hematitic iron ore, 



peroxide of manganese, and native gold. 



(5) That the Corniferous lime rock is the true carboniferous only. 



(6) That crystalline granite is not entitled to a place among general 

 strata, as it is never found other than as a bed or vein. 



(7) That granular quartz rock and granular lime rock are entitled to 

 a place among general strata. 



(8) That all primitive rocks, excepting granular quartz and lime 

 rocks, are contemporaneous. 



('.)) That there is evidence of a diluvian stratum having been depos- 

 ited near the termination of the deluge, which formed an universal 

 mantle about the earth. 



In discussing the "regular" deposits, he wrote: 



They exhibit grounds for conjecture, if not absolute demonstration, that the 

 surface of the earth had undergone five general modifications which no animals 

 survived. Four of these modifications were followed by as many new creations of 

 animals, two new creations succeeding the final depositions of all regular strata. In 

 the whole there appeared to have been five creations of animals at least, and per- 

 haps ten, since the primitive mass of earth was formed. 



