74 Geology, ^c. of the Connecticut. 



to describe these remains. But in other countries "these 

 fossil remains of fishes are found only in strata of very re- 

 cent origin." (Rees. Cyc. Ait. icthyolites.) 



The great dip of many of these rocks may be thought to 

 afford evidence of their being older than the old red sand- 

 stone, or the independent coal formation. But to show 

 that the dip of rocks is a very equivocal criterion of their 

 age, I need only to refer to the recent work of Greenough 

 on the first principles of geology. And besides, it is no un- 

 common thmg in real coal fields for rocks to be highly in- 

 clined. "This inclination or dip of the (coal) strata is found 

 every where ; in some places it varies very little from the 

 level; in others considerably, even so much as to be nearly 

 in a perpendicular direction;'' (Rees Cyclopedia, Art. 

 Coal,) and still farther, as already hinted, there is rea- 

 son to believe that Mount Toby, the strata of which 

 are almost horizontal, exhibits the original dip of these 

 rocks, and that those cases in which they are more 

 highly inclined are the result of some Plutonian convul- 

 sion. Such irregularity in the dip of coal fields is n» 

 uncommon occurrence. "In some coal fields," says Mr, 

 WiUiams, (Nat. Hist. Min. Kingd. vol. 1, p. 93,) "the stra- 

 ta acquire this horizontal and waving position, and afterward, 

 towards the south-west or toward the north-east, the decliv- 

 ity becomes again so steep as to form an angle of 45°, and 

 in some particular instances to approach still nearer to the 

 vertical position." Upon the whole, I think there are insu- 

 perable objections against referring the rocks of our coal for- 

 mation to grey wacke and grey wacke slate. 



Another opinion already advanced on the subject is more 

 probable. It is that of Mr. Brongniart, who gave it after 

 having seen only the rocks containing the Westfield fish 

 impressions. "This formation," says he, "appears to me 

 to have the strongest resemblance to that of the bituminous 

 marl slates of the copper-m^nes in the country of Mansfield 

 and Hesse." (Journal of Science, vol. 3, |). 220.) The 

 arguments in favor of such an opinion are, I. The great sim- 

 ilarity in the appearance of the German and American rocks 

 on which the fish are found — one species, at least, being 

 the same in both. 2. The occurrences of copper ores, and 

 similar ones too, along with native copper in both rocks. 

 3. The fact that both these varieties of rocks lie immedi- 

 ately above the old red sandstone. Perhaps there are oth- 



