Geology, ^c. of the Connecticut. 75 



er points of resemblance, but I have not been able to find 

 any minute account of the bituminous marlite formation.* 



On the other hand it may be said that no real bituminous 

 marlite occurs along the Connfcticut — provided the grand 

 distinction between this rock and bituminous shale consists, 

 as Professor Cleaveland says, (Mineral, vol. I, p. 191,) in 

 its effervescence with acids; for our rock, certainly that at 

 Sunderland, does not effervesce with acid, unless it contains, 

 as it sometimes does, a slight incrustation of carbonate of 

 lime. Mr. B. does not consider the occurrence of thin 

 beds or veins of coal as opposed to his opinion; but the 

 strata penetrated at Riegelsdorf in Hesse, in order to reach 

 the fish impressions, are totally different from those occur- 

 ring along the Connecticut. They are as follows: " No. 1. 

 Ferruginous clayey mould, from one to two fathoms. No. 

 2. Greyish white limestone, from six to eight fathoms. 

 No. 3. Blue clay, with imbedded fragments of selenite 

 crystals, from eight to ten fathoms. No. 4. Bluish lime- 

 stone, called Rauchivacke, from eight to nine fathoms. No. 

 5. Grey compact gypsum, traversed by ferruginous loam, 

 from seven to eight fathoms. No. 6. Black and grey stink- 

 stone, from one to one and an half fathoms. No. 7. Sand, 

 sometimes loose, sometimes cemented, from one to one and 

 an half fathoms. No. 8. A kind of limestone, called Zech- 

 stcin, of a greyish brown color, and soft above towards the 

 sand, but blacker and more compact below; from three and 

 a quarter to three and an half fathoms. No. 9. A black 

 slaty stratum, containing pyrites and forming the roof of the 

 bituminous marl slate, from eighteen to twenty inches. No. 

 10. Black cupriferous bituminous marl slate, from three to 

 eight inches : this is the principal depository of the icthyo? 



*Extract of a letter from Dr, J. W. Webster :~ 

 "The bituminous marl slate has been one of the most troublesome rocks 

 for years : some have placed it here and some there. From its effervescence 

 with acids we should perhaps more properly put it among- the limestones. 

 Again, from the richness of some specimens of it in copper, they would be 

 classed as copper ores — indeed, we know that it is worked for copper. It 

 occurs in the secondary limestone. Its external characters are very little 

 different from those of bituminous shale of the coal formation ; but from all I 

 have learned of it, I am pretty well satisfied that it is distinct from and above 

 the rocks of the coal formation. You will note one strikin* difference be- 

 tween the two — vegetable impressions are abundant in bituminous shale of 

 the coal field ; but rare in the B. M. slate— it is more abundant in fresh 

 water remains." 



