Classes of Detritus. 155 



and ascend it by way of the lake turnpike to the mountain 

 House, and return by way of the clove turnpike, will per- 

 ceive all the objections to such a method. He will see all 

 these varieties with the exception of the conglomerate, pass- 

 ing into each other, in the same continuous horizontal lay- 

 ers. The conglomerate caps the Round Hill south of the 

 Lakes. The most perfect old red sandstone of Werner oc- 

 cupies more than one hundred feet of the base of the moun- 

 tain at the mouth of the clove ; and further north, becomes 

 redwacke, and the most perfect compact gray wacke. Old 

 red sandstone has always been a perplexing subject to me. 

 I was greatly relieved when Conybeare gave the opinions of 

 the geologists of the continent against its admission into the 

 system. I most cordially accept the suggestion that it 

 ought to be struck from the list of general strata, and treated 

 as a variety of the second and third graywackes. The cal- 

 careous grit is a doubtful variety. It may be a bed of corni- 

 tiferous limerock. It appears a mile or two east of the vil- 

 lage of Bern, on the Helderberg. Contents. Grindstone 

 is very perfect in Blenheim in Scoharie county, and was 

 wrought to good advantage during the last war. The Nova 

 Scotia grindstones in our markets often have gray wacke at- 

 tached to them. Fibrous Barytes of Scoharie county, cal- 

 led Scoharrite, is found in a soft variety of this rock. 



IV. Superincumbent Rocks. 



20. Basalt. 



That this class of rocks is of volcanic origin, and that it 

 contains real basalt, I believe is no longer disputed. Every 

 variety, and every imbedded and every disseminated min- 

 eral may be seen at Deerfield and at Mount Holyoke in Mas- 

 sachusetts, — at New Haven in Connecticut, and at the Pali- 

 sadoes on the river Hudson. 



CLASSES OF DETRITUS. 



V. Alluvial Detritus. 



21. Anti Diluvion. 



Subdivisions. Plastic clay is found near Crown Point, 

 on the west side of lake Champlain ; also in Newark, New 

 Jersey, &c. I have seen it in beds in Rensselaer and Albany 

 counties. I should have considered it in all the localities I 



