-i2J, OBSERVATIONS ON THE GEOLOGY 



and hornblende rock on the other; this bed contains likewise 

 large quantities of blende; detached pieces of gold have been 

 found in the beds of some small streams in North Carolina and 

 other places, apparently in a quart? 'rock. Manganese has been 

 found in New-York, North Carolina, &c. Near the confines 

 of the red sandstone and primitive formations, a white ore of Co- 

 balt has been worked above Middletown on the Connecticut 

 river, and it is said near Morristown in New-Jersey. 



The general nature of metallic repositories in this formation 

 appears to be in beds, disseminated or lying in masses; when 

 in beds (as the magnetic iron ore, and black lead) or disseminated 

 as the iron pyrites, octahedral iron ore, Mohjbdcna, &c. they oc- 

 cur at intervals through the whole range of the formation ; 

 veins to any great extent have not yet been found in this for- 

 mation. 



TRANSITION FORMATION. 



This extensive field of transition rocks, is limited on the S. E. 

 side from a little to the eastward of lake Champlain, to near 

 the river Alabama, by the N. W. boundary prescribed to the 

 primitive rocks; on the N. W. side it touches the S. E. edge 

 of the great secondary formations, in a line,, that passes consi- 

 derably to the westward of the dividing ridge, in Georgia, 

 North Carolina, and part of Virginia, and runs near it in the 

 northern parts of that State, and to the eastward of it in the 

 States of Pennsylvania and New-York. 



This line of demarkation runs between the Alabama and 

 Tombigby rivers, to the westward of the north fork of the Hol- 

 stein river, until it joins the Alleghany mountains near the sul- 

 phur springs, along that dividing ridge to Bedford county in 

 Pennsylvania, and from thence N. E. to the east side of the 

 Catskill mountains on Hudson's river. This line of separation 

 of the transition and secondary formations, is not so regularly 

 and distinctly traced as in the other formations, many large 

 valleys are formed of horizontal secondary limestone, full of 

 shells, while the ridges on each side consist of transition rocks, 

 &c. the two formations interlock, and are mixed in many 



