GEOLOGY OF THE CONNECTICUT VALLEY DISTRICT. 46$ 



HuRONiAN IN New Hampshire. 



We seem to have in the Connecticut Valley area at least three groups, — the Lisbon, 

 Lyman, and auriferous conglomerate. To this should be added the SwiftWater series, 

 giving a thickness in all of 10,269 f^^t- The volume of these rocks is greater in Coos 

 county. The rocks present a greater similarity to the lower Huronian than those of 

 the Vermont area next the mountains. 



We have yet to consider a great thickness of rocks in the south-eastern part of New 

 Hampshire, consisting of quartzites and mica schists. These seem to us to be related 

 to the Upper Huronian, and may be thus described in the later chapters of this book. 

 These extend into Massachusetts, where are also developed very plainly the felsites of 

 the Lower Huronian. The porphyries of the White Mountain district resemble them, 

 and would be classed as Huronian, I suppose, by Dr. Hunt. 



Huronian of the Atlantic States. 



These same rocks occur at intervals in Connecticut, New Jersey, Pennsylvania, 

 Maryland, Virginia, North Carolina, South Carolina, Georgia, and Alabama. Litho- 

 logically, they agree with the areas mentioned in New England. Observers do not 

 agree in referring them to the Huronian. Geologists are beginning to study them, and 

 therefore will gradually accumulate the means for their final and correct determination. 



Fig- 75- — SECTION OF DISTORTED PEBBLE, LEBANON, ONE HALF NATURAL SIZE. 

 VOL. 11. 59 



