Southern section 



hickness 

 in feet 



Lithological characters 



Gravels, sands, clays, peat, 

 soil and ground-ice 



4,000 



600 + 



3,000 + 



Conglomerates, sandstones, 

 and shales 



Interbedded black, gray, and 

 red shales and cherts, in- 

 cluding some calcareous 

 shales 



Limestones and dolomites, 

 dominantly very siliceous 



Remarks 



Probably corresponds to the Laberge 

 series of Yukon. Contains inver- 

 tebrate remains 



Reddish conglomerate may represent 

 former Permo-Carboniferous gla- 

 cial period 



Nation River formation contains 

 abundance of plant remains 



All Carboniferous limestones contain 

 abundance of invertebrate remains 



Unmetamorphosed 



Devonian, Silurian, Ordovician, and 

 Upper and Middle Cambrian beds 

 are fossil iferous. Several hundred 

 feet of unfossiliferous limestones 

 and dolomites, considered to be 

 probably Lower Cambrian, under- 

 lie the beds which contain Middle 

 Cambrian fossils 



Unfossiliferous 



Indurated, but only slightly meta- 

 morphosed 



(?) 



Schistose amphibolites,quartz- 

 ite schists, and mica schists; 

 also includes occasional 

 limestone beds 



Highly metamorphosed 



It is from the members of this group 

 that the placer gold in the Klondike 

 and other important mining dis- 

 tricts in Yukon and Alaska has 

 been derived 



(?) 



Diabases, diorites, andesites 

 and other basic intrusives 



Occur only as occasional dikes and 

 small intrusive masses 



Occur dominantly associated with pre- 

 Cambrian (?) formations. Similar 

 appearing rocks also occur as occa- 

 sional dikes and small intrusive 

 masses cutting Mesozoic sediments 



