FAUNAS OF SOUTHEASTERN ALASKA 319 
from the Paleozoic down to the present. The sedimentary beds are 
known to include Tertiary, Mesozoic, and Paleozoic horizons as far 
back as the Silurian. By far the greater part of the sedimentaries 
belong to the Paleozoic, but a considerable thickness of the Mesozoic 
has been found in a few sections. The Mesozoic and Paleozoic beds 
have been folded together in a series of flexures, generally of the 
open fold type after which the Tertiary, now found only in a few 
isolated basins, was deposited upon them. ‘The general direction 
of the strike of the beds is northwesterly and southeasterly, approxi- 
mately parallel to the coast-line. The inclined beds have been cut 
by extensive intrusions. These take courses parallel in a general 
way to the strike of the sedimentaries. The granites, which com- 
prise the bulk of the Coast Range mountains, are the most important 
of these intrusive masses. This granite belt has a width of 40 to 80 
miles, and extends the entire length of the coast strip and beyond it 
both north and south. Granite intrusions, which are usually more 
or less local in character, occur through the islands. The older 
rocks over considerable areas in some parts of the region are buried 
under lavas of Tertiary age. 
The shales and limestone of the sedimentary series have in many 
parts of the region been altered to marbles and schistose rocks by 
the intrusives and deformational agencies. Frequently the alteration 
has been sufficient to destroy all traces of organic remains. 
The general order of the stratigraphic succession is shown in the 
following table: 
PROVISIONAL TABULAR STATEMENT OF STRATIGRAPHY 
7 
Correlation with : 
Age Lithological Character Nomenclature of Ce 
Brooks* ca 
Upper Carboniferous Light-colored limestone ........... 600+ 
Carbon- \ Middle Carboniferous | Argillites, cherts, shales, sandstone, Ketchikan series 
iferous ANGISLEENSLONE ie, a/ejate sis isiojecsisiesarens ? 
Lower Carboniferous | Dark-gray limestones and interbedded 
CHEESES Raines oisemtorere escrenererckeeiciets 1500+ 
Upper Devonian Dark-red volcanic material, limestone 
Devo- ANAVETeeMStONe® yee cieeler <ielsicterciers ? 
nian Middle Devonian Gravglimestone tari cc cis eae es ; Wallenaricertes Histo 
Lower Devonian Grayalimestone rye lc:re cis se cleleteveloieve)« Feoae 
Silurian Gray and buff limestones.......... 3000 
Silurian or pre-Silurian Graywacke, cherts, and some dark Wales series 
LIMESLONES cyte seistetoneioierele/ekeverereroret ? 
* Professional Paper No. 1, U. S. Geological Survey, 1902, pp. 41-45. 
