Geology of Pvyet Sound Basin. — Kirnhall. 307 
velopraent, according to Mr. Bailey Willis, is midistinguish- 
able from the Puget group.* 
Isolated survivals of the coal series at considerable alti- 
tudes in the western foot hills of Mt. Rainer continue at 
intervals from the coal field of Green and Cedar rivers as far 
south at least as the head waters of the Cowlitz, with more 
or less intimate environment of eruptives, the same as in the 
Cascade foot hills to the north, and with maintenance of the 
general quality of coal as distinguished at Wilkeson. These 
survivals constitute an elevated belt, according to Mr. Willis, 
from one to six miles in breadth, separated by a much higher 
eruptive range from the very extensive tract of lignite-bear- 
ing strata naturally exposed along the lower waters of the 
Nisqually and Cowlitz, and also in the upper waters of the 
Chehalis, well up in the southern foot hills of the Olympics. 
The occurrence of lignite on tire opposite slope of the same 
range has already been mentioned, but on neither slope have 
any steps been taken to precisely define its distribution. The 
carbonaceous products in elevated localities, especially in the 
neighborhood of intrusive rocks, are of the more bituminous 
types of lignite, even approaching in places semi-bituminous 
and anthracitic products. In the less disrupted and less 
folded parts of the series toward the sound axis, and within 
its southerly prolongation, the products are comparativelj'^ 
unaltered, or essentially brown coals of indifferent type. No 
differentiation of such gently undulating parts of the series 
from the Puget group, as distinguished farther to the north, 
has yet been recognized. South of the Chehalis only such 
shallow members of the carbonaceous sandstone series as 
have been penetrated by moderate river erosion have yet been 
brought to light, so that little has been revealed as to its sec- 
tional range. 
Whatever the taxonomic relations of the carbonaceous 
formation at the mouth of the Fraser, no substantial grounds 
are apparent for widely distinguishing apart the general hori- 
zon of the coal series of Bellingham bay, where it was first 
* Vid. Geol. Railway Guide 1890. p. 265. Correlation of coalbear- 
ing strata in the basin of the ux)per Columbia with the Neocene, as by 
Mr. RusPf^ll (189.3; is stated to rest on evidence of leaf imprepsions. 
This remark, it is presumed, refers to early determinations of impres- 
sions found in certain collections already mentioned from the sound 
basin. Bull. U. S. G. S., 189:5, p. 20. 
