234 The American Geologist. Apni, 1903. 
A geologic map of the territory at the close of this period of 
erosion would probably have displayed an irregular assortment 
of patches of hornblende schist in a ground work of mica 
schist. 
The Paleozoic series was deposited in a comparatively deep 
sea and extended far beyond the Klamath province. Upon its 
uplift at the close of the Carboniferous period, it was deeply 
eroded, so that the earliest Mesozoic formation rests indis- 
criminately upon its earlier and later members. However, there 
is no reason to believe that it was anywhere completely cut 
through and the underlying schists laid bare, except possibly in 
one ver}^ limited area near Lovvden's ranch in Trinity county, 
and even there the phenomenon of contact between the Meso- 
zoic rocks and the schists may be the result of faulting. 
The Clear Creek volcanic series was spread as a sheet of 
varying thickness (probably between limits of 200 and 2000 
feet) over the entire territory south of the Klamath river, ex- 
cept possibly not in the vicinity of the present Scott and Shasta 
valleys. It was then exposed to erosion in the country west 
of the Sacramento river and leveled off, but it seems not to 
have been cut through at any place except probably along the 
northwestern border of the province, in the vicinity of the 
present station of Delta. 
A study of the Bragdon formation has developed a curious 
bit of geologic history of northern California. It was un- 
doubtedly laid down in a sheet gradually thinning to the west- 
ward over the entire region of the Klamath river and west of 
the Sacramento river. It extends only a short distance east of 
the latter river in the vicinity of Delta and Elmore stations 
and in this region contains considerable beds of comparatively 
coarse conglomerate, which wedge out westward by becoming 
thinner and finer in texture. The pebbles are composed chiefly 
of the cherts of the Paleozoic series. 
Now, these Paleozoic chert pebbles could not have been 
derived in any of the territory from the Trinity mountain 
westward as, everywhere in that region, the Clear Creek vol- 
canic series intervenes between the two slate series. Near Delta 
and Elmore, on the Sacramento river, the volcanic series seems 
to be thin and discontinuous from erosion preceding the Brag- 
don epoch, a fact indicated not alone by my own observation 
