356 The American Geologist. Ju"e, i904. 
formation occur along- a north-south belt a few miles west of 
Redding. These shales are interstratified with the upper por- 
tion of the volcanic, material and I consider them Pit in age. 
They are quite unlike the Bragdon formation occurring ten 
miles farther west. I am certain that the Bragdon formation is 
not the equivalent of the Pit.* 
It is out of the question that the Hosselkus limestone rest- 
ing conformably on the Pit chales is the equivalent of the ab- 
solutely non-hmestone-bearing Bragdon series ; and the con- 
formably overlying Monotis-bearing shales are totally unlike 
the conglomerate-bearing Bragdon series. That closes the 
Triassic and we have found no place in it for the Bragdon 
formation. 
The first Jurassic formation on Squaw creek is a great mass 
of shales which appeared to me to be conformable to the Tri- 
assic strata. This Bend forniation is quite unlike the Bragdon 
series, not only in the character of the shales, but also in the 
absence of much conglomerate or sandstone and in the presence 
of coarse tnfif beds and much intruded igneous material. The 
succeeding formation, the Morrison sandstone, contains con- 
glomerates HI rather heavy beds, but there is little resemblance 
between them and the Bragdon conglomerates. The former 
formation is softer, lighter in color, more sandy and contains 
no shales which might be confounded with the Bragdon shales. 
Moreover, it is well supplied with intruded igneous material 
such as never is seen in the Bragdon areas. All the Devonian, 
Carboniferous, Triassic and Jurassic rocks up to the top of the 
Morrison formation, where^-er they are developed in north- 
western California, are abundantly supplied with dikc>= 
greenish rocks and the Bragdon is the only known pre-Cre- 
taceous formation in which they do not occur. Evidently the 
vulcanism continued until after the deposition of the Morrison 
sandstone, but ceased before the Bragdon sediments began to 
accumulate. Surely some significance must attach to this. 
The Bragdon formation is older than the Horsetown and 
Chico. It was folded, intruded by granite, deeply eroded and 
the Horsetown deposited unconformably on it and on the gran- 
ite. It is quite unlike the Knoxville shales. It is older than 
• It may be objected to my metViod of reasoning that any formation can be 
expected to change character in distance, but the distances here involved are 
too short. 
