SOME, (CISA AC ISOS: ie IDS) OUe IVOGIUNS JrsDVIEIN WOAIEILI ING 
OREGON: 
CONTENTS: 
Introduction. 
Geography. 
Pre-Cretaceous. 
Cretaceous. 
Transgression. 
Stratigraphy of the Cretaceous. 
Ashland locality. 
Griffin Creek. 
*49-Mines. 
Structure. 
Sections. 
Faults. 
Elevation. 
Notes on the fossils. 
INTRODUCTION. 
In the summer of 1894 a large part of the months of June 
and July was spent by the writer in studying the Cretaceous beds 
of southern Oregon.t* The deposits most thoroughly worked lie 
in the portion of Rogue River Valley west and southwest of 
Jacksonville, extending to the summit of the Siskiyous where 
these are crossed by the Oregon and California Railway. This 
region is more strictly an arm of what is commonly known as 
Rogue River Valley, and may, for the purpose of the present 
paper, better be called the Bear Creek Valley. Its general 
direction is northwest and southeast. It les between the high 
granitic ridges of the Siskiyous on the southwest and the south- 
ern portion of the Cascade range on the east. The upper por- 
tion of the valley, near where the railway crosses the summit, is 
not far from the point where the Siskiyous join the Cascades. 
From this point the valley widens gracefully into the deep basin, 
= The data obtained were studied at the laboratory of Stanford University, where 
much of the material collected is preserved. 
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