JURASSIC FLORA OF DOUGLAS COUNTY, ORECl. 49 



Buck Mountain, tho strike varies considerably. It is not stated how 

 much of the mountain is composed of these Ix'ds, hut the higliest of them 

 occur about 300 feet l)elow its top, where they are overlain by a heavy 

 conglomerate of Lower Cretaceous age. Here the fii'st discovery- of the 

 fossils was made by Mr. Todd. Plants were found in the strata in Buck 

 Mountain at least 30 feet below Todd's original locality. 



On Thompson Creek the plant beds are flanked to the east by a 

 thick mass of sandstones and conglomerates of unknown age, which dip 

 under them. Still further east this last-named group is bounded by a 

 belt of igneous rocks, to the east of which lies a l)elt of sandstones which 

 contains invertebrate fossils of Lower Cretaceous age. These sandstones 

 dip westward, as if lying imder the plant l)eds. They may be dropped in 

 this position l)y a dislocation. The sandstones are bounded on the east 

 by a great mass of serpentine. At the western end of the section, on 

 Thompson Creek, the Lower Cretaceous conglomerate, which overlies the 

 plant beds in the top of Buck Mountain, is absent, it having been removed 

 by erosion before the deposition of the Eocene. This last immediately 

 overlies the plant beds. 



Professor Ward states that on Thompson Creek, the first of the group 

 now in cjuestion that was found to contain plant fossils, is a slate that 

 lies to the west of the sandstone and conglomerate mass of unknown age 

 above mentioned. This occurs nearly due north of Buck Mountain. This 

 is stratigraphically the lowest plant bed on the creek. The stratum with 

 plants is only a few feet thick. This for distinction I shall call plant bed 

 No. L It is overlain by conglomerates 50 feet or more in thickness. 

 The conglomerate has overlying it another bed of slate similar in general 

 appearance to the first. This also contains plants and yielded much the 

 larger part of the specimens collected there. It ma}' l)e called plant bed 

 No. 2. In the vertical section it is about 75 feet above bed No. L This 

 seems to be the highest Ijed geologically from which collections were made 

 on Thompson Creek. The upper slate is overlain a short distance to the 

 west by Eocene beds. 



Mr. Diller and Mr. Brown followed the group containing the plants 

 southward into Buck Mountain, proving the identity of the plant beds of 

 that moimtain with those on Thompson Creek. From the moinitain the 

 strata were followed southward to the vicinity of Nichols station, where 



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