Notes on Upper California. 261 



This sandstone is easily worked, and some layers will make a 



good building material. The Sacramento Bute, though distant 



from the settlements, must become more valuable for its stone 



quarries, the material being both durable and of handsome ap- 

 pearance. 



North of the Bay of San Francisco, just east of Sausilito, we 

 again found talcose slate of various colors, and also hills of red 

 and yellow jasper in layers. The layers averaged two inches 

 in thickness, but varied from half an inch to four inches. The 

 talcose slate at one place, approached steatite in character and 

 contained actinolite and nodules of an impure serpentine. Some 

 fragments appearing like fossils were found in these rocks, but 

 they were afterwards lost. 



The region of the Sacramento is remarkable for the great ex- 

 tent of its alluvial flats. Two hundred miles from its mouth 

 they are twenty miles wide, and near Sutter's, we were informed 

 that the width was fifty or sixty miles. In the season of our 

 journey, there was no green grass to be seen, except immediately 

 along the water ; the whole surface was dry, and the grass re- 

 mained as standing hay for the cattle. The raius had not yet 

 begun. They are generally delayed till the latter part of Novem- 

 ber, when they set in for the winter and occur at frequent inter- 

 vals until the middle of March. The country about Sutter's is 

 then mostly under water, and the same is the fate, as we were 

 told, of a large part of the bottom-land of the river. 



The distinct outline of the terrace between the upper and lower 

 prairie is another marked feature of the region. This terrace is 

 mostly about sixty feet high ; but the plain above gradually rises 

 to 150 or 200 feet. Its pebbly features were retained both east 

 and west of the river, and also in the mere traces of it on the 

 Sacramento Bute. This volcano, therefore, since it became ex- 

 tln et, has been washed by waters sixty feet or more above its 

 present base. 



The prevalence of talcose rocks over the route travelled is a 

 striking fact. They abounded in the S hasty mountains, along 

 the head-waters of the Sacramento in that region ; and the peb- 

 bles of the upper prairie indicated their continuation far south. 

 Moreover, we again met with them adjoining the Bay of San 

 Francisco. 



We had found the same rocks on the route farther north, south 

 °f the Umpqua river, and in the Umpqua mountains, an east and 

 w est range, just south of latitude 4:* > ; and in some places they 

 abounded in quartz veins. Their peculiar features in the Ump- 

 qua region, and also in the Shasty mountains about the Sacra- 

 mento waters, as well as in pebbles farther south, led to the fol- 

 lowing statement in my Report, written soon after leaving the 



