The Shoshone Island. 91 



Recent deposits of this material are found 

 in both sea and fresh water, sometimes in 

 swamps and in peat bogs. Extensive beds of 

 it are found fossil along the upper DesChutes 

 river in old lake bed deposits. A fine bed of it 

 may be found in a sloping bank of Three 

 Mile creek, two or three miles south of The 

 Dalles, 



Geologically older than these deposits just 

 mentioned is a bed of this rock found in the 

 upper John Day valley, underlying the Plio- 

 cene rocks of that region and tilted at quite 

 an angle, while the Pliocene is nearly horizon- 

 tal, a fact that would at once place it among 

 the early Tertiaries. 



An interesting outcrop of this may be seen 

 at the old Belshaw ranch on the Canyon City 

 road in the John Day valley. The rock itself 

 floats on water, is white as chalk, and contains, 

 besides its microscopic plant cells, some finely 

 preserved leaf prints of oak, maple and other 

 forest trees. Like chalk this rock is made up 

 of the dead shells of a one-celled organism, 

 but the chalk is the cell covering of an ani- 



