SEDIMENTARY FORMATIONS. 45 
In the Escalante Desert clay is found mainly along the washes 
and in the low areas bordering them, while the gravels and sands 
are found in the areas between the washes. These coarser materials 
are fairly well rounded and appear to have been sorted. 
The area around Shirts Lake is composed of fine clay with a white 
coating of alkaline carbonates. Around the entrance to Leach Can- 
yon and in Rush Lake Valley east of Iron Springs are rolling hills 
of coarse subangular and rounded gravels, similar to those in the 
Escalante Desert. 
Out wash fans of fine and coarse angular material border all the 
hilly areas and extend out into the desert for half a mile or more. 
Some of these are perfectly fan shaped, but in general the separate 
fans encroach upon one another laterally and form continuous 
outwash aprons along the borders of the hills. They have a rela- 
tively steep slope near the hills and gradually become less steep until 
they merge imperceptibly into the flat deserts. 
These are the latest deposits in the area, and they are still accu- 
mulating. Their thickness is not known. 
