86 G. K. Gilbert—The Colorado Plateau Province. 
First, that there are no anticlinals and no synclinals, but 
only monoclinals and faults; . 
Second, that the throws of the displacements are not all on 
the same side; 
u. In some the block has been lifted more on one side that 
on the other, so as to acquire a dip; in other cases there are 2, 
number of blocks of different elevation in the same range; 1 
yet other, the blocks are somewhat curved. 
I shall not attempt to enumerate the variations of the typ 
which arise in these several ways. The purpose of the illustra 
uals of geology 
di 
When the splacements of the regi ked 
nies ‘ gion have all been worket 
out, 1t will be possible to construct a model which shall exhibit 
é least one hundred and fifty thousand square — 
— of the earth’s crust, showing the neice and position 7 
~ of the blocks which compose it; and I conceive that such 
