U. S. GEOLOGICAL SURVEY 
BULLETIN NO. 371 PL. Ill 
AGE. FOKMATIO 
Thickness, 
IN FEET. 
Description. 
Mostly Wasatch. 
-Unconformity 
Varicolored shales, buff sandstone, local basal 
conglomerate, and subordinate thin bedsof lime- 
stone containing fresh-water shells. Different 
sections showdiverse stratigraphy. These rocks 
form the highest cliffs and (-(institute the floor of 
the Uinta Basin. 
Alternating beds of buff sandstone and drab shale 
with workable beds of coal in the lower part of 
the formation. Fossils occur at several horizons, 
including leaves, invertebrates, and occasional 
hones. These are the cliff-making rocks of the 
Book Cliffs. 
Mancos shall 
Dakota sandstone. 
— Unconformity — 
Fissile black to drab clay shale and local lenses of 
limestone. Thin beds of buff sandstone at the top 
mark the transition to the overlying formation. 
Marine shells are abundant at two general hori- 
zons in the upper and lower parts of the forma- 
tion. This shale underlies the broad lowland 
at the base of the Book Cliffs. 
Buff sandstone, often conglomeratic. 
Red. green, and purple shales with lenses and thin 
bedsof bull' saiidstoiiecontaining dinosaur bonee 
GENERALIZED COLUMNAR SECTION OF THE ROCKS OF THE BOOK CLIFFS COAL FIELD. 
