e22 
LTH, JOOKINALE OF \GHOLO Ge 
Total thickness: 
Upper division - - 2 2 5 : 
Lower division = : pice S é 
Limestone in upper division — - = - - - 
Limestone in lower division - - - - 
UNKAR TERRANE. 
285 
The line of outcrop of the massive magnesian limestone below 
the base of the Chuar terrane extends south, in the face of the 
cliffs, to the north side of Unkar Valley. The section was taken 
from this point south across Unkar Valley and along the walls of 
the inner canyon of the Grand Canyon to a point south of Vish- 
nu’s Temple, where the sandstones and conglomerates rest uncon- 
formably upon the sandstones, schists, etc., of the Vishnu terrane 
the’ ‘gneisses, ‘schists, etc.,-of the Archean.. “The sections 
characterized by a great thickness of reddish-brown sandstones. 
and 
Section from the Summit downward. 
1. a. Massive beds of gray to reddish magnesian limestone, ue 
passing below into a calciferous sandrock - 50-150 
6. Light-gray shaly sandstone - - - - 25 
c. Irregular massive beds of yellowish-brown sandstone, — - 50 
d. Partially cross-bedded, fine-grained, purplish-brown sand- 
stone - - - - = 2 4 50 
e. Reddish-brown sandstone and sandy shales, ripple-marked — 200 
2. Lava beds: 
a. Dark-green basaltic rock with a reddish tinge. Breaks 
into small angular fragments. Upper surface slightly 
irregular - - - - - - 100 
Layers of a reddish-brown sandstone - - - §8-I0 
Solid, compact lava, of a dark-green and reddish tinge, 
with a slight tendency to columnar structure - = 70 
. A layer of sandstone, 1 foot in thickness, caps a massive 
flow of dark-green lava, which breaks up and weathers 
into a fine talus of a lighter green than the rock in place roo 
A flow not unlike d, and capped by a layer of sandstone 
2 feet in thickness - - - - - - 70 
Feet 
475 
