94 
INDEX. 
Page. 
Colorado River, flow of 74 
history of. See Historical geology. 
irrigable lands on 74-75 
rapids in 30 
view of 40 
Colorado Valley, description of. . 29-30, 34-37, 37-48 
gravel in, view of 40 
" relation of, to Detrital-Sacramento Valley 01 
sections across, gfiures showing 22 
tributary valleys of, description of 30-34, 37 
Cooley , , on river erosion 66 
Correlations, data on 68-74 
Cottonwood Cliffs, description of 13, 20 
location of 13, 19-20 
rocks of 20 
Cottonwood Valley, description of 37-38 
rocks in 26, 38 
Crustal movements, period of 58-59 
Cunningham 1 'ass, rocks in -•. 28 
D. 
Dartoii, N. H., work in charge of 9 
Date Creek, course of 22 
geology near 55 
Davis, W. M., on Plateau region 72 
Deluge Wash, detritus at mouth of, view of. 22 
gravels in 51 
section at, figure showing 51 
Denudation, period of 57 
Desert region, location and character of 11-12 
Detrital-Sacramento Valley, description of. . 52-53, 
60-61 
filling in 53, 63-64 
formation of 45, 60-61 
relation of, to Colorado Valley 61 
sections of, plate showing 24 
view in 52 
Diastrophism, progress of 10, 58-59 
Dike rocks, occurrence and character of 90-91 
Dome Rock Mountains, location of 29 
Drake, well at 78, 80 
well at, record of 79 
E. 
Eagle Rock, channels near 39 
channels near, figure showing 38 
Effusive rocks, occurrence and character of. . 82-90 
Erosion, forms of, view of 24 
period of 58 
Evaporation, data on 74 
F. 
Flood plains, formation of 66-67 
Flow breccia, description of 83-84 
Formations, description of 14-18 
distribution of 10 
Fortification Hill, rocks of 37 
Fossils, occurrence and character of 15, 16 
(i. 
Geography, description of 11-14 
Geologic history, outline of 56-74 
resume of 67 
Geologic sections, plate showing 24 
Geology, description of 14-18 
Page. 
Gilbert, G. K., on erosion 57 
on Lake Bonneville beds 68-71 
on Grand Wash fault 31 
on Redwall limestone 16 
Gilbert and Marvine, on region 11 
Girty, G. H., fossils determined by 16, 17 
Gold Basin, well at 78 
Gold Roads, rocks at 26 
Grand Canyon, cutting of 62 
description of 30 
mouth of, section of, figure showing 31 
view at 30 
rocks of 30 
section of, plate showing 24 
travertine in 30 
Grand Wash Cliffs, description of 13, 19, 31 
location of 13, 18 
rocks of 19 
Grand Wash fault, description of 31-32, 50 
formation of 59 
Granite Wash Hills, description of 28 
location of 28 
Grand Wash Trough, canyon of, wall of, view 
of 30 
description of 30-33 
formation of 59 
geologic history in 33 
rocks in 31 , 32-33 
sections of, plate showing 24 
Granite, occurrence and character of 14-15, 
19-27,51,81-82 
Great Colorado Valley, description of 45, 47 
map of 46 
rocks of 47 
silt in 47 
Greggs breccia, deposition of 59-60 
description of 17, 32 
Greggs Ferry, section near, figure showing. . . 34 
Gypsum, occurrence of 36 
H. 
Hackberry, well at 78, 80 
Hamlin, Homer, on Cocopah dam site 48 
on Colorado River irrigation 75 
Harcuvar Mountains, description of 14, 28 
location of 14, 28 
rocks of 28 
section of, plate showing 24 
Harquahala Mountains, description of 14, 28 
location of 14, 28 
rocks of 28 
section of, plate showing 24 
Harrisburg, rocks near 28 
well near 80 
Haviland, well at 79, 80 
well at, record of 79 
Hematite, occurrence of 29 
Highlands, geographic and geologic details of. 18-29 
History, geologic, outline of 56-74 
resume of 67 
Hualpai Mountains, description of 13, 24 
formation of 61 
location of 13, 24 
rocks of 25 
sections of, figures showing 24 
structure of 25 
view in 52 
