INDEX. 
493 
Page. 
Colorado,  copper  in,  gold  and  silver  in 95 
copper  in,  occurrence  of 26-27, 34 
production  of 93, 107 
faulting  in 36 
geology  of 226-228,  402 
gold  and  silver  in 25-40 
discovery  of 37 
gravels  in 31 
gypsum  deposits  of 401-403 
location  of,  map  showing 401 
sections  of 402-403 
hot  springs  in 38 
hydraulicking  in 31, 33 
iron  ores  of 196-198 
minerals  in 26,  37 
ores  of,  description  of 26-27, 37-40 
placers  of 31-32, 36 
porphyry  of,  gold  in 32 
railroad  construction  in 33 
rocks  of 25-26, 29-32,  34-36, 227-228 
Routt  County,  coal  field  of 226-239 
sections  in 32-33, 227, 229-231, 233, 236, 242 
structure  of 226-227 
telluride  ores  in 26-27 
veins  in 32-33, 38-39 
volcanic  ash  in 476-478 
work  in 17-18, 22, 204 
Colorado  group ,  coal  in 285, 31 1 
oil  in 314 
Colorado  Plateau,  rocks  of 28-29 
Colton,  Utah,  ozokerite  near 369, 370-371 
Columbia  River,  Oreg.,  sands  from  mouth 
of,  investigation  of 159-160 
Columbus,  Ky.,  clays  at 420 
analysis  of 421 
Colville,  Wash.,  marble  at 382 
analysis  of 382 
Conglomerates,  occurrence  of 36 
Conjecture  mine,  Idaho,  ores  of 46-47 
Connellviile  mine,  Utah,  coal  of 300 
Consolidated  Coal  Co.,  N.  Dak.,  lignite  of, 
analysis  of 323 
Copper,  bibliography  of 97, 144-145 
imports  and  exports  of 94 
mines  of,  location  of,  map  showing 94 
papers  on 93-145 
prices  of,  figure  showing 94 
production  of 93-94, 203 
figure  showing '   94 
Copper  deposits,  classification  of 96-97 
description  of 93-145 
investigation  of 17 
occurrence  of 34, 
37, 39,  47-48, 55-73, 79, 81-86, 308-309 
See  also  Arizona;  California;  Colorado; 
Georgia;  Idaho;  Michigan;  Mon- 
tana; North  Carolina;  Nevada; 
New  Mexico;  Oregon;  Tennessee; 
Utah;  Virginia;  Washington; 
Wyoming;  Cashin  mine;  St.  Joe 
River  basin;  Luray. 
Copper  ores,  character  of 97-124 
classes  of 9G 
gold  and  silver  in 94-95 
Copper  Queen  mine,  Ariz.,  production  of. . .        99 
Copper  Range,  Mich.,  ores  of 110 
Copperopolis  belt,  Cal.,  ores  of 106 
Bull.  285—06 32 
Page. 
Court,  J.  G.,  ore  discovered  by 58 
Cordingly  Canyon,  Utah,  coal  of 296 
Correlation  of  oil  sands,  table  of 3G3 
Cosgriff's  pit,  Wyo.,  bentonite  of 447 
bentonite  of,  analysis  of 446 
Cottonwood  Canyon,  Utah,  coal  of 301 
Cottonwood  Creek,  Wyo.,  coal  on 31 1-312 
coal  on,  section  of 312 
Covington,  Va.,  iron  ores  at 186-187 
section  at 1 86 
Craig  district,  Colo.,  coal  of 235 
Crain,  II.  E.,  work  of 100 
Crandall  Canyon,  coal  of 298 
Crawford  tract,  Colo.,  coal  of 237-238 
coal  of,  analyses  of 237-238 
Creston  quartzite,  occurrence  and  character 
of 43,49 
Cretaceous  rocks,  clays    in,  occurrence  and 
character  of 418-419 
coal  in 280 
occurrence  of 41 
Crider,  A.  F.,  on  clays  of  western  Kentucky 
and  Tennessee 417-427 
work  of 417 
Cripple  Creek,  Va.,  iron  ores  of.    See  New 
River,  Cripple  Creek  district. 
Crooked  Creek,  Ala.,  coal  near,  section  of..      216 
Cross,  Whitman,  work  in  charge  of 125 
Crudup,  Ala.,  iron  ores  at 177 
iron  ores  at,  analysis  of 177 
Cryolite,  bibliography  of 171 
Crystal  City,  Mo.,  glass  making  at 460 
glass  sand  at  and  near 468-469 
analysis  of 456-457 
Cumberland  Gap  district, Tenn.-Va., cement 
resources  of 374-376 
limestone  in,  analyses  of 375 
section  in 374 
shale  in,  analyses  of 375-376 
work  in 23 
Cuprite,  Nev.,  ore  deposits  of 59-61 
Cush  Creek  coal  field,  Pa.    See  Glen  Camp- 
bell field. 
I>. 
Dakota  Lignite  and   Brick  Co.,   N.   Dak., 
lignite  of,  analysis  of 323 
Dakota  formation,  occurrence  and  charac- 
ter of 30,125 
Dale,  T.  N.,on  new  variety  of  Maine  slate.  449-450 
work  of 24,  449 
Danleyton,  Ky.,  coal  at,  section  of 206 
Darton,    N.    II.,    on   mineral    resources   of 
Bighorn  Mountain  region.  . ..  303-310 
Dawson,  E.  M.,  jr.,  work  of 21 
Day,  D.  T.,  and  Richards,  R.  II.,  on  black 
sands 150-164 
De  Smet  formation,  coal  in 306-307 
De  Wolf,.  F.  W.,  work  of 204,362 
Deadman  Canyon,  Utah,  coal  of 296 
Deadwood  formation,  gold  in 307 
Decillion  mine,  Nev.,  description  of 71 
Deep  Creek  Lake,  Wash.,  iron  ores  near 195 
Deer  Creek,  N.  Dak.,  lignite  near,  seetion  of.      325 
Dennis  region,  Mass.,  clays  of 439 
Devonian  rocks,  iron  ore  in 180 
