588  INDEX    TO    PUBLICATIONS    OF    U.   S.    GEOL.   SURVEY,     [bull.  177. 
Ontario;  corundum  in,  occurrence  of Ann  20,  vi  cont,  pp  570-573 
iron-ore  deposits  and  statistics  of Ann  16,  in,  pp  51-53 
maps,  geologic,  of.     (See  Map,  geologic,  of  Canada,  Ontario. ) 
maps,  topographic,  of.     (See  Map,  topographic,  of  Canada.  Ontario. ) 
rainfall  at  various  points  in WS  24,  p  53 
sections,  geologic,  in.     (See  Section,  geologic,  in  Canada,  Ontario. ) 
(See,  also,  Canada.) 
Onustidse  from  clays  and  marls  of  New  Jersey Mon  xvin,  pp  135-137,  227-228 
Onyx  marble,  characteristics,  preparation,  occurrence,  etc.  .Ann  20,  vi  cont,  pp  286-291 
Oolite,  analysis  of,  from  Pennsylvania,  near  State  College Bull  150,  p  97 
from  Ireland  compared  with  Kentucky  limestone MR  1889-90,  p  395 
from  Pennsylvania,  Center  County,  description  of,  as  one  of  the  educational 
series  (siliceous) Bull  150,  pp  95-97 
thin  section  of,  from  Pennsylvania,  Center  County  (siliceous) .  .Bull  150,  pp  96-97 
Oolitic  limestone,  description  of  the  rock  as  one  of  the  educational  series. .  .Bull  150, 
pp  103-105 
Oolitic  sand,  analysis  of,  from  shore  of  Great  Salt  Lake Bull  27,  p  69 
description  of  the  rock,  as  one  of  the  educational  series Bull  150,  pp  102-103 
of  Lake  Bonneville  and  of  Great  Salt  Lake Mon  i,  p  169 
Oostanaula  River,  Georgia,  flow  of,  measurements  of Ann  18, 
iv,  pp  98-99, 108-109;  Ann  19,  iv,  pp  245-246;  Ann  20,  iv, 
pp  51,  190-191;  Ann  21,  iv,  pp  147-148;  WS  11,  pp  28- 
30;  WS  15,  p  50;  WS  27,  pp  52,  57,  58;  WS  36,  pp  146-147 
Opal,  analysis  of,  from  Colorado,  Buffalo  Peaks Bull  1,  p  15 
occurrence  and  statistics  of MR  1883-84,  pp  760-761 , 
MR  1888,  pp  581-582;  MR  1891,  pp  540,  549-550;  MR  1892, 
pp  776-777;  MR  1893,  pp  682,  698;  Ann  16,  iv,  pp  603,  604, 
605;  Ann  17,  in  cont,  pp  914-916,923;  Ann  18,  v  cont,  pp 
1209-1211, 1217;  Ann  19,  vi  cont,  pp  507-508,  513;  Ann  20, 
vi  cont,  pp  589-590,  599;  Ann  21,  vi  cont,  pp  453,454,461 
(See  Precious  stones.) 
Opeche  formation  of  Black  Hills Ann  21,  iv,  pp  513-514 
Ophir,  California,  gold-silver  veins  of Ann  14,  n,  pp  243-284 
Ophitoid  quartz-augite-diorite  of  Sierra  Nevada Ann  17,  i,  p  640 
Ophiuridse,  Mesozoic,  of  United  States Bull  97,  pp  29-31 
Optical  properties  of  plagioclase  in  pyroxene-andesite Mon  xx,  pp  350-354 
Oquirrh  Mountains,  Utah,  geology  and  economic  resources  of.. Ann  16,  n,  pp 349-369 
Archean  and  Algonkian  rocks  of Bull  86,  p  295 
rocks  of Ann  19,  in,  p  630 
Orange-sand  group  of  the  South.  .Ann  12,  i,  pp  498-501;  Bull  84,  pp  163-167,  329,  332 
Orangeburg  or  Tallahatta  formation,  correlation  of Ann  18,  n,  p  344 
Orangite,  chemical  constitution  of Bull  125,  pp  77-78 
Orbitolite  limestone  of  the  South Bull  84,  p  332 
Orbitoides  limestone  of  Alabama  and  Florida Bull  84,  pp  101-103,  331-332 
Orca  series  of  Alaska Alaska  (2) ,  p  57 
of  Alaska,  character,  correlation,  etc.,  of  the Ann  20,  vn,  pp  404-408 
Ordovician  rocks,  correlation  of Bull  30,  p  44 
.    of  Texas Ann  21,  vn,  p  90 
Ordovician  and  Cambrian  rocks,  relations  of,  in  New  York- Vermont  slate 
belt Ann  19,  in,  pp  290-297 
Ordovician  time,  North  American  land  in Ann  12,  i,  pp  565-566 
Ore,  carbonate.     (See  Carbonate  ore.) 
Ore,  iron.     (See  Iron  ore.) 
