892  PRE-CAMBRIAN    GEOLOGY   OF   NORTH   AMERICA. 
15  Exploration  of  the  Colorado  River  of  the  West  and  its  tributaries,  explored 
in  1869,  1870,  1871,  and  1872,  by  J.  W.  Powell,  1875,  pp.  291. 
"Report  on  the  geology  of  portions  of  Nevada,  Utah,  California,  and  Arizona, 
examined  in  the  years  1871  and  1872,  by  G.  K.  Gilbert.  Rept.  Geog.  and  Geol. 
Surveys  W.  100th  Mer.,  vol.  3,  Geology,  1875,  pp.  16-187,  with  atlas. 
"Report  on  the  geology  of  route  from  St.  George,  Utah,  to  Gila  River,  Ari- 
zona, by  A.  R.  Marvine.     Idem,  pp.  189-225,  with  atlas  sheets. 
18  Report  on  the  geology  of  the  eastern  portion  of  the  Uinta  Mountains  and  a 
region  of  country  adjacent  thereto,  by  J.  W.  Powell.  U.  S.  Geol.  and  Geog.  Sur- 
vey Terr.,  1876,  218  pp.,  with  atlas. 
19  Pre-Carboniferous  strata  in  the  Grand  Canyon  of  the  Colorado,  Arizona,  by 
Charles  D.  Walcott.    Am.  Jour.  Sci.,  3d  ser.,  vol.  26,  18S3,  pp.  437-442,  484. 
20  Second  contribution  to  the  studies  on  the  Cambrian  faunas  of  North  Amer- 
ica by  C.  I).  Walcott.  Bull.  U.  S.  Geol.  Survey  No.  30,  1886,  369  pp.,  33  pis. 
See  also  The  Cambrian  system  in  the  United  States  and  Canada.  Bull.  Philos. 
Soc.  Washington,  vol.  6,  1884,  pp.  98-102. 
21  Stratigraphic  position  of  the  Olenellus  fauna  in  North  America  and  Europe, 
by  Charles  D.  Walcott.  Am.  Jour.  Sci.,  3d  ser.,  vol.  37,  1S89,  pp.  374-392;  vol. 
38,  1889,  pp.  29^2. 
22  Study  of  a  line  of  displacement  in  the  Grand  Canyon  of  the  Colorado,  in 
northern  Arizona,  by  C.  D.  Walcott.  Bull.  Geol.  Soc.  America,  vol.  1,  1S90, 
pp.  49-64. 
^Algonkian  rocks  of  the  Grand  Canyon  of  the  Colorado,  by  C.  D.  .Walcott. 
Jour.  Geology,  vol.  3,  1895,  pp.  312^330 ;  Fourteenth  Ann.  Rept.  U.  S.  Geol.  Sur- 
vey, pt.  2,  1894,  pp.  497-524. 
24  Manuscript  notes  by  C.  R.  Van  Hise,  1897. 
25  Mining  in  Arizona,  by  Wm.  P.  Blake.  Rept.  Governor  Arizona  to  Sec. 
Interior,  1899,  p.  142. 
26  Notes  on  the  Colorado  district,  by  W.  M.  Davis.  Am.  Jour.  Sci.,  4th  ser., 
vol.  10,  1900,  pp.  251-259. 
27  The  geology  and  vein  phenomena  of  Arizona,  by  T.  B.  Comstock.  Trans. 
Am.  Inst.  Min.  Eng.,  vol.  30,  1900,  pp.  1038-1101. 
28  Some  salient  features  in  the  geology  of  Arizona,  with  evidences  of  shallow 
seas  in  Paleozoic  time,  by  Wm.  P.  Blake.  Am.  Geologist,  vol.  27,  1901,  pp. 
160-167. 
29  The  geology  and  ore  deposits  of  the  Bisbee  quadrangle,  by  F.  L.  Ransome. 
Prof.  Paper  U.  S.  Geol.  Survey  No.  21,  1904;  Geologic  Atlas  U.  S.,  folio  112, 
1904 ;  Bull.  U.  S.  Geol.  Survey  No.  213,  1904.  Geology  of  the  Globe  copper  dis- 
trict, Arizona,  by  F.  L.  Ransome.  Prof.  Paper  U.  S.  Geol.  Survey  No.  12,  1903 ; 
Geologic  Atlas  U.  S.,  folio  111,  1904. 
30  Description  of  the  Bradshaw  Mountains  quadrangle,  by  T.  A.  Jaggar,  jr., 
and  Charles  Palache.     Geologic  Atlas  U.  S.,  folio  126,  1905. 
31  Copper  deposits  at  Clifton,  Ariz.,  by  Waldemar  Lindgren.  Bull.  U.  S.  Geol. 
Survey  No.  213,  1903,  pp.  133-140.  Description  of  the  Clifton  quadrangle,  by 
Waldemar  Lindgren.  Geologic  Atlas  U.  S.,  folio  129,  U.  S.  Geol.  Survey,  1905. 
See  also  The  copper  deposits  of  the  Clifton-Morenci  district,  Arizona,  by  Wal- 
demar Lindgren.    Prof.  Paper  U.  S.  Geol.  Survey  No.  43,  1905. 
32A  comparison  of  some  Paleozoic  and  pre-Cambrian  sections  in  Arizona,  by 
F.  L.  Ransome.  Paper  read  before  Geol.  Soc.  Washington,  October  30,  1907. 
Summarized  in  Science,  new  ser.,  vol.  27,  1908,  pp.  68-69. 
33  On  the  geology  of  the  eastern  Uinta  Mountains,  by  O.  C.  Marsh.  Am.  Jour. 
Sci.,  3d  ser.,  vol.  1,  1871,  pp.  191-198. 
34  Report  of  F.  V.  Hayden.  Prelim.  Rept.  U.  S.  Geol.  Survey  Wyoming,  etc., 
1872,  pp.  1-188. 
