FOR    THE    YEARS    1901-1905,    INCLUSIVE.  277 
Puring-ton  (Chester  Welis). 
1.  Economic  geology.     La  Plata  folio,  Colo. 
U.  S.  Geol.  Sun-.,  Geol.  Atlas  of  U.  8.,  folio  no.  60,  1899.     . 
Describes  the  vein  systems,  the  occurrence  of  gold  and  silver  ores,  the  placer  deposits,  and 
the  occurrence  of  coal. 
2.  The  Contact,  Nevada,  quaquaversal. 
Colo.  Sci.  Soc,  Proc,  vol.  7,  pp.  127-138,  5  rigs.,  1903. 
Describes  physiographic  features  and  the  geologic  structure  of  the  region  and  the  occur- 
rence of  ore  bodies. 
3.  The  Camp  Bird  mine,  Ouray,  Colorado,  and  the  mining  and  milling  of  the  ore. 
Am.  Inst.  Mg.  Engrs.,  Trans.,  vol.  33,  pp.  499-528,  10  figs.,  1903. 
Describes  the  general  geology  of  the  region,  the  system  of  veins  and  fissures,  the  occurrence 
of  the  ores,  principally  galena,  and  discusses  the  origin  of  the  ore  deposits. 
4.  Secondary  enrichment. 
Eng.  &  Mg.  Jour.,  vol.  75.  pp.  472-473,  1903. 
5.  The  geological  structure  of  the  Camp  Bird  vein  [Colorado]. 
Eng.  &  Mg.  Jour.,  vol.  75,  pp.  820-822,  2  figs.,  1903. 
Describes  the  veins  and  fissures  and  their  rock  contents,  and  the  character  and  occurrence  of 
the  gold  and  silver  ores. 
6.  Observations  on  gold  deposits. 
Eng.  &  Mg.  Jour.,  vol.  75,  pp.  854-855,  893-894,  929-931,  1903. 
Discusses  occurrence  and  origin  of  gold  deposits  in  various  regions  of  the  world. 
7.  Geology  of  the  Virginius  mine  [Colorado] . 
Eng.  &  Mg.  Jour.,  vol.  76,  p.  458,  1903. 
Discusses  the  occurrence  and  origin  of  the  gold  ores. 
8.  Methods  and  costs  of  gravel  and  placer  mining  in  Alaska. 
U.  S.  Geol.  Surv.,  Bull.  no.  259,  pp.  32-46,  1905. 
9.  Methods  and  costs  of  gravel  and  placer  mining  in  Alaska. 
U.  S.  Geol.  Surv.,  Bull.  no.  263,  273  pp.,  42  pis.,  49  tigs.,  1905. 
10.  The  Camp  Bird  and  Smuggler- Union  fissures  [Colorado]. 
Eng.  &  Mg.  Jour.,  vol.  79,  pp.  1243-1244,  1  fig.,  1905. 
Discusses  Assuring  in  the  San  Juan  Mountains  region  and  its  explanation. 
11.  Ore  horizons  in  the  veins  of  the  San  Juan  Mountains,  Colorado. 
Eeon.  Geol.,  vol.  1,  pp.  129-133, 1905. 
Discusses  the  character,  occurrence,  and  relations  of  metalliferous  viens  in  this  region. 
Pynchon  (W.  H.  C). 
11.  Drilled  wells  of  the  Triassic  area  of  the  Connecticut  Valley. 
U.  S.  Geol.  Surv.,  Water-Supply  and  Irrigation  Paper  no.  110,  pp.  65-94,  2  rigs.,  1905. 
Includes  an  account  of  the  general  geology,  the  occurrence  and  character  of  Triassic  rocks, 
and  the  geologic  structure  of  the  area. 
a. 
Qrueneau  (Augustin  L. ). 
1.  The  gold  sands  of  Cape  Nome  [Alaska]. 
Eng.  Mag.,  vol.  23,  pp.  497-510,  13  figs.,  1902. 
Describes  physiographic  features  of  the  region  and  the  occurrence  of  the  beach  and  creek 
sands. 
2.  Size  of  grain  in  igneous  rocks  in  relation  to  the  distance  from  the  cooling  wall. 
School  of  Mines  Quart.,  vol.  23,  pp.  181-195,  6  pis.,  4  figs.,  1902;  Columbia  Univ.,  Geol.  Dept., 
Contr.,  vol.  9,  no.  80,  1902.     Abstract:  N.  Y.  Acad.  Sci.,  Annals,  vol.  14,  p.  163,  1901. 
Discusses  the  mathematical  treatment  of  the  diffusion  of  heat  and  applies  the  theory  to  cer- 
tain dike  rocks. 
R. 
Rabot  (Charles). 
1.  Geologie  du  Gronland  nord-oriental. 
G£ographie,  vol.  4,  pt.  2,  pp.  66-68,  3  figs.,  1901. 
Gives  a  brief  account  of  the  geology  of  Greenland. 
