352  BIBLIOGRAPHY    OF    NORTH    AMERICAN    GEOLOGY 
Webster  (Clement  L. )  —Continued. 
2.  On  some  species  of  fossils  from  the  Hackberry  group  of  Iowa. 
Iowa  Nat,,  vol.  1,  pp.  58-59,  1905. 
3.  Contributions  to  the  paleontology  of  the  Iowa  Devonian. 
Iowa  Nat.,  vol.  1,  pp.  70-71,  1905. 
4.  Preliminary  observations  on  some  of  the  constituent  elements  of  the  glacial-  drift 
of  northern  Iowa. 
Iowa  Nat.,  vol.  1,  pp.  82-83,  1  fig.,  1905. 
Weed  (Walter  Harvey). 
1.  The  enrichment  of  gold  and  silver  veins. 
Am.  Inst,  Mg.  Engrs.,  Trans.,  vol.  30,  pp.  426-448,  9  figs.,  1901. 
Discusses  the  genesis  of  rich  ore  bodies  occurring  near  ground  water  level  and  of  those  found 
in  deep  mine  workings  and  the  chemical  reactions  which  have  taken  place  during  the 
process  of  ore  deposition.  Describes  the  author's  observations  and  those  of  other  geologists 
in  various  mines. 
2.  Types  of  copper  deposits  in  the  southern  United  States. 
Am.  Inst.  Mg.  Engrs.,  Trans.,  vol.  30,  pp.  449-504,  22  tiers.,  1901. 
Describes  the  character  and  occurrence  of  copper  ores  in  certain  districts,  and  discusses  rela- 
tions of  the  ores  of  the  regions  with  these  type  deposits. 
3.  Notes  on  the  Carolina  gold  deposits. 
Eng.  &  Mg.  Jour.,  vol.  72,  p.  494,  1901. 
Brief  notes  on  the  character  of  the  ores. 
4.  The  El  Paso  tin  deposits  [Texas]. 
U.  s.  Geol.  Surv.,  Hull.  no.  178,  pp.  1-15,  1  pi.,  4  figs..  1901. 
Describes  the  general  geology  of  the  region  ami  the  occurrence  and  character  of  the  ore- 
bearing  veins. 
5.  Geology  and  ore   deposits   of  the  Elkhorn    mining   district,  .Jefferson    County, 
Montana. 
U.  S.  Geol.  Surv.,  22d  Ann.  Rept,,  pt.  2,  pp.  399-510,  20  pis.,  7  figs.,  1901. 
Describes  history  of  mining  operations  in  this  district,  the  character  and  occurrence  of  igneous 
and  metamorphic  rocks  and  strata  of  Algonkian,  Cambrian,  Devonian,  Carboniferous,  and 
Mesozoic  age,  and  discusses  the  general  geologic  structure,  relations  of  the  rock  masses,  the 
character,  occurrence,  mode  of  formation,  and  commercial  development  of  the  ore  bodies. 
6.  Influence  of  country  rock  on  mineral  veins. 
Am.  Inst.  Mg.  Engrs..  Trans.,  vol.  31,  pp.  634-653,  8  figs.,  1902. 
Discusses  origin  of  certain  on   deposits 
7.  [Discussion  of  "The  origin  of  ore  deposits/'] 
Am.  Inst.  Mg.  Engrs..  Trans.,  vol.  31,  pp.  959-962,  1902. 
8.  Notes  on  certain  mines  in  the  States  of  Chihuahua,  Sinaloa,  and  Sonora,  Mexico. 
Am.  Inst.  Mg.  Engrs.,  Trans.,  vol.  32,  pp.  396-443,  28  figs.,  1902. 
Contains  notes  on  the  geology  of  these  States,  and  the  character  and  occurrence  of  the  ores. 
9.  Notes  on  a  section  across  the  Sierra  Madre  Occidental  of  Chihuahua  and  Sinaloa, 
Mexico. 
Am.  Inst.  Mg.  Engrs..  Trans.,  vol.  32,  pp.  444-45S,  1  pi.  (sections),  1902. 
Contains  observations  on  the  geology  and  petrology  of  the  region. 
10.  Recent  development  of  southern  copper  deposits. 
Eng.  &  Mg.  Jour.,  vol.  74.  pp.  80-81,  1902. 
11.  Contact  metamorphic  and  other  ore  deposits  near  igneous  contacts. 
Eng.  &  Mg.  Jour.,  vol.  74,  p.  513,  1902. 
12.  The  Cananea  copper  deposits,  Mexico. 
Eng.  &  Mg.  Jour.,  vol.  74,  pp.  744-745,  4  figs.,  1902. 
13.  Geological  sketch  of  the  Hot  Springs  district,  Arkansas. 
57th  Cong.,  1st  Sess.,  Sen.  Doc.  no.  282,  Washington,  pp.  79-94,  10  pis.,  1902. 
Describes  location,  topography,  and  general  geology  of  the  region,  and  the  source,  character, 
and  geologic  relations  of  the  hot  springs,  and  discuss*  s  the  origin  of  their  heat. 
