CONTRIBUTIONS  TO  ECONOMIC  GEOLOGY, 
1906,  PART  I. 
S.  F.  Emmons  and  E.  C.  Eckel,  Geologists  in  charge. 
INTRODUCTION. 
By  0.  W.  Hayes,  Geologist  in  charge  of  geology. 
This  bulletin  is  the  fifth  of  a  series,  including  Bulletins  Nos.  213, 
225,  260,  and  285,  Contributions  to  Economic  Geology  for  1902,  1903, 
1904,  and  1905,  respectively.  These  bulletins  are  prepared  primarily 
with  a  view  to  securing  prompt  publication  of  the  economic  results  of 
investigations  made  by  the  United  States  Geological  Survey.  They 
are  designed  to  meet  the  wants  of  the  busy  man,  and  are  so  condensed 
that  he  will  be  able  to  obtain  results  and  conclusions  with  a  minimum 
expenditure  of  time  and  energy.  They  also  afford  a  better  idea  of  the 
work  which  the  Survey  as  an  organization  is  carrying  on  for  the  direct 
advancement  of  mining  interests  throughout  the  country  than  can 
readily  be  obtained  from  the  more  voluminous  final  reports. 
The  first  two  bulletins  of  this  series  included  numerous  papers  relat- 
ing to  the  economic  geology  of  Alaska.  In  view  of  the  rapid  increase 
of  economic  work  both  in  Alaska  and  in  the  States  and  the  organiza- 
tion of  a  division  of  Alaskan  mineral  resources,  distinct  from  the 
division  of  geology,  it  was  in  1905  considered  advisable  to  exclude 
all  papers  relating  to  Alaska.  These  were  brought  together  in  a  sepa- 
rate volume  entitled  "  Report  of  Progress  of  Investigations  of  Mineral 
Resources  of  Alaska  in  1904,"  Bulletin  No.  259.  A  similar  segrega- 
tion of  papers  relating  to  Alaska  was  made  last  year  (Bulletin  No. 
284)  and  will  be  made  this  year. 
During  1906  a  further  change  in  the  arrangement  of  the  economic 
bulletin  seemed  desirable.  The  former  section  of  iron  ores  and  non- 
metallic  minerals  was  divided,  M.  R.  Campbell  being  placed  in  charge 
of  a  new  section  devoted  to  the  investigation  of  fuels,  including  coal, 
oil,  gas,  and  asphalts;  and  E.-C.  Eckel  remaining  in  charge  of  investi- 
gations of  iron  ores,  structural  materials,  and  miscellaneous  nonmetals. 
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