INVESTIGATIONS    OF    IRON    ORES,  ETC.  23 
activity  has  occurred  in  the  well-known  Crimora  district  of  Virginia 
and  elsewhere.  These  developments  should  be  promptly  followed 
up  by  the  Survey,  and  it  is  desirable  that  a  preliminary  general 
report  on  the  manganese  ores  of  the  United  States  be  prepared  and 
issued  as  soon  as  possible. 
ALUMINUM    AND    BAUXITE. 
During  1905  bauxite  was  discovered  in  Tennessee,  Virginia,  and 
Pennsylvania,  far  north  of  the  deposits  previously  known.  Develop- 
ments in  the  use  of  low-grade  bauxite  for  the  manufacture  of  refrac- 
tory brick  have  also  stimulated  interest  in  the  industry,  so  that  pros- 
pecting for  bauxite  has  been  particularly  active  during  the  last  year. 
It  is  noteworthy,  however,  that  though  these  new  discoveries  extended 
the  area  known  to  contain  bauxite  deposits,  the  general  location  and 
character  of  the  deposits  fulfill  entirely  the  conditions  pointed  out 
by  Survey  geologists  a  decade  ago.  During  1905  the  Arkansas 
deposits  were  reexamined  by  Survey  parties,  and  it  is  probable  that 
the  new  eastern  districts  will  be  surveyed  and  reported  on  in  the  near 
future. 
The  recent  and  proximate  expiration  of  a  number  of  the  basic 
patents  on  which  the  aluminum  industry  is  founded  has  operated 
to  increase  greatly  the  general  interest  in  the  supply  of  ore;  and  it 
seems  probable  that  active  prospecting  and  development  work  will 
be  carried  on  in  all  promising  districts  during  1907. 
A  reported  bauxite  field  in  Arizona  was  examined  during  1906  by 
C.  W.  Hayes,  whose  report  is  presented  in  this  bulletin. 
STRUCTURAL   MATERIALS. 
Cement. — The  geological  investigation  of  cement  materials  by  the 
Survey  during  the  last  year  was  carried  on  mostly  in  connection 
with  the  ordinary  areal  work  of  the  Survey,  and  its  results  will  be 
published  only  in  the  texts  of  various  geologic  folios.  An  exception 
to  this,  however,  was  the  examination  of  the  cement  resources  of 
portions  of  Wyoming  by  Sydney  H.  Ball,  a  report  on  which  is 
included  in  the  present  bulletin.  Mr.  Burchard  has  also  submitted  a 
brief  report  on  the  cement  resources  near  Dubuque,  Iowa,  for  publi- 
cation in  this  volume. 
Bulletin  243  of  this  Survey,  dealing  with  the  "  Cement  materials 
and  cement  industry  of  the  United  States,"  has  been  out  of  print  for 
some  time.  The  demand  for  it  still  continues,  and  it  has  been 
decided  to  rewrite  it  completely  and  issue  the  revised  edition  in  1907 
if  possible. 
Lime. — In  the  course  of  his  studies  on  the  areal  geology  of  the  Bir- 
mingham district  of  Alabama,  Charles   Butts  collected  considerable 
