320  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1904.         [bull.  200. 
In  the  present  bulletin  is  presented  a  brief  preliminary  report  on  the 
brown  hematites  of  eastern  New  York  and  western  New  England! 
It  is  planned  to  take  up  a  detailed  study  of  these  Valley  ores  during 
1905,  commencing  with  their  important  developments  in  Virginia! 
where  cooperative  work  has  been  arranged,  and  continuing  the  work 
as  fast  as  possible  until  the  entire  area  has  been  investigated.  The 
brown  hematite  deposits  of  Alabama  will,  of  course,  be  studied  in  con 
nection  with  the  cooperative  survey  of  the  Birmingham  district 
referred  to  above. 
(4)  The  magnetites  of  the  East  occur  mostly  in  the  belt  of  pre- 
Cambrian  rocks  which  forms  the  Blue  Ridge  and  its  northward  con 
tinuation,  the  New  Jersey  and  Hudson  highlands;  but  important  out 
lying  districts  are  those  of  Cornwall,  Pa.,  and  the  Adirondacks  of  Ne 
York.  Professor  Kemp  has  mapped  and  studied  the  magnetites  o 
the  latter  area,  and  his  results  will  be  published  b}r  the  Survey  ii 
folio  form.  In  North  Carolina  Keith  has  studied  the  importan 
deposits  of  the  Cranberry  district  (Bull.  213,  pp.  243-240),  whil 
during  1004  Spencer  examined  a  number  of  magnetite  bodies  in  th 
New  Jersey  highlands.  Detailed  work  on  these  ores,  which  prese 
problems  of  unusual  difficulty  and  interest,  both  in  regard  to  sirat 
graphy  and  origin,  can  be  taken  up  profitably  only  in  connectio: 
with  folio  mapping  in  the  respective  areas,  or  after  the  completion  of 
such  mapping. 
(5)  The  Rocky  Mountain  ores  possess  a  certain  geographic  and 
commercial  unity  though  differing  widely  in  character  and  geologic 
association.  The  bulk  of  the  iron  ore  produced  west  of  the  Missisw 
sippi  comes  from  Colorado,  Wyoming,  and  New  Mexico,  but  smaller 
supplies  are  obtained  from  Utah  and  Nevada.  These  ores  are  mag- 
netites, specular  hematites,  and  limonites. 
Until  recently  little  attention  has  been  paid  to  these  deposits  by 
either  furnacemen  or  geologists,  as  the  ores  have  been  considered  all 
useful  fluxes  (for  precious  metal  and  other  smelters)  rather  than  all 
sources  of  iron.     The  rapid  manufacturing  development  of  the  Wesfll 
ern  States  has,  however,  brought  some  of  the  iron  ores  into  prominence  1 
With  the  practical  dose  of  detailed  work  in  the  Lake  Superior  i 
region,  the  Survey  is  now  free  to  take  up  the  examination  of  the  iron  i 
deposits  of  the  Rocky  Mountain  States.     Papers  by  Messrs.   Bout- 
well  and  Leith,  describing  several  Utah  ore  bodies,  appeared  in  Bul- 
letin 225. 
One  of  the  minor  producing  areas,  not  included  in  the  above  group-  • 
ing,  lies  in  northeast  Texas.  It  is  unique  among  American  sources  | 
of  iron  ore  in  occurring  in  the  Coastal  Plain,  being  associated  with  i 
sands,  gravels,  and  clays  of  Tertiary  age.  A  brief  reconnaissance  of  I 
this  Texas  area  was  made  in  1904,  and  a  report  on  the  district  is 
presented  later. 
