322  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1904.         [bull.  260. 
Butts,  on  pages  359  to  305  of  this  bulletin.  Bordering-  the  Coal  Meas- 
ures of  the  Warrior  field  on  the  southeast  and  striking  in  a  general 
direction  N.  30°  E.  is  a  belt  of  earlier  Paleozoic  rocks  that  have 
been  considerably  folded  and  faulted.  All  the  iron  ores  of  impor- 
tance in  the  quadrangle  occur  along  this  belt,  either  interstratifiec 
with  the  Paleozoic  or  immediately  above  them  in  later  deposits. 
There  are  represented  in  this  belt  shales  and  shaly  limestones  oi 
the  Cambrian  system;  massive  limestone,  dolomite,  and  chert  of 
the  Ordovician;  limestone,  sandstone,  bedded  iron  ore,  and  shale  oJ 
the  Silurian;  thin  black  Devonian  shale;  and  chert,  quartzite,  con- 
glomerate, and  shale  of  the  Mississippian  series  of  the  Carbon- 
iferous system.  For  the  most  part  these  beds  are  highly  inclined, 
and  the  differential  weathering  of  the  edges  of  the  soft  shales  anc 
hard  qiiartzites  and  sandstones,  together  with  solution  of  the  lime- 
stone beds,  has  produced  a  shallow  anticlinal  valley  bordered  by 
quartzitic  sandstone  ridges  and  inclosing  minor  sandstone  ridges. 
This  valley,  inclosed  between  Rock  Mountain,  on  the  northwest, 
and  Sand  and  Red  mountains,  on  the  southeast,  is  a  well-market 
feature,  which  may  be  recognized  on  the  topographic  map  of  the 
Brookwood  quadrangle,  from  the  vicinity  of  Woodstock  northeast 
to  McCalla,  where  it  .passes  beyond  the  border  of  the  area.  It  hai 
received  the  local  name,  of  Roups  Valley,  and  to  the  northeast,  in 
the  Birmingham  district,  is  known  as  Jones  Valley.  At  McCalla, 
near  the  eastern  border  of  the  quadrangle,  the  width  of  Roup] 
Valley  is  nearly  5  miles,  at  Green  Pond  it  is  about  3^  miles,  and  at 
Vance  it  is  8  miles.  To  the  southeast  the  valley  is  bordered  by 
the  Coal  Measures  of  the  Cahaba  coal  field.  To  the  northeast  these 
so-called  "valley"  rocks  extend  beyond  the  border  of  the  State, 
but  in  the  southwest  part  of  the  quadrangle  they  pass  beneath  un- 
consolidated Cretaceous,  Tertiary,  and  Quaternary  deposits.  These 
Cretaceous  and  later  deposits  completely  mantle  the  Paleozoic 
even  in  the  deepest  stream  cuttings  in  the  vicinity  of  Hagler  anl 
southward,  but  they  become  thinner  and  patchy  to  the  northeast 
and  practically  disappear  between  Goethite  and  Kimbrel.  Be 
tween  Green  Pond,  on  the  Alabama  Great  Southern  Railroad,  an< 
(iiles,  on  the  Louisville  and  Nashville  Railroad,  these  unconsoli- 
dated beds  contain  important  deposits  of  brown  iron  ore.  Area 
mapping  has  been  so  far  completed  as  to  make  it  possible  to  out 
line  the  distribution  of  those  "  valley "  formations  that  are  of 
economic  importance,  but  the  details  of  their  structure  have  not  yet 
been  fully  worked  out. 
