SALT,  GYPSUM,  ETC. 
ZUNI  SALT  DEPOSITS,  NEW  MEXICO. 
By  N.  H.  Darton. 
Forty  miles  south  of  the  pueblo  of  Zuni,  in  the  west  central  portion 
of  New  Mexico,  there  is  a  deposit  of  salt  which  is  not  only  of  great 
geologic  interest,  but  promises  to  prove  of  considerable  economic 
importance.  The  locality  is  80  miles  south  of  Gallup,  on  the  main 
line  of  the  Santa  Fe  Railroad,  and  about  the  same  distance  west  of 
Magdalena,  on  a  branch  of  the  same  railroad  system.  This  deposit 
has  been  a  source  of  supply  for  the  Indians  and  Mexicans  for  several 
centuries,  and  of  late  the  salt  is  hauled  to  ranches  in  a  wide  surround- 
ing district.  The  present  output  averages  only  about  a  thousand  tons 
a  year,  valued  at  about  $2.50  a  ton.  A  small  colony  of  Mexicans  at 
the  locality  collect  the  salt  in  a  very  crude  manner.  Ordinarily,  per- 
sons desiring  a  supply  go  to  the  place  and  help  themselves. 
The  deposits  occur  in  a  lake  occupying  a  portion  of  the  bottom  of  a 
deep  depression  in  a  plain  of  Cretaceous  sandstone.  This  depression 
is  about  a  mile  in  diameter,  and  has  walls  of  sandstone,  in  part  capped 
by  lava,  averaging  150  feet  in  height.  The  lake  is  about  4,000  feet 
long,  east  and  west,  and  about  3,000  feet  wide,  and  is  apparently  shal- 
low. The  water  contains  about  20  per  cent  of  salt,  mostly  chloride  of 
sodium.  The  region  is  arid  and  the  evaporation  causes  the  crystalli- 
zation of  the  salt,  especialty  in  the  shallow  waters.  On  the  south  side 
of  the  lake  extensive  bodies  of  the  salt  rise  a  few  inches  above  the 
surface  of  the  water. 
The  lake  i*  fed  by  a  spring  or  springs  that  rise  beneath  the  water 
near  the  southern  margin  of  the  lake.  Whether  or  not  the  spring- 
water  is  saturated  with  salt  was  not  ascertained.  The  springs  are 
believed  to  rise  from  red  beds,  which  lie  at  no  great  distance  below 
the  bottom  of  the  depression  and  are  usually  saliferous  to  a  moderate 
extent.  On  the  south  side  of  the  lake  rise  two  recent  cinder  cones. 
one  of  which  contains  a  crater,  having  in  its  bottom  a  salt  pool  in 
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