THE  GLASS-SAND   INDUSTRY  IN  EASTERN  WEST  VIRGINIA 
By  George  W.  Stose. 
The  deposits  of  pure  quartz  sandstones  occurring  between  Hancock,  Md.,  and  Berkeley 
Springs,  W.  Va.,  have  been  quarried  for  many  years,  but  it  is  only  within  the  past  few 
years  that  mining  operations  have  become  active. 
Geology. — The  sand  is  derived  from  a  white  sandstone  composing  the  Warm  Spring 
Ridge  in  West  Virginia,  which  runs  south-southwest  from  Potomac  River  opposite  Ban- 
cock,  Md.  This  formation  is  the  Oriskany  sandstone  and  is  part  of  a  monoclinal  series  of 
beds  between  a  massive  anticline  bringing  up  Medina  sandstone  in  Cacapon  Mountain,  1! 
miles  to  the  west,  and  a  sharp  syncline  of  Carboniferous  rocks  forming  Sleepy  Creek  Moun- 
tain, 6  miles  to  the  east.  The  rocks  strike  N.  10°-25°  E.  and  dip  50°  SE.  On  the  west , 
beneath  the  sandstone,  are  limestones  of  Helderberg  age  and  shales  of  Cayuga  age.  Above 
it,  on  the  east  flank  of  the  ridge,  is  a  belt  of  black  shales  of  Marcellus  and  Hamilton  age, 
followed  by  Chemung  rocks. 
Character  of  the  sand  rock. — The  sandstone  of  this  ridge  is  of  exceptional  purity.  In 
other  outcrops  of  this  formation  to  the  east  and  west,  where  it  is  brought  to  the  surface 
by  folding,  it  is  commonly  a  siliceous  limestone  with  chert  nodules  and  line  conglomerate. 
The  pure  sand  rock  seems  to  be  limited  to  a  few  miles  in  length  along  the  strike  of  the  Warm 
Spring  Ridge,  for  northward  in  Maryland  it  changes  to  a  yellow,  impure,  and  coarse  sand 
lock,  suitable  only  for  building  sand.  Its  extent  southward  has  not  been  determined.  It 
is  mined  as  far  as  Berkeley  Springs,  the  end  of  the  railroad  spur  up  the  Warm  Spring  Valley, 
but  the  same  character  of  rocks  at  the  surface  seems  to  continue  far  beyond,  and  the  land 
is  held  largely  as  sand  land,  its  development  awaiting  the  extension  of  the  railroad. 
This  pure  white  quartz  sand  is  evidently  a  beach  or  near-shore  deposit,  and  its  purity, 
freedom  from  mud  and  other  fine  detritus,  the  uniform  size  of  its  particles,  and  their  sub- 
rounded  character  indicate  long-continued  sorting  action  at  this  part  of  the  shore.  The 
grains  are  of  medium  fineness,  practically  all  passing  a  40-mesh  sieve  and  25  per  cent  passing 
a  60-mesh  sieve.  Particles  of  milky  cryptocrvstalline  silica  are  scattered  among  the  grains; 
whether  these  are  original  chert  fragments  or  were  deposited  there  from  solution  is  not 
known.  The  grains  are  loosely  cemented  by  lime,  the  Berkeley  Springs  water,  which  issues 
from  the  upper  beds  of  this  formation,  containing  a  small  percentage  of  carbonate  of 
calcium.  At  the  surface  the  rock  is  hardened  and  slightly  glazed,  apparently  by  the  solu- 
tion and  redeposition  of  silica  between  the  grains.  In  depth,  however,  the  rock  is  commonly 
soft,  breaking  into  grains  in  blasting  or  by  the  use  of  the  sledge  hammer 
Pennsylvania  Glass  Sand  Company.— The  oldest  mine,  located  near  the  north  end  of  the 
ridge,  is  operated  by  the  Pennsylvania  Glass  Sand  Company.  The  mine  is  but  2  miles  from 
Hancock.  It  is  located  on  the  top  of  the  ridge,  where  the  edges  of  the  sandstone  beds  out- 
crop in  rocky  ledges  300  feet  above  the  Baltimore  and  Ohio  Railroad  track  along  the  river  at 
the  west  foot  of  the  ridge.  This  mine  was  established  before  the  branch  railroad  up  the 
Warm  Spring  Valley  was  built,  and  the  only  direct  railroad  communication  was  by  the  main 
line  to  the  west.  The  western  side  of  the  ridge  is  composed  of  Helderberg  limestone, 
through  which  a  tunnel  had  to  be  constructed  to  reach  the  sandstone  on  the  eastern  side. 
The  mine  is  a  large  open  cut,  120  feet  deep,  about  130  feet  wide,  and  400  feet  long.  At  its 
south  end  is  a  tunnel  in  which  much  rock  has  been  quarried,  but  this  method  of  mining  has 
been  abandoned  and  the  whole  width  of  the  ledge  is  now  being  worked  as  an  open  cut. 
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