﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  83 
  

  

  Mercersburg 
  troughs 
  and 
  farther 
  south. 
  1 
  Since, 
  however, 
  the 
  

   Chambersburg 
  limestone 
  does 
  not 
  continue 
  > 
  in 
  the 
  Levis 
  trough 
  

   north 
  of 
  Pennsylvania, 
  the 
  conglomerate 
  can 
  not 
  be 
  referred 
  to 
  as 
  

   constituting 
  a 
  northern 
  continuation 
  or 
  a 
  part 
  of 
  the 
  Chambersburg 
  

   limestone 
  and 
  it 
  appears 
  that 
  the 
  Atlantic 
  fauna 
  found 
  in 
  the 
  Ryse- 
  

   dorph 
  Hill 
  conglomerate 
  was 
  able 
  to 
  enter 
  the 
  troughs 
  between 
  the 
  

   Appalachian 
  barriers 
  from 
  the 
  east 
  in 
  several 
  independent 
  places. 
  

  

  The 
  conglomerate 
  about 
  Bald 
  mountain, 
  which 
  is 
  here 
  correlated 
  

   with 
  the 
  Rysedorph 
  Hill 
  conglomerate 
  is 
  clearly 
  bound 
  to 
  the 
  

   large 
  overthrust 
  plane, 
  for 
  at 
  Bald 
  mountain 
  itself 
  it 
  is 
  asso- 
  

   ciated 
  with 
  the 
  Bald 
  Mountain 
  limestone, 
  and 
  to 
  the 
  north 
  of 
  it 
  

   it 
  is 
  even 
  infolded 
  with 
  Georgian 
  shales. 
  As 
  we 
  have 
  already 
  stated, 
  

   it 
  is 
  here 
  exposed 
  only 
  close 
  to 
  the 
  great 
  overthrust 
  fault 
  and 
  by 
  

   the 
  latter 
  brought 
  in 
  juxtaposition 
  with 
  the 
  Bald 
  Mountain 
  lime- 
  

   stone 
  and 
  Georgian 
  rocks. 
  This 
  position 
  is 
  probably 
  due 
  to 
  its 
  

   greater 
  resistant 
  power 
  as 
  compared 
  with 
  that 
  of 
  the 
  softer 
  shales, 
  

   which 
  have 
  been 
  ground 
  up. 
  

  

  Besides 
  this 
  conglomerate, 
  the 
  matrix 
  of 
  which 
  consists, 
  as 
  at 
  

   Rysedorph 
  hill, 
  largely 
  of 
  sandy 
  lime, 
  there 
  is 
  observed 
  at 
  Bald 
  

   mountain 
  a 
  breccia 
  of 
  remarkable 
  appearance 
  and 
  thickness. 
  This 
  

   is 
  seen 
  in 
  plates 
  12-14 
  between 
  the 
  Bald 
  Mountain 
  limestone 
  and 
  

   the 
  Georgian 
  in 
  very 
  irregular 
  masses. 
  It 
  is 
  be*st 
  exposed 
  on 
  the 
  

   south 
  face 
  of 
  the 
  quarry, 
  where 
  it 
  reaches 
  30 
  feet 
  in 
  thickness 
  in 
  

   one 
  place 
  and 
  can 
  be 
  easily 
  studied 
  since 
  it 
  descends 
  to 
  the 
  bottom 
  

   of 
  the 
  quarry. 
  It 
  consists 
  here 
  of 
  an 
  utterly 
  unstratified 
  black 
  mud 
  

   matrix 
  with 
  numerous 
  unassorted 
  small 
  more 
  or 
  less 
  angular 
  pieces, 
  

   mostly 
  of 
  the 
  size 
  of 
  a 
  pea 
  or 
  smaller, 
  of 
  limestone, 
  olive 
  grit, 
  

   chert 
  etc. 
  (see 
  plate 
  15, 
  which 
  is 
  a 
  photo 
  of 
  a 
  hand 
  specimen). 
  The 
  

   matrix 
  has 
  the 
  appearance 
  of 
  a 
  thoroughly 
  ground 
  up 
  shale 
  mass 
  

   and 
  with 
  pebbles 
  floating 
  in 
  it, 
  resembles 
  a 
  tillite. 
  There 
  is, 
  however, 
  

   no 
  doubt 
  that 
  this 
  mass 
  is 
  the 
  result 
  of 
  the 
  tremendous 
  friction 
  at 
  

   the 
  base 
  and 
  between 
  the 
  masses 
  of 
  Georgian 
  rocks 
  on 
  top 
  and 
  the 
  

   Bald 
  Mountain 
  limestone 
  below, 
  which 
  were 
  moved 
  on 
  a 
  nearly 
  

   horizontal 
  plane. 
  How 
  the 
  top 
  beds 
  of 
  the 
  Bald 
  mountain 
  limestone 
  

   were 
  torn 
  off 
  and 
  incorporated 
  in 
  the 
  shale 
  is 
  well 
  shown 
  in 
  plate 
  13, 
  

   where 
  strings 
  of 
  Bald 
  Mountain 
  limestone 
  are 
  seen 
  to 
  reach 
  into, 
  

   the 
  black 
  mudrock 
  in 
  the 
  process 
  of 
  being 
  torn 
  up. 
  The 
  black 
  soft 
  

  

  1 
  Stose, 
  G. 
  W., 
  Mercersburg-Chambersburg 
  folio, 
  Pa. 
  U. 
  S. 
  Geol. 
  Surv., 
  

   folio 
  170, 
  1909. 
  Bassler, 
  R. 
  S., 
  The 
  Cement 
  Resources 
  of 
  Virginia, 
  West 
  of 
  

   the 
  Blue 
  Ridge. 
  Va. 
  Geol. 
  Surv. 
  Bui. 
  2, 
  1909. 
  Ulrich, 
  E. 
  O., 
  Revision 
  of 
  

   the 
  Paleozoic 
  Systems, 
  pts. 
  1-3. 
  Geol. 
  Soc. 
  Amer. 
  Bui. 
  v. 
  22, 
  no. 
  3. 
  191 
  t. 
  

  

  