﻿E. 
  H. 
  Williams 
  — 
  Southern 
  Ice 
  Limit 
  hi 
  Pennsylvania. 
  1 
  79 
  

  

  Middle 
  field, 
  the 
  whole 
  of 
  the 
  anthracite 
  area 
  was 
  glaciated. 
  

   The 
  surface 
  dislocations 
  incident 
  to 
  mining, 
  and 
  the 
  distribu- 
  

   tion 
  of 
  culm 
  from 
  the 
  coal 
  washings 
  have 
  made 
  a 
  survey 
  diffi- 
  

   cult 
  as 
  far 
  as 
  connected 
  work 
  is 
  concerned. 
  Points 
  here 
  and 
  

   there 
  were 
  obtained, 
  and 
  the 
  intermediate 
  line 
  surmised 
  from 
  

   the 
  contour 
  of 
  the 
  country. 
  As 
  the 
  ice 
  was 
  found 
  to 
  have 
  

   been 
  at 
  Frackville, 
  it 
  must 
  have 
  crossed 
  the 
  Western 
  Middle 
  

   basin 
  at 
  Mahanoy 
  Plane 
  ; 
  but 
  Mahanoy 
  creek 
  is 
  so 
  clogged 
  

   with 
  culm 
  as 
  to 
  afford 
  no 
  sign 
  of 
  glacial 
  deposits. 
  As 
  the 
  red 
  

   shale 
  (Mauch 
  Chunk) 
  valley 
  between 
  Ashland 
  and 
  Gordon 
  

   showed 
  no 
  erratics 
  the 
  ice 
  did 
  not 
  intrude 
  there 
  ; 
  but 
  at 
  Locust 
  

   Gap 
  till 
  was 
  found, 
  and 
  a 
  thick 
  bed 
  of 
  it 
  lines 
  the 
  creek 
  of 
  the 
  

   same 
  name 
  at 
  Shainokin 
  ; 
  while 
  in 
  the 
  red 
  shale 
  valley 
  to 
  the 
  

   north 
  trial 
  shafts 
  were 
  sunk 
  through 
  a 
  great 
  thickness 
  of 
  till 
  

   and 
  bowlders. 
  The 
  records 
  of 
  shafts 
  in 
  many 
  places 
  in 
  this 
  

   region 
  show 
  that 
  the 
  first 
  part 
  of 
  the 
  work 
  was 
  through 
  

   " 
  gravel 
  " 
  or 
  " 
  drift." 
  At 
  Trevorton 
  and 
  down 
  Zerbe 
  Pun 
  

   gravels 
  exist; 
  but 
  not 
  as 
  far 
  as 
  Dornsife, 
  where 
  Mahoning 
  

   creek 
  cuts 
  through 
  the 
  ridge 
  into 
  the 
  Susquehanna 
  Yalley. 
  

   In 
  general, 
  glaciation 
  is 
  shown 
  by 
  the 
  removal 
  of 
  the 
  old 
  soil. 
  

   At 
  Hazelton 
  in 
  the 
  north, 
  and 
  Shamokin 
  in 
  the 
  south 
  there 
  

   was 
  a 
  uniformity 
  with 
  which 
  the 
  coal 
  beds 
  came 
  in 
  workable 
  

   condition 
  to 
  the 
  surface, 
  and 
  with 
  as 
  great 
  relative 
  solidity 
  as 
  

   the 
  enclosing 
  sandstones. 
  The 
  coal 
  strippings 
  at 
  and 
  about 
  

   Hazelton 
  show 
  plainly 
  that 
  the 
  glaciation 
  was 
  recent, 
  as, 
  other- 
  

   wise, 
  the 
  coal 
  beds 
  exposed 
  so 
  near 
  the 
  surface 
  to 
  the 
  action 
  of 
  

   solvents 
  would 
  have 
  long 
  ere 
  this 
  been 
  turned 
  to 
  black 
  mud, 
  

   while 
  the 
  sandstones 
  would 
  have 
  retained 
  a 
  good 
  deal 
  of 
  solid- 
  

   ity. 
  At 
  Hazelton 
  coal 
  has 
  been 
  mined 
  and 
  marketed 
  where 
  

   the 
  top 
  rock 
  was 
  entirely 
  removed 
  by 
  glacial 
  action, 
  and 
  only 
  a 
  

   loose 
  glacial 
  wash 
  capped 
  the 
  bed. 
  The 
  coal 
  was 
  rusty 
  ; 
  but 
  

   solid. 
  

  

  No 
  striations 
  were 
  found 
  over 
  this 
  region 
  ; 
  but 
  the 
  Potts- 
  

   ville 
  conglomerate 
  on 
  the 
  ridge 
  just 
  east 
  of 
  Delano 
  (1800-1900 
  

   A. 
  T.) 
  is 
  planed 
  over 
  large 
  areas, 
  and 
  large 
  erratics 
  of 
  the 
  same 
  

   formation 
  are 
  numerous. 
  Where 
  the 
  Pottsville 
  branch 
  of 
  the 
  

   Lehigh 
  Yalley 
  road 
  cuts 
  through 
  the 
  ridge 
  to 
  the 
  Silver 
  Brook 
  

   basin, 
  the 
  weight 
  and 
  force 
  of 
  the 
  ice 
  bent 
  and 
  crushed 
  the 
  

   vertical 
  hard 
  bands 
  of 
  Pottsville 
  conglomerate, 
  and 
  the 
  sand- 
  

   stones 
  lying 
  on 
  it, 
  as 
  readily 
  as 
  it 
  did 
  the 
  Hudson 
  Piver 
  slates 
  

   south 
  of 
  the 
  Blue 
  Pidge. 
  

  

  The 
  Susquehanna 
  Valley., 
  

  

  The 
  ice 
  moved 
  parallel 
  to 
  the 
  north 
  branch 
  of 
  this 
  river 
  

   along 
  the 
  Wyoming 
  valley, 
  and 
  crossed 
  it 
  at 
  increasing 
  angles 
  

   as 
  it 
  neared 
  the 
  main 
  stream 
  at 
  Northumberland. 
  The 
  bed 
  of 
  

   the 
  branch 
  is 
  generally 
  solid 
  rock, 
  with 
  the 
  inequalities 
  filled 
  

  

  