﻿308 
  Scientific 
  Intelligence. 
  

  

  highly 
  scientific 
  work, 
  which 
  also 
  has 
  its 
  practical 
  bearings 
  on 
  the 
  

   economic 
  products 
  of 
  the 
  area 
  studied. 
  

  

  In 
  general, 
  the 
  strata 
  lie 
  in 
  nearly 
  horizontal 
  attitude, 
  but 
  

   locally 
  they 
  rise 
  into 
  low 
  open 
  folds 
  with 
  the 
  dips 
  rising 
  to 
  as 
  

   much 
  as 
  10°. 
  At 
  Clifton 
  one 
  of 
  these 
  arches 
  rises 
  fully 
  250 
  feet, 
  

   and 
  at 
  Grandview 
  another 
  is 
  100 
  feet 
  high. 
  In 
  addition 
  to 
  the 
  

   gentle 
  folds, 
  the 
  southern 
  half 
  of 
  the 
  valley 
  is 
  considerably 
  

   faulted 
  and 
  the 
  vertical 
  throws 
  range 
  from 
  a 
  few 
  feet 
  to 
  perhaps 
  

   150 
  feet. 
  On 
  the 
  other 
  hand, 
  the 
  Harriman 
  and 
  Camden 
  cherts, 
  

   due 
  to 
  their 
  hard 
  and 
  brittle 
  nature, 
  are 
  thoroughly 
  fractured 
  

   and 
  crumpled, 
  so 
  that 
  locally 
  the 
  strata 
  may 
  have 
  dips 
  of 
  80° 
  

   or 
  more. 
  Gentle 
  warping 
  went 
  on 
  during 
  the 
  Devonian, 
  but 
  the 
  

   major 
  folding 
  and 
  faulting 
  is 
  thought 
  to 
  have 
  been 
  an 
  interior 
  

   consequence 
  of 
  the 
  Appalachian 
  orogeny 
  of 
  Permian 
  time. 
  

  

  The 
  Devonian 
  sequence 
  is 
  as 
  follows 
  : 
  At 
  the 
  top 
  is 
  the 
  thin 
  

   Chattanooga 
  shale 
  and 
  its 
  basal 
  Hardin 
  sandstone, 
  which 
  seem- 
  

   ingly 
  are 
  better 
  placed 
  in 
  the 
  Mississippian 
  period. 
  There 
  are 
  

   here 
  no 
  Upper 
  Devonian 
  nor 
  any 
  Hamilton 
  equivalents. 
  The 
  

   Middle 
  Devonian 
  begins 
  with 
  the 
  thin 
  Pegram 
  (= 
  Onondaga) 
  

   limestone 
  that 
  lies 
  disconformably 
  upon 
  the 
  Camden 
  chert. 
  The 
  

   Camden, 
  with 
  a 
  thickness 
  up 
  to 
  200 
  feet, 
  has 
  42 
  species, 
  many 
  of 
  

   which 
  occur 
  also 
  in 
  the 
  Clear 
  Creek 
  of 
  Illinois, 
  and 
  both 
  forma- 
  

   tions 
  appear 
  to 
  correlate 
  with 
  the 
  Esopus 
  and 
  Schoharie 
  of 
  New 
  

   York. 
  The 
  Lower 
  Devonian 
  of 
  Oriskanian 
  time 
  has 
  at 
  the 
  top 
  

   the 
  Harriman 
  chert, 
  with 
  a 
  fauna 
  of 
  25 
  species, 
  followed 
  below 
  

   by 
  the 
  Quail 
  limestone, 
  having 
  10 
  species; 
  both 
  correlate 
  with 
  

   the 
  typical 
  New 
  York 
  Oriskany 
  fauna. 
  Then 
  follows 
  a 
  long 
  

   series 
  of 
  Helderbergian 
  formations. 
  The 
  uppermost 
  one 
  is 
  the 
  

   very 
  thin 
  and 
  patchy 
  Decaturville 
  chert, 
  with 
  a 
  fauna 
  of 
  20 
  spe- 
  

   cies 
  relating 
  it 
  to 
  the 
  Becraft 
  of 
  New 
  York, 
  followed 
  below 
  by 
  

   the 
  Birdsong 
  shale, 
  35 
  to 
  65 
  feet 
  thick, 
  bearing 
  a 
  Helderbergian 
  

   (= 
  New 
  Scotland) 
  fauna 
  of 
  99 
  determined 
  species. 
  Then 
  comes 
  

   the 
  Olive 
  Hill 
  formation, 
  consisting 
  of 
  about 
  160 
  feet 
  of 
  lime- 
  

   stones, 
  with 
  local 
  beds 
  of 
  oolitic 
  iron-ores, 
  and 
  a 
  fauna 
  of 
  58 
  

   species, 
  best 
  comparable 
  with 
  that 
  of 
  the 
  late 
  Coeymans 
  of 
  New 
  

   York. 
  The 
  base 
  of 
  the 
  Helderbergian 
  consists 
  of 
  the 
  Rockhouse 
  

   shale 
  (up 
  to 
  26 
  feet 
  thick), 
  yielding 
  a 
  fauna 
  of 
  35 
  species, 
  with 
  

   several 
  Silurian 
  hold-overs, 
  correlating 
  best 
  with 
  the 
  basal 
  mem- 
  

   ber 
  of 
  the 
  Lower 
  Devonian 
  of 
  the 
  Arbuckle 
  Mountains 
  and 
  less 
  

   clearly 
  with 
  some 
  part 
  of 
  the 
  Keyser 
  formation 
  of 
  Maryland. 
  

   The 
  Rockhouse 
  rests 
  disconformably 
  upon 
  the 
  higher 
  formations 
  

   of 
  the 
  Middle 
  Silurian, 
  there 
  being 
  here 
  no 
  Upper 
  Silurian 
  

   strata. 
  

  

  The 
  work 
  closes 
  with 
  detailed 
  descriptions 
  of 
  forty 
  local 
  sec- 
  

   tions, 
  with 
  the 
  faunas 
  listed 
  for 
  each 
  zone. 
  

  

  In 
  the 
  second 
  paper, 
  Doctor 
  Dunbar 
  describes 
  and 
  illustrates 
  

   37 
  new 
  species 
  found 
  by 
  him 
  in 
  connection 
  with 
  the 
  work 
  above 
  

   reviewed, 
  and 
  proposes 
  3 
  new 
  gastropod 
  genera, 
  Saffordella, 
  

   Aulopea, 
  and 
  Bistemno 
  stoma, 
  c. 
  s. 
  

  

  9. 
  Paleo 
  geography 
  and 
  Diastrophism 
  in 
  the 
  Atlantic-Arctic 
  

   Region 
  during 
  Paleozoic 
  Time, 
  by 
  O. 
  Holtedahl. 
  — 
  Correc- 
  

  

  

  