﻿the 
  Connecticut 
  Valley 
  Sandstone. 
  447 
  

  

  I 
  pass 
  here 
  to 
  an 
  explanation 
  of 
  the 
  origin 
  of 
  the 
  dip 
  in 
  

   the 
  sandstone 
  which 
  appears 
  to 
  me 
  to 
  harmonize 
  best 
  with 
  the 
  

   facts. 
  

  

  Daubree's 
  experiments 
  on 
  the 
  effects 
  of 
  lateral 
  pressure, 
  pub- 
  

   lished 
  in 
  his 
  " 
  Geologie 
  Experimentale 
  " 
  (and 
  briefly 
  presented 
  

   in 
  my 
  Manual 
  of 
  Geology), 
  have 
  appeared 
  to 
  me 
  to 
  sustain 
  the 
  

   idea 
  that 
  the 
  great 
  fault-planes 
  of 
  the 
  earth's 
  crust 
  made 
  by 
  

   lateral 
  pressure 
  must 
  be, 
  as 
  a 
  general 
  rule, 
  very 
  oblique. 
  I 
  

   have 
  accordingly 
  been 
  led 
  to 
  suppose 
  that 
  the 
  fault 
  planes 
  in 
  

   the 
  case 
  of 
  the 
  Jury-Trias 
  were 
  examples, 
  and 
  I 
  have 
  referred 
  

   in 
  my 
  Geology 
  to 
  the 
  dip 
  of 
  nearly 
  45° 
  in 
  the 
  East 
  Rock 
  dike 
  

   as 
  having 
  this 
  explanation. 
  Two, 
  three 
  or 
  more 
  such 
  fault- 
  

   planes, 
  coming 
  up 
  from 
  the 
  depths 
  below 
  and 
  entering 
  the 
  

   geosyncline, 
  would 
  have 
  among 
  their 
  effects 
  : 
  (1) 
  the 
  narrowing 
  

   of 
  the 
  arc 
  of 
  the 
  Connecticut 
  valley 
  geanticline 
  ; 
  (2) 
  the 
  forc- 
  

   ing 
  of 
  the 
  sandstone 
  to 
  accommodate 
  itself 
  to 
  the 
  diminished 
  

   width 
  through 
  fractures, 
  faults 
  and 
  displacements 
  ; 
  (3) 
  the 
  pro- 
  

   duction 
  of 
  earth-shakings 
  of 
  great 
  violence 
  which 
  would 
  have 
  

   produced 
  other 
  fractures 
  through 
  the 
  5000 
  feet 
  or 
  so 
  of 
  sand- 
  

   stone 
  and 
  multitudes 
  of 
  pieces 
  by 
  minor 
  fractures. 
  In 
  this 
  

   state 
  of 
  the 
  sandstone, 
  the 
  shoving 
  of 
  it 
  to 
  the 
  westward 
  by 
  the 
  

   westward-and-upward 
  movement 
  of 
  the 
  faulting 
  blocks, 
  would 
  

   make 
  monoclines 
  with 
  eastward 
  dips, 
  and 
  not 
  flexures, 
  because 
  

   the 
  blocks 
  into 
  which 
  the 
  formation 
  had 
  been 
  divided 
  were 
  

   each 
  too 
  short 
  for 
  flexures 
  and 
  the 
  piles 
  of 
  layers 
  would 
  neces- 
  

   sarily, 
  under 
  the 
  circumstances, 
  become 
  pushed 
  up 
  one 
  over 
  

   another. 
  I 
  stated 
  in 
  my 
  former 
  paper 
  that 
  slickensided 
  surfaces 
  

   of 
  the 
  East 
  Haven 
  sandstone 
  covered 
  blocks 
  of 
  all 
  sizes, 
  from 
  

   those 
  no 
  larger 
  than 
  the 
  hand 
  to 
  those 
  constituting 
  large 
  sections 
  

   of 
  a 
  quarry, 
  and 
  also 
  in 
  some 
  places 
  the 
  upper 
  and 
  under 
  surfaces 
  

   of 
  the 
  layers 
  of 
  sandstone 
  ; 
  and 
  this 
  fact 
  accords 
  well 
  with 
  the 
  

   above 
  explanation 
  of 
  the 
  method 
  of 
  upturning. 
  

  

  If 
  this 
  view 
  is 
  the 
  right 
  one, 
  the 
  westward 
  dip 
  of 
  the 
  Jura- 
  

   Trias 
  sandstone 
  in 
  New 
  Jersey 
  and 
  to 
  the 
  south 
  was 
  due 
  to 
  

   fault-planes 
  having 
  a 
  reverse 
  direction 
  from 
  that 
  in 
  the 
  Con- 
  

   necticut 
  valley, 
  that 
  is, 
  a 
  westward 
  dip. 
  The 
  fundamental 
  fact 
  

   awaiting 
  explanation 
  is 
  not, 
  therefore, 
  the 
  opposite 
  directions 
  

   of 
  dip 
  in 
  the 
  Connecticut 
  Valley 
  and 
  ISTew 
  Jersey 
  sandstone, 
  

   but 
  the 
  opposite 
  directions 
  of 
  fault-planes 
  in 
  the 
  subjacent 
  

   rocks. 
  The 
  two 
  directions 
  of 
  strain 
  appear 
  to 
  have 
  anticlinal 
  

   relations. 
  

  

  The 
  above 
  explanations, 
  for 
  the 
  reasons 
  already 
  stated, 
  have 
  

   no 
  reference 
  to 
  the 
  origin 
  of 
  the 
  fissures 
  for 
  the 
  trap 
  ejection. 
  

   If 
  they 
  are 
  mostly 
  of 
  later 
  date 
  than 
  the 
  upturning, 
  tension 
  

   may 
  have 
  had 
  much 
  to 
  do 
  with 
  their 
  production. 
  In 
  any 
  case, 
  

   the 
  old 
  fissure, 
  or 
  part 
  of 
  them, 
  would 
  probably 
  have 
  again 
  

   been 
  used. 
  

  

  