﻿PETROLEUM 
  GEOLOGY 
  — 
  HEROY 
  165 
  

  

  realize 
  that 
  lack 
  of 
  porosity 
  was 
  one 
  of 
  the 
  reasons 
  for 
  lack 
  of 
  com- 
  

   munication 
  but 
  rather 
  attributed 
  it 
  to 
  changes 
  in 
  thickness 
  and 
  lensing. 
  

  

  The 
  presence 
  of 
  an 
  approximately 
  impervious 
  roof 
  over 
  the 
  oil 
  reser- 
  

   voir 
  was, 
  to 
  Orton, 
  the 
  primary 
  requisite 
  of 
  oil 
  accumulation. 
  Source 
  

   beds 
  were 
  plentiful 
  and 
  widely 
  distributed, 
  and 
  various 
  kinds 
  of 
  rocks 
  

   were 
  suitable 
  as 
  reservoirs, 
  but 
  "more 
  interest 
  centers 
  in 
  the 
  roof 
  shales 
  

   or 
  cover 
  than 
  in 
  any 
  other 
  part 
  of 
  the 
  system." 
  The 
  Utica 
  and 
  Hud- 
  

   son 
  River 
  shales 
  overlying 
  the 
  Trenton, 
  the 
  Niagara 
  shale 
  overlying 
  

   the 
  Clinton, 
  and 
  the 
  Cuyahoga 
  shale 
  overlying 
  the 
  Berea 
  were 
  con- 
  

   vincing 
  examples. 
  "It 
  is 
  apparent 
  that 
  the 
  composition 
  and 
  order 
  

   of 
  arrangement 
  of 
  a 
  series 
  of 
  strata 
  have 
  a 
  vitally 
  important 
  relation 
  

   to 
  the 
  accumulation 
  of 
  oil 
  and 
  gas 
  that 
  may 
  take 
  place 
  within 
  it." 
  

  

  Orton 
  accepted 
  the 
  conclusion 
  of 
  Carll 
  (1880) 
  that 
  the 
  yield 
  of 
  oil 
  

   wells 
  was 
  fully 
  accounted 
  for 
  by 
  the 
  presence 
  of 
  the 
  oil 
  in 
  the 
  pores 
  of 
  

   the 
  reservoir 
  and 
  that 
  there 
  was 
  no 
  necessity 
  for 
  resorting 
  to 
  other 
  ex- 
  

   planations, 
  such 
  as 
  "crevices" 
  in 
  the 
  rocks, 
  to 
  account 
  for 
  their 
  

   productivity. 
  

  

  STRUCTURE 
  

  

  The 
  principles 
  of 
  petroleum 
  geology 
  which 
  have 
  just 
  been 
  outlined 
  

   appear 
  to 
  have 
  been 
  quite 
  generally 
  accepted 
  by 
  the 
  geologists 
  who 
  

   were 
  contemporaries 
  of 
  Orton. 
  But 
  in 
  the 
  field 
  of 
  the 
  relation 
  of 
  

   structure 
  to 
  the 
  accumulation 
  of 
  petroleum 
  there 
  was 
  dissension 
  of 
  the 
  

   first 
  order. 
  

  

  I. 
  C. 
  White 
  was 
  connected 
  with 
  the 
  Second 
  Pennsylvania 
  Geological 
  

   Survey 
  from 
  1875 
  to 
  1883, 
  when 
  he 
  resigned 
  and 
  entered 
  commercial 
  

   work. 
  Two 
  years 
  later 
  (1885a) 
  he 
  published 
  his 
  epochal 
  statement 
  

   advocating 
  the 
  anticlinal 
  theory 
  of 
  oil 
  accumulation. 
  The 
  observation 
  

   that 
  accumulations 
  of 
  oil 
  were 
  associated 
  with 
  anticlinal 
  axes 
  had 
  been 
  

   made 
  25 
  years 
  before 
  by 
  several 
  geologists, 
  including 
  Hunt 
  (1861), 
  

   Rogers 
  (1860), 
  and 
  Logan, 
  but 
  their 
  opinions 
  had 
  been 
  forcefully 
  

   opposed 
  by 
  the 
  Director 
  of 
  the 
  Pennsylvania 
  Survey, 
  J. 
  P. 
  Lesley, 
  and 
  

   probably 
  had 
  little 
  influence 
  on 
  oil 
  discovery 
  or 
  development. 
  So 
  im- 
  

   portant 
  was 
  White's 
  revival 
  of 
  this 
  theory 
  that 
  Orton 
  (1888, 
  p. 
  93) 
  pro- 
  

   claimed 
  that 
  his 
  applications 
  of 
  the 
  theory 
  "mark 
  a 
  new 
  period 
  in 
  our 
  

   study 
  of 
  the 
  geology 
  of 
  oil 
  and 
  gas." 
  The 
  following 
  quotation 
  gives 
  

   White's 
  (1885a, 
  pp. 
  521-522) 
  views 
  in 
  his 
  own 
  words. 
  

  

  After 
  visiting 
  all 
  the 
  great 
  gas 
  wells 
  that 
  had 
  been 
  struck 
  in 
  western 
  Pennsyl- 
  

   vania 
  and 
  West 
  Virginia, 
  and 
  carefully 
  examining 
  the 
  geological 
  surroundings 
  of 
  

   each, 
  I 
  found 
  that 
  every 
  one 
  of 
  them 
  was 
  situated 
  either 
  directly 
  on, 
  or 
  near, 
  the 
  

   crown 
  of 
  an 
  anticlinal 
  axis, 
  while 
  wells 
  that 
  had 
  been 
  bored 
  in 
  the 
  synclines 
  on 
  

   either 
  side 
  furnished 
  little 
  or 
  no 
  gas, 
  but 
  in 
  many 
  cases 
  large 
  quantities 
  of 
  salt 
  

   water. 
  Further 
  observation 
  showed 
  that 
  the 
  gas 
  wells 
  were 
  confined 
  to 
  a 
  narrow 
  

   belt, 
  only 
  one-fourth 
  to 
  1 
  mile 
  wide, 
  along 
  the 
  crests 
  of 
  the 
  anticlinal 
  folds. 
  These 
  

   facts 
  seem 
  to 
  connect 
  gas 
  territory 
  unmistakably 
  with 
  the 
  disturbance 
  in 
  the 
  

   rocks 
  caused 
  by 
  their 
  upheaval 
  into 
  arches, 
  but 
  the 
  crucial 
  test 
  was 
  yet 
  to 
  be 
  

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