﻿50 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  derived 
  from 
  a 
  feldspathic 
  sandstone 
  or 
  arkose. 
  The 
  hornblende 
  

   gneiss 
  and 
  mica 
  schist 
  on 
  the 
  other 
  hand, 
  are 
  doubtless 
  to 
  be 
  

   referred 
  to 
  an 
  argillaceous 
  deposit, 
  and 
  the 
  crystalline 
  limestone 
  to 
  

   a 
  calcareous 
  one. 
  The 
  order 
  of 
  succession 
  presented 
  by 
  the 
  series 
  is 
  

   thus 
  a 
  normal 
  one, 
  such 
  as 
  is 
  found 
  in 
  sedimentary 
  strata 
  which 
  

   have 
  been 
  deposited 
  on 
  a 
  gradually 
  sinking 
  shore 
  line. 
  

  

  Description 
  of 
  the 
  mines 
  

  

  Hammondville 
  mines. 
  The 
  accompanying 
  plan, 
  reproduced 
  

   from 
  the 
  original 
  recently 
  prepared 
  by 
  the 
  Oliver 
  Iron 
  Mining 
  

   Co., 
  indicates 
  the 
  distribution 
  of 
  the 
  principal 
  deposits 
  and 
  to 
  

   some 
  extent 
  their 
  underground 
  continuations. 
  The 
  mine 
  maps 
  

   of 
  the 
  Crown 
  Point 
  Iron 
  Co. 
  have 
  unfortunately 
  been 
  destroyed 
  

   and 
  complete 
  details 
  regarding 
  the 
  workings 
  can 
  no 
  longer 
  be 
  had. 
  

   The 
  present 
  plan 
  has 
  been 
  compiled 
  from 
  such 
  records 
  as 
  are 
  still 
  

   available 
  and 
  from 
  the 
  results 
  of 
  diamond 
  drilling; 
  it 
  can 
  be 
  relied 
  

   upon 
  no 
  doubt 
  as 
  reproducing 
  the 
  more 
  important 
  features 
  [fig. 
  3]. 
  

  

  The 
  deposits 
  in 
  all 
  cases 
  are 
  surrounded 
  by 
  the 
  plagioclase 
  gneiss 
  

   which 
  has 
  been 
  called 
  the 
  ore-bearing 
  formation. 
  They 
  show 
  no 
  

   relation 
  to 
  the 
  latter 
  in 
  the 
  way 
  of 
  gradation, 
  but 
  have 
  well 
  defined 
  

   boundaries. 
  The 
  only 
  noticeable 
  change 
  in 
  the 
  gneiss 
  as 
  the 
  ore 
  

   bodies 
  are 
  approached 
  consists 
  in 
  an 
  increased 
  proportion 
  of 
  mag- 
  

   netite, 
  which 
  gives 
  it 
  a 
  somewhat 
  darker 
  appearance, 
  and 
  the 
  

   development 
  at 
  times 
  of 
  a 
  hematite 
  stain 
  resulting 
  from 
  the 
  oxida- 
  

   tion 
  of 
  this 
  mineral. 
  The 
  magnetite 
  seldom 
  amounts 
  to 
  more 
  than 
  

   5 
  per 
  cent 
  of 
  the 
  whole. 
  

  

  In 
  their 
  arrangement 
  and 
  form 
  the 
  deposits 
  are 
  characterized 
  by 
  

   great 
  irregularity. 
  Over 
  30 
  different 
  openings 
  have 
  been 
  made 
  on 
  

   as 
  many 
  ore 
  bodies. 
  Whether 
  or 
  not 
  they 
  occupy 
  a 
  definite 
  hori- 
  

   zon 
  in 
  the 
  gneiss 
  scarcely 
  admits 
  of 
  determination, 
  because 
  the 
  

   foliation 
  of 
  the 
  latter 
  is 
  so 
  obscure 
  that 
  little 
  can 
  be 
  learned 
  as 
  to 
  

   the 
  stratigraphic 
  structure. 
  Putnam 
  has 
  expressed 
  the 
  view 
  that 
  

   they 
  do 
  occur 
  in 
  such 
  a 
  relation. 
  With 
  due 
  allowance, 
  however, 
  

   for 
  folding 
  and 
  faulting, 
  the 
  existence 
  of 
  which 
  has 
  been 
  estab- 
  

   lished 
  in 
  the 
  ore 
  bodies 
  themselves, 
  it 
  would 
  be 
  difficult 
  to 
  bring 
  

   them 
  all 
  into 
  alinement, 
  and 
  it 
  is 
  more 
  likely 
  that 
  there 
  were 
  

   originally 
  two 
  or 
  three 
  parallel 
  series 
  of 
  deposits, 
  probably 
  tabular 
  

   in 
  shape; 
  by 
  compression 
  and 
  displacement 
  these 
  have 
  been 
  folded 
  

   and 
  broken 
  up 
  into 
  the 
  large 
  number 
  of 
  lenses, 
  shoots, 
  pockets 
  and 
  

   bands 
  now 
  distributed 
  with 
  little 
  apparent 
  order. 
  The 
  strike 
  per- 
  

   haps 
  in 
  the 
  majority 
  of 
  cases 
  is 
  northeasterly, 
  but 
  it 
  is 
  sometimes 
  

   nearly 
  east 
  and 
  west 
  and 
  occasionally 
  northwest. 
  The 
  dip 
  is 
  more 
  

  

  