﻿418 
  Wadsworth—Trap 
  Range 
  of 
  Keweenawan 
  Series. 
  

  

  although 
  far 
  from 
  being 
  as 
  decisive 
  as 
  could 
  be 
  wished, 
  yet 
  

   the 
  observations 
  would 
  appear 
  to 
  be 
  of 
  considerable 
  interest 
  

   and 
  importance. 
  

  

  " 
  Silver 
  Mt." 
  (Sec. 
  1, 
  T. 
  49, 
  R 
  36 
  W.) 
  was 
  found 
  to 
  be 
  com- 
  

   posed 
  of 
  interbedded 
  lava 
  flows, 
  of 
  which 
  at 
  least 
  ten 
  flows 
  

   were 
  made 
  out 
  with 
  more 
  or 
  less 
  certainty. 
  These 
  flows 
  dip 
  

   to 
  the 
  northwest 
  at 
  an 
  angle 
  of 
  from 
  ten 
  to 
  sixteen 
  degrees. 
  

   ~No 
  sandstone 
  was 
  found 
  nearer 
  than 
  two 
  miles. 
  This 
  has 
  a 
  

   slight 
  dip 
  to 
  the 
  northwest. 
  On 
  Sec. 
  29, 
  T. 
  47, 
  E. 
  37 
  W., 
  a 
  

   series 
  of 
  melaphyr 
  flows 
  were 
  observed 
  dipping 
  at 
  a 
  low 
  angle 
  

   to 
  the 
  north 
  or 
  a 
  little 
  west 
  of 
  north. 
  The 
  angle 
  of 
  their 
  

   greatest 
  inclination 
  being 
  from 
  15° 
  to 
  '20°. 
  

  

  These 
  flows 
  are 
  interbedded 
  with 
  sandstone 
  which 
  holds 
  

   fragments 
  of 
  the 
  melaphyr. 
  A 
  felsite 
  dike 
  also 
  cuts 
  through 
  

   the 
  beds. 
  

  

  Similar 
  lava 
  beds 
  are 
  found 
  on 
  Sec. 
  25, 
  T. 
  47, 
  K. 
  38 
  W., 
  

   and 
  Sec. 
  30, 
  T. 
  47, 
  K. 
  37 
  W., 
  which 
  lie 
  at 
  a 
  low 
  angle, 
  9° 
  

   to 
  16° 
  north 
  or 
  a 
  little 
  west 
  of 
  north 
  ; 
  while 
  on 
  Sec. 
  1, 
  T. 
  46, 
  

   R. 
  39, 
  the 
  flows 
  dip 
  from 
  9° 
  to 
  20°, 
  the 
  principal 
  dip 
  being 
  to 
  

   the 
  north 
  at 
  an 
  angle 
  of 
  14°. 
  Outcrops 
  of 
  the 
  same 
  old 
  

   basaltic 
  rocks 
  occur 
  on 
  Sec. 
  35, 
  T. 
  47, 
  R 
  38 
  W. 
  and 
  Sec. 
  8, 
  

   T. 
  46, 
  R. 
  39 
  W., 
  which 
  show 
  a 
  very 
  low 
  inclination. 
  

  

  The 
  most 
  important 
  observations 
  were 
  made 
  in 
  Sees. 
  11, 
  13 
  

   and 
  14, 
  T. 
  46, 
  R. 
  41 
  W., 
  where 
  the 
  sandstone 
  was 
  found 
  over- 
  

   laid 
  by 
  some 
  of 
  the 
  lava 
  flows. 
  The 
  sandstone 
  is 
  found 
  in 
  con- 
  

   tact 
  with 
  schists 
  presumably 
  of 
  the 
  Archaean 
  or 
  Azoic 
  Age. 
  

   The 
  base 
  of 
  the 
  sandstone 
  is 
  of 
  a 
  conglomeritic 
  character 
  com- 
  

   posed 
  of 
  rolled 
  pebbles 
  of 
  quartz 
  cemented 
  by 
  an 
  argillaceous 
  

   matrix 
  formed 
  from 
  the 
  debris 
  of 
  the 
  underlying 
  steeply 
  in- 
  

   clined 
  and 
  contorted 
  schists. 
  This 
  sandstone 
  dips 
  at 
  a 
  low 
  

   angle 
  of 
  from 
  12° 
  to 
  14° 
  northerly, 
  its 
  strike 
  being 
  S. 
  60° 
  E. 
  

  

  The 
  conglomerate 
  passes 
  into 
  a 
  coarse 
  reddish 
  sandstone 
  

   which 
  can 
  be 
  traced 
  in 
  pits 
  and 
  exposures 
  northwesterly, 
  

   where 
  the 
  same 
  coarse 
  red 
  sandstone 
  is 
  seen 
  to 
  pass 
  up 
  into 
  a 
  

   fine 
  grained 
  indurated 
  sandstone 
  or 
  quartzite, 
  which 
  in 
  its 
  turn 
  

   passes 
  into 
  a 
  fine-grained 
  indurated 
  argillaceous 
  schist 
  and 
  chert. 
  

   This 
  indurated 
  zone 
  is 
  in 
  immediate 
  contact 
  with 
  the 
  over- 
  

   lying 
  lava 
  flow 
  of 
  the 
  south 
  trap 
  range. 
  The 
  structure 
  here 
  is 
  

   apparently 
  that 
  of 
  a 
  series 
  of 
  flows 
  arising 
  along 
  a 
  pipe 
  or 
  fis- 
  

   sure, 
  and 
  shows 
  the 
  remains 
  of 
  the 
  solidified 
  neck 
  with 
  the 
  

   downward 
  bent 
  sandstone 
  or 
  schist 
  strata, 
  together 
  with 
  the 
  

   strong 
  induration 
  produced 
  by 
  the 
  overflowing 
  lava. 
  The 
  

   structure 
  is 
  indicated 
  in 
  the 
  accompanying 
  figure. 
  

  

  It 
  may 
  be 
  remembered 
  that 
  this 
  structure 
  is 
  similar 
  to 
  that 
  

   observed 
  by 
  the 
  present 
  writer 
  in 
  1879, 
  on 
  the 
  Douglass 
  

   Houghton 
  and 
  Hungarian 
  Rivers, 
  except 
  that 
  at 
  the 
  latter 
  two 
  

   places 
  much 
  decomposition 
  has 
  occurred, 
  leaving 
  it 
  a 
  disputed 
  

  

  