﻿R. 
  L. 
  Smyth 
  — 
  Geology 
  of 
  Steep 
  Rock 
  Lake, 
  Ont. 
  327 
  

  

  posed, 
  the 
  shore 
  line 
  again 
  crosses 
  the 
  intermediate 
  formations 
  

   in 
  descending 
  order, 
  the 
  strikes 
  bending 
  round 
  gradually 
  to 
  N. 
  

   20° 
  E. 
  A 
  line 
  drawn 
  a 
  little 
  west 
  of 
  south 
  through 
  the 
  eastern 
  

   point 
  of 
  the 
  limestone 
  of 
  the 
  Elbow 
  marks 
  the 
  intersection 
  of 
  

   the 
  axial 
  plane 
  of 
  the 
  middle 
  anticlinal 
  with 
  a 
  horizontal 
  plane. 
  

   West 
  of 
  this 
  line 
  the 
  limestone 
  of 
  the 
  Elbow, 
  Formation 
  VI, 
  

   and 
  the 
  various 
  members 
  of 
  Formation 
  VII, 
  which 
  alone 
  are 
  

   exposed 
  on 
  the 
  southern 
  and 
  western 
  shore, 
  strike 
  again 
  to 
  the 
  

   northwest, 
  gradually 
  bending 
  round 
  along 
  the 
  latter 
  to 
  the 
  

   east 
  of 
  north. 
  The 
  limestone 
  at 
  Conglomerate 
  Bay 
  abuts 
  

   against 
  a 
  cliff 
  of 
  the 
  basement 
  granite, 
  the 
  line 
  of 
  separation 
  

   marking 
  the 
  position 
  of 
  a 
  fault. 
  About 
  6000 
  feet 
  S.W. 
  along 
  

   the 
  line 
  of 
  this 
  fault, 
  which 
  is 
  well 
  marked 
  by 
  a 
  breccia 
  in 
  the 
  

   peninsula 
  N.W. 
  of 
  the 
  upper 
  narrows, 
  Formations 
  I 
  and 
  II 
  are 
  

   found 
  again 
  on 
  the 
  opposite 
  side, 
  striking 
  N.W., 
  and 
  farther 
  

   north 
  on 
  the 
  large 
  island 
  in 
  N.W. 
  Bay, 
  bending 
  round 
  again 
  

   to 
  the 
  southwest. 
  On 
  the 
  west 
  shore 
  of 
  the 
  lake 
  west 
  of 
  N.W. 
  

   Bay 
  green 
  slates, 
  probably 
  belonging 
  to 
  Formation 
  VII, 
  are 
  

   found 
  west 
  of 
  Formation 
  II, 
  and 
  again 
  on 
  Birch 
  Point 
  indicat- 
  

   ing 
  another 
  fault 
  which 
  trends 
  to 
  the 
  west 
  of 
  north. 
  These 
  

   two 
  faults 
  so 
  complicate 
  the 
  structure 
  of 
  the 
  western 
  part 
  of 
  

   the 
  lake, 
  that 
  the 
  relations 
  of 
  the 
  rocks, 
  which 
  are 
  all 
  recog- 
  

   nizable 
  as 
  belonging 
  to 
  one 
  or 
  another 
  of 
  the 
  IX 
  formations 
  

   of 
  the 
  series, 
  could 
  not 
  be 
  worked 
  out 
  in 
  the 
  time 
  available. 
  

  

  There 
  are 
  two 
  points 
  in 
  the 
  general 
  structure 
  of 
  the 
  rocks 
  

   of 
  the 
  lake 
  which 
  are 
  especially 
  noteworthy 
  and 
  significant. 
  

   They 
  are 
  : 
  

  

  1st. 
  The 
  high 
  pitch 
  of 
  the 
  axes 
  of 
  the 
  great 
  folds. 
  At 
  the 
  

   turn 
  of 
  the 
  middle 
  anticlinal 
  at 
  the 
  Elbow, 
  dips, 
  which 
  are 
  

   well 
  marked 
  in 
  the 
  limestone, 
  range 
  from 
  vertical 
  to 
  75° 
  to 
  

   the 
  south, 
  (Section 
  II.) 
  At 
  the 
  turn 
  of 
  the 
  western 
  synclinal 
  

   in 
  Northwest 
  Bay 
  the 
  dip 
  is 
  about 
  60° 
  in 
  the 
  same 
  direction. 
  

   We 
  have 
  here, 
  then, 
  folds 
  with 
  very 
  high 
  south-pitching 
  axes, 
  

   the 
  pitch 
  in 
  the 
  case 
  of 
  the 
  anticlinal 
  being 
  nearly 
  90° 
  and 
  in 
  

   the 
  case 
  of 
  the 
  synclinal 
  at 
  a 
  lower 
  angle. 
  In 
  the 
  case 
  of 
  the 
  

   eastern 
  synclinal 
  the 
  pitch 
  is 
  also 
  high, 
  though 
  apparently 
  

   considerably 
  less 
  than 
  90°, 
  as 
  indicated 
  by 
  the 
  greater 
  thick- 
  

   ness 
  of 
  the 
  series 
  measured 
  along 
  the 
  axis 
  than 
  across 
  it. 
  The 
  

   Steep 
  Bock 
  series 
  therefore 
  dips 
  away 
  from 
  the 
  granites, 
  at 
  

   the 
  turns 
  of 
  folds, 
  at 
  angles 
  which 
  do 
  not 
  differ 
  materially 
  

   from 
  those 
  observed 
  in 
  the 
  long 
  straight 
  stretches 
  ; 
  as, 
  for 
  

   example, 
  that 
  in 
  East 
  Bay. 
  

  

  2nd. 
  The 
  regional 
  cleavage. 
  Throughout 
  the 
  whole 
  area 
  

   is 
  observed 
  a 
  regional 
  cleavage, 
  which 
  has 
  a 
  tolerably 
  uniform 
  

   direction 
  between 
  the 
  limits 
  N. 
  38° 
  and 
  N. 
  48° 
  E., 
  and 
  trav- 
  

   erses 
  all 
  the 
  rocks 
  of 
  the 
  region, 
  both 
  the 
  eruptive 
  and 
  sedi- 
  

   mentary 
  members 
  of 
  the 
  Steep 
  Rock 
  Series, 
  and 
  the 
  rocks 
  of 
  

   basement 
  complex. 
  It 
  has 
  largely 
  obliterated 
  the 
  original 
  

  

  