﻿GEOLOGY 
  OF 
  THE 
  NORTH 
  CREEK 
  QUADRANGLE 
  55 
  

  

  valley 
  of 
  Minerva 
  stream. 
  From 
  North 
  Creek 
  to 
  the 
  map 
  edge 
  

   the 
  line 
  of 
  the 
  fault 
  is 
  marked 
  by 
  a 
  distinct 
  depression 
  which 
  has 
  

   been 
  formed 
  along 
  the 
  belt 
  of 
  weakness. 
  Except 
  near 
  the 
  Hudson 
  

   river 
  where 
  the 
  weak 
  Grenville 
  is 
  crossed 
  by 
  the 
  fault, 
  a 
  well- 
  

   defined 
  fault 
  scarp 
  forms 
  the 
  upthrow 
  side 
  on 
  the 
  west 
  and 
  it 
  is 
  

   important 
  to 
  note 
  that 
  this 
  scarp 
  strikes 
  at 
  a 
  high 
  angle 
  across 
  the 
  

   foliation 
  of 
  the 
  rocks, 
  thus 
  proving 
  the 
  independence 
  of 
  the 
  fault 
  

   and 
  foliation 
  planes. 
  One 
  and 
  one-fourth 
  miles 
  north 
  of 
  North 
  

   Creek 
  decomposed 
  and 
  somewhat 
  crushed 
  granite 
  marks 
  the 
  passage 
  

   of 
  the 
  fault. 
  Just 
  at 
  the 
  map 
  edge 
  the 
  eastern 
  face 
  of 
  the 
  Moxham 
  

   mountain 
  mass 
  is 
  a 
  fine 
  illustration 
  of 
  a 
  steep 
  fault 
  scarp 
  rising 
  to 
  

   a 
  height 
  of 
  900 
  feet. 
  Since 
  the 
  fault 
  here 
  passes 
  through 
  a 
  great 
  

   mass 
  of 
  rather 
  homogeneous, 
  igneous 
  rock, 
  it 
  is 
  certain 
  that 
  the 
  

   amount 
  of 
  displacement 
  is 
  not 
  less 
  than 
  1000 
  feet. 
  An 
  interesting 
  

   feature 
  is 
  the 
  large 
  inclusion 
  of 
  Grenville 
  gneiss 
  just 
  south 
  of 
  

   Moxham 
  mountain; 
  it 
  occupies 
  such 
  an 
  unusual 
  position 
  because 
  

   it 
  lies 
  on 
  the 
  upthrow 
  side 
  of 
  the 
  fault 
  in 
  a 
  place 
  fairly 
  well 
  pro- 
  

   tected 
  from 
  erosion. 
  

  

  In 
  the 
  stone 
  quarry 
  just 
  east 
  of 
  the 
  main 
  fault 
  and 
  near 
  the 
  

   map 
  edge, 
  a 
  fault 
  plane 
  with 
  breccia 
  is 
  clearly 
  exposed 
  in 
  both 
  walls 
  

   of 
  the 
  quarry. 
  Its 
  strike 
  is 
  north 
  30 
  east 
  and 
  it 
  appears 
  to 
  be 
  a 
  

   minor 
  fracture 
  parallel 
  to 
  the 
  larger 
  one. 
  

  

  At 
  the 
  map 
  edge 
  a 
  fault 
  branches 
  off 
  the 
  main 
  line 
  of 
  fracture 
  

   and 
  follows 
  the 
  steep 
  mountain 
  side 
  to 
  Fuller 
  pond. 
  Just 
  east 
  of 
  

   the 
  pond 
  the 
  scarp 
  of 
  Grenville 
  gneiss 
  rises 
  almost 
  vertically 
  for 
  

   several 
  hundred 
  feet. 
  

  

  South 
  of 
  the 
  village 
  the 
  North 
  Creek 
  fault 
  is 
  clearly 
  traceable 
  

   by 
  the 
  steep 
  mountain 
  sides 
  of 
  igneous 
  rock 
  against 
  which 
  the 
  

   Grenville 
  comes 
  in 
  contact 
  along 
  a 
  straight 
  or 
  at 
  least 
  very 
  regular 
  

   line 
  as 
  far 
  south 
  as 
  Baker's 
  Mills 
  (Thirteenth 
  Lake 
  sheet). 
  

  

  Holcombville 
  fault. 
  There 
  is 
  considerable 
  evidence 
  for 
  a 
  fault 
  

   with 
  a 
  northwest-southeast 
  strike 
  along 
  a 
  nearly 
  straight 
  line 
  pass- 
  

   ing 
  through 
  the 
  village 
  of 
  Holcombville. 
  It 
  is 
  represented 
  by 
  a 
  

   broken 
  line 
  on 
  the 
  map 
  because 
  its 
  presence 
  is 
  not 
  regarded 
  as 
  con- 
  

   clusive. 
  It 
  is 
  thought 
  to 
  extend 
  for 
  some 
  miles 
  into 
  the 
  Thirteenth 
  

   Lake 
  quadrangle 
  or 
  nearly 
  to 
  the 
  village 
  of 
  North 
  River. 
  The 
  chief 
  

   evidences 
  for 
  faulting 
  are 
  the 
  long, 
  straight 
  contacts 
  of 
  the 
  Gren- 
  

   ville 
  against 
  the 
  bases 
  of 
  the 
  high 
  Oven 
  mountain 
  mass 
  of 
  igneous 
  

   rock 
  and 
  the 
  great 
  mass 
  of 
  syenite 
  within 
  the 
  Thirteenth 
  Lake 
  sheet. 
  

   No 
  shear 
  zones 
  were 
  noted 
  and 
  the 
  usual 
  steep 
  scarp 
  and 
  the 
  tilted 
  

   character 
  of 
  the 
  fault 
  block 
  are 
  absent. 
  

  

  