﻿GEOLOGY 
  OF 
  THE 
  NORTH 
  CREEK 
  QUADRANGLE 
  TI 
  

  

  pyrrhotite 
  scattered 
  through 
  the 
  mass. 
  The 
  quartz 
  grains 
  usually 
  

   range 
  in 
  size 
  up 
  to 
  five 
  or 
  six 
  millimeters 
  and 
  stand 
  out 
  as 
  pale 
  

   straw 
  yellow 
  or 
  clear 
  masses 
  in 
  very 
  bold 
  relief 
  upon 
  the 
  weath- 
  

   ered 
  surfaces. 
  Tiny 
  garnet 
  and 
  green 
  pyroxene 
  crystals 
  are 
  rarely 
  

   present. 
  This 
  variety 
  is 
  also 
  widely 
  distributed 
  and 
  among 
  many 
  

   other 
  good 
  outcrops 
  are: 
  just 
  east 
  of 
  North 
  Creek; 
  at 
  the 
  Natural 
  

   Bridge; 
  just 
  south 
  of 
  Crane 
  mountain; 
  and 
  iy 
  2 
  miles 
  due 
  north 
  of 
  

   Warrensburg. 
  

  

  A 
  third 
  variety 
  which 
  is 
  rather 
  widely 
  distributed 
  though 
  not 
  

   so 
  common 
  as 
  those 
  above 
  described 
  may 
  be 
  called 
  serpentine 
  lime- 
  

   stone 
  or 
  green 
  marble. 
  One 
  kind 
  of 
  this 
  rock 
  is 
  medium-grained, 
  

   nearly 
  white, 
  crystalline 
  limestone 
  but 
  with 
  many 
  large 
  blotches 
  

   or 
  irregular 
  streaks 
  of 
  dark 
  to 
  light 
  olive 
  green 
  serpentine 
  scattered 
  

   through 
  it. 
  A 
  second 
  kind 
  has 
  scattered 
  through 
  it 
  numerous 
  

   specks 
  of 
  serpentine 
  or 
  small 
  pale 
  green 
  serpentinized 
  pyroxenes. 
  

   Different 
  names 
  have 
  been 
  applied 
  to 
  this 
  green 
  marble 
  which 
  has 
  

   been 
  briefly 
  described 
  by 
  G. 
  P. 
  Merrill 
  who 
  says 
  1 
  : 
  " 
  The 
  serpen- 
  

   tine 
  in 
  the 
  Warren 
  county 
  Ophiolite, 
  Ophicalcite 
  or 
  Verdantique 
  

   as 
  it 
  has 
  been 
  variously 
  called, 
  is 
  an 
  alteration 
  or 
  metasomatic 
  

   product 
  after 
  a 
  mineral 
  of 
  the 
  pyroxene 
  group. 
  The 
  original 
  rock 
  

   would 
  appear 
  to 
  have 
  been 
  simply 
  a 
  pyroxenic 
  limestone, 
  the 
  py- 
  

   roxene 
  occurring 
  either 
  in 
  scattering 
  granules 
  or 
  in 
  granular 
  aggre- 
  

   gates 
  of 
  considerable 
  size." 
  Among 
  other 
  places 
  this 
  green 
  marble 
  

   is 
  well 
  shown 
  in 
  the 
  quarries 
  one-half 
  of 
  a 
  mile 
  southwest 
  and 
  

   three-fourths 
  of 
  a 
  mile 
  southeast 
  of 
  Thurman 
  village, 
  and 
  in 
  the 
  

   prospect 
  hole 
  at 
  the 
  western 
  base 
  of 
  Hackensack 
  mountain. 
  

  

  Pure 
  white 
  tremolite 
  crystals 
  are 
  sometimes 
  closely 
  associated 
  

   with 
  the 
  limestone 
  as 
  in 
  many 
  outcrops 
  about 
  a' 
  mile 
  east 
  of 
  Little 
  

   mountain 
  pond. 
  One 
  and 
  one-half 
  miles 
  due 
  north 
  of 
  Warrens- 
  

   burg 
  irregular 
  streaks 
  or 
  veins 
  of 
  tremolite, 
  quartz, 
  pyroxene, 
  and 
  

   titanite 
  are 
  closely 
  involved 
  with 
  the 
  limestone. 
  The 
  tremolite 
  

   crystals 
  are 
  up 
  to 
  two 
  inches 
  long 
  and 
  the 
  green 
  pyroxenes 
  up 
  to 
  

   one-quarter 
  of 
  an 
  inch 
  and 
  perfectly 
  formed. 
  

  

  Asbestos 
  veins 
  sometimes' 
  occur 
  in 
  the 
  serpentine 
  marble, 
  these 
  

   being 
  best 
  shown 
  at 
  the 
  asbestos 
  mine 
  three-quarters 
  of 
  a 
  mile 
  

   southeast 
  of 
  Thurman 
  where 
  numerous 
  veins 
  attain 
  a 
  width 
  up 
  to 
  

   three-quarters 
  of 
  an 
  inch. 
  

  

  Green 
  pyroxene 
  or 
  rusty 
  biotite 
  gneisses 
  are 
  sometimes 
  involved 
  

   in 
  the 
  contorted 
  limestone 
  in 
  the 
  form 
  of 
  streaks 
  or 
  inclusions 
  

   which 
  have 
  been 
  drawn 
  out 
  or 
  broken 
  by 
  the 
  pressure. 
  See 
  figure 
  

   9 
  and 
  plate 
  12. 
  

  

  1 
  Amer. 
  Jour. 
  Sci., 
  Mar. 
  1889, 
  p. 
  191. 
  

  

  