﻿44 
  N£ 
  W 
  YORK 
  STATE 
  MUSEUM 
  

  

  largely 
  of 
  rather 
  homogeneous, 
  serpentinous 
  material 
  (bluish 
  gray 
  

   interference 
  tints) 
  which 
  is 
  apparently 
  igneous 
  glass 
  into 
  which 
  ser- 
  

   pentine 
  marble 
  has 
  been 
  fused. 
  Occasional 
  well-formed 
  laths 
  of 
  

   plagioclase 
  and 
  many 
  specks 
  of 
  magnetite 
  occur. 
  The 
  outer 
  I 
  or 
  

   2 
  millimeters 
  of 
  this 
  zone 
  are 
  very 
  rich 
  in 
  magnetite 
  specks. 
  This 
  

   zone 
  shows 
  a 
  rapid 
  transition 
  into 
  the 
  next 
  one. 
  

  

  Zone 
  4 
  One-third 
  of 
  an 
  inch 
  wide. 
  Reddish 
  brown, 
  glassy 
  look- 
  

   ing. 
  Apparently 
  good 
  igneous 
  glass 
  filled 
  with 
  many 
  tiny 
  specks 
  of 
  

   what 
  seem 
  to 
  be 
  magnetite 
  and 
  perhaps 
  io 
  per 
  cent 
  of 
  plagioclase 
  

   mostly 
  in 
  laths 
  but 
  some 
  in 
  stout 
  prisms 
  with 
  distinct 
  zonal 
  struc- 
  

   ture. 
  This 
  grades 
  perfectly 
  into 
  the 
  next 
  zone. 
  

  

  Zone 
  5 
  One-half 
  of 
  an 
  inch 
  wide. 
  Pale 
  green 
  color 
  and 
  much 
  

   like 
  no. 
  4 
  except 
  for 
  absence 
  of 
  the 
  tiny 
  specks. 
  The 
  green 
  color 
  

   is 
  due 
  to 
  serpentinous 
  material 
  which 
  appears 
  to 
  have 
  been 
  absorbed 
  

   by 
  the 
  molten 
  mass. 
  The 
  contact 
  between 
  this 
  and 
  the 
  next 
  zone 
  is 
  

   rugged 
  though 
  pretty 
  sharp. 
  

  

  Zone 
  6 
  Ordinary 
  bluish 
  black 
  diabase 
  from 
  within 
  the 
  dike 
  and 
  

   with 
  no 
  serpentinous 
  admixture. 
  This 
  rock 
  is 
  mostly 
  a 
  dark 
  glass 
  

   which 
  contains 
  5 
  per 
  cent 
  plagioclase 
  laths 
  and 
  5 
  per 
  cent 
  pale 
  red- 
  

   dish 
  brown, 
  euhedral 
  augite 
  crystals 
  and 
  numerous 
  specks 
  of 
  pre- 
  

   sumably 
  magnetite. 
  

  

  PALEOZOIC 
  OUTLIERS 
  

  

  No 
  actual 
  outcrop 
  of 
  Paleozoic 
  strata 
  has 
  been 
  found 
  within 
  the 
  

   borders 
  of 
  the 
  quadrangle, 
  but 
  certain 
  nearby 
  Paleozoic 
  outliers 
  

   have 
  an 
  important 
  bearing 
  upon 
  the 
  geologic 
  history 
  of 
  the 
  region. 
  

   Two 
  of 
  these 
  outliers 
  have 
  been 
  described 
  by 
  Professor 
  Kemp, 
  one 
  

   of 
  them 
  being 
  Little 
  Falls 
  dolomite 
  which 
  occurs 
  at 
  Schroon 
  Lake 
  

   village 
  (Schroon 
  Lake 
  sheet), 
  and 
  the 
  other 
  being 
  Potsdam 
  sand- 
  

   stone 
  which 
  occurs 
  near 
  the 
  village 
  of 
  North 
  River 
  (Thirteenth 
  

   Lake 
  sheet). 
  

  

  During 
  the 
  summer 
  of 
  1910 
  the 
  writer 
  discovered 
  a 
  small 
  Paleo- 
  

   zoic 
  outlier 
  1 
  mile 
  south 
  of 
  the 
  map 
  edge 
  and 
  1 
  mile 
  due 
  west 
  of 
  

   High 
  Street 
  village 
  (Luzerne 
  sheet). 
  The 
  exposures 
  are 
  rather 
  poor 
  

   and 
  small 
  but 
  the 
  rock 
  is 
  quite 
  certainly 
  in 
  place 
  with 
  the 
  strata 
  

   lying 
  in 
  nearly 
  horizontal 
  position. 
  Both 
  sandstone 
  and 
  dolomite 
  

   beds 
  occur 
  and 
  it 
  is 
  not 
  certain 
  whether 
  the 
  rocks 
  represent 
  the 
  pas- 
  

   sage 
  beds 
  of 
  the 
  Theresa 
  formation 
  or 
  the 
  contact 
  between 
  the 
  Pots- 
  

   dam 
  and 
  the 
  Little 
  Falls 
  dolomite, 
  though 
  the 
  former 
  is 
  more 
  prob- 
  

   able. 
  This 
  outlier 
  lies 
  at 
  1400 
  feet 
  elevation 
  and 
  not 
  far 
  to 
  the 
  west 
  

   of 
  the 
  No. 
  9 
  mountain 
  fault 
  and 
  on 
  its 
  downthrow 
  side. 
  

  

  