﻿Report 
  of 
  the 
  State 
  Geologist. 
  609 
  

  

  rusty 
  color, 
  alternating 
  with 
  lighter-colored 
  quartzitic 
  beds, 
  of 
  

   which 
  one 
  conspicuous 
  member 
  is 
  alight-gray 
  quartzite 
  about 
  four 
  

   feet 
  thick. 
  The 
  total 
  thickness 
  exposed 
  is 
  about 
  twenty-five 
  

   feet. 
  The 
  relations 
  of 
  this 
  outlier 
  are 
  shown 
  in 
  figure 
  2. 
  

  

  

  Fig. 
  2. 
  — 
  Cross-section 
  of 
  Sacandaga 
  Valley, 
  at 
  Wells, 
  Hamilton 
  county, 
  N. 
  Y. 
  Looking 
  

   north. 
  U., 
  Utica 
  slate; 
  T., 
  Trenton 
  limestone; 
  C, 
  Calciferous 
  sandstone; 
  P., 
  Potsdam 
  sand- 
  

   stone; 
  A., 
  Crystalline 
  rocks; 
  D., 
  Drift. 
  

  

  The 
  exposures 
  of 
  Potsdam 
  sandstones 
  west 
  of 
  Johnstown 
  are 
  

   on 
  the 
  high 
  ridge 
  west 
  of 
  the 
  " 
  ^Noses 
  " 
  fault 
  scarp 
  and 
  cover 
  an 
  

   extensive 
  area. 
  The 
  formation 
  consists 
  of 
  light 
  colored, 
  rather 
  

   massive 
  sandstones. 
  They 
  are 
  moderately 
  soft, 
  but 
  usually 
  

   quartzitic 
  near 
  the 
  contact 
  with 
  the 
  crystalline 
  rocks. 
  The 
  contact 
  

   with 
  the 
  crystalline 
  rocks 
  was 
  not 
  observed, 
  but 
  it 
  was 
  seen 
  

   that 
  there 
  is 
  no 
  conglomerate 
  exposed 
  in 
  their 
  vicinity. 
  The 
  

   best 
  exposure 
  in 
  this 
  region 
  is 
  in 
  a 
  quarry 
  along 
  the 
  road, 
  half 
  a 
  

   mile 
  north 
  of 
  Keek's 
  Centre, 
  where 
  twenty 
  feet 
  of 
  cream- 
  

   colored 
  sandstones 
  are 
  exhibited 
  in 
  beds 
  two 
  to 
  three 
  feet 
  thick. 
  

   Near 
  their 
  base 
  there 
  is 
  a 
  thin 
  intercalation 
  of 
  drab-gray 
  

   shales 
  which 
  outcrops 
  on 
  the 
  road 
  a 
  couple 
  of 
  rods 
  north 
  of 
  the 
  

   quarry. 
  

  

  These 
  beds 
  become 
  calcareous 
  southward 
  and 
  may 
  also 
  thin. 
  

   Approaching 
  the 
  Mohawk 
  they 
  have 
  either 
  thinned 
  out 
  or 
  

   merged 
  into 
  the 
  Calciferous, 
  for 
  this 
  formation 
  is 
  seen 
  at 
  several 
  

   points 
  within 
  a 
  foot 
  or 
  two 
  of 
  the 
  crystalline 
  rocks 
  along 
  the 
  

   slope 
  of 
  the 
  fault 
  scarp. 
  At 
  the 
  " 
  Little 
  Nose 
  " 
  the 
  contact 
  is 
  

   finely 
  exhibited 
  on 
  the 
  south 
  side 
  of 
  the 
  river 
  in 
  a 
  cut 
  of 
  the 
  

   "West 
  Shore 
  railroad. 
  This 
  contact 
  was 
  described 
  and 
  figured 
  

   in 
  the 
  fifth 
  annual 
  report 
  of 
  the 
  State 
  Geologist, 
  page 
  10, 
  

   published 
  in 
  1886.* 
  

  

  In 
  plate 
  8 
  the 
  general 
  features 
  of 
  the 
  outcrop 
  are 
  shown. 
  

  

  In 
  the 
  report 
  just 
  cited 
  Prof. 
  Hall 
  gives 
  the 
  sequence 
  from 
  

   below 
  upward 
  as 
  labradorite, 
  ferruginous 
  labradorite, 
  decom- 
  

  

  * 
  Field 
  STotes 
  on 
  the 
  Geology 
  of 
  the 
  Mohawk 
  Valley. 
  5th 
  Report 
  of 
  State 
  Geologist 
  (of 
  New- 
  

   York) 
  for 
  1885, 
  pp. 
  9-10. 
  

  

  77 
  

  

  