﻿Report 
  of 
  the 
  State 
  Geologist. 
  415 
  

  

  five 
  feet, 
  and 
  to 
  a 
  hundred 
  feet 
  in 
  the 
  ridges 
  which 
  rise 
  to 
  the 
  

   southwest. 
  About 
  Lake 
  Mohonk 
  fully 
  160 
  feet 
  are 
  exposed 
  and 
  

   at 
  the 
  falls 
  of 
  the 
  Peterkill 
  there 
  are 
  110 
  feet, 
  but 
  these 
  are 
  local- 
  

   ities 
  at 
  which 
  the 
  upper 
  part 
  of 
  the 
  formation 
  has 
  been 
  more 
  or 
  

   less 
  deeply 
  eroded. 
  The 
  thickness 
  of 
  the 
  formation 
  in 
  the 
  

   wider 
  part 
  of 
  the 
  mountain 
  is 
  about 
  200 
  feet, 
  for 
  in 
  Sam's 
  point 
  

   and 
  Millbrook 
  mountain 
  the 
  precipices 
  expose 
  fully 
  this 
  amount. 
  

   Along 
  the 
  western 
  slope, 
  near 
  Ellen 
  viile. 
  200 
  feet 
  seems 
  to 
  be 
  a 
  

   fair 
  estimate 
  and 
  the 
  entire 
  thickness 
  is 
  exposed, 
  but 
  I 
  made 
  no 
  

   exact 
  measurements. 
  

  

  In 
  greater 
  part 
  the 
  rock 
  consists 
  of 
  white 
  quartz 
  pebbles 
  of 
  

   small 
  or 
  moderate 
  size 
  in 
  a 
  matrix 
  of 
  sand 
  and 
  silicious 
  cement. 
  

   Locally 
  there 
  are 
  beds 
  of 
  coarse 
  quartzhe 
  sandstone, 
  but 
  the 
  

   conglomerate 
  is 
  the 
  prevailing 
  rock. 
  The 
  color 
  is 
  white 
  with 
  

   local 
  exceptions 
  of 
  gray, 
  blue-gray 
  or 
  buff, 
  the 
  latter 
  due 
  mainly 
  

   to 
  staining 
  from 
  pyrites 
  which 
  is 
  frequently 
  disseminated 
  in 
  the 
  

   rocks. 
  The 
  bedding 
  is 
  predominantly 
  massive, 
  averaging 
  tiiree 
  

   to 
  four 
  feet, 
  but 
  thinner 
  bedding 
  is 
  sometimes 
  seen 
  particularly 
  

   in 
  the 
  finer 
  grained 
  materials. 
  The 
  most 
  conspicuous 
  exposure 
  

   of 
  thinner 
  bedding 
  is 
  xl 
  Peterkill 
  Falls. 
  

  

  Hudson 
  river 
  formation 
  — 
  The 
  shales 
  and 
  sandstones 
  of 
  this 
  

   formation 
  constitute 
  the 
  general 
  basement 
  of 
  the 
  region, 
  and, 
  

   although 
  I 
  saw 
  much 
  of 
  them. 
  I 
  gave 
  no 
  special 
  attention 
  to 
  their 
  

   details. 
  They 
  consist 
  of 
  dark 
  gray, 
  brown 
  and 
  black 
  dates 
  and 
  

   shales, 
  with 
  alternating 
  beds 
  of 
  very 
  fine 
  grained 
  gray, 
  brown 
  to 
  

   black 
  sandstones 
  in 
  the 
  upper 
  members 
  norhward 
  Their 
  thick- 
  

   ness 
  is 
  great, 
  but 
  I 
  have 
  made 
  no 
  estimate 
  of 
  its 
  amount. 
  Near 
  

   Altanront 
  there 
  are 
  nearly 
  600 
  feet 
  in 
  the 
  slope 
  to 
  the 
  southward, 
  

   and 
  the 
  gas 
  well 
  bored 
  in 
  1SS8 
  penetrated 
  2.SS0 
  feet 
  to 
  the 
  Tren- 
  

   ton 
  limestone,* 
  giving 
  a 
  total 
  of 
  3,480 
  feet 
  as 
  the 
  thickness 
  at 
  

   that 
  locality. 
  

  

  The 
  Oveelaps 
  and 
  theie 
  Hjstoey. 
  

  

  The 
  absence 
  of 
  a 
  portion 
  of 
  the 
  members 
  of 
  the 
  upper 
  Silurian 
  

   column 
  in 
  part 
  of 
  eastern 
  New 
  York 
  has 
  been 
  discussed 
  at 
  greater 
  

   or 
  less 
  length 
  by 
  many 
  writers. 
  Davis, 
  in 
  his 
  papers 
  on 
  the 
  Cats- 
  

   kill, 
  Becraf 
  t's 
  mountain 
  and 
  Bondout 
  regions, 
  has 
  reviewed 
  these 
  

   discussions 
  and 
  added 
  much 
  new 
  light 
  for 
  these 
  regions. 
  aTv 
  

  

  * 
  See 
  Ashburner, 
  loc 
  cit, 
  pp. 
  46-4? 
  . 
  

  

  