﻿Report 
  of 
  the 
  State 
  Geologist. 
  657 
  

  

  Series 
  VI. 
  The 
  sands 
  and 
  clays 
  extend 
  north 
  from 
  Essex 
  and 
  

   form 
  a 
  north 
  and 
  south 
  strip 
  a 
  short 
  distance 
  back 
  from 
  the 
  lake. 
  

   Evidently 
  in 
  the 
  post-glacial 
  times 
  there 
  was 
  a 
  rather 
  deep 
  arm 
  

   of 
  Lake 
  Champlain, 
  then 
  standing 
  higher 
  than 
  now, 
  which 
  ran 
  

   south 
  from 
  Willsborough 
  bay 
  to 
  Split 
  Kock 
  ridge, 
  and 
  which 
  had 
  

   a 
  great 
  reef 
  of 
  the 
  palas 
  >zoic 
  sediments 
  between 
  it 
  and 
  the 
  lake 
  

   basin 
  proper. 
  Across 
  this 
  reef 
  there 
  were 
  passages 
  or 
  channels 
  

   at 
  four 
  points. 
  The 
  Boquet 
  river 
  formed 
  a 
  large 
  delta 
  which 
  

   is 
  now 
  represented 
  by 
  sandy 
  hillocks. 
  

  

  Mines 
  and 
  quarries. 
  — 
  There 
  are 
  no 
  mines 
  in 
  Willsborough. 
  

   The 
  quarries 
  of 
  Chazy 
  limestone 
  have 
  already 
  been 
  referred 
  to. 
  

   Forty 
  feet 
  or 
  more 
  of 
  heavy-bedded 
  blue 
  limestone 
  are 
  exposed 
  dip- 
  

   ping 
  north 
  seven 
  to 
  eight 
  degrees 
  and 
  striking 
  east 
  and 
  west. 
  

   Several 
  acres 
  have 
  been 
  quarried 
  over, 
  and 
  one 
  or 
  two 
  men 
  were 
  

   still 
  working 
  last 
  summer. 
  The 
  business 
  of 
  late 
  years 
  has 
  

   languished. 
  

  

  C 
  FIBSTER* 
  I 
  ELD. 
  

  

  Series 
  I. 
  No 
  undoubted 
  exposure 
  of 
  Series 
  I 
  was 
  met. 
  There 
  

   is 
  much 
  rock 
  of 
  a 
  gneissoid 
  character, 
  especially 
  on 
  the 
  north- 
  

   west, 
  but 
  it 
  all 
  proved 
  in 
  thin 
  sections 
  to 
  contain 
  plagioclase, 
  

   hornblende 
  and 
  pyroxene, 
  and 
  is, 
  therefore, 
  esteemed 
  gneissoid 
  

   anorthosite. 
  The 
  gneisses 
  do 
  come 
  in, 
  however, 
  not 
  very 
  far 
  to 
  the 
  

   west 
  and 
  north 
  of 
  the 
  line. 
  

  

  Series 
  II. 
  This 
  is 
  limited 
  to 
  a 
  considerable 
  area 
  near 
  Trout 
  

   Fond, 
  and 
  as 
  the 
  rock 
  has 
  been 
  quarried 
  for 
  burning, 
  the 
  exposures 
  

   are 
  excellent. 
  A 
  quarry 
  face 
  of 
  white, 
  graphitic 
  limestone 
  is 
  

   opened, 
  which 
  is 
  thickly 
  seamed 
  by 
  bunches 
  of 
  the 
  silicates, 
  

   pyroxene, 
  hornblende, 
  wollastonite, 
  etc. 
  On 
  the 
  north 
  it 
  is 
  cut 
  

   by 
  a 
  diabase 
  dike, 
  at 
  which 
  the 
  workings 
  stop. 
  Some 
  ophicalcite 
  

   also 
  appears. 
  Anorthosite 
  occurs 
  all 
  around 
  it, 
  and 
  to 
  this 
  is 
  

   doubtless 
  due 
  the 
  great 
  development 
  of 
  silicates 
  in 
  the 
  limestone. 
  

   No 
  dips 
  and 
  strike 
  worth 
  record 
  are 
  to 
  be 
  noted. 
  

  

  Another 
  most 
  curious 
  outcrop 
  may 
  be 
  noted 
  in 
  this 
  connection. 
  

   It 
  occurs 
  in 
  the 
  eastern 
  central 
  part 
  of 
  the 
  t^wn 
  from 
  

   which 
  specimen 
  55 
  is 
  recorded. 
  At 
  Buttermilk 
  falls 
  a 
  brook 
  

   drops 
  about 
  sixty 
  feet 
  over 
  a 
  ledge 
  of 
  anorthosite. 
  On 
  the 
  opposite 
  

   side 
  of 
  the 
  ravine 
  is 
  a 
  wall 
  whose 
  lower 
  forty 
  feet 
  are 
  anorthosite. 
  

   Above 
  this 
  is 
  a 
  layer 
  of 
  dense, 
  green 
  serpentine, 
  which 
  is 
  capped 
  

   by 
  soft, 
  friable 
  sandstone, 
  apparently 
  a 
  little 
  remnant 
  of 
  

   83 
  

  

  