﻿Report 
  of 
  the 
  State 
  Geologist. 
  655 
  

  

  or 
  less 
  shaly, 
  and 
  very 
  f 
  ossiferous, 
  ruDs 
  along 
  the 
  water 
  to 
  

   the 
  north, 
  with 
  practically 
  no 
  dip. 
  The 
  Utica 
  slates 
  extend 
  

   south 
  from 
  the 
  fault 
  for 
  two 
  miles, 
  and 
  then 
  after 
  a 
  low 
  drift- 
  

   covered 
  break, 
  are 
  found 
  against 
  the 
  Split 
  Kock 
  anorthosites, 
  up 
  

   to 
  100 
  feet 
  above 
  the 
  lake. 
  

  

  Series 
  V. 
  The 
  dikes 
  and 
  porphyries 
  find 
  their 
  best 
  develop- 
  

   ment 
  in 
  this 
  region. 
  At 
  Cannon's 
  Point 
  there 
  is 
  a 
  fine 
  laccolite 
  

   of 
  feldspar 
  porphyry, 
  of 
  which 
  Emmons 
  gave 
  a 
  sketch 
  and 
  

   description. 
  (Geol. 
  2nd 
  Disk, 
  p. 
  85.) 
  The 
  sheet 
  is 
  a 
  thousand 
  

   feet 
  long 
  or 
  more, 
  lies 
  interbedded 
  in 
  the 
  slates, 
  with 
  many 
  

   apophyses, 
  and 
  forms 
  a 
  high 
  cliff. 
  It 
  has 
  an 
  excellent 
  trachytic 
  

   structure, 
  lacks 
  dark 
  silicates 
  almost 
  entirely 
  and 
  is 
  a 
  curious 
  and 
  

   interesting 
  rock. 
  It 
  is 
  described 
  at 
  length 
  in 
  Bulletin 
  107 
  of 
  the 
  

   United 
  States 
  Geological 
  Survey. 
  Strangely 
  enough 
  it 
  has 
  

   exerted 
  almost 
  no 
  effect 
  on 
  its 
  walls. 
  Other 
  outcrops 
  appear 
  to 
  

   the 
  northwest 
  and 
  two 
  large 
  dikes 
  cut 
  the 
  banks 
  of 
  the 
  lake 
  to 
  

   the 
  south. 
  A 
  most 
  interesting 
  camptonite 
  dike 
  cuts 
  the 
  faulted 
  

   block 
  of 
  Chazy 
  limestone, 
  and 
  appears 
  in 
  the 
  quarries 
  to 
  the 
  west. 
  

   Several 
  basic 
  dikes 
  pierce 
  Split 
  Rock, 
  and 
  a 
  single 
  small 
  one 
  was 
  

   met 
  on 
  Boquet 
  mountain. 
  

  

  Series 
  VI 
  Between 
  the 
  Potsdam 
  fringe 
  and 
  the 
  lake 
  shore 
  the 
  

   rocks 
  are 
  buried 
  beneath 
  the 
  sands 
  and 
  clays 
  of 
  the 
  Potsdam. 
  

   T. 
  G-. 
  White, 
  of 
  my 
  party, 
  discovered 
  a 
  few 
  marine 
  shells 
  south 
  of 
  

   Cannon's 
  Point. 
  Much 
  drift 
  is 
  met 
  in 
  the 
  western 
  part 
  of 
  the 
  

   town. 
  Wells 
  near 
  the 
  Essex 
  railway 
  station 
  have 
  shown 
  the 
  clay 
  

   to 
  be 
  over 
  sixty 
  feet 
  deep. 
  

  

  Mines 
  and 
  quarries. 
  — 
  There 
  are 
  no 
  mines 
  in 
  Essex. 
  For 
  rough 
  

   masonry, 
  the 
  Chazy 
  beds 
  back 
  of 
  the 
  village 
  afford 
  excellent 
  stone 
  

   and 
  have 
  been 
  worked 
  to 
  a 
  considerable 
  degree. 
  A 
  quarry 
  has 
  

   also 
  been 
  opened 
  along 
  the 
  lake 
  shore, 
  near 
  the 
  contact 
  with 
  the 
  

   Utica 
  slate. 
  

  

  WlLLSBOKOTJGH. 
  

  

  Series 
  I. 
  ~No 
  gneisses 
  appear 
  in 
  Willsborough. 
  

  

  Series 
  II 
  In 
  the 
  cuts 
  of 
  the 
  Delaware 
  and 
  Hudson 
  rail- 
  

   road 
  along 
  Willsborough 
  bay, 
  a 
  small 
  showing 
  of 
  ophicalcite 
  

   appears, 
  apparently 
  an 
  inclusion 
  in 
  the 
  anorthosite 
  of 
  Trembleau 
  

   mountain. 
  The 
  igneous 
  rock 
  shows 
  just 
  over 
  it. 
  

  

  Series 
  III. 
  The 
  anorthosites 
  cover 
  all 
  the 
  w 
  r 
  estern 
  portion, 
  and 
  

   are 
  of 
  the 
  usual 
  type, 
  meriting 
  no 
  special 
  description. 
  Some- 
  

  

  