﻿GEOLOGIC 
  FORMATIONS 
  OF 
  NEW 
  YORK 
  171 
  

  

  TEIASSIC 
  SYSTEM 
  

  

  This 
  system 
  received 
  its 
  name 
  in 
  Germany 
  where 
  it 
  consists 
  

   of 
  three 
  distinct 
  members. 
  In 
  England 
  it 
  is 
  know^n 
  as 
  the 
  New 
  

   Red 
  Sandstone 
  and 
  contains 
  the 
  salt 
  deposits 
  of 
  that 
  country. 
  

   West 
  of 
  the 
  Mississippi 
  river 
  the 
  Triassic 
  is 
  well 
  represented 
  in 
  

   the 
  United 
  States, 
  but 
  in 
  the 
  east 
  it 
  is 
  found 
  only 
  in 
  narrow 
  

   troughs 
  on 
  the 
  east 
  side 
  of 
  the 
  Appalachian 
  chain 
  and 
  approxi- 
  

   mately 
  parallel 
  to 
  it. 
  It 
  is 
  well 
  developed 
  in 
  the 
  Connecticut 
  

   valley 
  and 
  is 
  again 
  found 
  near 
  Stony 
  Point, 
  New 
  York, 
  from 
  

   which 
  locality 
  it 
  extends 
  southw^est 
  across 
  Rockland 
  county 
  into 
  

   New 
  Jersey, 
  thence 
  through 
  Pennsylvania 
  and 
  Virginia. 
  In 
  the 
  

   latter 
  state 
  it 
  includes 
  the 
  Deep 
  and 
  Dan 
  river 
  coal 
  basins 
  which 
  

   are 
  of 
  considerable 
  importance. 
  

  

  The 
  Triassic 
  deposits 
  of 
  New 
  York 
  and 
  New 
  England 
  were 
  

   apparently 
  formed 
  in 
  estuaries 
  and 
  consist 
  of 
  shales 
  and 
  sand- 
  

   stones. 
  These 
  bear 
  ripple 
  marks, 
  sun 
  cracks, 
  rain 
  prints 
  and 
  

   the 
  foot 
  prints 
  of 
  enormous 
  biped 
  reptiles 
  with 
  three 
  toes. 
  These 
  

   were 
  at 
  first 
  supposed 
  to 
  be 
  bird 
  tracks. 
  Fishes 
  are 
  also 
  abund- 
  

   ant 
  in 
  the 
  sandstones 
  of 
  New 
  York 
  and 
  New 
  Jersey. 
  

  

  The 
  eastern 
  Triassic 
  rocks 
  are 
  important 
  as 
  having 
  furnished 
  

   the 
  greater 
  part 
  of 
  the 
  brown 
  sandstone, 
  w^hich 
  is 
  used 
  so 
  exten- 
  

   sively 
  for 
  building 
  houses 
  in 
  our 
  eastern 
  cities. 
  The 
  Triassic 
  

   period 
  was 
  also 
  characterized 
  by 
  eruptions 
  of 
  igneous 
  rock, 
  which 
  

   formed 
  the 
  well 
  knowm 
  trap 
  dykes 
  of 
  Connecticut 
  and 
  New 
  Jer- 
  

   sey. 
  In 
  the 
  latter 
  state 
  the 
  most 
  prominent 
  is 
  that 
  known 
  as 
  

   the 
  ' 
  Palisades 
  of 
  the 
  Hudson,' 
  which 
  extend 
  along 
  the 
  west 
  

   shore 
  of 
  the 
  Hudson 
  river 
  from 
  Staten 
  Island 
  to 
  a 
  point 
  north- 
  

   west 
  of 
  Nyack. 
  At 
  the 
  level 
  of 
  the 
  river 
  the 
  rock 
  is 
  a 
  nearly 
  

   horizontally 
  stratified 
  red 
  sandstone; 
  but 
  between 
  the 
  bedding 
  

   planes 
  a 
  vast 
  volume 
  of 
  melted 
  rock 
  has 
  been 
  injected, 
  and 
  

   in 
  cooling 
  has 
  assumed 
  the 
  rudely 
  crystalline 
  or 
  columnar 
  struc- 
  

   ture 
  so 
  common 
  in 
  basaltic 
  or 
  trap 
  rocks. 
  The 
  broken 
  edge 
  of 
  

   this 
  enormous 
  sheet 
  of 
  trap, 
  fronting 
  on 
  the 
  river, 
  forms 
  the 
  

   precipice 
  so 
  well 
  know^n 
  as 
  ' 
  the 
  Palisades.' 
  The 
  Orange 
  moun- 
  

   tains 
  are 
  also 
  of 
  the 
  same 
  formation. 
  

  

  