﻿Report 
  of 
  the 
  State 
  Geologist. 
  417 
  

  

  On 
  Oniskethau 
  creek 
  northeast 
  of 
  South 
  Bethlehem 
  the 
  con- 
  

   tact 
  is 
  covered 
  with 
  drift, 
  but 
  the 
  Hudson 
  river 
  slates 
  in 
  the 
  

   immediate 
  vicinity 
  are 
  vertical 
  and 
  the 
  limestones 
  just 
  west 
  have 
  

   a 
  general 
  westward 
  dip 
  with 
  a 
  series 
  of 
  gentle 
  undulations. 
  On 
  

   Sprayt 
  creek, 
  farther 
  within 
  the 
  flexed 
  region, 
  the 
  relations 
  are 
  

   as 
  is 
  shown 
  in 
  figure 
  2. 
  In 
  the 
  synclinal 
  ridge 
  eastward 
  there 
  is 
  

   essential 
  conformity 
  in 
  bedding 
  between 
  the 
  limestones 
  and 
  

   slates. 
  To 
  the 
  west 
  the 
  eastern 
  dip 
  steepens 
  and 
  continues 
  in 
  the 
  

   slates, 
  but 
  the 
  limestones 
  lie 
  in 
  a 
  succession 
  of 
  gentle 
  flexures. 
  

   Along 
  the 
  creek 
  the 
  slates 
  are 
  continuously 
  exposed, 
  dipping 
  

   steeply 
  eastward 
  and 
  the 
  nearly 
  flat 
  Limestones 
  cap 
  the 
  crest 
  of 
  

   the 
  southern 
  banks. 
  The 
  fault 
  is 
  a 
  local 
  feature 
  dying 
  out 
  a 
  

   short 
  distance 
  southward 
  and 
  the 
  relations 
  cannot 
  be 
  due 
  to 
  

   a 
  general 
  overthrust. 
  The 
  limestone 
  here 
  was 
  apparently 
  

   deposited 
  on 
  a 
  truncated 
  arch 
  of 
  the 
  slates 
  and 
  at 
  the 
  synclinal 
  

   ridge 
  eastward 
  on 
  a 
  plane. 
  

  

  On 
  the 
  slope 
  just 
  west 
  of 
  Coeymans 
  Junction 
  and 
  at 
  some 
  

   other 
  points 
  in 
  the 
  vicinity, 
  the 
  Helderberg 
  and 
  Salina 
  beds 
  dip 
  

   W. 
  20° 
  and 
  the 
  Hudson 
  river 
  shales 
  and 
  sandstones 
  dip 
  E. 
  60°. 
  

   Contacts 
  were 
  not 
  observed 
  but 
  the 
  rocks 
  are 
  seen 
  within 
  a 
  few 
  

   feet 
  of 
  each 
  other. 
  Two 
  miles 
  southwest 
  of 
  New 
  Baltimore 
  the 
  

   relations 
  are 
  similar 
  ; 
  on 
  Aquetuck 
  creek 
  the 
  contact 
  is 
  obscured, 
  

   but 
  the 
  unconformity 
  prevails 
  in 
  its 
  vicinity. 
  

  

  On 
  the 
  road 
  two 
  miles 
  southwest 
  of 
  West 
  Coxsackie 
  the 
  lime- 
  

   stones 
  and 
  slates 
  are 
  seen 
  near 
  together, 
  dipping 
  70° 
  east 
  in 
  an 
  

   overturn 
  ; 
  possibly 
  the 
  dip 
  may 
  be 
  slightly 
  steeper 
  in 
  the 
  slates. 
  

   Davis 
  found 
  essential 
  conformity 
  to 
  prevail 
  in 
  the 
  Catskill 
  region 
  

   and 
  I 
  found 
  it 
  to 
  continue 
  to 
  West 
  Camp 
  where 
  the 
  Niagara 
  

   outlier 
  is 
  well 
  exposed. 
  In 
  the 
  Rondout 
  region, 
  as 
  described 
  by 
  

   Davis, 
  the 
  unconformity 
  is 
  very 
  marked, 
  the 
  Niagara 
  limestone 
  

   and 
  overlying 
  members 
  dipping 
  steeply 
  westward, 
  and 
  the 
  

   Hudson 
  river 
  formations 
  steeply 
  eastward. 
  Davis* 
  observed 
  the 
  

   details 
  of 
  contact 
  here 
  in 
  one 
  of 
  the 
  quarries 
  and 
  found 
  that 
  the 
  

   limestones 
  filled 
  irregularities 
  in 
  the 
  eroded 
  surface 
  of 
  the 
  slates, 
  

   precluding 
  the 
  possibility 
  of 
  a 
  fault. 
  

  

  The 
  degree 
  of 
  unconformity 
  decreases 
  southward, 
  and 
  near 
  

   Rosendale 
  and 
  in 
  the 
  jShawangunk 
  mountain 
  the 
  Shawangunk 
  

   grit 
  lies 
  on 
  an 
  eroded 
  surface 
  of 
  Hudson 
  river 
  shales, 
  with 
  a 
  

  

  *The 
  Nonconformity 
  at 
  Rondout; 
  Am. 
  Jour. 
  Sci., 
  3d 
  series, 
  vol. 
  26, 
  pp. 
  392-398. 
  

  

  53 
  

  

  