﻿Keport 
  of 
  the 
  Director. 
  13 
  

  

  Mr. 
  Andrew 
  Sherwood, 
  with 
  the 
  assistance 
  of 
  his 
  brother 
  

   Mr. 
  Clark 
  Sherwood, 
  has 
  continued 
  the 
  investigations 
  in 
  the 
  

   Chemung 
  group 
  and 
  Catskill 
  mountain 
  formation. 
  At 
  the 
  

   same 
  time, 
  they 
  have 
  made 
  extensive 
  collections 
  of 
  the 
  rocks 
  

   and 
  fossils, 
  which 
  have 
  been 
  received 
  at 
  the 
  Museum. 
  

  

  The 
  field-work 
  has 
  been 
  essentially 
  completed, 
  and 
  Mr. 
  

   Sherwood 
  has 
  been 
  for 
  some 
  time 
  engaged 
  in 
  the 
  preparation 
  

   of 
  the 
  map 
  and 
  sections. 
  This 
  work 
  was 
  originally 
  under- 
  

   taken 
  with 
  a 
  view 
  of 
  tracing 
  more 
  accurately 
  the 
  limits 
  of 
  the 
  

   several 
  formations 
  in 
  the 
  southern 
  counties 
  of 
  the 
  State, 
  a 
  

   work 
  which 
  could 
  not 
  be 
  satisfactorily 
  accomplished 
  during 
  

   the 
  original 
  geological 
  survey. 
  On 
  several 
  occasions 
  questions 
  

   had 
  arisen 
  regarding 
  the 
  existence 
  of 
  certain 
  formations 
  within 
  

   the 
  limits 
  of 
  the 
  State 
  ; 
  and 
  in 
  the 
  report 
  on 
  the 
  State 
  Cabinet 
  

   of 
  1862, 
  the 
  curator 
  (E. 
  Jewett) 
  stated 
  that 
  from 
  the 
  observa- 
  

   tions 
  of 
  himself 
  and 
  others, 
  the 
  Old 
  Red 
  sandstone 
  or 
  the 
  

   Catskill 
  formation, 
  did 
  not 
  occur 
  within 
  the 
  State 
  of 
  JSTew 
  

   York. 
  

  

  A 
  review 
  of 
  the 
  ground 
  during 
  the 
  following 
  year 
  (1863) 
  

   convinced 
  me 
  that 
  the 
  observations 
  on 
  which 
  this 
  conclusion 
  

   was 
  based, 
  had 
  been 
  conducted 
  along 
  the 
  line 
  of 
  an 
  eroded 
  

   anticlinal 
  valley; 
  and 
  that 
  the 
  red 
  rock 
  of 
  the 
  Catskill 
  forma- 
  

   tion 
  occupied 
  the 
  higher 
  portions 
  of 
  the 
  country 
  on 
  either 
  side. 
  

   Having 
  made 
  geological 
  sections 
  across 
  this 
  part 
  of 
  the 
  country 
  

   in 
  1844, 
  I 
  saw 
  nothing 
  on 
  this 
  review 
  to 
  conflict 
  with 
  the 
  obser- 
  

   vations 
  made 
  at 
  that 
  time 
  ; 
  but 
  as 
  the 
  lines 
  of 
  section 
  had 
  

   been 
  carried 
  southward 
  from 
  the 
  Mohawk, 
  they 
  had 
  extended 
  

   only 
  to 
  the 
  higher 
  portions 
  of 
  country 
  in 
  the 
  range 
  of 
  the 
  

   Catskills 
  ; 
  and 
  these 
  elevated 
  outcrops, 
  of 
  which 
  several 
  are 
  

   visible 
  on 
  looking 
  from 
  the 
  north, 
  proved 
  to 
  be, 
  as 
  I 
  had 
  

   before 
  asserted, 
  synclinals, 
  preserving 
  the 
  red 
  shales 
  and 
  

   sandstones 
  in 
  their 
  upper 
  members. 
  This 
  structure, 
  however, 
  

   left 
  the 
  broader 
  valleys 
  exhibiting 
  the 
  outcropping 
  edges 
  of 
  

   the 
  strata 
  of 
  the 
  Chemung 
  and 
  Portage 
  groups, 
  which 
  are 
  

   here 
  not 
  separable 
  from 
  each 
  other 
  by 
  any 
  well 
  marked 
  limi- 
  

   tation 
  of 
  either 
  lithological 
  or 
  palaeontological 
  evidence. 
  

  

  It 
  became 
  apparent, 
  therefore, 
  that 
  no 
  true 
  representation 
  of 
  

   these 
  strata 
  could 
  be 
  made 
  upon 
  a 
  map, 
  without 
  first 
  having 
  

   a 
  careful 
  survey 
  of 
  the 
  country, 
  and 
  tracing 
  and 
  locating 
  the 
  

   outcrops 
  upon 
  township-plats, 
  the 
  best 
  means 
  at 
  our 
  disposal; 
  

   and 
  then 
  combining 
  the 
  whole 
  on 
  a 
  larger 
  map. 
  

  

  