﻿80 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  is 
  also 
  indicated 
  by 
  the 
  Rysedorph 
  Hill 
  conglomerate, 
  occurring 
  at 
  

   Bald 
  mountain 
  with 
  its 
  Mohawkian 
  fauna. 
  

  

  The 
  stratigraphic 
  relation 
  of 
  the 
  Bald 
  Mountain 
  limestone 
  to 
  the 
  

   shales 
  is 
  nowhere 
  apparent, 
  the 
  observed 
  contacts 
  between 
  the 
  two 
  

   being 
  along 
  fault 
  planes. 
  Thus 
  the 
  limestone 
  is 
  seen 
  to 
  rest 
  by 
  a 
  

   westerly 
  rising 
  plane 
  on 
  the 
  folded 
  Snake 
  Hill 
  shales 
  below 
  the 
  

   falls 
  at 
  Middle 
  Falls; 
  since 
  the 
  shales 
  are 
  younger 
  than 
  the 
  lime- 
  

   stone, 
  the 
  latter 
  is 
  here 
  overthrust 
  on 
  the 
  shale. 
  The 
  interbedding 
  

   of 
  shale 
  between 
  the 
  dolomite 
  and 
  shale, 
  assumed 
  in 
  Walcott's 
  Bald 
  

   Mountain 
  section, 
  is 
  due 
  to 
  a 
  mass 
  of 
  shale 
  folded 
  or 
  thrust 
  locally 
  

   into 
  the 
  Bald 
  Mountain 
  limestone. 
  The 
  limestone 
  belt 
  is 
  on 
  one 
  side 
  

   bounded 
  by 
  the 
  shale, 
  on 
  the 
  other 
  by 
  the 
  Georgian 
  rocks; 
  and, 
  

   as 
  a 
  glance 
  at 
  the 
  map 
  will 
  show, 
  it. 
  ends 
  abruptly 
  where 
  the 
  edge 
  

   of 
  the 
  Georgian 
  overthrust 
  blanket 
  southwest 
  of 
  Louse 
  hill 
  turns 
  

   east, 
  suggesting 
  that 
  this 
  overthrust 
  mass 
  brought 
  the 
  limestone 
  with 
  

   it 
  (see 
  postea 
  page 
  no). 
  We 
  have 
  thus, 
  principally 
  from 
  the 
  

   fossil 
  evidence, 
  to 
  assume 
  that 
  the 
  Bald 
  Mountain 
  limestone, 
  which 
  

   surely 
  is 
  older 
  than 
  the 
  Normanskill 
  shale, 
  overlies 
  the 
  Deep 
  Kill 
  

   shale. 
  But 
  it 
  may 
  come 
  from 
  an 
  entirely 
  different 
  trough 
  or 
  basin, 
  

   that 
  originally 
  was 
  east 
  of 
  the 
  Levis 
  trough. 
  

  

  RYSEDORPH 
  HILL 
  CONGLOMERATE 
  

  

  Associated 
  with 
  the 
  Bald 
  Mountain 
  limestone 
  in 
  the 
  Bald 
  Moun- 
  

   tain 
  section 
  and 
  for 
  2 
  miles 
  north 
  of 
  it, 
  occurs 
  a 
  conglomerate 
  of 
  

   striking 
  character. 
  It 
  is 
  best 
  exposed 
  at 
  the 
  north 
  end 
  of 
  the 
  Bald 
  

   Mountain 
  quarry, 
  and 
  along 
  the 
  brook 
  skirting 
  the 
  north 
  side 
  of 
  the 
  

   mountain, 
  below 
  the 
  road. 
  The 
  rock 
  consists 
  of 
  a 
  black 
  mud 
  matrix. 
  

   In 
  it 
  float 
  without 
  assortment 
  pebbles 
  of 
  all 
  sizes, 
  from 
  that 
  of 
  a 
  

   pea 
  to 
  those 
  2 
  to 
  3 
  feet 
  in 
  diameter. 
  The 
  smaller 
  pebbles 
  are 
  well 
  

   rounded/ 
  the 
  larger 
  ones 
  subangular 
  with 
  rounded 
  edges. 
  They 
  

   are 
  in 
  part 
  the 
  Georgian 
  limestone, 
  but 
  also 
  deep 
  blue 
  dolomite 
  

   and 
  gray 
  and 
  dove 
  limestones. 
  A 
  few 
  of 
  the 
  pebbles 
  have 
  furnished 
  

   fragmentary 
  fossils 
  which 
  indicate 
  the 
  Trenton 
  age 
  of 
  these 
  pebbles. 
  

   The 
  fossils 
  were: 
  

  

  Lingula 
  sp. 
  (fragment) 
  

  

  Siphonotreta 
  cf. 
  minnesotensis 
  Hall 
  & 
  Clarke 
  

  

  Rafinesquina 
  sp. 
  (fragment) 
  

  

  Plectambonites 
  pisum 
  Ruedemann 
  

  

  Ceraurus 
  cf. 
  pleurexanthemus 
  (Green), 
  fragment 
  

  

  Bythocypris 
  cylindrica 
  (Hall) 
  

  

  Isochilina 
  armata 
  Walcott 
  var. 
  pygmaea 
  Ruedemann 
  

  

  