﻿68 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Table 
  shov/ing 
  the 
  Lower 
  Cambric 
  series 
  as 
  exposed 
  in 
  Rensselaer 
  

   county 
  and 
  part 
  of 
  Columbia 
  county, 
  N. 
  Y. 
  

  

  SERIAL 
  

   LETTER 
  

  

  DESCRIPTION 
  OF 
  STRATA 
  

  

  FAUNA 
  

  

  ESTIMATED 
  

  

  THICKNESS 
  

  

  IN 
  FEET 
  

  

  D 
  

  

  Greenish 
  shale 
  , 
  

  

  Thin-bedded 
  limestone, 
  or 
  dolo- 
  

   mitic 
  limestone, 
  in 
  varying 
  alter- 
  

   nations 
  with 
  black 
  or 
  greenish 
  

   shale 
  and 
  calcareous 
  quartz 
  sand- 
  

   stone. 
  Some 
  of 
  the 
  limestone 
  

   beds 
  brecciated 
  within 
  the 
  sand- 
  

   stone 
  or 
  shale 
  and 
  forming 
  brec- 
  

   ciation 
  pebbles, 
  in 
  places, 
  how- 
  

   ever, 
  beach 
  pebbles 
  

  

  Greenish, 
  reddish, 
  purplish 
  shale, 
  

   in 
  places 
  with 
  small 
  beds 
  of 
  more 
  

   or 
  less 
  calcareous 
  quartzite. 
  

  

  At 
  Troy, 
  in 
  upper 
  part 
  a 
  2\ 
  foot 
  bed 
  

   of 
  calcareous 
  sandstone 
  

  

  Granular 
  quartzite, 
  in 
  places 
  a 
  cal- 
  

   careous 
  sandstone 
  

  

  Olive 
  grit, 
  metamorphic, 
  usually 
  

   weathering 
  reddish; 
  absent 
  at 
  

   south 
  

  

  Greenish, 
  or 
  reddish 
  and 
  greenish, 
  

   shale 
  with 
  small 
  quartzite 
  or 
  grit 
  

   beds 
  

  

  Massive 
  greenish 
  quartzite, 
  in 
  

   places 
  very 
  coarse 
  

  

  Reddish 
  and 
  greenish 
  shale 
  with 
  

   small 
  beds 
  of 
  quartzite 
  or 
  grit 
  

   (rarely 
  up 
  to 
  5 
  feet 
  thick) 
  

  

  Massive 
  greenish 
  quartzite, 
  in 
  

   places 
  very 
  coarse 
  

  

  Reddish 
  and 
  greenish 
  shale 
  with 
  

   small 
  beds 
  of 
  quartzite 
  or 
  grit, 
  

   from 
  1 
  to 
  12 
  and, 
  rarely, 
  24 
  

   inches 
  thick 
  

  

  Olenellus 
  fauna. 
  

  

  Oldhamia, 
  

   trails 
  

  

  annelid 
  

  

  Hyolithes 
  and 
  

   lithellus 
  

  

  Hyo- 
  

  

  Traces 
  of? 
  

  

  Casts 
  of 
  impressions 
  

   Oldhamia 
  & 
  

  

  Casts 
  of 
  impressions, 
  

   Oldhamia 
  

  

  Casts 
  of 
  impressions, 
  

   Oldhamia 
  

  

  50 
  

  

  25?-IOO 
  + 
  

  

  10-40 
  

  

  18-50 
  

  

  65-535 
  

  

  10-50 
  

   30-80 
  

  

  8-40 
  

   50-80 
  

  

  « 
  Usually 
  50. 
  

   all 
  three. 
  

  

  Minimum, 
  286. 
  Maximum, 
  1225 
  + 
  

  

  b 
  Oldhamia 
  occurs 
  in 
  A, 
  C, 
  or 
  E, 
  and 
  quite 
  possibly 
  in 
  

  

  