﻿GEOLOGY 
  OF 
  THE 
  PORT 
  LEYDEN 
  QUADRANGLE 
  

  

  23 
  

  

  A 
  massive 
  bed 
  of 
  blue 
  granular 
  limestone, 
  mottled 
  and 
  lam- 
  

   inated 
  and 
  with 
  pebbles 
  of 
  blue 
  dove 
  limestone 
  

  

  Hard, 
  gray 
  white 
  limestone 
  with 
  spots 
  of 
  crystallized 
  calcite.. 
  

  

  Bluish 
  gray, 
  thin 
  bedded 
  limestone, 
  with 
  ripple 
  marks 
  and 
  

   ostracods 
  

  

  Shaly, 
  dirty 
  white 
  mud 
  limestone 
  beds, 
  mud 
  cracked 
  

  

  Bluish 
  subgranular, 
  thin 
  bedded 
  limestone 
  

  

  Blue 
  dove, 
  hard, 
  mottled 
  limestone, 
  shaly 
  below, 
  traces 
  of 
  

   fossils 
  

  

  Hard, 
  gray 
  granular 
  limestone, 
  pinkish 
  tinge, 
  much 
  calcite.. 
  

  

  Thin, 
  ripple 
  marked, 
  dirty 
  white, 
  mud 
  limestone 
  beds 
  

  

  Hard, 
  blue 
  gray 
  subgranular 
  limestone, 
  sand 
  grains 
  and 
  ostra- 
  

   cods 
  above 
  

  

  Hard, 
  gray 
  white 
  limestone, 
  less 
  earthy 
  than 
  usual 
  ; 
  calcite 
  

   spots 
  

  

  Subgranular, 
  blue, 
  laminated 
  limestone; 
  welded 
  contact 
  with 
  

   above 
  

  

  Very 
  massive, 
  gray 
  white, 
  earthy 
  limestone, 
  irregular 
  splitting. 
  

  

  Massive 
  blue 
  dove 
  limestone 
  in 
  two 
  layers; 
  laminated; 
  sty- 
  

   liolites 
  and 
  traces 
  of 
  fossils 
  

  

  Thin 
  and 
  thick 
  bedded, 
  blue 
  subgranular 
  limestone 
  ; 
  massive 
  

   basal 
  layer 
  ; 
  laminated 
  ; 
  much 
  mud 
  cracked 
  

  

  Earthy, 
  impure, 
  gray 
  white 
  beds; 
  massive 
  and 
  irregular 
  split- 
  

   ting; 
  lower 
  12-18 
  inches 
  hard, 
  gray 
  white, 
  calcite 
  spotted, 
  

   bunchy 
  surfaced 
  

  

  Gray 
  white, 
  impure, 
  earthy, 
  blocky 
  beds 
  

  

  Impure, 
  gray 
  white, 
  reddish 
  tinged, 
  earthy 
  limestone, 
  with 
  

   purer 
  layer 
  of 
  reddish 
  limestone 
  at 
  base; 
  quite 
  massive; 
  

   summit 
  less 
  red 
  

  

  Bluish 
  black, 
  fine, 
  hard 
  limestone, 
  like 
  2d 
  beneath 
  but 
  unfossil. 
  

  

  Gray 
  to 
  blue 
  gray, 
  magnesian 
  looking 
  limestone 
  in 
  3--6-inch 
  

   beds 
  

  

  3 
  heavy 
  layers 
  of 
  hard, 
  bluish 
  black 
  limestone 
  ; 
  ringing 
  ; 
  multi- 
  

   tude 
  of 
  small 
  fossils, 
  lamellibranchs, 
  cephalopods, 
  one- 
  

   celled 
  Tetradium, 
  etc 
  

  

  Red 
  and 
  green, 
  impure, 
  calcareous, 
  sandy 
  mudstone, 
  large 
  sand 
  

   grains; 
  upper 
  6 
  inches 
  thin 
  bedded, 
  rest 
  massive 
  

  

  Very 
  sandy 
  firm 
  green 
  limestone, 
  full 
  of 
  quartz 
  grains 
  

  

  Hard, 
  gray 
  white, 
  somewhat 
  sandy 
  limestone 
  or 
  dolomite 
  ; 
  

   calcite 
  spots 
  

  

  Hard, 
  ringing, 
  green, 
  calcareous 
  sandstone 
  

  

  Red, 
  sandy, 
  rotten 
  shale 
  

  

  More 
  solid, 
  red 
  and 
  green 
  calcareous 
  sandstone; 
  rots 
  easily.. 
  

  

  Red 
  and 
  green, 
  rotten, 
  calcareous 
  sandstone 
  

  

  Green 
  and 
  red 
  arkose 
  ; 
  perhaps 
  calcareous 
  

  

  Conglomerate 
  resting 
  on 
  Precambric 
  

  

  Feet 
  Inches 
  

  

  6 
  

   9 
  

  

  2 
  

   6 
  

   9 
  

  

  4 
  

   6 
  

  

  2 
  

  

  5 
  

  

  5 
  

  

  9 
  

  

  I 
  

  

  9 
  

  

  7 
  

  

  9 
  

  

  3 
  

  

  II 
  

  

  I 
  

  

  8 
  

  

  7 
  

  

  8 
  

  

  I 
  . 
  

  

  

  2 
  

  

  10 
  

  

  6 
  

  

  Total 
  

  

  71 
  

  

  