﻿Belated 
  Sedimentary 
  Surface 
  Forms. 
  

  

  265 
  

  

  current 
  ripples 
  described 
  were 
  produced 
  by 
  tidal 
  currents. 
  

   Those 
  of 
  the 
  Brassfield 
  formation 
  in 
  Kentucky 
  offer 
  a 
  

   direct 
  analogy 
  to 
  those 
  of 
  the 
  English 
  Coast. 
  

  

  The 
  ripples 
  of 
  the 
  Lorraine 
  and 
  Richmond 
  Formations, 
  

   however, 
  offer 
  an 
  additional 
  problem. 
  

  

  1. 
  They 
  are 
  not 
  limited 
  to 
  a 
  relatively 
  narrow 
  zone 
  

   in 
  the 
  neighborhood 
  of 
  the 
  shore, 
  but 
  formed 
  (probably 
  

   more 
  or 
  less 
  synchronously) 
  throughout 
  the 
  area 
  of 
  the 
  

   Cincinnati 
  Anticline, 
  that 
  is, 
  over 
  an 
  area 
  of 
  at 
  least 
  

   15,000 
  square 
  miles 
  and 
  probably 
  much 
  more. 
  

  

  2. 
  They 
  trend 
  in 
  all 
  directions, 
  although 
  a 
  north-south 
  

   trend 
  is 
  more 
  common 
  than 
  an 
  east- 
  west 
  trend 
  (see 
  fig. 
  

   14, 
  c-h). 
  

  

  At 
  first 
  sight 
  this 
  seems 
  to 
  offer 
  a 
  serious 
  objection 
  to 
  

   my 
  interpretation, 
  since 
  in 
  open 
  waters 
  the 
  direction 
  of 
  

   the 
  current 
  passes 
  through 
  all 
  the 
  points 
  of 
  the 
  compass 
  

   in 
  the 
  course 
  of 
  twelve 
  hours, 
  which 
  would 
  render 
  the 
  

   formation 
  of 
  permanent 
  ripples 
  impossible. 
  The 
  follow- 
  

   ing 
  observations, 
  however, 
  offer 
  a 
  clue 
  to 
  this 
  problem. 
  

  

  In 
  1881 
  Hunt 
  63 
  visited 
  the 
  broad 
  open 
  gulf 
  of 
  Torbay 
  

   on 
  the 
  south 
  shore 
  of 
  Devonshire 
  two 
  weeks 
  after 
  a 
  heavy 
  

  

  M91N-M9L& 
  

  

  N75ES76E 
  

  

  Figure 
  14, 
  a-Tc. 
  Diagram 
  illustrating 
  the 
  relative 
  frequency 
  of 
  the 
  differ- 
  

   ent 
  directions 
  of 
  strike 
  observed 
  in 
  para-ripples 
  of 
  the 
  Brassfield 
  formation 
  

   (Z>), 
  Eden 
  group 
  (c-g), 
  and 
  Eichmond 
  group 
  (h-Tc) 
  of 
  the 
  Jessamine 
  dome. 
  

  

  Fig. 
  a 
  illustrates 
  the 
  method 
  by 
  which 
  the 
  diagrams 
  were 
  constructed. 
  

   The 
  directions 
  observed 
  were 
  divided 
  into 
  six 
  groups 
  and 
  plotted 
  on 
  six 
  

   rays, 
  each 
  representing 
  all 
  the 
  directions 
  lying 
  within 
  15° 
  on 
  either 
  side. 
  

   The 
  total 
  number 
  of 
  observations 
  in 
  each 
  group 
  is 
  shown, 
  relatively, 
  by 
  the 
  

   length 
  of 
  the 
  rays, 
  and, 
  absolutely, 
  by 
  the 
  figures 
  at 
  their 
  ends. 
  

  

  63 
  Hunt, 
  A. 
  E., 
  On 
  the 
  formation 
  of 
  Eipple 
  Marks, 
  Proc. 
  Eoy. 
  Soc, 
  vol. 
  

   34, 
  p. 
  4, 
  1S82. 
  

  

  