﻿Vol. 
  53.] 
  THE 
  RED 
  ROCKS 
  NEAR 
  BUNMAHON. 
  269 
  

  

  21. 
  The 
  Red 
  Hocks 
  near 
  Btjnmahon 
  on 
  the 
  Coast 
  of 
  Co. 
  Waterford. 
  

   By 
  P. 
  R. 
  Cowper 
  Reed, 
  Esq., 
  M.A., 
  F.G.S. 
  (Read 
  March 
  10th, 
  

   1897.) 
  

  

  Contents. 
  

  

  Page 
  

  

  I. 
  Introduction 
  269 
  

  

  II. 
  General 
  Structure 
  of 
  the 
  District 
  270 
  

  

  III. 
  Mode 
  of 
  Occurrence 
  and 
  Relations 
  of 
  the 
  Red 
  Rocks 
  of 
  

  

  Bumnahon 
  and 
  Neighbourhood 
  , 
  272 
  

  

  IV. 
  Summary 
  of 
  the 
  Evidence 
  282 
  

  

  V. 
  Probable 
  Explanation 
  of 
  the 
  Mode 
  of 
  Occurrence 
  of 
  the 
  Red 
  

  

  Rocks 
  282 
  

  

  I. 
  Introduction. 
  

  

  There 
  are 
  a 
  few 
  patches 
  of 
  red 
  sandstone, 
  shale, 
  and 
  conglomerate 
  

   on 
  the 
  coast 
  of 
  Co. 
  Waterford 
  whose 
  age 
  has 
  been 
  the 
  subject 
  

   of 
  much 
  divergence 
  of 
  opinion, 
  owing 
  to 
  the 
  obscurity 
  of 
  their 
  

   stratigraphical 
  relations 
  and 
  isolated 
  positions. 
  A 
  recent 
  visit 
  

   which 
  I 
  paid 
  to 
  these 
  parts 
  enabled 
  me 
  to 
  collect 
  evidence 
  which 
  

   seems 
  to 
  my 
  mind 
  to 
  settle 
  their 
  age 
  conclusively. 
  

  

  The 
  earliest 
  description 
  of 
  these 
  rocks 
  with 
  which 
  I 
  am 
  acquainted 
  

   was 
  published 
  by 
  Mr. 
  J. 
  Hodgson 
  Holdsworth 
  1 
  in 
  1833. 
  He 
  main- 
  

   tained 
  the 
  view 
  that 
  they 
  were 
  of 
  the 
  same 
  age 
  as 
  the 
  ' 
  great 
  con- 
  

   glomerate-formation 
  ' 
  of 
  the 
  Monovoulagh 
  or 
  Comeragh 
  Mountains, 
  

   which 
  he 
  rightly 
  ascribed 
  to 
  the 
  Old 
  Red 
  Sandstone. 
  He 
  pointed 
  

   out 
  also 
  the 
  fact 
  that 
  they 
  rest 
  unconformably 
  on 
  the 
  ' 
  Silurian 
  ' 
  

   rocks. 
  

  

  The 
  next 
  mention 
  of 
  these 
  beds 
  is 
  by 
  Mr. 
  T. 
  Weaver 
  2 
  in 
  1835, 
  

   when 
  he 
  described 
  a 
  gradual 
  passage 
  from 
  the 
  greenstone 
  rocks 
  into 
  

   the 
  red 
  sandstone 
  ' 
  through 
  the 
  medium 
  of 
  a 
  compound 
  con- 
  

   glomerate 
  ' 
  of 
  greenstone 
  with 
  red 
  sandstone-fragments 
  and 
  of 
  red 
  

   sandstone 
  with 
  greenstone-fragments. 
  Thus 
  he 
  apparently 
  favoured 
  

   the 
  view 
  of 
  their 
  ' 
  Silurian 
  ' 
  age. 
  

  

  Mr. 
  J. 
  Beete 
  Jukes 
  3 
  in 
  1852 
  put 
  forward 
  the 
  view 
  that 
  these 
  

   patches 
  were 
  blocks 
  of 
  Old 
  Red 
  Sandstone 
  let 
  into 
  the 
  ' 
  Silurian 
  J 
  

   rocks 
  of 
  the 
  coast 
  by 
  complicated 
  faults. 
  

  

  In 
  1860 
  Messrs. 
  W. 
  B. 
  Brownrigg 
  and 
  Theo. 
  Cooke, 
  4 
  in 
  a 
  brief 
  

   description 
  of 
  the 
  coast, 
  accepted 
  the 
  view 
  that 
  these 
  patches 
  are 
  

   faulted 
  masses 
  of 
  Old 
  Red 
  Sandstone. 
  

  

  In 
  the 
  Geological 
  Survey 
  memoir 
  of 
  this 
  district 
  5 
  Mr. 
  G. 
  V. 
  Du 
  

   Noyer 
  rejected 
  the 
  idea 
  of 
  the 
  Old 
  Red 
  Sandstone 
  age 
  of 
  these 
  red 
  

   sandstones 
  and 
  conglomerates, 
  and 
  maintained 
  that 
  there 
  are 
  two 
  

  

  1 
  ' 
  On 
  the 
  Geology 
  of 
  the 
  District 
  of 
  the 
  Knockmahon 
  Mines 
  in 
  the 
  County 
  

   of 
  Waterford,' 
  Journ. 
  Geol. 
  Soc. 
  Dublin, 
  vol. 
  i. 
  (183-3) 
  p. 
  85. 
  

  

  2 
  • 
  On 
  the 
  Geological 
  Relations 
  of 
  the 
  South 
  of 
  Ireland,' 
  Trans. 
  Geol. 
  Soc. 
  

   Lond. 
  ser. 
  2, 
  vol. 
  v. 
  pt. 
  i. 
  (1837) 
  p. 
  14. 
  

  

  3 
  ' 
  Sketch 
  of 
  the 
  Geology 
  of 
  the 
  County 
  of 
  Waterford,' 
  Journ. 
  Geol. 
  Soc. 
  

   Dublin, 
  vol. 
  v. 
  (1852) 
  p. 
  147. 
  

  

  4 
  Journ. 
  Geol. 
  Soc. 
  Dublin, 
  vol. 
  ix. 
  (1860) 
  p. 
  8. 
  

  

  5 
  Explan. 
  Sheets 
  167, 
  168, 
  178, 
  and 
  17K, 
  Geol. 
  Surv. 
  Ireland 
  (1855), 
  p. 
  10. 
  

  

  