﻿150 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Feb. 
  3, 
  

  

  occur 
  abundantly 
  in 
  the 
  neighbourhood 
  of 
  Brough 
  andKirkby 
  Stephen. 
  

   Here 
  the 
  magnesian-limestone 
  fragments 
  frequently 
  present 
  them- 
  

   selves 
  hollow 
  in 
  the 
  interior, 
  possessing 
  the 
  characters 
  of 
  potato-stone. 
  

   Besides 
  dolomitic 
  limestones, 
  these 
  higher 
  breccias 
  have 
  fragments 
  

   of 
  vein-quartz 
  and 
  Silurian 
  slates 
  entering 
  into 
  their 
  composition. 
  

  

  The 
  Lower 
  Permians 
  of 
  the 
  Valley 
  of 
  the 
  Eden 
  have 
  a 
  great 
  thick- 
  

   ness 
  (2000 
  feet), 
  but 
  have 
  hitherto 
  afforded 
  no 
  fossils. 
  Footprints 
  

   have, 
  however, 
  been 
  obtained 
  from 
  some 
  of 
  the 
  beds 
  near 
  Penrith, 
  

   and 
  are 
  considered 
  to 
  be 
  analogous 
  to 
  those 
  of 
  Corncockle 
  Muir 
  in 
  

   Dumfriesshire. 
  

  

  Although 
  the 
  breccias 
  of 
  the 
  Penrith 
  sandstones 
  have, 
  to 
  a 
  great 
  

   extent, 
  only 
  a 
  local 
  persistence, 
  they 
  afford 
  important 
  information 
  

   concerning 
  certain 
  superinduced 
  structures 
  which 
  are, 
  perhaps, 
  more 
  

   peculiar 
  to 
  the 
  Permian 
  formation 
  than 
  to 
  any 
  other 
  of 
  the 
  groups 
  

   of 
  British 
  sedimentary 
  rocks. 
  This 
  is 
  seen 
  in 
  the 
  abundance 
  of 
  dolo- 
  

   mitized 
  or 
  magnesian 
  limestones 
  which 
  are 
  contained 
  in 
  and 
  towards 
  

   the 
  central 
  portion 
  of 
  the 
  Permian 
  series. 
  These 
  dolomitized 
  frag- 
  

   ments 
  of 
  the 
  higher 
  breccias, 
  there 
  is 
  every 
  reason 
  to 
  infer, 
  were 
  

   originally 
  deposited 
  in 
  the 
  condition 
  of 
  simple 
  limestones 
  like 
  those 
  

   of 
  the 
  lower 
  breccias 
  of 
  the 
  same 
  group. 
  The 
  magnesian 
  breccias 
  

   are 
  not 
  confined 
  to 
  the 
  Yale 
  of 
  the 
  Eden 
  ; 
  they 
  occur 
  also 
  in 
  the 
  

   course 
  of 
  the 
  Shalk-beck, 
  about 
  two 
  miles 
  south 
  of 
  Curthwaite 
  

   Station, 
  on 
  the 
  Carlisle 
  and 
  Maryport 
  Eailway, 
  where 
  they 
  form 
  the 
  

   higher 
  member 
  of 
  the 
  Penrith 
  sandstones. 
  

  

  The 
  Lower 
  Permian 
  sandstones 
  of 
  Cumberland 
  and 
  Westmoreland 
  

   have 
  a 
  feature 
  which 
  serves 
  to 
  distinguish 
  them 
  from 
  other 
  and 
  higher 
  

   sandstones 
  of 
  the 
  group, 
  and 
  which 
  will 
  be 
  subsequently 
  alluded 
  to. 
  

   They 
  abound 
  in 
  hard 
  transverse 
  veins 
  composed 
  of 
  quartzose 
  sand- 
  

   stone, 
  the 
  particles 
  of 
  which 
  are 
  similar 
  to 
  those 
  of 
  the 
  ordinary 
  red 
  

   sandstone. 
  These 
  veins 
  are 
  white 
  in 
  colour, 
  and 
  much 
  harder 
  than 
  

   the 
  mass 
  of 
  red 
  sandstone 
  which 
  encloses 
  them 
  ; 
  every 
  good 
  section 
  

   of 
  the 
  Penrith 
  sandstones 
  exposes 
  them, 
  but 
  they 
  are 
  best 
  seen 
  in 
  

   the 
  middle 
  portion 
  of 
  the 
  series. 
  They 
  are 
  strikingly 
  exposed 
  on 
  

   the 
  banks 
  of 
  the 
  Eden, 
  in 
  the 
  faces 
  of 
  the 
  romantic 
  cliffs 
  near 
  the 
  

   Nunnery, 
  about 
  two 
  miles 
  north-west 
  of 
  Kirkoswald. 
  Here 
  they 
  

   stand 
  out 
  from 
  the 
  red 
  and 
  white 
  sandstones 
  in 
  consequence 
  of 
  their 
  

   superior 
  hardness, 
  and 
  at 
  one 
  spot 
  a 
  vein 
  about 
  two 
  feet 
  thick 
  is 
  a 
  

   mass 
  of 
  perfect 
  chert. 
  

  

  Yeins 
  also 
  occur 
  in 
  connexion 
  with 
  the 
  magnesian 
  breccias 
  at 
  

   Hilton-beck, 
  where 
  they 
  possess 
  a 
  somewhat 
  different 
  mineral 
  na- 
  

   ture, 
  being 
  composed 
  of 
  sand 
  cemented 
  together 
  by 
  magnesian 
  lime- 
  

   stone, 
  the 
  latter 
  having 
  doubtless 
  been 
  derived 
  from 
  the 
  dolomitized 
  

   fragments 
  imbedded 
  in 
  the 
  strata. 
  The 
  character 
  of 
  the 
  veins 
  

   changes 
  as 
  we 
  descend 
  Hilton-beck 
  towards 
  the 
  underlying 
  red 
  

   sandstones, 
  where 
  ordinary 
  white-sandstone 
  veins 
  make 
  their 
  ap- 
  

   pearance. 
  The 
  latter 
  are 
  usually 
  widest 
  in 
  their 
  upper 
  parts, 
  and 
  

   seem 
  to 
  have 
  been 
  filled 
  in 
  from 
  above. 
  

  

  b. 
  Barroivmouili, 
  near 
  Whitehaven. 
  — 
  At 
  Barrowmouth, 
  near 
  

   Whitehaven, 
  on 
  the 
  north-east 
  side 
  of 
  St. 
  Bees 
  Head, 
  we 
  have 
  a 
  

   small 
  area 
  of 
  Penrith 
  sandstones 
  exhibited, 
  and 
  here 
  also 
  other 
  Per- 
  

  

  