﻿ON 
  THE 
  ASHPRINGTON 
  VOLCANIC 
  SERIES 
  OF 
  SOUTH 
  DEVON. 
  369 
  

  

  23. 
  On 
  the 
  Ashprington 
  Volcanic 
  Series 
  of 
  South 
  Devon. 
  By 
  the 
  

   late 
  Arthur 
  Champernowne, 
  Esq., 
  M.A., 
  F.G.S.* 
  (Head 
  May 
  8, 
  

   1889.) 
  

  

  (Communicated 
  by 
  Prof. 
  A. 
  Geikie, 
  LL.D., 
  F.R.S., 
  F.G.S.) 
  

   Introduction. 
  

  

  There 
  exists 
  in 
  South 
  Devon 
  an 
  extensive 
  series 
  of 
  igneous 
  and 
  

   quasi-igneous 
  rocks 
  occupying 
  a 
  considerable 
  area, 
  mainly 
  east 
  of 
  the 
  

   River 
  Avon, 
  which 
  have 
  as 
  yet 
  received 
  scarcely 
  more 
  than 
  passing 
  

   notice, 
  and 
  the 
  study 
  of 
  which 
  is 
  attended 
  with 
  much 
  perplexity 
  

  

  Sir 
  Henry 
  De 
  la 
  Bechet 
  noticed 
  the 
  Yalberton 
  trappean 
  rocks 
  

   south-west 
  of 
  Paignton, 
  which 
  are 
  included 
  in 
  our 
  subject, 
  and 
  spoke 
  

   of 
  them 
  as 
  interposed 
  between 
  the 
  Yalberton 
  limestone 
  and 
  that 
  

   of 
  Watton, 
  which 
  forms 
  the 
  western 
  termination 
  of 
  the 
  Berry 
  Head 
  

   mass. 
  The 
  relations 
  of 
  the 
  igneous 
  rocks 
  to 
  the 
  Devonian 
  limestones 
  

   will 
  be 
  considered 
  de 
  novo 
  as 
  we 
  proceed. 
  

  

  Dr. 
  HollJ 
  mentions 
  the 
  rocks 
  of 
  this 
  series 
  in 
  the 
  neighbourhood 
  

   of 
  Totnes, 
  Ashprington, 
  &c, 
  as 
  "thick 
  slates, 
  in 
  which 
  much 
  vol- 
  

   canic 
  matter 
  is 
  disseminated." 
  He 
  observes 
  that 
  " 
  volcanic 
  rocks 
  

   are 
  frequent," 
  and 
  that 
  " 
  beds 
  which 
  are 
  light-coloured 
  often 
  yield 
  

   a 
  red 
  soil." 
  This 
  was 
  written 
  with 
  reference 
  to 
  rocks 
  which 
  occupy 
  

   the 
  ground 
  between 
  Harberton 
  and 
  the 
  Dart. 
  Though 
  we 
  might 
  

   reason 
  ably 
  take 
  exception 
  to 
  the 
  term 
  " 
  slates 
  " 
  as 
  not 
  strictly 
  ap- 
  

   plicable 
  to 
  any 
  portion 
  of 
  these 
  rocks 
  with 
  which 
  we 
  are 
  acquainted, 
  

   yet 
  as 
  it 
  is 
  quite 
  certain 
  that 
  Dr. 
  Holl 
  well 
  appreciated 
  the 
  im- 
  

   portance 
  of 
  the 
  group, 
  and 
  as 
  no 
  spot 
  could 
  be 
  pointed 
  out 
  where 
  

   they 
  attain 
  a 
  greater 
  development 
  than 
  [at] 
  Ashprington 
  and 
  its 
  

   neighbourhood, 
  the 
  provisional 
  term 
  " 
  Ashprington 
  volcanic 
  series" 
  

   has 
  been 
  here 
  retained. 
  

  

  Many 
  patches 
  and 
  lines 
  of 
  " 
  greenstone 
  " 
  were 
  laid 
  down 
  by 
  

   De 
  la 
  Beche 
  within 
  the 
  tract 
  of 
  country 
  to 
  be 
  described 
  ; 
  but 
  these 
  

   represent 
  only 
  a 
  very 
  small 
  fraction 
  of 
  the 
  actual 
  spread 
  of 
  the 
  

   rocks, 
  which 
  occupy 
  on 
  the 
  east 
  of 
  the 
  Avon 
  a 
  large 
  part 
  of 
  Dipt- 
  

   ford, 
  Harberton, 
  Totnes, 
  Ashprington, 
  Oornworthy, 
  and 
  Dittisham 
  

   parishes, 
  and 
  on 
  the 
  east 
  of 
  the 
  Dart, 
  Berry 
  Pomeroy, 
  Stoke 
  Gabriel, 
  

   and 
  Churston 
  Ferrers. 
  

  

  On 
  the 
  west 
  of 
  the 
  Avon 
  they 
  range 
  through 
  North 
  Hewish 
  and 
  

   Ugborough 
  towards 
  the 
  Yealmpton 
  and 
  Plymouth 
  district, 
  but 
  are 
  

  

  * 
  [The 
  MS. 
  of 
  this 
  paper 
  was 
  found 
  by 
  Mrs. 
  Champernowne 
  among 
  her 
  

   husband's 
  papers 
  after 
  his 
  death, 
  and 
  was 
  handed 
  over 
  to 
  me. 
  I 
  believe 
  it 
  to 
  

   have 
  been 
  intended 
  as 
  an 
  instalment 
  of 
  a 
  general 
  description 
  of 
  the 
  Devonian 
  

   rocks 
  of 
  the 
  Totnes 
  district, 
  which, 
  at 
  my 
  request, 
  he 
  had 
  agreed 
  to 
  prepare. 
  

   Though 
  incomplete 
  and 
  evidently 
  the 
  first 
  rough 
  draft, 
  it 
  possesses 
  much 
  interest 
  

   as 
  an 
  expression 
  of 
  some 
  of 
  the 
  latest 
  views 
  of 
  one 
  of 
  the 
  most 
  careful 
  geologists 
  

   who 
  ever 
  studied 
  the 
  rocks 
  of 
  Devonshire. 
  The 
  map 
  to 
  which 
  reference 
  is 
  

   made 
  is 
  the 
  1-inch 
  Ordnance 
  Survey 
  Sheet, 
  no. 
  22, 
  which 
  was 
  coloured 
  after 
  an 
  

   original 
  geological 
  survey 
  by 
  the 
  author. 
  This 
  work 
  was 
  presented 
  by 
  him 
  to 
  

   the 
  Geological 
  Survey, 
  and 
  it 
  will 
  be 
  embodied 
  in 
  the 
  new 
  edition 
  of 
  the 
  Survey 
  

   Map 
  (no. 
  22) 
  now 
  in 
  preparation. 
  — 
  A. 
  Geikie.] 
  

  

  t 
  Hep. 
  Geol. 
  Cornwall, 
  Devon, 
  and 
  West 
  Somerset, 
  1839, 
  p. 
  72. 
  

  

  \ 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  1868, 
  vol. 
  xxiv. 
  p. 
  434. 
  

  

  Q. 
  J. 
  G. 
  S. 
  No. 
  179. 
  2 
  e 
  

  

  