﻿274 
  

  

  J. 
  W. 
  JTJDD 
  ON 
  THE 
  SECONDARY 
  ROCKS 
  OF 
  SCOTLAND. 
  

  

  spathic 
  lavas, 
  have, 
  as 
  yet, 
  furnished 
  no 
  organic 
  remains. 
  They 
  are 
  

   evidently, 
  as 
  a 
  mass, 
  post-Cretaceous 
  ; 
  but 
  I 
  have 
  observed 
  some 
  phe- 
  

   nomena, 
  which 
  will 
  be 
  described 
  hereafter, 
  apparently 
  pointing 
  to 
  

   the 
  conclusion 
  that 
  volcanic 
  activity 
  must 
  have 
  commenced 
  in 
  the 
  

   district 
  before 
  the 
  Cretaceous 
  period 
  had 
  altogether 
  closed. 
  May 
  we 
  

   not, 
  therefore, 
  bearing 
  in 
  mind 
  these 
  facts 
  and 
  also 
  the 
  strong 
  proofs 
  

   already 
  detailed 
  of 
  unconformable 
  relations 
  between 
  these 
  felspathic 
  

   lavas 
  and 
  the 
  Miocene 
  basalts, 
  venture 
  to 
  refer 
  the 
  former, 
  at 
  least 
  

   provisionally, 
  to 
  the 
  great 
  Eocene 
  period 
  ? 
  

  

  The 
  proofs 
  of 
  the 
  Miocene 
  age 
  of 
  the 
  basalts 
  constituting 
  the 
  great 
  

   plateaux, 
  both 
  in 
  the 
  Hebrides 
  and 
  in 
  Antrim, 
  are 
  as 
  follows 
  : 
  — 
  

  

  At 
  Ardtun 
  in 
  Mull, 
  low 
  down 
  in 
  the 
  series, 
  the 
  following 
  species 
  

   of 
  plants 
  have 
  been 
  obtained 
  from 
  the 
  pond-like 
  hollows 
  buried 
  

   under 
  streams 
  of 
  mud 
  and 
  lavas 
  as 
  before 
  described. 
  

  

  Sequoia 
  Langsdorffii, 
  Ad. 
  Brongn. 
  

  

  (Taxites 
  Campbellii, 
  Forbes.) 
  

   Rhamnites 
  (?) 
  multinervatus, 
  

  

  Forbes. 
  

   major, 
  Forbes. 
  

  

  Rhamnites 
  lanceolatus, 
  Forbes. 
  

   Equisetum 
  Campbellii, 
  Forbes. 
  

   Filicites 
  (?) 
  hebridicus, 
  Forbes. 
  

   Alnites 
  (?) 
  McQuarrii, 
  Forbes. 
  

   Corylus 
  grosse-dentata, 
  Heer. 
  

  

  In 
  the 
  plant-beds 
  intercalated 
  in 
  a 
  series 
  of 
  lacustrine 
  deposits 
  at 
  

   Ballypalidy, 
  Co. 
  Antrim, 
  the 
  following 
  have 
  been 
  found 
  : 
  — 
  

  

  Sequoia 
  Du 
  Noyeri, 
  Baity. 
  

   Pinus 
  (?) 
  Plutonis, 
  Baily. 
  

   Cupressites 
  MacIIenryi, 
  Baily. 
  

  

  Eucalyptus 
  oceanica, 
  linger. 
  

   Daphnogene 
  Kanii, 
  Heer. 
  

  

  with 
  fragments 
  referred, 
  somewhat 
  doubtfully, 
  to 
  the 
  genera 
  Pla- 
  

   tanusl, 
  Fagus, 
  Podocarpus, 
  Andromeda, 
  Quercus, 
  Rhamnus, 
  Hakea, 
  

   Celastrus, 
  and 
  Oraminites. 
  Also 
  the 
  elytra 
  of 
  two 
  species 
  of 
  beetles. 
  

   In 
  " 
  ash-beds 
  " 
  between 
  the 
  basalts 
  near 
  Shane's 
  Castle, 
  Lough 
  

   Neagh, 
  Co. 
  Antrim, 
  the 
  following 
  were 
  obtained 
  : 
  — 
  

  

  Platanus 
  aceroides, 
  Gopp. 
  Sequoia 
  Langsdorfii, 
  Ad. 
  Brongn. 
  

  

  with 
  fragments 
  referred 
  to 
  the 
  genera 
  Juglans, 
  Fagus, 
  Laurus, 
  &c* 
  

   Both 
  Prof. 
  Edward 
  Eorbes 
  and 
  Prof. 
  Heer 
  concur 
  in 
  the 
  opinion 
  

   that 
  these 
  floras 
  indicate 
  that 
  the 
  beds 
  in 
  which 
  they 
  occur 
  were 
  

   deposited 
  during 
  the 
  Miocene 
  period. 
  

  

  Concerning 
  the 
  age 
  of 
  the 
  last 
  of 
  the 
  three 
  periods 
  of 
  eruption, 
  

   that 
  of 
  the 
  " 
  puys," 
  the 
  evidence 
  from 
  organic 
  remains 
  is 
  much 
  more 
  

   scanty. 
  It 
  consists 
  only 
  of 
  the 
  fossil 
  wood 
  (known 
  as 
  Pinites 
  

   eggensis, 
  With.) 
  found 
  under 
  the 
  lava 
  stream 
  of 
  the 
  Scur 
  of 
  Eigg, 
  

   upon 
  which, 
  of 
  course, 
  no 
  conclusion 
  can 
  be 
  founded. 
  Considering, 
  

   however, 
  the 
  proofs 
  already 
  adduced, 
  from 
  their 
  unconformable 
  re- 
  

   lations, 
  of 
  the 
  separation 
  of 
  the 
  deposits 
  of 
  this 
  period 
  alike 
  from 
  

   those 
  of 
  the 
  Miocene 
  and 
  the 
  recent 
  epochs, 
  we 
  can 
  scarcely 
  hesitate 
  

   to 
  regard 
  them 
  as 
  belonging, 
  at 
  least 
  approximately, 
  to 
  the 
  Pliocene 
  f. 
  

  

  * 
  Vide 
  Forbes, 
  Quart. 
  Journ. 
  G-eol. 
  Soc. 
  vol. 
  vii. 
  (1853), 
  p. 
  103 
  ; 
  W. 
  H. 
  Baily, 
  

   ibid. 
  vol. 
  xxv. 
  (1869), 
  p. 
  357; 
  and 
  Tate 
  and 
  Holden, 
  ibid. 
  vol. 
  xxvi. 
  (1870.), 
  

   pp. 
  162-63. 
  

  

  t 
  In 
  venturing 
  thus 
  to 
  compare 
  the 
  three 
  periods 
  of 
  volcanic 
  activity 
  in 
  the 
  

   north-western 
  parts 
  of 
  the 
  British 
  Islands 
  with 
  those 
  divisions 
  of 
  the 
  Tertiary 
  

   epoch 
  which 
  Sir 
  Charles 
  Lyell 
  has 
  founded 
  upon 
  a 
  comparison 
  of 
  the 
  mollusean 
  

  

  