﻿1863.] 
  TATE 
  LIAS 
  OF 
  BELFAST. 
  103 
  

  

  2. 
  On 
  the 
  Liassic 
  Strata 
  of 
  the 
  Neighbourhood 
  of 
  Belfast. 
  By 
  

   Ralph 
  Tate, 
  Esq., 
  F.G.S. 
  With 
  Descriptions 
  o/New 
  Species 
  of 
  

   Molltjsca, 
  &c. 
  ; 
  by 
  R. 
  Etheridge, 
  Esq., 
  F.G.S., 
  F.R.S.E. 
  

  

  Contents. 
  

  

  5. 
  Zone 
  of 
  the 
  White 
  Lias. 
  

  

  6. 
  Zone 
  of 
  the 
  Lower 
  Lias. 
  

  

  7. 
  Distribution 
  of 
  the 
  Liassic 
  Rocks 
  

   in 
  the 
  North 
  of 
  Ireland. 
  

  

  1. 
  Introduction. 
  

  

  2. 
  General 
  Geological 
  Description 
  

  

  3. 
  Zone 
  of 
  Avicula 
  contorta. 
  

  

  4. 
  Section 
  at 
  Whitehead. 
  

  

  Notes 
  on 
  Species. 
  

  

  1. 
  Introduction. 
  — 
  General 
  Portlock, 
  in 
  his 
  Geological 
  Report 
  on 
  

   Londonderry, 
  Tyrone, 
  and 
  Fermanagh 
  (1843), 
  was 
  the 
  first 
  to 
  direct 
  

   attention 
  to 
  certain 
  beds 
  linking 
  the 
  Triassic 
  and 
  Liassic 
  formations. 
  

   In 
  that 
  Report 
  he 
  refers 
  to 
  the 
  occurrence 
  of 
  beds 
  at 
  Colin 
  Glen, 
  

   Belfast, 
  characterized 
  by 
  the 
  same 
  Shell 
  (Cardium 
  striatulum) 
  as 
  

   that 
  which 
  occurs 
  in 
  the 
  Lisnagrib 
  section 
  (pp. 
  49, 
  56, 
  107). 
  

  

  It 
  is 
  now 
  my 
  purpose 
  to 
  describe 
  in 
  detail 
  the 
  strata 
  thus 
  referred 
  

   to, 
  and 
  their 
  extension 
  to 
  neighbouring 
  localities. 
  

  

  Within 
  the 
  last 
  few 
  years 
  the 
  stratigraphical 
  relations 
  and 
  the 
  

   fauna 
  of 
  the 
  Lower 
  Liassic 
  and 
  Avicula- 
  contorta 
  series, 
  as 
  developed 
  in 
  

   England, 
  have 
  been 
  made 
  known 
  by 
  the 
  labours 
  of 
  Dr. 
  Wright* 
  and 
  

   Mr. 
  Charles 
  Moore 
  f. 
  

  

  I 
  trust 
  the 
  value 
  of 
  the 
  present 
  communication 
  is 
  enhanced 
  by 
  the 
  

   attention 
  I 
  have 
  given 
  to 
  the 
  correlation 
  of 
  the 
  Belfast 
  beds 
  with 
  

   the 
  members 
  of 
  the 
  same 
  epoch, 
  as 
  detailed 
  in 
  papers 
  read 
  before 
  this 
  

   Society, 
  and 
  referred 
  to 
  above. 
  

  

  The 
  following 
  members 
  of 
  the 
  Liassic 
  period 
  are 
  developed 
  in 
  the 
  

   neighbourhood 
  of 
  Belfast, 
  namely, 
  the 
  zone 
  of 
  Ammonites 
  Bucklandi, 
  

   the 
  zone 
  of 
  the 
  White 
  Lias, 
  and 
  the 
  zone 
  of 
  Avicula 
  contorta 
  ; 
  but 
  

   before 
  proceeding 
  to 
  the 
  details 
  of 
  these 
  formations, 
  I 
  shall 
  give 
  a 
  

   short 
  description 
  of 
  the 
  geological 
  features 
  of 
  the 
  locality, 
  rendered 
  

   somewhat 
  necessary 
  by 
  the 
  peculiarities 
  that 
  here 
  occur. 
  

  

  2. 
  General 
  Geological 
  Description. 
  — 
  The 
  neighbourhood 
  of 
  Belfast 
  

   is 
  divided 
  by 
  the 
  Belfast 
  Lough 
  and 
  the 
  River 
  Lagan 
  into 
  two 
  

   naturally 
  well-marked 
  sections, 
  both 
  as 
  regards 
  the 
  geological 
  forma- 
  

   tions 
  and 
  its 
  geographical 
  relations 
  : 
  — 
  the 
  Northern 
  Section 
  is 
  part 
  

   of 
  the 
  county 
  of 
  Antrim, 
  and 
  the 
  geological 
  formations 
  are 
  Neozoic 
  ; 
  

   the 
  Southern 
  Section 
  is 
  situated 
  in 
  the 
  county 
  of 
  Down, 
  where 
  the 
  

   formations 
  are 
  Palaeozoic. 
  

  

  The 
  Northern 
  Section 
  is 
  occupied 
  by 
  the 
  Belfast 
  Hills 
  range, 
  the 
  

   basis 
  of 
  which 
  is 
  the 
  Keuper 
  formation, 
  presenting 
  a 
  steep 
  incline, 
  

   rising 
  from 
  the 
  shore 
  and 
  the 
  River 
  Lagan 
  to 
  a 
  maximum 
  elevation 
  

   of 
  650 
  feet. 
  The 
  New 
  Red 
  is 
  surmounted 
  by 
  the 
  Lias, 
  Gault, 
  Upper 
  

   Greensand, 
  Hard 
  Chalk, 
  and 
  Basalt 
  ; 
  forming 
  a 
  bold 
  escarpment 
  

   extending 
  from 
  Whitehead 
  on 
  the 
  north-east 
  to 
  Lisburn, 
  &c, 
  on 
  the 
  

   south-west, 
  with 
  an 
  average 
  elevation 
  of 
  1000 
  feet. 
  Numerous 
  trap- 
  

   dykes 
  intersect 
  or 
  cut 
  through 
  all 
  the 
  sedimentary 
  rocks, 
  and 
  may 
  be 
  

   carried 
  up 
  into 
  the 
  overlying 
  Basalt. 
  The 
  prevailing 
  strike 
  of 
  the 
  

   dykes 
  varies 
  between 
  N.E. 
  and 
  N.W. 
  

  

  * 
  See 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xvi. 
  p. 
  374, 
  &c. 
  f 
  Ibid. 
  vol. 
  xvii. 
  p. 
  483, 
  &c. 
  

  

  