﻿Geological 
  Society. 
  6 
  49 
  

  

  March 
  8th, 
  1911.— 
  Prof. 
  W. 
  W. 
  Watts, 
  Sc.D., 
  M.Sc, 
  F.E.S., 
  

   President, 
  in 
  the 
  Chair. 
  

  

  The 
  following 
  communication 
  was 
  read: 
  — 
  

  

  ' 
  Contributions 
  to 
  the 
  Geology 
  of 
  Cyrenaica.' 
  

   By 
  Prof. 
  J. 
  W. 
  Gregory 
  and 
  others. 
  

  

  (i) 
  The 
  Geology 
  of 
  Cyrenaica. 
  By 
  John 
  Walter 
  Gregory, 
  

   D.Sc, 
  F.R.S., 
  F.G.S., 
  Professor 
  of 
  Geology 
  in 
  the 
  University 
  

   of 
  Glasgow. 
  

  

  According 
  to 
  the 
  scanty 
  evidence 
  available 
  in 
  1908 
  regarding 
  

   Cyrenaica, 
  which 
  Hildebrand 
  described 
  in 
  1904 
  as 
  ' 
  heute 
  noch 
  

   so 
  gut 
  wie 
  unbekannt,' 
  the 
  country 
  might 
  be 
  interpreted 
  as 
  a 
  

   fragment 
  of 
  a 
  mountain-loop, 
  an 
  off-branch 
  from 
  the 
  Atlas, 
  or 
  as 
  a 
  

   plateau 
  of 
  Miocene 
  rocks. 
  

  

  In 
  a 
  journey 
  across 
  the 
  country, 
  the 
  Author 
  found 
  that 
  it 
  was 
  

   a 
  plateau 
  of 
  Lower 
  Kainozoic 
  Limestones, 
  which 
  are 
  classified 
  as 
  

   follows 
  : 
  — 
  

  

  Oligocenk 
  Ojrene 
  Limestones. 
  

   (Aquitanian) 
  

  

  (Slonta 
  Limestones 
  = 
  Priabonian. 
  

   Derna 
  Limestones 
  = 
  Moqattam 
  Series 
  of 
  Egypt. 
  

   Apollonia 
  Limestones 
  = 
  Libyan 
  Series 
  of 
  Egypt. 
  

  

  Some 
  Miocene 
  limestones 
  000111" 
  in 
  places 
  on 
  the 
  plateau, 
  and 
  lying 
  against 
  

   its 
  western 
  foot. 
  

  

  These 
  rocks 
  are 
  all 
  limestones, 
  containing 
  very 
  little 
  clastic 
  

   material. 
  They 
  must 
  have 
  been 
  deposited 
  in 
  a 
  clear 
  sea, 
  at 
  depths 
  

   ranging 
  clown 
  to 
  nearly 
  1000 
  fathoms. 
  

  

  Intervals 
  of 
  shallow 
  sea 
  are 
  indicated 
  by 
  some 
  limestone-con- 
  

   glomerates 
  and 
  a 
  band 
  of 
  coral-reef 
  limestone. 
  The 
  country 
  was 
  

   uplifted 
  in 
  later 
  Miocene 
  times, 
  and 
  was 
  then 
  part 
  of 
  a 
  wide 
  land 
  

   which 
  included 
  Crete 
  and 
  occupied 
  the 
  site 
  of 
  the 
  ./Egean 
  Sea. 
  

   This 
  land 
  was 
  broken 
  up 
  by 
  great 
  subsidences, 
  which 
  left 
  Cyrenaica 
  

   as 
  a 
  horst 
  bounded 
  by 
  fault-scarps 
  on 
  the 
  north 
  and 
  west. 
  

   Eastwards 
  the 
  country 
  sinks 
  by 
  a 
  slight 
  dip 
  and 
  a 
  succession 
  of 
  

   faults, 
  until 
  the 
  Miocene 
  limestones, 
  which 
  occur 
  on 
  the 
  plateau 
  

   in 
  Cyrenaica, 
  are 
  at 
  sea-level 
  on 
  the 
  coasts 
  of 
  Western 
  Egypt. 
  

   Cyrenaica 
  may 
  thus 
  be 
  regarded 
  as 
  part 
  of 
  the 
  western 
  limb 
  of 
  

   the 
  geosyncline 
  of 
  Western 
  Egypt. 
  

  

  The 
  formation 
  of 
  the 
  river-valleys 
  probably 
  began 
  during 
  a 
  period 
  

   of 
  wetter 
  climate 
  than 
  the 
  present, 
  but 
  there 
  is 
  no 
  evidence 
  of 
  any 
  

   appreciable 
  change 
  in 
  the 
  climate 
  or 
  water-supply 
  since 
  the 
  date 
  

   of 
  the 
  Greek 
  and 
  Roman 
  colonization. 
  

  

  Ann. 
  & 
  Mag. 
  N. 
  Hist. 
  Ser. 
  8. 
  Vol. 
  vii. 
  43 
  

  

  