Yol.  49.] 
COAST-SECTIONS  AT  THE  LIZARD. 
199 
14.  Notes  on  some  Coast-sections  at  the  Lizard.  By  Howard  Pox, 
Esq.,  F.G.S.,  and  J.  J.  H.  Teall,  Esq.,  M.A.,  F.R.S.,  F.G.S. 
(Read  Eebruary  8th,  1893.) 
Contexts. 
Page 
I.  Introduction . .  199 
II  Relations  of  Serpentine  to  Hornblende-schist  at  Pol  Oornick  .  199 
(a)  Interbanding  of  Schist  and  Serpentine. 
( b )  Folding  and  Faulting  of  the  Complex. 
III.  Basic  Dykes,  and  the  Conxersion  of  Dolerite  into  Hornblende-schist...  204 
IV.  Relation  between  the  Serpentine  and  the  Granulitic  Series  east  of  the 
Lion  Rock  .  200 
V.  Summary  of  Results . 210 
I.  Introduction. 
The  well-known  serpentine  of  the  Lizard  may  be  seen  in  contact 
with  hornblende-schist,  and  also  with  the  rocks  for  which  Prof. 
Bonney  proposed  the  term  ‘  Granulitic  Series.’  The  object  of  the 
present  communication  is  to  describe  two  small  portions  of  the 
western  coast,  where  phenomena  which  throw  important  light  on 
the  nature  of  the  relations  of  the  serpentine  to  the  adjacent  rocks 
may  be  observed.  The  first  is  in  the  neighbourhood  of  Ogo  Dour, 
and  the  second  east  of  the  Lion  Rock,  Kynance. 
II.  Relations  of  Serpentine  to  Hornblende-schist  at 
Pol  Cornice. 
In  his  classic  ‘  Report  on  the  Geology  of  Devon,  Cornwall,  and 
West  Somerset,’  De  la  Beche  says  (p.  30)  : — “  It  [the  hornblende- 
slate]  supports  the  great  mass  of  the  Lizard  serpentine,  with  an 
apparent  passage  of  the  one  into  the  other  in  many  places .  In 
contradiction  to  this  apparent  passage,  we  find  a  mass  of  serpentine 
amid  the  hornblende-slate  between  Dranna  Point  and  Porthalla,  on  the 
north  of  the  principal  mass  of  serpentine,  which  has  every  appear¬ 
ance  of  having  been  thrust  up  among  the  hornblende-slate,  twisting 
and  contorting  the  laminse  adjoining  it  in  directions  which  we 
should  consider  consistent  with  the  passage  of  the  serpentine  in  a 
state  of  igneous  fusion  through  them.”  In  these  sentences  De  la 
Beche  shows  that  he  had  observed  facts  which  apparently  contra¬ 
dicted  each  other,  and  with  characteristic  candour  he  states  the  two 
more  or  less  opposed  views,  leaving  the  question  undetermined. 
In  1877  and  1883  Prof.  Bonney  communicated  to  this  Society 
important  papers  in  which  he  maintained  that  the  serpentine  was 
the  result  of  the  alteration  of  somewhat  different  types  of  rock,  all 
of  which  belonged  to  the  peridotite  family,  and  that  fit,  or  rather  the 
original  rock  of  which  it  is  the  altered  representative,  had  been 
intruded  into  the  hornblende-schist.  In  the  years  1879  and  1884 
Mr.  J.  H.  Collins  joined  issue  with  Prof.  Bonney,  and  finally  summed 
up  his  conclusions  as  follows  : — “  Of  an  originally  differing  series 
