7 
Yol.  49.]  PROCEEDINGS  OE  THE  GEOLOGICAL  SOCIETY. 
granites,  asbestiform  actinolite,  and  marble.  The  Author  discusses 
the  mode  of  origin  of  the  granite,  marble,  and  actinolite- rock. 
Discussion. 
The  President  remarked  that  the  Author  seldom  failed  to  make 
good  use  of  his  time  when  travelling.  The  conditions  displayed  in 
his  principal  section  might  possibly  be  explained  on  the  shearing 
theory,  two  different  sets  of  beds  being  sandwiched  into  one  another. 
But  this  could  scarcely  account  for  the  peculiar  relations  of  the 
quartz-conglomerates  to  the  Author’s  gneisses  and  mica-schists. 
We  might  believe  almost  anything  of  these  very  ancient  (Archaean) 
rocks. 
Dr.  Hicks  asked  what  was  the  evidence  to  show  that  the  gneiss 
was  of  the  same  age  as  the  conglomerates  and  shales  ?  Were  there 
not  evidences  of  faults  such  as  would  cause  two  distinct  series  to  be 
brought  together  in  apparent  sequence  ? 
Dr.  Hinde  did  not  think  the  Author  was  right  in  attributing 
the  origin  of  the  lakelets  and  basiu-like  rock-depressions  in  the 
districts  referred  to,  to  the  action  of  frost  in  exfoliating  the  rock- 
surfaces  ;  for  in  this  case  they  would  not  show  the  glacial  strioe  and 
polishing  now  present,  not  only  in  the  raised  bosses  but  in  the 
hollows  as  well.  The  debris  resulting  from  exfoliation,  if  such  had 
taken  place  to  any  extent,  would  also  have  prevented  the  frost  from 
penetrating  deep  enough  to  form  the  hollows. 
Mr.  Monckton  also  spoke. 
The  Author,  in  reply  to  the  President  and  to  Dr.  Hicks,  said 
that  he  thought  the  shale-actinolite  series  might  be  of  different  age 
from  that  of  the  gneiss-conglomerate  series  ;  the  strike  was  perhaps 
not  precisely  the  same,  and  the  junction  was  concealed  by  a  stream. 
But  the  stratigraphic  relations  of  the  conglomerate-beds  were  per¬ 
fectly  clear,  and  he  had  no  doubt  whatever  as  to  their  forming  part 
of  the  gneissic  series.  He  applied  the  term  4  gneiss,’  as  it  was 
generally  used  in  Canada,  to  a  more  or  less  foliated  crystalline  rock 
consisting  of  quartz,  felspar,  and  mica  in  varying  proportions.  He  did 
not  really  think  the  marbles  were  segregations,  but  the  suggestion 
had  been  made  and  he  thought  it  worthy  of  some  consideration. 
In  reply  to  Dr.  Hinde,  he  said  that  only  the  smaller  lakelets  could 
be  formed  by  frost-flaking,  and  perhaps  he  ought  to  have  spoken  of 
these  as  rock-pools  rather  than  lakelets.  The  flakes  did  not  accu¬ 
mulate,  because  they  were  soon  split  up  into  minute  fragments  by 
succeeding  frosts  and  removed  by  the  winds. 
The  following  specimens  were  exhibited : — 
Eock-specimens  and  microscopic  sections,  exhibited  by  Prof.  T.  Gr. 
Bonney,  D.Sc.,  LL.D.,  E.E.S.,  Y.P.G.S.,  in  illustration  of  his  papers, 
Eock-specimens  and  photographs,  exhibited  by  J.  H.  Collins,  Esq., 
F.G.S.,  in  illustration  of  his  paper. 
