342 
REV.  S.  HAUGHTON  ON  THE  PHYSICAL  STEUCTL'EE  OF  THE 
This  bearing  of  the  cleavage  planes  is  nearly  coincident  with  that  of  the  same  system 
of  faults,  viz.  7°  30'  North  of  East. 
This  may  be  considered  as  an  east  and  west  system,  so  far  as  strike  or  bearinsr  is 
concerned;  but  it  is  divisible  into  two  systems  with  respect  to  dip. 
System  A'. 
The  system  A'  contains  60  observations ; of  these 
24  planes  are  vertical. 
21  dip  North  at  71°  average. 
16  dip  South  at  79°  average. 
The  average  bearing  of  the  whole  system  is  33°  10'  North  of  East,  which  agrees  with 
the  bearing  of  the  system  of  faults  called  A',  in  p.  335,  viz.  34°  22'  North  of  East.  This 
system.  A',  is  the  second  east  and  west  system,  and  the  cleavage  planes  are  sometimes 
found  in  this  direction,  though  more  generally  in  the  dkection  A.  It  is  to  be  observed 
of  both  these  systems,  that  the  planes  dip  to  the  north  at  a smaller  angle  than  to  the 
south. 
System  C. 
This  system  contains  twenty-five  observations ; of  these 
14  planes  are  vertical. 
6 dip  East  at  80°  average. 
5 dip  West  at  78°  average. 
The  average  bearing  of  this  system  of  planes,  which  is  conjugate  to  the  system  (A),  is 
7°  38'  West  of  North. 
System  C. 
This  system,  east  of  Red  Head,  consists  of  nineteen  observed  planes ; of  which 
8 are  vertical. 
4 dip  East  at  70°  average. 
7 dip  West  at  74°  average. 
The  average  bearing  of  this  system  is  33°  35'  West  of  North. 
The  following  Table  contains  the  planes  belonging  to  the  conjugate  systems  A and 
and  also  A'  and  C',  observed  westward  of  Red  Head ; where  the  faults  are  more  nume- 
rous than  to  the  east,  and  their  downthrows  in  the  opposite  direction. 
