Yol.  49.] 
ST.  CASSIAS  STEATA  IE  SOTJTHEEX  TTEOL. 
61 
towards  Tra  i  Sassi  (on  the  eastern  limb  of  the  horseshoe)  by  Raibl 
and  Dachstein  strata.  On  the  southern  wall  itself  these  rocks 
have  been  eroded,  but  are  seen  lying  conformably  upon  the  Schlern 
Dolomite  in  the  Yalparola  hollow;  here  the  clip  of  the  beds  is 
steeper  than  the  angle  of  incline  of  the  mountain  (see  fig.  3,  p.  21). 
On  the  western  limb  of  the  horseshoe  the  Raibl  and  Dachstein  rocks 
have  a  wider  outcrop  than  on  the  eastern  limb,  and  are  brought 
against  the  Schlern  Dolomite  and  the  Raibl  strata  at  Yalparola  by 
means  of  a  south-west  and  north-east  fault-line. 
The  fault  is  seen  again  at  the  south-western  corner  of  Sett  Sass, 
between  Raibl  strata  and  Schlern  Dolomite.  It  is,  however,  merely 
of  minor  importance,  branching  from  the  north-and-south  fault 
which  extends  between  the  whole  of  the  western  limb  and  the 
Stuores  Wiese.  Roth  transverse  faults  are  then  cut  off  by  the  main 
longitudinal  east-and-west  Yalparola  fault,  this  triangular  break 
having  thrown  the  western  limb  farther  down  than  the  rest  of  Sett 
Sass.  Towards  Prelongei,  long  lines  of  Raibl  and  Dachstein  blocks 
and  debris  occur  in  the  course  of  the  fault  below  Sett  Sass  and 
above  Stuores  wood. 
The  system  of  Monte  Sief  and  Col  di  Lana  belongs  to  the  pre¬ 
viously-mentioned  anticlinal  outcrop  of  older  Triassic  strata.  In 
the  valley  between  Andraz  and  Pieve  the  Werfen  Beds  strike 
east-and-west ;  above  them  Muschelkalk,  Buchenstein  Beds,  and 
augite-porphyry  follow  in  symmetrical  succession,  both  southward 
towards  Marmolata  and  northward  towards  Sett  Sass.  This  valley 
was  not  included  in  my  detailed  study,  although  in  the  map  I  have 
for  convenience  indicated  the  general  relation  of  the  older  Trias  to 
the  strata  exposed  on  Prelongei. 
On  the  northern  side  of  the  valley  the  Buchenstein  limestones 
and  the  augite-porphyry  and  sedimentary  tuffs  have  an  unusually 
thick  development  on  the  Col  di  Lana  hill.  The  strata  dip  north¬ 
ward,  and  are  bent  up  towards  the  south  as  an  anticlinal  arch, 
which  may  be  very  clearly  observed  in  the  north-east  and  north¬ 
west  of  Monte  Sief — in  the  north-east,  where  the  stream  running  to 
Castello  takes  its  source ;  in  the  north-west,  where  the  slopes  of 
Monte  Sief  descend  steeply  to  Montagna  della  Corte.  Here  the 
bed-surface  is  often  almost  parallel  with  the  slope  of  the  hill,  and  in 
many  places,  where  the  Wengen  Beds  have  been  eroded,  augite- 
porphyry  reappears  suddenly,  sometimes  with  a  fairly  large  out¬ 
crop. 
The  strike  of  the  older  Triassic  rocks  continues  west  over  Cherz 
and  Yarda  to  Arabba.  They  dip  northward,  and  are  here  also 
conformably  succeeded  by  Wengen  Beds.  A  complication  is  caused 
by  an  east-and-west  fault  above  Yarda,  throwing  down  the  southern 
wing,  and  cutting  off  the  exposure  of  Werfen  Beds  on  the  northern 
wing.  I  found,  however,  Werfen  Beds  (which  I  identified  by  the 
fossils  occurring  in  them)  on  the  right  hand  of  the  ascent  to  Campo- 
lungo  Pass.  These  strike  north-east  and  south-west,  dip  30°-40°  S.E., 
and  are  succeeded  by  Muschelkalk  and  Buchenstein  Be,ds.  This  small 
outcrop  of  older  Trias  is  then  faulted  from  the  Buchenstein  Beds  and 
