Yol.  49.] 
ST.  CASSIAS  STRATA  IN  SOUTHERN  TYROL. 
67 
The  Lagazuoi  system  consists  of  Dachstein  Dolomite  forming 
Fanis  Spitz,  then  a  hand  of  Raibl  strata,  resting  conformably  upon 
the  Schlern  Dolomite  rock  of  Lagazuoi,  and  lastly,  below  the 
Schlern  Dolomite,  the  St.  Cassian  strata  exposed  west  of  Ospizio;  south 
of  these  we  meet  again  Raibl  strata  on  Nuvolau.  Whereas  the 
St.  Cassian  strata  below  Lagazuoi  dip  only  slightly  northward,  the 
Raibl  Beds  on  Nuvolau  dip  very  steeply  in  the  same  direction,  and 
the  Schlern  Dolomite  below  them  is  exposed  on  the  high  ridge  of 
Nuvolau.  Farther  south  (on  the  slopes  of  Nuvolau  towards  Andraz 
and  Buchenstein),  St.  Cassian,  Wengen,  and  older  Triassic  strata 
follow  in  regular  succession  below  the  Schlern  Dolomite. 
These  strata  on  Yuvolau  form  the  continuation  in  part  of  the 
anticlinal  fold  of  Wengen  and  older  Triassic  strata  on  Monte  Sief 
and  in  the  Buchenstein  Yalley,  while  the  continuation  of  the  east- 
and-west  fault  from  Sett  Sass  throws  down  the  Nuvolau  system 
against  the  St.  Cassian  strata,  west  of  Ospizio  in  Falzarego. 
Before  I  follow  the  Falzarego  fault  farther  east,  I  would  like  to 
refer  to  certain  observations  of  Hoernes  which  seem  to  indicate  the 
eastward  continuation  of  the  fault  between  Centurinus  Spitz  and 
Lagazuoi  (see  Mojsisovics’  ‘  Dolomit-Riffe,’  p.  291).  According 
to  Hoernes,  the  southern  peak  of  Tofana  Secunda  is  formed 
by  Dachstein  Dolomite  and  Lias,  the  northern  peak  by  Jurassic 
rocks  alone  ;  a  fault  separates  the  two  peaks,  and  the  strata  to  the 
north  of  it  have  sunk.  Jt  seems  probable  that  the  fault-line  which 
I  observed  at  Centurinus  Spitz  coincides  with  this  one  observed  on 
Tofana  Secunda,  in  which  case  relations  analogous  to  those  farther 
west  at  Yalparola  and  Sett  Sass  exist  here : — 
North.  North. 
Monte  Casale  (northern peak  of  Tofana  Secunda)...  Sunk. 
*  *  Fault  *  *  * 
Tofana.  Secunda  (southern  peak)  .  Raised. 
*  *  Fault  *  *  * 
Nuvolau  .  Sunk. 
(With  passage  to  the  anticlinal  fold  of  older  strata.) 
South.  South. 
Looking  up  from  the  Falzarego  road  at  the  dolomite- cliff  of 
Lagazuoi,  nothing  can  be  seen  either  of  the  Raibl  strata  or  of  the 
Dachstein  Dolomite.  They  lie  at  a  height  of  more  than  1000  feet 
above  the  road,  and  their  outcrop  is  some  little  distance  north  of  it. 
East  of  Ospizio  in  Falzarego,  the  Raibl  strata  are  seen  on  Col  dei 
Bos  at  a  relatively  low  level,  and  above  them  the  Dachstein  Dolomite 
forms  the  imposing  wall  of  Tofana  Prima.  Associated  with  this 
unexpected  geological  feature,  a  change  in  the  mere  terrain  makes 
itself  felt  (see  fig.  6,  p.  29). 
Lagazuoi  descends  southward  with  steep  walls  close  to  the 
Falzarego  road,  and  eastward  it  descends  towards  a  good  stretch  of 
meadow,  the  Roces  Alp.  Some  little  distance  back  from  the  road, 
Tofana  rises  above  the  meadow,  and  between  Lagazuoi  and  Tofana  a 
narrow  ravine  leads  up  from  the  Roces  Alp  to  the  Travernanzes  Pass. 
In  this  ravine  there  is  a  north-and-south  fault-line  cutting  Lagazuoi 
completely  off  from  the  Roces  Alp  and  from  Tofana  Prima. 
