Yol.  49.]  ST.  CASSIAS'  STRATA  IX  SOUTHERN  TYROL.  73 
South  of  Mesner  Kofi  large  blocks  of  the  characteristic  Buchen- 
stein  limestones  with  siliceous  secretions  are  found  on  the  grassy 
slope,  and  on  the  Sari  Alp  Wengen  Beds  are  in  place.  Kowhere 
is  it  possible  to  see  the  thinning-out  of  the  Mesner  Kofi  dolomite- 
rock  in  the  series  of  Buchenstein  and  Wengen  strata,  and  we  are 
confronted  therefore  by  two  stratigraphic-al  possibilities : — 
(1)  The  dolomite  of  Hesner  Kofi  may  he  a  reef-dolomite  thinning 
out  in  Buchenstein  and  Wengen  strata,  although,  owing  to  later 
faulting,  the  relations  of  dolomitic  and  non-dolomitic  beds  have  been 
obscured. 
(2)  The  dolomite  of  Hesner  Kofi  may  he  Mendola  Dolomite 
brought  into  its  present  position  as  the  axis  of  a  small  anticlinal  fold 
embracing  the  whole  system  between  Sari  Kofele  in  the  south  and 
Lung  Kofi  in  the  north.  This  anticlinal  fold  is  the  result  of  crush, 
and  is  broken  in  several  places  by  fault-planes. 
The  same  conclusions  are  applicable  with  slight  differences  to  the 
case  of  the  Heimwald  Kofi,  dolomite-rock  and  its  relations  with  the 
Kameriod  Y’iesen  system  of  non-dolomitic  rocks. 
The  dolomite  of  Sari  Kofele  (below  the  St.  Cassian  strata)  and  of 
Kasamiitz  (also  underlying  Cipit  Limestones  probably  of  St.  Cassian 
age)  forms  a  no  less  debatable  point.  Thinning-out  of  the  dolomite 
in  bedded  limestones  and  shales  is  said  to  occur  between  these  two 
prominent  rocks.  But  the  limestones  and  shales  which  are  exposed 
do  not  occur  in  the  same  direct  east-and-west  line  with  the  dolomite, 
and  their  exposure  might  be  explained  as  the  result  of  erosion. 
Leaving  this  for  the  present,  we  find  that  below  Kasamiitz  the  whole 
of  the  Sari  Alp  system  of  strata  is  cut  off  against  the  dolomite. 
This  system  is  also  cut  off  north  and  south  above  the  rocky  ravine 
of  Sari  Bach,  so  that  nowhere  is  thinning-out  of  the  Sari  Alp 
non-dolomitic  strata  directlv  observable. 
The  St.  Cassian  strata  above  Kasamiitz  are  still  very  thick,  nor 
are  they  observed  to  thin  out  gradually  in  the  dolomite  of  Hock- 
boden.  In  short,  the  disappearance  of  the  Buchenstein  and  Wengen 
strata  on  the  Alpe  below  and  of  the  St.  Cassian  strata  on  Kasa- 
miitz  is  not  gradual,  but  sharp,  and  takes  place  exactly  in  the  same 
north-and-south  line.  This  is  a  north-and-south  fault-plane  sepa¬ 
rating  the  central  or  Sari  Alp  system  (general  strike  E.— W.)  from 
the  eastern  or  Toblach  Talley  system  (general  strike  K.H.W.-S.S.E.). 
It  may  be  said  that  in  this  case,  as  at  Mesner  Kofi,  the  actual 
thinning-out  of  the  strata  has  been  faulted  out  of  sight,  and  this  is 
very  possible.  It  is  at  the  same  time  striking  that  there  should 
be  a  perfectly  normal  thickness  and  perfectly  characteristic  de¬ 
velopment  of  non-dolomitic  St.  Cassian  strata  on  Kasamiitz,  so  close 
to  the  dolomitic  facies  of  Kockboden. 
Following  the  dolomitic  rock  exposed  on  Sari  Kofele  westward, 
it  is  seen  to  strike  across  to  Kirchenschroffen.  Here  it  meets 
the  Schafriedl  system  of  non-dolomitic  beds,  with  which  it  has  no 
possible  relation  of  thinning-out.  A  further  complication  is  intro¬ 
duced  by  the  Diirrenstein  system,  and  the  beds  at  Kirchenschroffen 
