Yol.  49.] 
ST.  CASSIAN  STRATA  IN  SOUTHERN  TYROL. 
25 
Upper 
St.  Cassian. 
Middle 
St.  Cassian. 
Lower  St.  Cassian. 
Wengen  Beds. 
f  Av.  Gea,  d’Orb.  ;  ( Unionites)  Anoplophora  Milnsteri, 
Wissm. ;  Omphalophyllia  boletiformis,  Miinst.  sp. 
■{  The  horizon  containing  these  fossils  extends  some  dis¬ 
tance  above  and  below  the  Heiligkreuz  Kirche  (thickness 
^about  70  feet). 
Series  of  marls  and  concretionary  shales,  with  occasional 
thicker  beds  of  limestone  much  disturbed  by  slips. 
Fossils : — Nucula  strigilata,  Goldf. ;  N.  lineata,  Groldf. ; 
Mytilus  Milnsteri,  Klipst. ;  Halobia  Eichthofeni , 
'  Mojs.  sp. ;  KonincJcina  Leonhardti,  Wissm.  sp. ;  Fen- 
tacrinus  propinquus ,  Miinst. ;  F.  Icevigatus,  Miinst. ; 
Cidaris  (various) ;  Omphalophyllia  cyclolitiformis, 
v  Laube;  Lobites  pisum,  Wissm. 
[These  beds  were  apparently  included  by  Wissmann  with 
the  4  Heiligkreuz  Schichten.’] 
Thick  beds  of  limestone  below  the  1900-metre  contour 
(at  this  horizon  the  weathered  stones  and  blocks  scattered 
about  had  the  Cipit  Limestone  character).  Encrinus 
cassianus  frequent. 
^Limestones,  thinly-bedded  and  full  of  Posidonomya 
wengensis,  Wissm.  (below  the  1800-metre  contour). 
Ferruginous  clays  and  shales. 
|  Plant-bearing  sandstones  and  shales. 
(  Ashy  rock,  chiefly  earthy  unfossiliferous  tuffs  and  grits. 
Although  the  Wengen  Beds  on  both  sides  of  the  valley 
have  a  large  outcrop,  they  are  seldom  favourably  exposed, 
and  I  did  not  succeed  in  finding  good  fossils. 
Haying  convinced  one’s  self  of  the  conformable  succession  of  the 
Schlern  Dolomite  upon  the  St.  Cassian  strata  at  this  part  of  the 
Gardenazza  massif,  it  is  the  more  striking  to  find  this  dolomitic 
horizon  entirely  absent  in  the  section  of  the  eastern  side  of  the  valley. 
This  fact,  no  less  than  the  special  character  of  the  fossils  in  the 
so-called  ‘  Heiligkreuz  Schichten/  has  made  the  Abtey  valley  almost 
as  interesting  to  geologists  as  the  neighbourhood  of  St.  Cassian. 
The  stratigraphical  question  will  be  discussed  later,  but  the 
palaeontological  difficulty  is  to  fix  the  age  of  the  ‘  Heiligkreuz  strata.’ 
The  beds  immediately  above  them  are  indisputably  of  Raibl  age ; 
they  are  also  very  fossiliferous,  and  they  have  gradually  become 
known  in  the  literature  as  4  Heiligkreuz  strata.’  This  confusion 
was  largely  due  to  a  generally-held  opinion  that  both  series  of  strata 
were  of  Baibl  age,  and  the  main  line  of  effort  in  the  literature  has 
been  to  determine  with  what  horizons  of  the  Eaibl  Beds  they 
should  be  correlated. 
Biehthofen’s  sequence  of  strata  from  below  the  Heiligkreuz  Kirche 
up  to  the  Dachstein  Kalk  may  be  thus  shortly  quoted  (in  descending 
order) : — 
^Limestone  of  Kreuz  Kofi. 
Bed  sandstone  with  lignite,  interstratified  with  fossi¬ 
liferous  limestone  ( Ostrcea  montis-caprilis,  Klipst. ; 
Fimbria  ( Corbis )  Mellingi ,  Hauer,  sp.,  etc.). 
f  Beddish  limestone. 
‘  Heiligkreuz  Schichten  ’  with  Anoplophora  Milnsteri , 
Wissm.,  Avicula  Gea ,  d’Orb.,  etc. 
Dolomite-bank  with  baryta. 
^Fine-grained  sandstone. 
