﻿18 
  GEOLOGICAL 
  MEMOIRS. 
  

  

  ness 
  of 
  this 
  Loess 
  is 
  reduced 
  to 
  from 
  six 
  to 
  eighteen 
  feet, 
  and 
  beneath 
  

   it 
  there 
  appears 
  a 
  rather 
  varied 
  series 
  of 
  older 
  strata, 
  through 
  which 
  

   the 
  Danube 
  has 
  cut 
  its 
  way. 
  One 
  Austrian 
  mile 
  west 
  of 
  Tultscha, 
  

   at 
  a 
  place 
  called 
  "Girba," 
  limestones 
  dipping 
  eastward 
  at 
  a 
  low 
  

   angle 
  are 
  exposed, 
  both 
  by 
  erosion 
  and 
  in 
  quarries. 
  These 
  limestones 
  

   are 
  probably 
  of 
  the 
  age 
  of 
  the 
  Lower 
  Trias 
  of 
  the 
  Alps 
  ; 
  near 
  the 
  

   Danube 
  they 
  are 
  cut 
  through 
  by 
  a 
  vein 
  of 
  augite-rock, 
  decomposed 
  

   into 
  dark-brown 
  argillaceous 
  iron-ore. 
  Beneath 
  the 
  fortress 
  of 
  Old 
  

   Tultscha 
  appear 
  (almost 
  conformable 
  to 
  the 
  before-mentioned 
  lime- 
  

   stones) 
  red 
  and 
  white 
  quartzites, 
  with 
  occasionally 
  imbedded 
  layers 
  

   of 
  reddish-brown 
  or 
  greenish-grey 
  slaty 
  marls, 
  identical 
  with 
  the 
  

   " 
  Quartzite 
  Series" 
  so 
  extensively 
  developed 
  in 
  Hungary, 
  Transyl- 
  

   vania, 
  and 
  Banat 
  ; 
  and 
  although 
  its 
  geological 
  age 
  is 
  still 
  imperfectly 
  

   known, 
  it 
  should 
  probably 
  be 
  placed 
  between 
  the 
  Carboniferous 
  for- 
  

   mation 
  and 
  the 
  typical 
  " 
  Werfen" 
  (Lower 
  Triassic) 
  slates. 
  These 
  

   quartzites, 
  with 
  an 
  abrupt 
  easterly 
  dip, 
  rise 
  east 
  of 
  Tultscha, 
  so 
  as 
  to 
  

   form 
  a 
  cliff 
  from 
  sixty 
  to 
  seventy 
  feet 
  high, 
  well 
  known 
  to 
  the 
  Da- 
  

   nubian 
  navigators. 
  South 
  of 
  this 
  cliff, 
  a 
  hill, 
  rising 
  out 
  of 
  the 
  Loess 
  

   to 
  a 
  height 
  of 
  480 
  feet 
  above 
  the 
  sea-level, 
  is 
  composed 
  of 
  sandstones 
  

   and 
  dark-coloured 
  limestones 
  overlying 
  the 
  before-mentioned 
  Triassic 
  

   limestones, 
  and 
  probably 
  of 
  Liassic 
  age. 
  A 
  considerable 
  mountain- 
  

   range 
  south 
  of 
  Tultscha, 
  striking 
  from 
  west 
  to 
  east, 
  and 
  rising 
  in 
  one 
  of 
  

   its 
  peaks 
  (" 
  Krasni-Most," 
  south-west 
  of 
  Tultscha) 
  to 
  an 
  altitude 
  of 
  

   about 
  3000 
  feet 
  above 
  the 
  sea-level, 
  is 
  composed 
  of 
  an 
  augitic 
  erup- 
  

   tive 
  rock, 
  nearly 
  allied 
  to 
  some 
  augite 
  -porphyries 
  of 
  the 
  south-west 
  

   of 
  Transylvania. 
  The 
  specimens 
  obtained 
  from 
  the 
  inner 
  valleys 
  of 
  

   the 
  Dobrudscha, 
  south 
  and 
  south-east 
  of 
  Tultscha, 
  show 
  the 
  occur- 
  

   rence 
  of 
  several 
  varieties 
  of 
  sandstone 
  of 
  probably 
  newer 
  Tertiary 
  age, 
  

   Crinoidal 
  limestone, 
  phonolite 
  rocks 
  with 
  distinct 
  tabular 
  crystals 
  of 
  

   sanidine, 
  compact 
  sandstone 
  with 
  carbonized 
  vegetable 
  remains, 
  

   specular 
  iron-ore 
  in 
  veins, 
  &c. 
  As 
  far 
  as 
  the 
  organic 
  remains 
  

   (merely 
  casts) 
  transmitted 
  byM. 
  Tchihatcheff 
  and 
  Prof. 
  Szabo 
  ad- 
  

   mit 
  of 
  determination, 
  the 
  following 
  species 
  may 
  be 
  said 
  to 
  occur 
  in 
  

   the 
  Dobrudscha 
  : 
  — 
  Natica 
  macrostoma 
  ?, 
  Roem., 
  Diceras 
  (a 
  small 
  form 
  

   differing 
  from 
  D. 
  arietina, 
  although 
  associated 
  with 
  it 
  in 
  typical 
  lo- 
  

   calities 
  of 
  western 
  Europe), 
  Nerincea 
  Visurgis, 
  Pteroeera, 
  sp., 
  Chama, 
  

   sp. 
  (similar 
  to 
  C. 
  ammonia, 
  with 
  well-preserved 
  traces 
  of 
  the 
  hinges) 
  ; 
  

   all 
  of 
  them 
  Upper 
  Jurassic, 
  and 
  imbedded 
  not 
  in 
  a 
  compact 
  or 
  oolitic 
  

   limestone, 
  but 
  in 
  a 
  yellowish-white, 
  chalk-like 
  substance, 
  very 
  much 
  

   resembling 
  certain 
  varieties 
  of 
  Kimmeridge 
  clay. 
  A 
  specimen 
  of 
  

   this 
  rock 
  with 
  Nerincea 
  Visurgis 
  is 
  filled 
  with 
  fragments 
  of 
  Corals 
  and 
  

   Echinoderms. 
  The 
  Cretaceous 
  specimens 
  are 
  imbedded 
  in 
  an 
  argil- 
  

   laceous 
  marl. 
  A 
  rock-specimen, 
  collected 
  by 
  Prof. 
  Szabo 
  near 
  Czer- 
  

   nawoda,bears 
  lithologically,and 
  from 
  the 
  numerous 
  casts 
  of 
  Tapes 
  gre- 
  

   garia 
  ? 
  which 
  it 
  contains, 
  a 
  striking 
  resemblance 
  to 
  the 
  argillaceous 
  

   brackish 
  Cerithian 
  strata 
  of 
  the 
  Hungarian 
  Miocene 
  deposits. 
  

  

  [Count 
  M.] 
  

  

  