﻿Geological 
  Survey 
  of 
  the 
  Wit 
  waters 
  rand. 
  281 
  

  

  stratified 
  deposits 
  composed 
  of 
  sea-sand 
  with 
  volcanic 
  fragments 
  

   These 
  are 
  partly 
  denuded, 
  and 
  are 
  mantled 
  round 
  by 
  coral-reef 
  and 
  

   beach 
  sand-flats. 
  A 
  remarkable 
  cavern 
  in 
  the 
  lava 
  of 
  Sol 
  Mapii, 
  

   with 
  lava-stalactites, 
  is 
  described 
  ; 
  there 
  is 
  a 
  similar 
  cavern 
  in 
  

   Au 
  Huf 
  Huf. 
  

  

  An 
  account 
  of 
  the 
  prevalent 
  meteorological 
  conditions 
  is 
  also 
  

   given. 
  

  

  In 
  an 
  Appendix 
  by 
  Mr. 
  H. 
  Woods, 
  M.A., 
  some 
  of 
  the 
  rocks 
  are 
  

   described. 
  They 
  consist 
  of 
  olivine-dolerites 
  and 
  basalts 
  and 
  asso- 
  

   ciated 
  fragmental 
  rocks. 
  

  

  2. 
  * 
  A 
  Geological 
  Survey 
  of 
  the 
  "Wit 
  waters 
  rand 
  and 
  other 
  Districts 
  

   in 
  the 
  Southern 
  Transvaal.' 
  By 
  Frederick 
  H. 
  Hatch, 
  Ph.D., 
  F.G.S. 
  

  

  After 
  giving 
  an 
  account 
  of 
  the 
  physical 
  characters 
  of 
  the 
  area, 
  

   the 
  author 
  proceeds 
  to 
  describe 
  the 
  various 
  rocks, 
  referred 
  to 
  

  

  (1) 
  The 
  Karoo 
  System, 
  

  

  (2) 
  The 
  Cape 
  System, 
  

  

  (3) 
  The 
  Primary 
  or 
  Archaean 
  System. 
  

  

  The 
  Archaean 
  rocks 
  protrude 
  in 
  a 
  few 
  places 
  through 
  the 
  sedi- 
  

   mentary 
  beds, 
  which 
  form 
  the 
  greater 
  part 
  of 
  the 
  area, 
  and 
  consist 
  

   of 
  an 
  igneous 
  complex 
  of 
  rocks 
  of 
  varied 
  composition. 
  

  

  The 
  Cape 
  System 
  is 
  capable 
  of 
  division 
  into 
  five 
  distinct 
  series: 
  — 
  

  

  ( 
  Magaliesberg 
  and 
  Gatsrand 
  series 
  ; 
  alternating 
  quartzites, 
  shales, 
  and 
  

  

  Upper 
  ' 
  lava 
  ' 
  flows 
  - 
  16,000 
  to 
  20,000 
  feet. 
  

  

  -o 
  ■{ 
  Dolomite 
  and 
  cherts, 
  thickly 
  bedded. 
  6000 
  to 
  8000 
  feet. 
  

  

  j 
  Black 
  Reef 
  ; 
  a 
  bed 
  of 
  quartzite 
  and 
  conglomerate, 
  20 
  to 
  50 
  feet, 
  and 
  | 
  

   I 
  Klipriversberg 
  amygdaloid 
  ; 
  a 
  basic 
  volcanic 
  roek, 
  5000 
  to 
  6000 
  feet, 
  j 
  

   f 
  Witwatersrand 
  Beds 
  ; 
  sandstones 
  and 
  conglomerate 
  (in 
  part 
  auri- 
  

  

  Lower 
  I 
  ferous). 
  11,000 
  to 
  15,000 
  feet. 
  

   Beds, 
  i 
  Hospital 
  Hill 
  Series; 
  quartzites 
  and 
  ferruginous 
  shales. 
  8000 
  to 
  

  

  I 
  

  

  10,000 
  feet. 
  

  

  A 
  full 
  description 
  of 
  each 
  of 
  the 
  series, 
  and 
  the 
  associated 
  

   volcanic 
  and 
  igneous 
  rocks, 
  is 
  given 
  in 
  the 
  paper. 
  

  

  The 
  Karoo 
  formation 
  is 
  represented 
  by 
  the 
  Coal 
  Measures 
  of 
  

   Vereeniging 
  and 
  the 
  district 
  south 
  of 
  Heidelberg, 
  and 
  by 
  the 
  measures 
  

   of 
  other 
  coal-areas. 
  They 
  have 
  furnished 
  plants 
  which 
  Mr. 
  Seward 
  

   refers 
  to 
  in 
  a 
  note 
  as 
  being 
  of 
  Permo-Carboniferous 
  age. 
  

  

  The 
  age 
  of 
  the 
  Cape 
  System 
  is 
  doubtful. 
  The 
  Upper 
  beds 
  rest 
  

   unconformably 
  on 
  the 
  Lower 
  ones, 
  and 
  if 
  the 
  latter 
  be 
  of 
  Devonian 
  

   age, 
  as 
  has 
  been 
  inferred, 
  the 
  former 
  may 
  represent 
  the 
  Lower 
  

   Carboniferous 
  rocks. 
  

  

  In 
  conclusion, 
  the 
  author 
  makes 
  some 
  observations 
  upon 
  the 
  

   geotectonic 
  relations 
  of 
  the 
  area. 
  

  

  3. 
  'Observations 
  on 
  the 
  Genus 
  Adis'ma, 
  de 
  Koninck, 
  with 
  De- 
  

   scriptions 
  of 
  British 
  Species, 
  and 
  of 
  some 
  other 
  Carboniferous 
  Gas- 
  

   tropoda.'" 
  By 
  Miss 
  J. 
  Donald, 
  of 
  Carlisle. 
  

  

  