﻿Geology 
  and 
  Mineralogy. 
  451 
  

  

  oil 
  and 
  gas 
  accumulations 
  to 
  the 
  geology 
  and 
  structure 
  of 
  eastern 
  

   Kansas, 
  Oklahoma, 
  and 
  north 
  central 
  Texas. 
  The 
  character 
  of 
  

   the 
  oil 
  and 
  gas 
  is 
  also 
  discussed, 
  along 
  with 
  the 
  production 
  of 
  

   helium 
  and 
  gasoline 
  from 
  the 
  natural 
  gas, 
  and 
  something 
  is 
  said 
  

   of 
  the 
  salinity 
  of 
  the 
  water 
  of 
  the 
  oil 
  fields. 
  The 
  geologic 
  termi- 
  

   nology 
  is 
  American. 
  For 
  anyone 
  wishing 
  a 
  good 
  general 
  account 
  

   of 
  the 
  Mid-Continent 
  oil 
  fields, 
  and 
  references 
  to 
  the 
  more 
  tech- 
  

   nical 
  publications 
  on 
  the 
  areas, 
  this 
  book 
  is 
  recommended, 
  c. 
  s. 
  

  

  4. 
  The 
  Mackenzie 
  River 
  Basin; 
  by 
  Charles 
  Camsell 
  and 
  

   Wyatt 
  Malcolm. 
  Geological 
  Survey 
  Canada, 
  Mem. 
  108, 
  154 
  

   pp., 
  14 
  pis., 
  1 
  text 
  fig., 
  1 
  map, 
  1919. 
  — 
  This 
  valuable 
  compilation 
  

   brings 
  together 
  concisely 
  the 
  present 
  knowledge 
  of 
  the 
  economic 
  

   possibilities 
  of 
  the 
  Mackenzie 
  Basin 
  and 
  particularly 
  the 
  obser- 
  

   vations 
  of 
  travelers 
  in 
  regard 
  to 
  the 
  geological 
  formations 
  and 
  

   their 
  possible 
  mineral 
  resources. 
  The 
  senior 
  author 
  has 
  long 
  been 
  

   directly 
  acquainted 
  with 
  the 
  region 
  and 
  is, 
  therefore, 
  enabled 
  to 
  

   write 
  much 
  at 
  first 
  hand. 
  A 
  large 
  map 
  gives 
  the 
  known 
  distri- 
  

   bution 
  of 
  the 
  geologic 
  formations 
  along 
  the 
  various 
  water 
  routes 
  

   of 
  travel. 
  c. 
  s. 
  

  

  5. 
  Recherches 
  Geologiques 
  et 
  Petrographiques 
  sur 
  le 
  District 
  

   Minier 
  de 
  Nicolai-Pawda; 
  by 
  Louis 
  Duparc 
  and 
  Augustin 
  

   Grosset. 
  A 
  Monograph 
  published 
  in 
  Geneva, 
  1916. 
  294 
  pp., 
  

   62 
  figs., 
  54 
  photographic 
  reproductions, 
  7 
  pis., 
  and 
  an 
  atlas 
  con- 
  

   taining 
  a 
  geological 
  map. 
  — 
  This 
  monograph 
  is 
  an 
  exhaustive 
  

   study 
  of 
  the 
  geology 
  of 
  the 
  district 
  about 
  the 
  village 
  of 
  Pawda, 
  

   situated 
  at 
  the 
  confluence 
  of 
  the 
  Pawda 
  and 
  Lialia 
  rivers 
  on 
  the 
  

   eastern 
  watershed 
  of 
  the 
  Ural 
  Mts. 
  near 
  latitude 
  59° 
  15' 
  N. 
  The 
  

   rock 
  formations 
  of 
  the 
  region 
  show 
  igneous 
  rocks, 
  including 
  

   deep-seated, 
  effusive 
  and 
  dike 
  types, 
  and 
  metamorphic 
  and 
  sedi- 
  

   mentary 
  rocks. 
  The 
  deep-seated 
  igneous 
  rocks 
  are 
  mostly 
  basic, 
  

   consisting 
  of 
  the 
  gabbros, 
  together 
  with 
  smaller 
  amount 
  of 
  pyrox- 
  

   enites, 
  peridotites, 
  dunites, 
  hornblendites 
  and 
  a 
  quartz-diorite. 
  

   The 
  acid 
  rocks 
  are 
  represented 
  in 
  much 
  smaller 
  amounts, 
  chiefly 
  

   by 
  an 
  amphibole-granite. 
  The 
  effusive 
  rocks, 
  while 
  showing 
  also 
  

   both 
  basic 
  and 
  acid 
  types, 
  belong 
  largely 
  to 
  the 
  diabase 
  group. 
  

   The 
  dike 
  rocks 
  are 
  very 
  numerous, 
  presenting 
  the 
  three 
  types, 
  

   melanocratic, 
  mesoeratic 
  and 
  leucocratic. 
  They 
  vary 
  in 
  size 
  from 
  

   narrow 
  ribbons 
  to 
  immense 
  dikes. 
  All 
  these 
  igneous 
  rocks 
  belong 
  

   apparently 
  to 
  a 
  single 
  petrographic 
  province^ 
  being 
  derived 
  from 
  

   a 
  single 
  magma 
  by 
  differentiation. 
  The 
  metamorphic 
  rocks 
  Con- 
  

   sist 
  also 
  of 
  basic 
  types 
  derived 
  from 
  related 
  igneous 
  rocks 
  and 
  of 
  

   acid 
  types 
  derived 
  from 
  quartzites. 
  

  

  The 
  valuable 
  mineral 
  deposits 
  of 
  the 
  region 
  consist 
  in 
  ores 
  of 
  

   iron 
  which 
  have 
  been 
  formed 
  by 
  segregation, 
  by 
  contact 
  processes 
  

   or 
  by 
  alteration; 
  of 
  chromite 
  formed 
  by 
  direct 
  segregation; 
  of 
  

   copper 
  in 
  veins 
  ; 
  of 
  gold 
  in 
  quartz 
  veins 
  and 
  in 
  gravels 
  ; 
  and 
  of 
  

   platinum 
  in 
  placer 
  deposits. 
  Of 
  these 
  various 
  metals, 
  platinum 
  

   is 
  by 
  far 
  the 
  most 
  important, 
  this 
  district 
  being 
  the 
  third 
  in 
  value 
  

  

  