Page 21 - Geochemical Remote Sensing of The Sub-Surface
P. 21

XX                                                               Contents

                    Helium  surveys  in  petroleum  exploration .................................................................  338
                    Helium  surveys  in geothermal  resource  exploration  .................................................  343
                      Helium  in  thermal  waters  and  gases ......................................................................  343
                      Helium  surveys  for geothermal  resources .............................................................  344
                    Helium  associated  with  faults ....................................................................................  346
                      Faults  as  secondary  sources  of helium ..................................................................  346
                        Groundwater  surveys ........................................................................................  346
                        Soil  gas  surveys ................................................................................................  348
                      Helium  monitoring  in  earthquake  prediction  ........................................................  349
                    Conclusions ...............................................................................................................  350
                      Migration  of helium  in  the  near-surface  environment ...........................................  350
                      Application  of helium  surveys ..............................................................................  352

           Chapter  11.  Radon ........................................................................................................................  353
                    W.  Dyck  and  I.R.  Jonasson
                    Introduction ...............................................................................................................  353
                    Physical  and  chemical  properties  of radon ................................................................  354
                    Definitions .................................................................................................................  356
                    Geochemistry  of radon ..............................................................................................  357
                      Concentrations  of radon  and  radium  in  natural  environments ...............................  358
                      Disequilibrium  in  the  uranium  decay  series ..........................................................  365
                      Emanation  and  mobility  of radon ..........................................................................  367
                    Analytical  methods ....................................................................................................  382
                      Principles  of methods ............................................................................................  383
                      Instantaneous  mode ...............................................................................................  384
                      Semi-integrating  mode ..........................................................................................  386
                      Fully-integrated  mode ...........................................................................................  388
                    Field  methods ............................................................................................................  389
                      Determination  of radon  in  natural  waters ..............................................................  389
                      Determination  of radon  in  soil  emanations  ...........................................................  391
                    Comparison  studies  and  case  histories  ......................................................................  392
                    Future  needs ..............................................................................................................  394

           Chapter  12.  Mercury .....................................................................................................................  395
                    G.R.  Cart  and  J.R.  Wilmshurst
                    Introduction ...............................................................................................................  395
                    Geochemistry  of mercury ..........................................................................................  396
                    Behaviour  of mercury  in the  primary  environment  ...................................................  399
                      Low  temperature  epithermal  base-metal  deposits .................................................  399
                      Volcanogenic  massive  sulphide  deposits ...............................................................  400
                      Sediment-hosted  massive  sulphide  deposits  .........................................................  402
                      Gold  deposits  ........................................................................................................  403
                      The  role of metamorphism ....................................................................................  404
                    Behaviour  of mercury  in the  secondary  environment ................................................  406
                      Outcropping  mineral  deposits  in  dry  climates .......................................................  406
                      Outcropping  mineral  deposits  in  wet  climates  ......................................................  412
                      Blind  and  buried  mineral  deposits  in dry  climates ................................................  417
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