﻿SUGGESTIONS 
  FOE 
  STUDY 
  239 
  

  

  Where 
  the 
  covering 
  of 
  soil 
  and 
  other 
  loose 
  material 
  is 
  thick, 
  

   outcrops 
  should 
  be 
  sought 
  along 
  the 
  beds 
  of 
  rivers, 
  creeks 
  and 
  

   rivulets. 
  Running 
  water 
  usually 
  cuts 
  through 
  the 
  softer 
  material 
  

   and 
  reaches 
  the 
  harder 
  rock 
  below. 
  For 
  this 
  reason 
  the 
  gutters 
  

   and 
  ditches 
  by 
  the 
  sides 
  of 
  roads 
  should 
  be 
  examined 
  for 
  expos- 
  

   ures, 
  if 
  no 
  other 
  source 
  of 
  information 
  is 
  available. 
  

  

  It 
  is 
  not 
  possible 
  here 
  to 
  give 
  any 
  adequate 
  directions 
  for 
  the 
  

   study 
  of 
  soft 
  geology. 
  This 
  branch 
  is 
  still 
  immature 
  and 
  is 
  chiefly 
  

   in 
  the 
  hands 
  of 
  specialists. 
  The 
  literature 
  of 
  Quaternary 
  geology 
  

   is, 
  however, 
  very 
  large 
  and 
  by 
  a 
  careful 
  study 
  of 
  it, 
  the 
  beginner 
  

   may 
  form 
  some 
  conception 
  of 
  its 
  scope. 
  A 
  single 
  field 
  day 
  with 
  

   a 
  good 
  geologist 
  is 
  worth 
  more 
  than 
  many 
  weeks 
  of 
  reading. 
  

  

  FOSSILS 
  

  

  It 
  is 
  important 
  for 
  the 
  beginner 
  to 
  realize 
  that 
  perfect 
  speci- 
  

   mens 
  of 
  fossils 
  such 
  as 
  are 
  exhibited 
  in 
  the 
  museums 
  and 
  figured 
  

   in 
  the 
  works 
  on 
  palaeontology 
  are 
  not 
  every 
  where 
  to 
  be 
  found 
  

   and 
  that 
  the 
  more 
  common 
  examples 
  are 
  fragmentary. 
  Were 
  it 
  

   not 
  for 
  the 
  dissolving 
  action 
  of 
  atmospheric 
  water 
  on 
  carbonate 
  

   of 
  lime 
  the 
  study 
  of 
  fossils 
  would 
  still 
  be 
  in 
  its 
  infancy, 
  as 
  in 
  many 
  

   cases 
  the 
  fossil 
  is 
  wholly 
  inclosed 
  in 
  a 
  firm 
  mass 
  of 
  limestone 
  from 
  

   which 
  it 
  can 
  not 
  be 
  separated 
  by 
  the 
  hammer 
  alone. 
  On 
  the 
  sur- 
  

   face 
  exposures 
  of 
  limestone, 
  the 
  action 
  of 
  the 
  w^eather 
  removes 
  a 
  

   part 
  of 
  the 
  matrix, 
  exposing 
  for 
  a 
  time 
  the 
  surface 
  of 
  the 
  shell. 
  

   This 
  after 
  a 
  few 
  years 
  may 
  in 
  turn 
  yield 
  to 
  the 
  dissolving 
  action 
  

   of 
  atmospheric 
  water 
  and 
  gradually 
  disappear, 
  another 
  specimen 
  

   at 
  a 
  lower 
  level 
  being 
  gradually 
  brought 
  to 
  view 
  in 
  its 
  place. 
  In 
  

   sandstones, 
  the 
  calcareous 
  fossils 
  are 
  usually 
  entirely 
  dissolved 
  

   out 
  of 
  the 
  surface 
  layers 
  and 
  it 
  is 
  only 
  by 
  the 
  impressions 
  or 
  casts 
  

   which 
  they 
  leave 
  behind, 
  that 
  we 
  know 
  of 
  their 
  existence. 
  If 
  

   means 
  are 
  afforded 
  for 
  excavation 
  and 
  blasting, 
  below 
  the 
  reach 
  

   of 
  the 
  rain 
  water, 
  will 
  be 
  found 
  a 
  bed 
  of 
  rock 
  from 
  which 
  the 
  

   calcareous 
  matter 
  has 
  not 
  been 
  dissolved 
  away, 
  but 
  in 
  this 
  case 
  

   it 
  is 
  often 
  difficult 
  to 
  separate 
  the 
  fossils 
  except 
  by 
  long 
  and 
  

   tedious 
  process 
  of 
  cleaning 
  or 
  developing 
  with 
  small 
  tools. 
  

  

  