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  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Paleozoic 
  altitude 
  and 
  climate 
  

  

  During 
  the 
  Lower 
  Siluric 
  the 
  immediate 
  region 
  was 
  from 
  time 
  

   to 
  time 
  submerged, 
  at 
  other 
  times 
  was 
  above 
  sea 
  level. 
  During 
  

   submergence 
  there 
  were 
  neighboring 
  lands. 
  It 
  is 
  apparent 
  that 
  all 
  

   were 
  of 
  low 
  altitude. 
  During 
  emergence 
  there 
  was 
  but 
  trifling 
  wear 
  

   on 
  the 
  exposed 
  land 
  surface. 
  During 
  submergence 
  the 
  adjacent 
  

   lands 
  furnished 
  but 
  little 
  land 
  wash, 
  though 
  the 
  Precambric 
  rocks 
  

   of 
  which 
  they 
  were 
  formed 
  were 
  capable 
  of 
  supplying 
  great 
  quanti- 
  

   ties 
  of 
  sand 
  and 
  mud 
  under 
  conditions 
  of 
  any 
  freedom 
  of 
  drainage 
  ; 
  

   and 
  they 
  were 
  near 
  at 
  hand 
  and 
  of 
  much 
  extent. 
  A 
  small 
  thickness 
  

   of 
  sand 
  marks 
  the 
  horizon 
  of 
  the 
  Pamelia-Lowville 
  break, 
  other- 
  

   wise 
  the 
  formations 
  are 
  unbroken 
  limestone, 
  until 
  the 
  shales 
  of 
  the 
  

   upper 
  division 
  come 
  in 
  ; 
  and 
  these 
  are 
  more 
  indicative 
  of 
  stronger 
  

   currents 
  in 
  the 
  marine 
  waters, 
  than 
  of 
  especially 
  increased 
  altitudes 
  

   of 
  the 
  neighboring 
  lands. 
  The 
  succeeding 
  Oswego 
  sandstone 
  seems 
  

   a 
  continental, 
  rather 
  than 
  a 
  marine 
  deposit 
  and 
  indicates 
  freer 
  

   drainage 
  and 
  somewhat 
  greater 
  altitude. 
  

  

  But 
  little 
  has 
  been 
  gleaned 
  from 
  the 
  region 
  itself 
  as 
  to 
  climatic 
  

   oscillations 
  in 
  these 
  early 
  times. 
  The 
  upper 
  Pamelia 
  was 
  marked 
  

   by 
  a 
  somewhat 
  arid, 
  and 
  perhaps 
  warm 
  climate, 
  as 
  has 
  been 
  seen. 
  

   Probably 
  the 
  same 
  was 
  true 
  of 
  the 
  Oswego-AIedina, 
  though 
  that 
  lies 
  

   outside 
  our 
  district. 
  The 
  Potsdam 
  climate 
  is 
  a 
  puzzle. 
  Farther 
  

   east, 
  where 
  the 
  basal 
  Potsdam 
  consists 
  largely 
  of 
  arkose, 
  and 
  where 
  

   the 
  Precambric 
  underneath 
  shows 
  the 
  same 
  freshness 
  and 
  the 
  same 
  

   irregularity 
  of 
  surface 
  under 
  the 
  Potsdam 
  that 
  it 
  does 
  here, 
  we 
  

   have 
  expressed 
  the 
  opinion 
  that 
  the 
  sandstone 
  was 
  a 
  continental 
  de- 
  

   posit, 
  so 
  far 
  as 
  the 
  basal 
  portion 
  is 
  concerned, 
  and 
  that 
  the 
  climate 
  

   was 
  arid. 
  Here 
  however, 
  with 
  the 
  same 
  character 
  of 
  floor, 
  we 
  have 
  

   a 
  pure 
  sand 
  deposit, 
  instead 
  of 
  arkose. 
  The 
  unweathered 
  character 
  

   of 
  the 
  Precambric 
  rocks, 
  the 
  absence 
  of 
  residual 
  weathered 
  material, 
  

   except 
  in 
  very 
  scanty 
  amount 
  in 
  the 
  most 
  sheltered 
  situations, 
  

   and 
  the 
  general 
  base-leveled 
  character 
  of 
  the 
  surface, 
  seem 
  to 
  

   point 
  to 
  long 
  continued 
  wear 
  under 
  conditions 
  of 
  aridity 
  and 
  

   removal 
  of 
  disintegrated 
  material 
  by 
  the 
  wind. 
  Under 
  those 
  

   circumstances 
  however 
  the 
  residual 
  products 
  should 
  be 
  arkose, 
  in- 
  

   stead 
  of 
  pure 
  quartz 
  sand 
  such 
  as 
  constitutes 
  the 
  Potsdam 
  here. 
  

   There 
  is 
  much 
  more 
  feldspar 
  in 
  the 
  basal 
  Pamelia 
  sand 
  than 
  in 
  

   the 
  Potsdam, 
  and 
  even 
  in 
  that 
  it 
  is 
  not 
  in 
  great 
  quantity. 
  We 
  are 
  

   unable 
  to 
  correlate 
  this 
  quartz 
  sand 
  with 
  conditions 
  of 
  climatic 
  arid- 
  

   ity, 
  and 
  equally 
  unable 
  to 
  explain 
  the 
  character 
  of 
  the 
  Precambric 
  

   surface, 
  and 
  the 
  unweathered 
  condition 
  of 
  the 
  rocks, 
  satisfactorily 
  

   to 
  ourselves, 
  on 
  any 
  other 
  basis. 
  

  

  