﻿46 
  Washington 
  — 
  Igneous 
  Bocks 
  from 
  Smyrna, 
  etc. 
  

  

  slightly 
  greenish 
  gray, 
  waxy 
  groundmass, 
  with 
  the 
  usual 
  pheno- 
  

   crysts. 
  It 
  contains 
  also 
  an 
  angular 
  enclosure 
  of 
  a 
  finegrained 
  

   reddish 
  rock, 
  showing 
  only 
  few 
  phenocrysts 
  of 
  feldspar. 
  This 
  

   is 
  separated 
  in 
  part 
  from 
  the 
  enclosing 
  rock 
  by 
  a 
  crevice, 
  the 
  

   walls 
  of 
  which 
  are 
  lined 
  with 
  crystals 
  of 
  prehnite. 
  Seen 
  in 
  

   thin 
  section, 
  the 
  main 
  rock 
  is 
  seen 
  to 
  be 
  much 
  decomposed, 
  but 
  

   resembled 
  originally 
  the 
  red 
  bands 
  just 
  described. 
  The 
  labra- 
  

   dorite 
  phenocrysts 
  are 
  fresh, 
  but 
  the 
  diopsides 
  and 
  biotites 
  are 
  

   decomposed 
  as 
  before, 
  though 
  the 
  product 
  is 
  rather 
  darker. 
  

   The 
  abundant 
  vitreous 
  groundmass 
  is 
  of 
  a 
  brown 
  glass, 
  rather 
  

   dusty, 
  and 
  the 
  numerous 
  straight 
  trichites 
  are 
  black 
  through 
  

   decomposition. 
  

  

  The 
  reddish 
  enclosure 
  is 
  so 
  thoroughly 
  decomposed 
  as 
  to 
  

   render 
  examination 
  very 
  unsatisfactory. 
  It 
  is 
  evidently 
  a 
  vol- 
  

   canic 
  rock, 
  probably 
  more 
  basic 
  than 
  the 
  andesites 
  previously 
  

   described, 
  and 
  allied 
  to 
  the 
  oli 
  vine-free 
  basalts. 
  The 
  only 
  

   phenocrysts 
  visible 
  in 
  thin 
  section 
  are 
  of 
  colorless 
  diopside, 
  in 
  

   stout 
  prisms 
  often 
  with 
  pyramidal 
  terminations. 
  These 
  show 
  

   the 
  usual 
  brown 
  decomposition 
  border. 
  The 
  groundmass 
  is 
  

   much 
  decomposed 
  in 
  general 
  to 
  an 
  indeterminate 
  dirty 
  mass, 
  

   with 
  spots 
  of 
  calcite 
  here 
  and 
  there. 
  In 
  parts 
  of 
  the 
  slide, 
  

   however, 
  it 
  preserves 
  fairly 
  well 
  its 
  original 
  structure 
  — 
  being 
  

   composed 
  of 
  long 
  slender 
  prisms, 
  or 
  perhaps 
  sections 
  of 
  plates, 
  

   of 
  feldspar, 
  with 
  interstitial 
  brown 
  glass 
  base. 
  These 
  feldspars 
  

   show 
  no 
  twinning, 
  and 
  in 
  many 
  cases 
  extinguish 
  parallel 
  to 
  

   their 
  length, 
  or 
  nearly 
  so, 
  while 
  in 
  others 
  the 
  extinction 
  is 
  

   oblique 
  at 
  angles 
  up 
  to 
  26°. 
  We 
  may 
  then 
  suppose 
  them 
  to 
  

   be 
  of 
  orthoclase 
  or 
  oligoclase, 
  and 
  labradorite. 
  In 
  general 
  

   they 
  form 
  groups 
  of 
  needles 
  parallel 
  to 
  each 
  other, 
  but 
  in 
  a 
  

   few 
  cases 
  compose 
  sheaf-like, 
  diverging 
  forms. 
  No 
  evidence 
  

   of 
  the 
  former 
  presence 
  of 
  olivine 
  or 
  biotite 
  could 
  be 
  made 
  out. 
  

  

  The 
  only 
  specimen 
  of 
  the 
  rock 
  of 
  Gioz 
  Tepe* 
  (Eye 
  Hill) 
  

   shows 
  a 
  compact, 
  greenish 
  gray 
  groundmass, 
  with 
  brownish 
  

   feldspars 
  and 
  a 
  few 
  small 
  augites 
  and 
  biotites. 
  

  

  Under 
  the 
  microscope 
  this 
  also 
  is 
  seen 
  to 
  be 
  somewhat 
  

   decomposed, 
  though 
  in 
  a 
  different 
  manner 
  from 
  the 
  preceding. 
  

   While 
  the 
  substance 
  of 
  the 
  feldspar 
  phenocrysts 
  is 
  fresh, 
  yet 
  

   they 
  are 
  traversed 
  by 
  numerous 
  brown 
  dusty 
  cracks, 
  and 
  their 
  

   glass 
  inclusions 
  are 
  all 
  similarly 
  altered. 
  The 
  few 
  augite 
  

   phenocrysts 
  present 
  are 
  pale 
  green 
  and 
  quite 
  fresh, 
  without 
  the 
  

   usual 
  dark 
  borders. 
  The 
  dark 
  green 
  biotites 
  are 
  profoundly 
  

   decomposed, 
  though 
  there 
  is 
  usually 
  a 
  core 
  of 
  unaltered 
  sub- 
  

   stance. 
  There 
  are 
  also 
  present 
  many 
  rather 
  long 
  stout 
  prisms 
  

   of 
  a 
  dull, 
  opaque, 
  brownish, 
  granular 
  decomposition 
  product, 
  

  

  * 
  This 
  is 
  the 
  name 
  as 
  given 
  on 
  Kiepert's 
  Map 
  of 
  Western 
  Asia 
  Minor 
  (Berlin, 
  

   1 
  892), 
  and 
  is 
  not 
  an 
  uncommon 
  one 
  in 
  the 
  country. 
  Rosenbusch 
  renders 
  it 
  Yous 
  

   Tepe. 
  

  

  