﻿50 
  Washington 
  — 
  Igneous 
  Hocks 
  from 
  Smyrna, 
  etc, 
  

  

  basalts, 
  nepheline-basalts 
  and 
  rhyolites. 
  There 
  is 
  some 
  evi- 
  

   dence 
  of 
  the 
  Troad 
  rocks 
  being 
  on 
  a 
  line 
  extending 
  westward 
  

   through 
  Mytilene 
  and 
  Samothrace,* 
  where 
  quartz-trachytes, 
  

   trachytes 
  and 
  basalts 
  occur, 
  to 
  Thessaly, 
  where 
  basalt 
  is 
  found 
  at 
  

   Persufli.f 
  Since 
  the 
  analyses 
  of 
  the 
  andesitic 
  "basalts" 
  of 
  

   Mytilene 
  and 
  Persufli 
  offer 
  certain 
  analogies 
  with 
  the 
  rocks 
  of 
  

   Smyrna 
  and 
  Pergamon, 
  they 
  may 
  be 
  here 
  inserted. 
  

  

  1 
  2 
  

  

  Si0 
  2 
  56-58 
  53-61 
  

  

  Ti0 
  2 
  0-V7 
  0-34 
  

  

  A1 
  2 
  3 
  14-88 
  16-11 
  

  

  Fe 
  2 
  3 
  ._ 
  2-31 
  3-05 
  

  

  FeO 
  3-04 
  4-45 
  

  

  MnO 
  0-16 
  0-14 
  

  

  MgO 
  3-76 
  6-80 
  

  

  CaO 
  8-69 
  7-00 
  

  

  BaO 
  ._ 
  0-07 
  

  

  Na 
  2 
  3-36 
  3-95 
  

  

  K 
  2 
  2-18 
  3-08 
  

  

  P 
  2 
  6 
  0-15 
  

  

  H 
  2 
  2-12 
  1-65 
  

  

  CO 
  _ 
  2-32 
  

  

  100-39 
  100-18 
  

  

  No. 
  1J 
  is 
  of 
  the 
  Mytilene 
  rock, 
  but 
  I 
  can 
  find 
  no 
  description 
  

   of 
  it. 
  Lepsius 
  describes 
  the 
  Persufli 
  rock 
  (No. 
  2) 
  as 
  a 
  quite 
  

   typical 
  olivine 
  basalt, 
  amygdaloidal, 
  and 
  somewhat 
  decom- 
  

   posed. 
  The 
  interest 
  in 
  these 
  at 
  present 
  chiefly 
  centers 
  in 
  the 
  

   nigh 
  alkalies, 
  in 
  which 
  they 
  resemble 
  the 
  rocks 
  above, 
  though 
  

   soda 
  is 
  slightly 
  higher 
  than 
  potash. 
  The 
  two 
  resemble 
  each, 
  

   other 
  quite 
  closely 
  and 
  the 
  potash 
  is 
  high 
  enough 
  to 
  lead 
  one 
  

   to 
  infer 
  the 
  presence 
  of 
  orthoclase. 
  

  

  It 
  is 
  of 
  interest 
  also 
  to 
  note 
  that 
  an 
  augite-hornblende-an 
  de- 
  

   site 
  is 
  described 
  by 
  Becke§ 
  from 
  the 
  Island 
  of 
  Chios, 
  which 
  

   lies 
  west 
  of 
  Smyrna. 
  This 
  is 
  propylitic 
  in 
  habit 
  and 
  is 
  com- 
  

   pared 
  by 
  him 
  with 
  the 
  andesites 
  of 
  the 
  Bosphorus. 
  

  

  South 
  of 
  Smyrna 
  no 
  igneous 
  rocks 
  are 
  noted 
  on 
  Tchihat- 
  

   cheff's 
  map 
  till 
  the 
  promontory 
  of 
  Budrum 
  (Halicarnassos) 
  is 
  

   reached. 
  These, 
  however, 
  as 
  well 
  as 
  the 
  rocks 
  of 
  Kos 
  and 
  

   Nisyros 
  near 
  by, 
  are, 
  as 
  I 
  have 
  pointed 
  out 
  elsewhere,! 
  proba- 
  

   bly 
  connected 
  with 
  the 
  Aegina-Santorini 
  line, 
  the 
  rocks 
  of 
  

   which 
  show 
  lower 
  alkalies, 
  with 
  soda 
  higher 
  than 
  potash. 
  

  

  *Niedzwiedzki: 
  Tsch. 
  Min. 
  Mitth., 
  1875, 
  89. 
  f 
  Lepsius, 
  op. 
  cit, 
  169. 
  

  

  JChatard 
  anal., 
  Bull. 
  U. 
  S. 
  G-. 
  S., 
  No. 
  60, 
  1890, 
  158. 
  

  

  In 
  Teller: 
  Geol. 
  Beob. 
  Insel 
  Chios, 
  Denksschr. 
  Akad. 
  Wiss. 
  Wien, 
  xl, 
  34*7, 
  1880. 
  

  

  H. 
  S. 
  Washington: 
  Jour, 
  of 
  Geology, 
  iii, 
  158, 
  1895. 
  

  

  