﻿72 
  JOURNAL 
  OF 
  THE 
  WASHINGTON 
  ACADEMY 
  OP 
  SCIENCES 
  VOL. 
  12, 
  NO. 
  3 
  

  

  replacement 
  of 
  country 
  rock 
  by 
  carbonate 
  or 
  silicate 
  minerals 
  occur 
  in 
  south- 
  

   western 
  and 
  northeastern 
  Oregon. 
  

  

  In 
  Washington, 
  in 
  the 
  Olympic 
  Mountains 
  and 
  the 
  northern 
  part 
  of 
  the 
  

   Puget 
  Sound 
  region, 
  are 
  uncommon 
  deposits 
  that 
  consist 
  chiefly 
  of 
  bementite 
  

   a 
  silicate 
  of 
  manganese. 
  Associated 
  with 
  the 
  bementite 
  are 
  quartz, 
  rhodonite, 
  

   manganocalcite 
  and 
  unidentified 
  oxides 
  of 
  manganese. 
  Hematite 
  forms 
  

   separate 
  though 
  closely 
  related 
  bodies. 
  Locally 
  the 
  bementite 
  is 
  cut 
  by 
  

   veinlets 
  of 
  neotocite, 
  a 
  kindred 
  silicate, 
  and 
  in 
  places 
  it 
  contains 
  specks 
  and 
  

   flakes 
  of 
  native 
  copper. 
  The 
  deposits 
  are 
  thought 
  to 
  be 
  manganiferous 
  

   marine 
  sediments, 
  greatly 
  altered 
  by 
  regional 
  metamorphism. 
  J. 
  T. 
  P. 
  

  

  GEOLOGY. 
  — 
  Deposits 
  of 
  chromite 
  in 
  California, 
  Oregon, 
  Washington 
  and 
  

   Montana. 
  J. 
  S. 
  Diller, 
  L. 
  G. 
  Westgate 
  and 
  J. 
  T. 
  Pardee, 
  U. 
  S. 
  

   Geol. 
  Surv. 
  Bull. 
  No. 
  725-A. 
  Pp. 
  84 
  with 
  maps, 
  5 
  plates 
  and 
  23 
  figures. 
  

  

  During 
  the 
  World 
  War 
  it 
  became 
  necessary 
  to 
  determine 
  as 
  closely 
  as 
  

   possible 
  the 
  chromium 
  resources 
  of 
  the 
  country. 
  It 
  was 
  demonstrated 
  that 
  

   the 
  United 
  States 
  had 
  reserve 
  deposits 
  adequate 
  to 
  supply 
  a 
  war 
  demand 
  for 
  

   several 
  years. 
  Now 
  that 
  the 
  war 
  is 
  over 
  the 
  country 
  is 
  conserving 
  its 
  domes- 
  

   tic 
  supplies 
  by 
  employing 
  higher 
  grade 
  and 
  cheaper 
  ore 
  from 
  foreign 
  countries. 
  

  

  The 
  first 
  paper 
  "Chromite 
  in 
  the 
  Klamath 
  Mountains, 
  California 
  and 
  Ore- 
  

   gon" 
  discusses 
  in 
  detail 
  the 
  occurrence 
  and 
  origin 
  of 
  chromite, 
  and 
  in 
  this 
  re- 
  

   spect 
  serves 
  as 
  an 
  introduction 
  to 
  all 
  the 
  papers 
  that 
  follow. 
  

  

  In 
  the 
  Klamath 
  Mountains 
  chromite 
  deposits 
  have 
  three 
  distinct 
  struc- 
  

   tures, 
  even 
  granular, 
  nodular 
  and 
  banded. 
  The 
  nodular 
  is 
  concretionary 
  and 
  

   the 
  banded 
  is 
  gneissoid. 
  The 
  even 
  granular 
  deposits 
  are 
  the 
  most 
  abundant 
  

   and 
  widely 
  distributed 
  in 
  California, 
  Oregon 
  and 
  Washington. 
  The 
  nodular 
  

   structure 
  occurs 
  in 
  California 
  and 
  Oregon 
  and 
  the 
  banded 
  structure 
  in 
  Cali- 
  

   fornia 
  and 
  Montana. 
  In 
  California 
  the 
  banded 
  structure 
  is 
  distinctly 
  as- 
  

   sociated 
  with 
  gneiss 
  ; 
  and 
  in 
  Montana 
  it 
  occurs 
  in 
  a 
  remarkable 
  dike 
  of 
  peri- 
  

   dotitic 
  rock. 
  ^ 
  T. 
  S. 
  D. 
  

  

  GEOLOGY. 
  — 
  Geology 
  of 
  the 
  vicinity 
  of 
  Tuxedni 
  Bay, 
  Cook 
  Inlet, 
  Alaska. 
  

   Fred 
  H. 
  Moffit. 
  U. 
  S. 
  Geol. 
  Surv. 
  Bull. 
  722-D. 
  Pp. 
  7, 
  with 
  geologic 
  

   map, 
  1921. 
  

  

  The 
  paper 
  describes 
  the 
  marine 
  sedimentary 
  rocks 
  of 
  a 
  small 
  area 
  on 
  the 
  

   west 
  side 
  of 
  Cook 
  Inlet 
  where 
  a 
  section 
  of 
  Middle 
  and 
  Upper 
  Jurassic 
  beds 
  

   is 
  particularly 
  well 
  displayed. 
  These 
  beds 
  comprise 
  a 
  succession 
  of 
  sand- 
  

   stones, 
  arkoses, 
  shales, 
  and 
  conglomerates, 
  derived 
  in 
  large 
  part 
  from 
  a 
  

   nearby 
  ancient 
  land 
  mass 
  where 
  granitic 
  rocks 
  were 
  abundant, 
  and 
  reach 
  a 
  

   thickness 
  of 
  possibly 
  9000 
  feet. 
  The 
  beds 
  are 
  especially 
  fossiliferous 
  in 
  the 
  

   lower 
  part 
  and 
  are 
  there 
  characterized 
  by 
  an 
  abundance 
  of 
  plant 
  remains 
  

   intermingled 
  with 
  the 
  marine 
  invertebrate 
  forms. 
  The 
  Jurassic 
  beds 
  are 
  

   faulted 
  against 
  the 
  volcanic 
  rocks 
  of 
  the 
  Aleutian 
  Range 
  on 
  the 
  west 
  and 
  dip 
  

   at 
  angles 
  ranging 
  from 
  10° 
  to 
  25° 
  south-southeast 
  or 
  toward 
  Cook 
  Inlet. 
  

  

  Petroleum 
  seeps 
  are 
  known 
  in 
  these 
  rocks 
  in 
  the 
  vicinity 
  of 
  Iniskin 
  Bay 
  

   about 
  40 
  miles 
  southwest 
  of 
  Tuxedni 
  Bay 
  but 
  were 
  not 
  seen 
  in 
  the 
  area 
  

   which 
  is 
  described. 
  F. 
  H. 
  M. 
  

  

  