﻿184 
  JOURNAL 
  OF 
  THE 
  WASHINGTON 
  ACADEMY 
  OF 
  SCIENCES 
  VOL. 
  12, 
  NO. 
  7 
  

  

  islands 
  of 
  the 
  same 
  group 
  are 
  near 
  the 
  bending-point 
  of 
  the 
  geanticlinal 
  

   axis 
  of 
  the 
  Tukang 
  Besi 
  Islands 
  and 
  southeastern 
  Celebes. 
  The 
  

   narrow 
  Manipa 
  Strait, 
  nearly 
  5,000 
  meters 
  deep 
  between 
  Ceram 
  and 
  

   Buru 
  is 
  another 
  example 
  of 
  an 
  important 
  gap 
  where 
  there 
  is 
  strong 
  

   bending 
  of 
  the 
  geanticlinal 
  axis 
  in 
  a 
  horizontal 
  plane, 
  while 
  the 
  strait 
  

   between 
  Halmaheira 
  and 
  Morotai 
  and 
  the 
  important 
  gap 
  between 
  

   Halmaheira 
  and 
  the 
  islands 
  to 
  the 
  southwest 
  of 
  the 
  Pelew 
  group 
  may 
  

   in 
  part 
  be 
  the 
  result 
  of 
  fractures 
  near 
  a 
  bending-point, 
  which 
  possibly 
  

   exist 
  between 
  Halmaheira 
  and 
  those 
  islands. 
  Of 
  course 
  in 
  large 
  bend- 
  

   ings 
  of 
  the 
  geanticlinal 
  axis 
  the 
  submarine 
  parts 
  of 
  the 
  axis 
  may 
  be 
  

   due 
  to 
  a 
  pitch 
  of 
  the 
  axis, 
  but 
  for 
  relatively 
  short 
  bendings 
  this 
  ex- 
  

   planation 
  of 
  submarine 
  portions 
  alone 
  is 
  not 
  applicable. 
  The 
  fracture- 
  

   movement 
  may 
  be 
  more 
  or 
  less 
  parallel 
  to 
  a 
  fault-plane 
  or 
  the 
  move- 
  

   ment 
  may 
  have 
  an 
  important 
  component 
  normal 
  to 
  the 
  fracture-plane 
  

   The 
  bending-points 
  of 
  the 
  surface 
  of 
  the 
  geanticline, 
  considered 
  in 
  a 
  

   vertical 
  cross 
  section 
  of 
  the 
  geanticline 
  at 
  right 
  angles 
  to 
  the 
  geanti- 
  

   clinal 
  axis, 
  are 
  between 
  the 
  deep 
  sea-basins 
  and 
  the 
  elevated 
  islands, 
  

   where 
  longitudinal 
  faults 
  may 
  cut 
  away 
  the 
  land 
  at 
  the 
  coast 
  as 
  has 
  

   been 
  mentioned 
  for 
  many 
  islands 
  of 
  the 
  Archipelago. 
  If 
  two 
  more 
  or 
  

   less 
  parallel 
  rows 
  of 
  islands 
  are 
  developing 
  as 
  two 
  secondary 
  geanticlines 
  

   with 
  an 
  intermediate 
  secondary 
  geosyncline, 
  longitudinal 
  faults 
  may 
  

   exist 
  on 
  both 
  sides 
  of 
  the 
  secondary 
  geosyncline 
  and 
  on 
  the 
  outer 
  sides 
  of 
  

   the 
  secondary 
  geanticlines. 
  The 
  duration, 
  speed, 
  and 
  place 
  of 
  the 
  

   fracture-movements 
  will 
  in 
  large 
  measure 
  depend 
  upon 
  the 
  evolution 
  of 
  

   the 
  mountain-building. 
  If 
  the 
  plane 
  of 
  movement 
  is 
  not 
  constant 
  and 
  

   the 
  traces 
  of 
  older 
  fracture-movements 
  are 
  elevated 
  "above 
  the 
  sea, 
  they 
  

   will 
  usually 
  disappear 
  rapidly 
  through 
  erosion 
  on 
  the 
  outer 
  side 
  of 
  the 
  

   geanticline. 
  If 
  the 
  secondary 
  geosyncline 
  during 
  its 
  slow 
  subsidence 
  

   constantly 
  remained 
  fairly 
  well 
  filled 
  with 
  an 
  accumulation 
  of 
  sedi- 
  

   ments 
  and 
  if 
  in 
  a 
  later 
  stage 
  of 
  evolution 
  a 
  general 
  elevation 
  of 
  the 
  

   secondary 
  geosyncline 
  and 
  geanticlines 
  takes 
  place, 
  the 
  filling 
  of 
  the 
  

   central 
  basin 
  w411 
  serve 
  as 
  evidence 
  of 
  older 
  fracture-movements 
  on 
  

   both 
  sides 
  of 
  the 
  original 
  secondary 
  geosyncline. 
  Different 
  stages 
  in 
  

   this 
  evolution 
  are 
  represented 
  in 
  the 
  Timor-Ceram 
  row 
  of 
  islands.^ 
  

   The 
  islands 
  of 
  the 
  Tenimber 
  group 
  consist 
  of 
  two 
  rows 
  with 
  elevated 
  

   reefs, 
  which 
  are 
  separated 
  by 
  a 
  zone 
  in 
  which 
  during 
  the 
  latest 
  stage 
  

   of 
  the 
  mountain-building 
  process 
  positive 
  movements 
  have 
  prevailed. 
  

   At 
  Timor 
  the 
  geanticline 
  may 
  have 
  already 
  passed 
  through 
  the 
  stage 
  of 
  

  

  * 
  H. 
  A. 
  Brouwer. 
  The 
  horizontal 
  movement 
  of 
  geanticlines 
  and 
  the 
  fractures 
  near 
  their 
  

   surface. 
  Journ. 
  of 
  Geol. 
  29: 
  566. 
  1921. 
  

  

  