336  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull. 225. 
form  a  large  mountain  mass  which  is  practically  the  southern  terminus 
of  the  basin.  The  main  synclinal  basin  lies  on  the  west  side  of  Middle 
Ridge,  and  south  of  the  public  road  it  is  so  compressed  that  it  forms 
a  single  mountain  range  which  extends  for  a  distance  of  3  or  4  miles 
and  then  is  terminated  by  the  lifting  of  the  syncline  near  the  Virginia 
State  line. 
On  the  eastern  side  of  the  basin  the  anticlinal  fold  just  described  is 
bordered  by  a  minor  syncline  which  makes  its  first  appearance  near 
the  Meadows  road  and  extends  southward  lying  between  Middle  Ridge 
on  the  west  and  Third  Hill  Mountain  on  the  east.  The  point  of  maxi- 
mum development  of  this  syncline  is  about  halfway  between  the 
Meadows  road  and  the  Martinsburg  and  Romney  road.  Toward  the 
southwest  the  basin  lifts  and  is  compressed  by  the  big  anticline  lying 
to  the  west,  so  that  south  of  the  latter  road  it  has  but  a  slight  devel- 
opment. The  sandstone  shows  a  dip  of  about  40°  on  the  western 
limb  of  the  syncline  and  stands  about  vertical  on  the  eastern  limb. 
Farther  south  the  eastern  limb  is  eroded  and  the  western  limb  is  con- 
tinued topographically  as  a  single  ridge  for  a  distance  of  2  or  3  miles 
until  the  syncline  disappears  and  the  ridge  is  broken  down  by  erosion. 
The  principal  synclinal  basin  is  unsymmetrical,  the  axis  or  line  of 
greatest  depression  being  generally  near  the  southeastern  side  of  the 
basin.  So  far  as  could  be  determined  in  the  hasty  examination  made  b}7 
the  writer  the  axis  lies  a  little  west  of  Meadow  Branch  at  the  northern 
extremity  of  the  mountain.  It  passes  west  of  the  knob  at  the  northern 
extremity  of  Third  Hill  Mountain,  but  it  corresponds  with  this  ridge 
for  a  distance  of  about  3  miles  from  its  northern  end.  At  Pinkerton 
Knob,  where  Third  Hill  Mountain  bends  to  the  east  and  forms  the 
rim  of  the  basin,  the  axis  follows  the  western  foot  of  the  mountain, 
and  it  crosses  the  Meadows  road  at  Tom  Myer's  place,  which  is  located 
at  the  foot  of  Third  Hill  Mountain. 
The  synclinal  basin  is  slightly  complicated  by  a  small  fold  which 
lies  on  the  western  side  of  the  synclinal  axis  and  extends  from  the 
vicinity  of  Whites  Gap  to  near  the  southern  extremity  of  the  basin. 
The  exact  nature  of  this  fold  could  not  be  determined.  Presumably 
it  is  a  monoclinal  wrinkle  in  the  bottom  of  the  basin,  but  possibly  the 
rocks  may  be  folded  into  an  anticlinal  arch. 
COAL  BEDS. 
The  coal  beds  of  the  Meadow  Branch  field  are  generally  poorly 
exposed.  The  coal  itself  is  extremely  tender  and  friable,  and  it  has 
been  so  badly  crushed  by  the  general  folding  which  the  rocks  have 
undergone  that  it  disintegrates  rapidly,  and  its  outcrop  is  generally 
deeply  covered  by  debris  from  the  other  rocks.  The  history  of  the 
development  of  the  field  dates  back  to  1835  when  an  effort  was  made 
