352 
CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull.  225. 
About  3  miles  southeast  of  Dickie  mine  No.  1,  and  1  mile  north  of 
( J  rass  Creek,  Mr.  Dickie  has  opened  a  coal  bed  8  feet  3  inches  thick, 
which  is  locally  known  as  Dickie  mine  No.  2.  The  coal  occurs  in  the 
basal  Laramie  sandstone,  which  here  comprises  the  west  rim  of  a  large 
eroded  anticline  extending  from  the  vicinity  of  Gooseberry  Creek 
southeastward  to  Grass  Creek  and  intersecting  the  latter  at  a  point  3 
miles  above  the  mouth  of  Prospect  Creek.  The  longitudinal  axis  of  this 
anticline  is  12  to  15  miles  long  and  the  transverse  axis  is  considerably 
shorter.  The  central  body  of  the  basin  is  composed  of  Pierre  shale, 
sin  rounded  by  coal-bearing  Laramie  sandstone.  The  only  coal  open- 
ings observed  on  this  sandstone  rim  were  the  Dickie  mine  No.  2,  and 
a  small  showing  on  the  south  side  of  Grass  Creek  about  a  mile  distant. 
Coal  of  this  horizon  is  said  to  outcrop,  however,  at  frequent  intervals 
along  the  southern  rim  of  the  anticline  for  some  distance.  The  coal 
seam  in  Dickie  mine  No.  2  consists  of  two  benches,  separated  by  the 
usual  bluish-white  shaly  parting  near  the  middle.  A  2-inch  layer  of 
light-gray  shale  also  occurs  near  the  top  of  the  upper  bench,  but 
neither  of  these  partings  are  sufficiently  thick  to  affect  materially  the 
productive  capacity  of  the  seam.  The  coals  of  the  upper  and  lower 
benches  exhibit  no  essential  points  of  difference  in  quality.  The  prod- 
uct is  rather  hard  and  compact,  with  an  unusually  bright  luster,  and 
the  chemical  analysis  shows  it  to  be  a  good  variety  of  lignite.  The 
mine  is  not  operated  at  present,  but  the  quality  of  the  material,  com- 
bined with  the  size  and  character  of  the  seam,  render  it  a  desirable 
property.     A  section  of  the  bed  is  given  below: 
Section  of  Dickie  mine  No.  2,  near  Grass  Creek,  Wyoming. 
Ft.       In. 
Coal 4  6 
Light  bluish-gray  slate 0  3 
Coal 0  9 
Light-gray  slate 0  2 
Coal 3  0 
The  small  detached  Laramie  area  lying  west  of  Wood  River  is 
structurally  a  synclinal  trough  comprising  about  20  square  miles  and 
extends  from  a  point  3  miles  north  of  Gray  Bull  River  southeastward 
to  Wood  River.  This  area  is  about  10  miles  long  and  2  to  3  miles 
wide.  Its  axis  trends  N.  5°  W.  The  formation  is  the  basal  sandy 
series,  the  overlying  shaly  division  being  absent.  The  sandstones  of 
the  Laramie  in  this  region  are  heavily  developed,  and  there  occur 
immediately  above  and  below  the  coal  horizon  massive  sandstone  layers 
20  to  30  feet  thick,  the  upper  having  a  white  and  the  lower  a  yellowish 
tint.  The  color  and  thickness  of  these  two  sandstone  layers  are 
very  persistent  throughout  the  Meeteetse  district  and  serve  as  an 
indicator  of  the  position  of  the  coal.     The  dips  vary  from  20°  to  40° 
