294         •  ONTKIBUTIONS    TO   ECONOMIC    GEOLOGY,  lflOG,  PART    I. 
The  shale  dips  at  a  low  degree  to  the  east  and,  as  it  outcrops  near 
the  top  of  a  hill,  conditions  for  quarrying  arc  very  favorable.  The 
20  feet  of  reddish  shale  may  differ  from  the  underlying  15  feet  of i 
dark  shale  only  in  being  more  weathered.  While  the  lower  30  feet 
o(  gray  shale  has  been  used,  only  that  from  the  upper  35  feet  is  used 
at  present  in  the  proportion  of  two  parts  of  red  shale  to  one  of  dark, 
A  test,  apparently  of  the  red  shale,  showed  that  vitrification  takes 
place  at  2,000°  F.  and  viscosity  at  2,150°  F.  The  brick  are  burned 
in  round  down-draft  kilns  for  nine  days.  They  are  red  or  brown. 
The  capacity  of  this  planl  is  30,000  daily. 
The  shale  lying  100  to  200  feel  below  the  Black  ('reek  seam  is  used 
for  dry-press  brick  by  the  Sibley-Menge  Press  Brick  Company,  whose 
plant  is  about  1  mile  north  of  Coaldale.  The  shale  lies  nearly  flat  and 
the  bed  is  al  least  70  feet  thick,  but  only  shale  from  the  bottom.  20 
feci  is  used  ni  present.  In  its  weathered  condition  this  is  a  gray  clay 
shale,  apparent  ly  wit  h  wry  little  mica  and  sand.  It  makes  a  line  dr\  - 
press  face  brick  of  a  pleasing  red  color.  As  stated  on  page  292,  it  is 
mixed  with  t  he  underclay  of  t  he  Black  ( "reck  coa  I  sea  in  for  gray  brick. 
The  capacity  of  the  plant  is  about  60,000  brick  daily.  No  analyses  of 
the  shale  no]'  physical  tests  of  the  brick  have  been  made,  so  far  as 
known  to  the  writer,  nor  does  he  know  whether  the  upper  part  of  the 
shale  bed  is  equally  good  for  brick. 
At  Lovick,  in  the  Cahaba  coal  field,  shale  lying  between  the  Gould 
and  Nunnally  coal  groups  i>  being  extensively  worked  at  I  he  brick 
plant  of  L.  L.  Stevenson.  The  whole  bed  utilized  has  the  following 
section: 
Section  "/  Stevenson  brick  works,  Lovick. 
Feet. 
Reddish  Bhale,  probably  weathered  phase  of  gray  shale  below I<> 
Gray  clay  Bhale IS 
Blue-black  carbonaceous  clay  shale,  with  fossils 20 
Shale  from  all  t  hoe  layers  i>  mixed  and  used  for  pale-red  common 
brick  <>r  brown  vitrified  brick.  The  time  of  firing  is  nine  days,  three 
day-  at  low  heat  to  expel  the  water  and  six  days  at  red  heat  and 
finally  at  while  heat.  The  capacity  of  the  plant  is  80,000  brick  daily 
and  the  actual  outpul  is  large.     No  analyses  nor  physical  tests  have 
been  made. 
The  Lovick  shale  is  traceable  by  its  characteristic  dark  fossiliferous 
shale  band  for  (>  miles  southwest  of  Lovick.  Jt  is  particularly  well 
shown  along  the  Leeds-Birmingham  road  in  the  southwest  corner  of 
sec.  28,  T.  17  S.,  K.  1  W.  It  extends  northeastward  along  the  west 
side  of  Owens  Mountain  to  Parsons  station  and  beyond.  At  Lovick 
this  shale  dips  8°  E.,  but  both  to  the  north  and  the  south  the  dip 
reaches  20°. 
