CLAYS    AND    SHALES    IN    CAMBRIA    COUNTY,  PA.  349 
North  of  Sheridan,  at  the  quarry  of  Bruce  H.  Campbell,  the  follow- 
ing section  was  measured,  showing  6  feet,  or  possibly  more,  of  clay 
below  the  Mercer  coal : 
Section  of  Mercer  coal  and  shales  at  Bruce  H.  Campbell  quarry,  north  of  Sheridan. 
Massive  sandstone  bowlders.  Ft.  In. 
Red  clay  with  rounded  1  >owlders  (Pleistocene?) 5-10  0 
Shales  .  . .' 20  0 
Coal  and  bone 1  3 
( 'lay 6  0 
Shales 6  0 
This  clay  has  never  been  worked,  but  it  is  apparently  of  good 
grade. 
Shales. — It  has  been  remarked  that  the  most  important  shale  hori- 
zons about  Johnstown  are  confined  to  the  lower  300  feet  of  the  Cone- 
maugh  formation.  The  section  given  on  page  346  shows  the  character 
of  the  lower  400  feet  of  beds  in  this  group  of  rocks  in  the  hill  east  of 
the  city.  From  about  50  feet  above  the  top  of  the  Coke  Yard  coal  to 
the  top  of  the  hill  numerous  promising  beds  of  shale  are  exposed. 
Most  of  the  shale  group  lying  between  165  feet  and  210  feet  above  the 
Coke  Yard  coal  is  being  worked  by  the  Johnstown  Pressed  Brick 
Company  into  a  good  grade  of  building  brick.  In  the  hill  north  of 
the  city  the  Cambria  Steel  Company  has  quarried  shales  lying  100  feet 
above  the  Coke  Yard  coal  seam  and  has  utilized  them  in  connection 
with  the  overlying  surface  clays,  in  the  manufacture  of  red  building 
bricks  of  good  quality. 
The  geological  structure  of  the  region  immediately  around  the  city 
is  such  that  the  beds  lie  fairly  flat,  and  the  lower  few  hundred  feet  of 
the  Conemaugh  formation  are  exposed.  Sections  obtained  in  the 
hills  around  the  city  and  along  the  Pennsylvania  Railroad  to  the 
west  indicate  that  the  lower  part  of  this  formation  is  of  prevailingly 
shaly  character,  comparable  with  that  seen  in  the  hill  to  the  east.  It 
is  therefore  probable  that  a  great  deal  of  brickmaking  material 
exists  in  these  hills  which  has  never  been  tested.  Though  all  this 
shale  may  not  be  of  the  grade  of  that  worked  by  the  Johnstown 
Pressed  Brick  Company  some  of  it  probably  is,  and  much  of  it  may 
be  suitable  for  paving  brick,  sewer  pipe,  nreproofmg  of  various  sorts, 
and  for  other  rough  material.  All  the  shale  in  the  hills  about  the 
city  and  to  the  west  is  fairly  accessible  to  transportation,  and  cheap 
fuel  is  assured  by  the  presence  of  valuable  coal  beds  300  feet  or 
more  below. 
The  lowest  promising  shale  horizon  in  this  district  is  associated 
with  the  Mercer  coal.  The  prospect  pits  on  the  Baltimore  and  Ohio 
Railroad  south  of  Krings  station  show  the  presence  of  dark  shales 
at  this  horizon.     At  points  north  of  Sheridan  the  Mercer  shales  are 
Bull.  315—07 23 
