woolsey.]  CLAYS    OF    OHIO    VALLEY    IN    PENNSYLVANIA.  475 
forms  all  of  the  high  country  back  from  the  river  and  is  exposed  over  most 
of  Beaver  County.  Owing  to  lack  of  transportation  facilities  the  clays 
of  this  formation  are  at  a  disadvantage,  but,  curiously,  there  are  few, 
if  any,  beds  of  pure,  nonconsolidated  fire  clay  in  the  formation.  Many 
of  the  conspicuous  red  clays  and  variegated  shales,  however,  may  be 
found  valuable  for  brick  purposes.  Indeed,  the  analyses  compare 
favorably  with  those  of  high-grade  clays,  and  these  clays  and  shales 
of  the  Barren  Measures  have,  in  fact,  been  used  for  paving  brick  and 
terra  cotta  at  Glouster,  Ohio  (see  No.  5  of  analyses  above).  At  Bell- 
aire,  Ohio,  20  feet  of  shale  just  under  the  Pittsburg  coal  is  made  into 
paving  brick  and  sewer  pipe. 
General  section  of  Conemaugh  formation. 
Pittsburg  coal  at  top.  Feet, 
1.  Shale 25 
2.  Limestone 3 
3.  Shaly  sandstone  and  shale 50 
4.  Red  shales 40 
5.  Morgantown  sandstone 65 
6.  Elk  Lick  coal „  Blossom. 
7.  Variegated  shale 40 
8.  Ames  limestone  ' '  Crinoidal " 2  to  5 
9.  Coal  (Piatt?) 1 
10.  Red  shale 30 
11.  Green  shale , : 25 
12.  Red  shale 15 
13.  Bakerstown  coal,  cannel 2  to  7 
14.  Sandy  shale  and  laminated  sandstone 85 
15.  Brush  Creek  limestone,  dark 1 
16.  Dark  shale 20 
17.  Brush  Creek  coal Blossom. 
18.  Shale 35 
19.  Yellow  and  red  caky  shale 20 
20.  Sandy  shale 10 
21.  Mahoning  sandstone 30 
Upper  Freeport  coal. 
As  seen  from  the  section,  most  of  the  formation  is  composed  of 
shales  in  such  enormous  quantities  that  the  manufacture  of  brick  can 
be  carried  on  for  centuries.  Nearly  all  of  the  shales,  the  exceptions 
being  the  very  arenaceous  types,  are  well  adapted  to  the  manufacture 
of  brick,  and  all  show  evidence  of  the  presence  of  more  or  less  iron, 
ferrous  in  the  fresh  shale  and  ferric  in  the  weathered.  The  most  com- 
mon varieties  are  yellowish,  drab,  or  bluish  gray.  Recently  M.  Lanz 
&  Sons,  of  Pittsburg,  have  succeeded  in  making  brick  of  good  color 
and  quality  for  building  purposes  from  these  shales. a  Red  shales  are 
not  very  abundant,  but  where  they  do  occur  they  generally  have  dis- 
integrated to  red  residual  clay. 
a  Prof.  Paper  U.  S.  Geol.  Survey  No.  11,  p.  233. 
