diller.]  REDDING    QUADRANGLE,    CALIFORNIA.  179 
Bricks  were  made  several  years  ago  of  the  sandy  alluvial  clay  in  the 
flood  plain  of  Sacramento  River,  several  miles  south  of  Redding,  where 
there  is  a  large  deposit,  but  a  few  miles-  farther  down  the  valley 
beyond  Clear  Creek  and  near  Anderson  there  is  a  brickyard  that  made 
about  2,500,000  of  brick  in  1903  and  supplied  much  of  the  trade  of  the 
Sacramento  Valley. 
BUILDING  STONES. 
A  variety  of  stones  have  been  used  locally  for  structural  purposes, 
but  scarcely  any  were  shipped  from  the  quadrangle.  The  Chico 
sandstone  from  Sand  Flat  and  from  Clear  Creek,  near  Texas  Springs, 
was  formerly  used  for  some  of  the  railroad  culverts  and  furnished 
trimmings  for  several  buildings  in  Redding.  It  is  soft,  grayish  red 
or  bluish,  and  easily  worked,  but  occasionally  marred  by  mud  spots. 
A  granodiorite  of  bright-gray  color  forms  a  hill  at  the  southwest 
corner  of  the  quadrangle  and  is  locally  used  to  a  limited  extent  for 
tombstones,  also  for  street  curbing  in  Redding,  and  for  doorsteps. 
This  granitic  rock  weathers  gray  with  slight  discoloration  from  the 
decomposition  of  the  ferromagnesian  minerals.  It  is  only  6  miles 
from  the  railroad,  with  eas\^  grade,  and  deserves  consideration  for 
any  large  structure  in  the  northern  part  of  the  Sacramento  Valley. 
The  Tuscan  tuff  stands  lire  well,  and,  being  soft,  is  easily  hewn  to 
any  shape.  It  is  commonly  used  for  chimneys  and  fireplaces,  and  in 
the  vicinity  of  Millville  a  small  church  and  several  smokehouses  are 
made  of  it.  The  Tuscan  tuff  is  similar  to  the  trass  of  the  Rhine  Val- 
ley, which  is  so  extensively  used  in  the  manufacture  of  cement,  and 
there  appears  to  be  no  good  reason  why  it  might  not  be  used  in  the 
Redding  region  for  the  same  purpose.  This  is  especially  true  since 
the  necessary  lime  for  admixture  is  abundant. 
