CLAYS    OF    CAPE    COD,    MASSACHUSETTS.  437 
The  clay,  although  present  in  large  amounts,  can  not  be  readily  worked,  owing  to  the 
thick  covering  of  sand  and  gravels.  The  depressions  which  occur  in  the  bluff  from  time  to 
time  are  due  to  folding,  and  the  clay  is  little  if  any  nearer  the  surface  in  the  valleys  than  in 
the  ridges.  The  exposure  to  the  open  Atlantic  will  probably  always  prevent  the  working 
of  the  clays  from  this  side  of  the  cape. 
On  the  bay  side  of  the  cape  no  clay  was  seen  in  the  bluffs  from  Pamet  River  south  to 
Great  Beach  Hill.  On  the  east  side  of  Great  Beach  Hill  and  on  the  mainland  north  of 
Great  Island  the  talus  is  somewhat  darkened,  possibh  indicating  clay  beneath  the  surface. 
On  Indian  Neck,  south  of  Wellfleet,  and  in  the  bluff  on  the  small  point  between  the  neck 
and  the  railroad,  exposures  of  clay  or  clayey  sand  are  found.  In  the  southeastern  portion 
of  the  bluffs  at  Indian  Neck  from  4  to  5  feet  of  interstratified  sand  and  clay  are  exposed 
along  the  beach  for  several  hundred  feet.  This  probably  belongs  to  the  Jacob  formation, 
but  it  is  said  that  blue  clay,  presumably  Gardiner,  was  dug  from  the  beach  for  use  on  the 
State  road.  In  the  northern  bluff  at  Indian  Neck  from  6  to  10  feet  of  blue  clay,  overlain 
by  fine  brown  and  gray  sands,  outcrop  in  an  undulating  layer  for  several  hundred  feet.  It 
is  believed  that  this  clay  layer  belongs  to  the  Gardiner  formation,  while  the  overlying  sand 
is  Jacob.  The  clay  is  blue,  somewhat  shaly,  and  jointed.  The  same  or  another  layer  of 
the  Gardiner  clay  comes  near  the  surface  in  the  fields  back  of  the  hill,  where  a  number  of 
pits  were  opened  and  considerable  clay  was  taken  out  during  the  building  of  the  State  road. 
On  the  small  point  mentioned  as  occurring  between  Indian  Neck  and  the  railroad,  a  small 
bed  of  clay  is  exposed  in  a  broad  arch  in  the  bluff,  but  the  clay  here  is  not  reported  to  have 
been  worked.  In  the  interior  of  this  part  of  the  cape  near  the  level  of  the  swamp,  1  mile 
north  of  Wellfleet,  clay  was  seen  in  a  local  pit  from  which  material  for  the  State  road  had 
been  taken.  Another  pit  which  has  yielded  considerable  quantities  of  clay  is  located  on 
the  north  side  of  the  same  swamp  a  little  over  one-fourth  mile  to  the  west.  Again,  on  the 
south  side  of  the  swamp,  about  one-half  mile  northwest  of  Wellfleet,  there  is  a  pit  20  feet 
in  depth  in  which  8  feet  of  brownish  clay,  becoming  greenish  toward  the  bottom,  inter- 
laminated  with  sand,  and  carrying  occasional  granite  pebbles,  are  exposed  under  2  or  3 
feet  of  Wisconsin  till  and  gravel.  Blue  clay  is  said  to  have  been  taken  out  below  the  portion 
of  the  pit  now  exposed.  The  pebble  content  of  the  clay  is  believed  to  indicate  that  it 
belongs  to  the  Montauk  drift,  though  doubtless  derived  from  closely  adjacent  masses  of 
Gardiner  clay.  Just  south  of  the  road  leading  from  Wellfleet  Center  westward  across  the 
railroad  there  is  another  pit  of  similar  clay.  Clay  occurring  in  alternate  streaks  of  blue, 
yellow,  and  brown,  with  some  sand,  is  also  said  to  outcrop  in  the  woods  one-half  mile  south- 
east of  North  Wellfleet.  Pilgrim  Spring,  emerging  from  the  base  of  the  bluff,  just  east  of 
Indian  Neck,  may  flow  from  the  top  of  a  similar  clay  layer. 
Eastham  region. — The  Eastham  region  includes  the  area  between  South  Wellfleet  on  the 
north  and  Eastham  station  on  the  south.  The  region  is  mainly  one  of  flat  plains,  with  the 
exception  of  the  southern  portion,  which  has  a  rolling  topography.  A  traverse  of  the  beach 
from  South  Wellfleet  to  the  end  of  the  bluffs  1{  miles  south  of  Nauset  Beacons  failed  to 
show  clay,  except  in  the  vicinity  of  the  beacons.  A  little  south  of  this  point  a  small  knob 
about  10  feet  in  height  of  bluish  Gardiner  clay  and  brown  Jacob  sands  shows  in  the  face  of 
the  bluff.  Just  beyond  several  feet  of  folded  gray  to  light-chocolate  Gardiner  clay  out- 
crop for  100  feet  or  so  along  the  beach.  The  clay  as  here  exposed  is  too  thin  and  would 
require  too  much  stripping  to  be  of  economic  value  except  for  local  purposes.  South  of 
these  outcrops  no  clay  appears  in  the  bluffs,  although  the  Montauk  drift  is  at  points  quite 
clayey.  No  clays  were  found  on  the  bay  side  of  the  cape,  except  near  the  south  side  of  the 
mouth  of  Blackfish  Creek  southwest  of  South  Wellfleet.  At  this  point  a  hard  blue  putty 
clay  without  pebbles  was  found  below  tide  level  and  was  excavated  to  a  depth  of  4  feet  for 
use  on  the  State  road.  It  probably  belongs  to  the  Gardiner  formation.  In  general  the 
clay  is  not  to  be  expected  above  sea  level  in  the  Eastham  region. 
Orleans  region. — Under  this  head  is  included  the  area  south  from  Eastham  station  to 
Pleasant  Bay,  Chatham,  and  west  to  the  vicinity  of  Brewster.  Throughout  most  of  the 
area  the  Gardiner  clay  seems  to  be  below  sea  level.     Three-fourths  of  a  mile  east  of  Tonset, 
