570  PRE-CAMBBIAN   GEOLOGY   OP   NORTH   AMERICA. 
At  Whateiy  occurs  a  peculiar  conglomeratic  syenite,  which  is  gener- 
ally found  between  the  granite  and  metamorphic  rocks  and  may  be 
due  to  the  conversion  of  the  granite  into  syenite  or  else  to  the  eruption 
of  the  syenite  at  a  different  epoch.  The  pseudo  stratification  of 
granite  is  regarded  as  due  to  concretionary  action  on  a  gigantic  scale. 
The  granite  cuts  and  is  interstratified  with  all  the  stratified  rocks  and 
certain  of  the  other  eruptives  in  the  most  intricate  fashion. 
In  Massachusetts  are  six  systems  which  are  unconformable  and  suc- 
ceed one  another  in  age.  These  are  as  follows:  The  Oldest  Merid- 
ional system,  the  Northeast  and  Southwest  system,  the  East  and 
West  system,  the  Hoosac  Mountain  system,  the  Red  Sandstone  sys- 
tem, the  Northwest  and  Southeast  system.  In  western  Massachu- 
setts, from  Hoosao  Mountain  to  the  Taconic  Range,  a  powerful  force 
has  folded  the  strata  so  that  in  many  cases  they  have  actually  been 
reversed. 
Lyell,44  in  1844,  describes  the  plumbago ,  and  anthracite  in  the 
mica  schist  near  Worcester.  This  is  in  the  immediate  neighborhood 
of  masses  of  granite  and  syenite,  the  character  of  the  plumbago  and 
anthracite  being  due  to  this  local  metamorphosing  effect  and  to  more 
general  chemical  or  plutonic  action.  The  difference  in  dip  of  these 
rocks  from  the  nearest  Carboniferous  of  Rhode  Island  and  Massa- 
chusetts is  no  evidence  that  they  are  not  equivalent  and  that  the 
graphite  is  not  metamorphosed  organic  material. 
Rogers,45  in  1857,  describes  trilobites  belonging  to  Paradoxides  as 
occurring  in  the  metamorphic  beds  of  eastern  Massachusetts  at  Brain- 
tree,  which  shows  that  these  ancient  and  highly  altered  sediments  are 
the  base  of  the  Paleozoic  column. 
Hitchcock  (C.  H.),4G  in  1859,  describes  the  rocks  from  Greenfield 
to  Claremont,  Mass.,  as  having  the  following  order:  Micaceous  slates 
and  schists  interstratified  with  siliceous  limestone,  mica  slate,  horn- 
blende slate,  mica  slate  interstratified  with  limestone,  and,  lastly, 
calcareo-mica  slate.  The  dip  as  far  as  the  West  Shelburne  Falls 
gneiss  is  to  the  east ;  at  this  latter  point  it  is  to  the  west.  The  whole 
is  regarded  as  an  anticline. 
Gregory,47  in  18G2,  describes  Marblehead  as  consisting  mainly  of 
the  Primitive  formation.  The  northern  part  of  the  peninsula  is 
greenstone,  intersected  by  dikes  of  the  same  rock.  In  the  southern 
section  syenite  contends  with  the  greenstone  for  supremacy,  for  here 
the  two  rocks  are  thoroughly  intermingled.  The  deposits  of  green- 
stone, syenite,  and  porphyry  are  for  the  most  part  distinct,  although 
occasionally  the  greenstone  grades  into  the  syenite. 
Jackson,48  in  1866,  gives  the  following  section  at  the  base  of  South 
Mountain,  at  Chester,  Mass.,  from  the  base  upward:  Hornblende 
rock,  magnetic  iron  ore,  emery  bed,  granular  quartzite,  chlorite  slate 
and  talc  slate,  crystallized  talc,  talcose  slate  rock,  soapstone  or  talcose 
