NEW   ENGLAND.  581 
land  schist  to  the  south  and  east,  which  latter  rock  has  been  so  intri- 
cately injected  by  this  granite,  and  locally  so  largely  pegmatized,  that 
it  has  been  found  impossible  in  mapping  to  delimit  the  sedimentary 
from  the  igneous  material.  These  intricately  injected  areas,  origin- 
ally occupied  in  large  part  (though  probably  not  wholly)  by  Hart- 
land  schist,  occur  especially  in  the  neighborhood  of  Waterbury,  and 
the  name  Waterbury  gneiss  has  been  applied  to  them. 
Near  the  southern  border  of  the  pre-Cambrian  core,  or  near  the 
city  of  Litchfield,  a  hypersthene-bearing  intrusive  is  found,  which 
may  be  pre-Cambrian. 
The  structure  of  the  area  has  been  brought  about  in  part  by  fold- 
ing and  in  part  by  disjunctive  processes.  The  folds  in  the  gneiss 
are  seldom  simple  folds,  and  are  both  longitudinal  and  transverse. 
The  transverse  folds  have  a  variable  trend,  but  on  the  average  this 
direction  runs  with  the  extension  of  the  formations,  which  is  roughly 
northeast-southwest.  The  folds  are  seldom  symmetrical,  but  usually 
overturned,  sometimes  eastward,  at  other  times  westward.  More- 
over, upon  the  large  folds  are  superimposed  folds  of  secondary  or 
even  tertiary  magnitude  which  preserve  in  the  main  the  same  forms 
as  the  larger  folds. 
Upon  this  intricate  complex  of  flexures  has  been  superimposed 
a  joint  and  fault  system  which  has  profoundly  modified  the  areal 
distribution  of  formations  and  the  location  of  their  boundaries,  and 
has  impressed  its  influence  profoundly  upon  the  relief  of  the  region. 
The  characteristics  of  this  elaborate  joint  and  fault  system  have 
been  determined  by  the  study  of  favored  or  "  key  "  localities,  particu- 
larly, however,  the  fortuitously  preserved  areas  of  the  later  Newark 
formation. 
SECTION    5.     CONNECTICUT. 
SUMMARY   OF  LITERATURE. 
Stlltman,71  in  18-20,  states  that  Primitive  rocks  occur  in  many 
places  in  the  counties  of  New  Haven  and  Litchfield.  These  rocks 
succeed  each  other  with  almost  precisely  the  arrangement  and 
succession  laid  down  by  AVerner — clay  slate,  including  beds  of  trap; 
mica  slate;  gneiss.  Granite  crowns  the  whole,  although  it  occupies 
but  a  small  extent  compared  with  the  gneiss  and  slaty  rocks.  A-  a 
whole  the  slates  occupy  the  lowest  and  the  granites  and  gneiss  the 
highest  situations. 
Mather,72  in  1832,  describes  the  succession  from  Killingly  to  Had- 
dam  as  consisting  of  gneiss,  granite,  syenite,  mica  slate,  hornblende 
slate,  and  granular  quartz  rock,  the  latter  underlying  thick  strata 
of  gneiss.  Powerful  veins  of  granite  traverse  the  gneiss,  while  in 
other  places  the  granite  is  found  both  in  veins  and  in  beds. 
