NEW   ENGLAND. 
587 
blue  quartz  which  is  derived  from  the  gneiss.  The  gneiss  is  a  north- 
ward continuation  of  the  Eozoic  rocks  of  New  Jersey  and  the  High- 
lands of  New  York  and  of  southern  New  England.  In  Maine  the 
Cambrian,  Huronian,  and  Taconic  rocks  are  placed  together,  and 
also  the  Montalban  and  Laurentian.  The  granite  and  trap  and  altered 
slates  are  not  placed  in  the  stratigraphic  column.  The  gneisses 
are  regarded  as  older  than  either  the  Cambrian  or  the  Huronian. 
The  pre-Silurian  rocks  of  New  Hampshire  are  classified  as  follows: 
Classification  of  the  pre-Silurian  rocks  of  New  Hampshire. 
Laurentian Porphyritic  gneiss. 
Bethlehem  group 
Atlantic 
Eozoic 
Labrador  or  Pemigewasset.. 
Paleozoic Cambrian 
Lake  Winnipiseogee  gneiss. 
Montalban  or  White  Mountain  series. 
Franconia  breccia. 
Conway  granite. 
Albany  granite. 
Chocorua  granite. 
Ossipyte. 
Compact  feldspar. 
Exeter  syenites. 
Lisbon  group. 
Huronian..  -J  Lyman  group. 
Villiferous  conglomerate. 
'Rockingham  schists. 
Calciferous  mica  schist. 
Coos  group. 
Clay  slates. 
.Mount  Mote  conglomerate. 
The  name  Atlantic  system  is  proposed  to  cover  all  the  rocks  along 
the  Atlantic  coast  from  Maine  to  Alabama,  being  regarded  posterior 
in  time  to  the  Laurentian  but  anterior  to  the  Cambrian  and  later 
formations. 
Walcott,91  in  1888,  in  a  consideration  of  the  Taconic,  places  the 
western  core  of  the  Green  Mountains  as  pre-Cambrian,  the  bounding 
line  being  at  a  considerable  but  varying  distance  east  of  Rutland, 
Middlebury,  Burlington,  and  St.  Albans.  All  of  the  rocks  of  west- 
ern Massachusetts  are  regarded  as  Cambrian  or  post-Cambrian,  in- 
cluding the  Stockbridge  limestone,  the  granular  quartz  rock,  the 
magnesian  slate,  Sparry  limestone,  and  Taconic  slate.  In  north- 
western Connecticut  is  an  area  of  pre-Cambrian  rocks  which  is  sur- 
rounded by  quartzite  referred  to  the  Georgia  formation. 
Van  Hise,92  in  1  DO  1 .  visited  the  metamorphic  crystalline  areas  of 
southern  Vermont,  western  and  central  Massachusetts  and  western 
Connecticut.  He  finds  that  though  nearly  all  the  members  of  the 
crystalline  series  of  this  region  have  locally  been  so  profoundly  meta- 
morphosed that  the  determination  of  their  age  and  stratigraphic  rela- 
