VAX   HtSE.] 
EASTERN    UNITED    STATES.  359 
and  hornblende  have  been  noticed.  At  Asciitney  all  traces  of  stratifi- 
cation in  the  conglomerate  are  lost  and  it  passes  first  into  an  imperfect 
porphyry  and  then  into  a  granite  without  hornblende  in  the  same  con- 
tinuous mass.  Where  the  conglomerate  is  least  altered  it  is  made  up 
almost  entirely  of  quartz  pebbles  and  a  larger  amount  of  laminated 
grits  and  shales,  the  fragments  rounded  somewhat,  and  the  cement  in 
small  quantity.  The  fragments  are  sometimes  metamorphosed  to  mica- 
schist.  The  conviction  can  not  be  resisted  that  the  granitic*  rocks  of 
this  mountain  are  nothing  more  than  conglomerate  melted  down  and 
crystallized.  At  Gran  by  the  bowlders  are  of  all  sizes,  from  a  few  hun- 
dred pounds  to  50  to  00  tons.  They  cover  many  acres,  are  associated 
with  those  of  contorted  mica-slate,  qnartzose  granite,  and  many  other 
varieties  common  in  the  region. 
At  several  localities  in  Vermont,  Oraftsbury,  Northneld,  New  Fane, 
Proctorsville,  and  Stanstead,  just  beyond  the  Canada  line,  is  a  remark 
able  variety  of  white,  fine  grained,  highly  feldspathic  granite  which  con 
tains  scattered  through  its  face  numerous  spherical  or  elongated  and 
somewhat  flattened  nodules  of  black  mica  from  half  an  inch  to  2  inches 
in  diameter.  They  are  usually  more  or  less,flattened  and  have  a  shriv- 
eled appearance  like  dried  fruit.  In  some  cases  the  concretions  occupy 
more  th an  half  the  mass.  These  concretions  have  sometimes  been  called 
petrified  butternuts.  The  rock  is  regarded  as  produced  by  the  meta 
morphism  of  a  stratified  rock. 
Veins  of  granite  are  found  to  cut  syenite,  schist,  gneiss,  and  limestone, 
in  a  most  intricate  manner  at  many  localities.  Sometimes  there  are 
several  generations  of  granite  veins.  The  foregoing  facts  lead  to  the 
conviction  that  the  granite  acts  essentially  like  a  liquid  mass,  but  it  is 
regarded  as  the  product  of  aqueo-igneous  fusion  rather  than  dry  fusion. 
Also  it  is  believed  that  for  the  most  part  the  granites  have  formed  in 
situ,  their  material  being  furnished  by  the  sedimentary  rocks,  hence 
they  are  called  metamorphic.  As  evidence  that  they  are  metamorphic 
is  the  fact  that  it  is  often  difficult  to  tell  where  a  gneiss  ceases  and  a 
granite  begins.  It  is  sometimes  found,  where  granite  masses  come  in 
contact  with  stratified  rocks,  that  the  latter  have  been  more  or  less 
disturbed  and  broken,  but  oidy  to  a  limited  extent  and  often  not  at 
all.  In  many  cases  also  the  adjoining  strata  have  suffered  mechanical 
displacement,  such  as  the  forcible  injection  of  melted  matter  would  pro- 
duce. For  a  considerable  distance  around  the  granitic  masses  also, 
the  strata  are  frequently  indurated  and  metamorphosed  as  if  by  heat,  a 
fact  that  seems  to  decide  the  question  of  the  emanation  of  much  heat 
from  granitic  foci.  The  granites  are  more  abundant  in  the  crystalline 
than  in  the  fossiliferous  series,  in  fact  it  is  uncertain  whether  any  occur 
in  rocks  which  bear  fossils,  although  they  are  found  in  those  which  are 
regarded  as  the  equivalent  of  the  Devonian.  The  granite  is  most  com- 
mon in  gneiss  and  mica-schist,  less  so,  especially  in  the  form  of  veins,  in 
clay-slates,  and  least  of  all  in  talcose  schist.     In   the  stratified  rocks 
