NOTE  ON  A  MINERAL  PROSPECT  IN  MAINE 
By  ( ! eorg e  (  >iis  Smith. 
Within  the  past  few  years  there  has  been  a  revival  of  interest  in 
mineral  deposits  in  eastern  Maine.  In  several  localities  where  small 
copper,  zinc,  or  lead  mines  were  opened  thirty  years  ago,  the  proper- 
tics  have  been  reexamined  and  in  a  few  places  shafts  have  been 
pumped  out.  At  other  places  metalliferous  veins  have  been  pros- 
pected to  determine  whether  the  ore  can  be  mined  with  profit  under 
modern  methods  of  ore  treatment. 
At  the  request  of  the  Maine  State  Survey  Commission  the  writer 
visited  one  of  these  prospects  during  the  last  season,  and  the  following 
note  is  published,  as  it  is  believed  thai  the  deposit  is  somewhat  typical 
of  tin1  disseminated  sulphides  of  this  region,  so  that  the  conclusions 
reached  here  may  at  least  suggest  the  value  of  other  similar  deposit! 
The  locality  visited  is  in  the  town  of  West  Pembroke  on  the  farm  of 
B.  S.  Sinclair,  about  a  mile  southeast  of  Avers  Junction  on  the  Wash- 
ington County  Railroad.  During  L906  considerable  prospect  work 
was  done  here,  and  shallow  openings  have  been  made  at  a  dozen  places 
on  the  hillside. 
The  country  rock  is  met  amorphic  and  of  volcanic  origin,  much  of  it 
being  a  greenstone  breccia  with  amygdaloid  fragments.  The  beddinl 
of  I  he  volcanic  deposits  appears  to  be  represented  by  the  sheets  m 
varying  texture,  which  have  an  east-west  strike  and  steep  dip.  The 
rock  i>  t  horoughly  silicified  and  more  or  less  jointed. 
The  metalliferous  minerals  are  sphalerite,  galena,  pyrite,  and  dial- 
copyrite,  with  quartz  and  calcite  as  gangue  minerals.  Oxidatioj 
has*  penetrated  the  rock  for  only  1  to  2  inches,  and  copper  carbonate 
were  seen  at  one  place.  These  sulphides  are  scattered  throughoui 
irregular  bands  of  the  greenstone,  the  mineralized  and  unniineralizec 
portions  of  the  rock  not  being  sharply  contrasted.  In  no  place  is  an} 
well-defined  vein  exposed,  although  at  one  opening,  No.  2,  the  more 
compact  greenstone  contains  several  small  lenticular  areas  of  (piartz 
including  small  bunches  of  chalcopyrite.  These  cut  across  the  sheet 
ing  of  the  rock.     Where  the  breccia  character  of  the  greenstone  i: 
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