KEL.] 
LIMONITE    OF    NEW    YORK    AND    NEW    ENGLAND. 
337 
'he  normal  type  of  fold  for  this  district  seems  to  have  been  a  closely 
ressed  succession  of  anticlines  and  synclines,  often  overturned,  so  as 
)  give  uniform  dips  on  both  flanks  of  the  fold.  As  the  tops  of 
lese  folds  have  been  subsequently  beveled  off  by  erosion,  the  strata 
ow  occur  as  monoclines,  striking  N.  30°  E.  or  thereabout,  and  usually 
ipping  at  high  angles  (35°  to  60°).  This  condition,  taken  in  coll- 
ection with  the  overturned  character  of  most  of  the  folding,  often 
roduces  outcrops  showing  the  geologically  older  rock  apparently 
verlying  conformably  the  newer  rocks.  This  is  well  shown  in  the 
jction  of  the  National  mine,  where  the  older  Stockbridge  limestone 
pparently  overlies  the  newer  Hudson  schist.  The  section  of  the 
jnenia  mine  shows  several  of  these  typical,  close,  overturned  folds. 
DESCRIPTIONS   OF   BROWN-HEMATITE   MINES. 
The  time  available  for  field  work  in  this  district  was  too  limited 
>  permit  the  writer  to  examine  all  or  eve*i  the  majority  of  the  brown- 
3matite  deposits.  All  the  mines  at  present  operated  were  visited 
id  in  addition  such  unworked  mines  as  from  description  seemed  to 
:omise  results  of  value  in  the  study.  The  mines  visited  are  de- 
ribed  below,  being  taken  up  in  order  from  those  near  AVest  Stock- 
•idgc-Mass.,  on  the  north,  to  the  Pawling,  N.  Y..  mine  on  the  south. 
JLeet  mines. — The  three  openings  known  as  the  Leet  and  Goodrich 
ines  are  located  about  H  miles  west  of  West  Stockbridge,  Mass. 
Iiese  openings  were  extensive,  but  are  now  filled  with  water.  The 
e  body  evidently  lay  on  or  in  the  limestone,  as  no  schist  or  quartz- 
i  is  exposed  anywhere  in  its  vicinity,  and  certainly  none  could  have 
I  purred  in  direct  contact  with  the  ore  body.  The  limestones  strike 
irtheast-southwest  and  dip  to  the  southeast,  varying  considerably 
amount  of  dip — from  15°  to  50°,  the  latter  high  dip  being  that 
evading  near  the  ore  body.  The  exposures  near  the  Leet  mines 
e  very  satisfactory  in  spite  of  the  present  condition  of  the  mines. 
d  prove  conclusively  that  no  schist  or  quartzite  beds  were  con- 
*ned  in  the  localization  of  this  ore  body.  Xo  carbonate  ore  was  seen 
the  writer,  but  Dana  "  states  that  it  occurs  in  the  Leet  mine. 
The  following  partial  analyses  of  ore  from  this  group  of  mines 
i  given  in  the  Tenth  Census,  vol.  15,  p.  86 : 
Analyses  of  iron  ore  from  Leet  mines,  near  West  Stockbridge,  Mass. 
1. 
2. 
•A. 
4. 
tallic  iron 
i ; .  52 
46.65 
40.  71 
47.87 
Pbspliorus  
.  is; 
.174 
.142 
.  1 24 
Pbspliorus  in  100  parts  iron 
.  394 
.  373 
.348 
.".Mil 
"Am.  Jour.  Sci.,  3d  ser.,  vol.  28,  p.  398. 
Bull.  260—05  m 22 
