396  PRE-CAMBRIAN    GEOLOGY   OF    NORTH   AMERICA. 
194  The  geological  structure  of  the  western  part  of  the  Vermilion  range,  Min- 
nesota, by  H.  L.  Smyth  and  J.  Ralph  Finlay.  Trans.  Am.  Inst.  Min.  Eug., 
vol.  25,  1895,  pp.  595-645. 
195  The  Koochiching  granite,  by  Alexander  Winchell.  Am.  Geol.,  vol.  20,  1897, 
pp.  293-299. 
190  Some  new  features  in  the  geology  of  northeastern  Minnesota,  by  N.  H. 
Winchell.    Am.  Geol.,  vol.  20,  1897,  pp.  41-51. 
197  The  origin  of  the  Archean  igneous  rocks,  by  N.  H.  Winchell.  Proc.  Am. 
Assoc.  Adv.  Sci.,  vol.  47,  1898,  pp.  303,  304  (abstract).  Also  Am.  Geol.,  vol.  22, 
1898,  pp.  299-310. 
198  Some  resemblances  between  the  Archean  of  Minnesota  and  of  Finland,  by 
N.  H.  Winchell.    Am.  Geol.,  vol.  21,  1898,  pp.  222-229. 
199  The  significance  of  the  fragmental  eruptive  debris  at  Taylors  Falls,  Minn., 
by  N.  H.  Winchell.    Am.  Geol.,  vol.  22,  189S,  pp.  72-78. 
i00The  oldest  known  rock,  by  N.  H.  Winchell.  Proc.  Am.  Assoc.  Adv.  Sci., 
vol.  47,  1898,  pp.  302,  303    (abstract). 
201  Sketch  of  the  geology  of  the  eastern  end  of  the  Mesabi  iron  range  in  Min- 
nesota, by  U.  S.  Grant.  Engineers'  Year  Book,  Univ.  Minnesota,  1898,  pp.  49- 
62.     With  sketch  map. 
202  The  oreoi0gy  of  Minnesota,  by  N.  H.  Winchell,  IT.  S.  Grant,  James  E.  Todd, 
Warren  Fpham,  and  H.  V.  Winchell.  Final  Kept.  Geol.  and  Nat.  Hist.  Survey 
Minnesota,  vol.  4,  1899,  pp.  630.  With  31  geological  plates.  Structural  geology 
of  Minnesota,  by  N.  H.  Winchell,  assisted  by  U.  S.  Grant.  Idem,  vol.  5,  1900, 
pp.  1-80,  972-1000. 
Vol.  4  contains  an  account  of  detailed  field  work  in  northeastern  Minnesota, 
with  incidental  discussion  of  general  problems.  The  area  is  treated  by  counties 
and  smaller  arbitrary  geographical  divisions,  in  the  description  of  which  several 
men  have  taken  part.  This  manner  of  treatment  leads  to  repetition  in  the  dis- 
cussion of  the  general  geological  features,  and  in  many  cases  it  is  extremely 
difficult  to  correlate  the  facts  recorded  in  the  different  sections.  Vol.  5  con- 
tains an  account  of  the  general  structural  geology  of  the  State,  based  on  the 
detailed  work  described  in  vol.  4.  Grant's  views,  as  indicated  in  the  detailed 
descriptions  of  special  areas,  in  some  cases  differ  somewhat  widely  from  those  of 
Winchell. 
03  The  gneisses,  gabbro  schists,  and  associated  rocks  of  southwestern  Minne- 
sota, by  C.  W.  Hall.  Bull.  U.  S.  Geol.  Survey  No.  157,  1899,  pp.  131.  With 
geological  maps. 
2t,i  Mineralogical  and  petrographic  study  of  the  gabbroid'  rocks  of  Minnesota, 
and  more  particularly  of  the  plagioclastites,  by  Alexander  Winchell.  Am. 
Geologist,  vol.  26,  1900,  pp.  153-162,  with  geological  sketch  map  of  northeastern 
Minnesota. 
205  Unpublished  field  notes,  summer  of  1900,  by  C.  R.  Van  Hise  and  J.  Morgan 
Clements. 
200  Geol.  and  Nat.  Hist.  Survey  Minnesota,  vol.  6,  1900-1901. 
207  Keewatin  area  of  eastern  and  central  Minnesota,  by  C.  W.  Hall.  Bull. 
Geol.  Soc.  America,  vol.  12,  1901,  pp.  343-376,  pis.  29-32. 
208  Keweenawan  area  of  eastern  Minnesota,  by  C.  W.  Hall.  Bull.  Geol.  Soc. 
America,  vol  12,  1901,  pp.  313-342,  pis.  27-28. 
209  Sketch  of  the  iron  ores  of  Minnesota,  by  N.  H.  Winchell.  Am.  Geologist, 
vol.  29,  1902,  pp.  154-162. 
210  The  Mesabi  iron-bearing  district  of  Minnesota,  by  C.  K.  Leith.  Mon.  U.  S. 
Geol.  Survey,  vol.  43,  1903,  pp.  316. 
211  The  Vermilion  iron-bearing  district  of  Minnesota,  by  J.  Morgan  Clements. 
Mon.  U.  S.  Geol.  Survey,  vol.  45,  1903,  pp.  463. 
