394  PRE-CAMBRIAN    GEOLOGY   OF    NORTH    AMERICA. 
155  Report  of  geological  observations  made  in  northeastern  Minnesota  during 
the  season  of  18SG,  by  Alexander  Winchell.  Fifteenth  Ann.  Kept.  Geol.  and 
Nat.  Hist.  Survey  Minnesota,  for  1886,  pp.  5-207. 
156  Geological  report  of  N.  H.  Winchell.     Idem,  pp.  209-399,  with  a  map. 
157  Report  of  N.  II.  Winchell.  Sixteenth  Ann.  Rept.  Geol.  and  Nat.  Hist  Survey 
Minnesota,  for  1887,  pp.  13-129. 
158  Report  of  Alexander  Winchell.  Idem,  pp.  133-391.  See  also  The  uncon- 
formities of  the  Animikie  in  Minnesota.  Am.  Geologist,  vol.  1,  1888,  pp.  14-24. 
Two  systems  confounded  in  the  Huronian.  Idem,  vol.  3,  1889,  pp.  212-214, 
339-340.  Systematic  results  of  a  field  study  of  the  Archean  rocks  of  the  North- 
west. Proc.  Am.  Assoc.  Adv.  Sci.,  37th  meeting,  1889,  p.  205.  The  geological 
position  of  the  Ogishki  conglomerate.     Idem,  38th  meeting,  1890,  pp.  234-235. 
159  Report  of  II.  V.  Winchell.  Sixteenth  Ann.  Rept.  Geol.  and  Nat.  Hist. 
Survey  Minnesota,  for  1S87,  pp.  395-162,  with  map. 
wo  rp|;ie  distribution  of  the  granites  of  the  Northwestern  States,  and  their  gen- 
eral lithologic  characters,  by  C.  W.  Hall.  Proc.  Am.  Assoc.  Adv.  Sci.,  37th 
meeting,  1889,  p.  189. 
161  Report  of  N.  H.  WTinchell.  Seventeenth  Ann.  Rept.  Geol.  and  Nat.  Hist. 
Survey  Minnesota,  for  1888,  pp.  5-74.  See  also  The  Animikie  black  slates  and 
quartzites,  and  the  Ogishki  conglomerate  of  Minnesota,  the  equivalent  of  the 
"  Original  Huronian."  Am.  Geologist,  vol.  1,  1888,  pp.  11-14.  Methods  of 
stratigraphy  in  studying  the  Huronian.     Idem,  vol.  4,  1889,  342-357. 
162  Report  of  field  observations  made  during  the  season  of  1888  in  the  iron 
regions  of  Minnesota,  by  H.  V.  Winchell.  Seventeenth  Ann.  Rept.  Geol.  and 
Nat.  Hist.  Survey  Minnesota,  for  1888,  pp.  77-145.  See  also  The  diabasic 
schists  containing  the  jaspilite  beds  of  northeastern  Minnesota.  Am.  Geologist, 
vol.  3,  1889,  pp.  18-22. 
163  Report  of  geological  observations  made  in  northeastern  Minnesota  during 
the  summer  of  1888,  by  U.  S.  Grant.  Seventeenth  Ann.  Rept.  Geol.  and  Nat. 
Hist.  Survey  Minnesota,  for  188S,  pp.  149-215. 
164  Conglomerates  inclosed  in  gneissic  terranes,  by  Alexander  Winchell.  Am. 
Geologist,  vol.  3,  1S89,  153-165,  256-262. 
165  Some  thoughts  on  eruptive  rocks,  with  special  reference  to  those  of  Minne- 
sota, by  N.  H.  Winchell.  Proc.  Am.  Assoc.  Adv.  Sci.,  37th  meeting,  1888,  pp. 
212-221. 
166  The  Stillwater,  Minn.,  deep  well,  by  A.  D.  Meads.  Am.  Geologist,  vol.  3, 
1889,  p.  342. 
167  On  a  possible  chemical  origin  of  the  iron  ores  of  the  Keewatin  in  Minne- 
sota, by  N.  H.  and  H.  V.  Winchell.  Idem,  vol.  4,  1889,  pp.  291-300,  382-386. 
Also  Proc.  Am.  Assoc.  Adv.  Sci.,  38th  meeting,  1890,  pp.  235-242. 
168  Some  results  of  Archean  studies,  by  Alexander  Winchell.  Bull.  Geol.  Soc. 
America,  vol.  1,  1890,  pp.  357-394. 
169  Tlle  T/aconic  iron  ores  of  Minnesota  and  of  western  New  England,  by  N.  H. 
and  H.  V.  Winchell.    Am.  Geologist,  vol.  6,  1890,  pp.  263-274. 
170  Record  of  field  observations  in  1888  and  1889,  by  N.  H.  Winchell.  Eight- 
eenth Ann.  Rept.  Geol.  and  Nat.  Hist.  Survey  Minnesota,  for  1889,  pp.  7^7. 
171  The  iron  ores  of  Minnesota,  by  N.  H.  and  H.  V.  Winchell.  Bull.  Geol.  and 
Nat.  Hist.  Survey  Minnesota  No.  6,  1891,  pp.  430,  with  a  geological  map. 
172  Geological  age  of  the  Saganaga  syenite,  by  Horace  V.  Winchell.  Am.  Jour. 
Sci.,  3d  ser.,  vol.  41,  1891,  pp.  386-390. 
173  Notes  on  the  petrography  and  geology  of  the  Akeley  Lake  region,  in  north- 
eastern Minnesota,  by  W.  S.  Bayley.  Nineteenth  Ann.  Rept.  Geol.  and  Nat. 
Hist.  Survey  Minnesota,  for  1890,  pp.  193-210. 
