THE  GEOLOGICAL  RESURVEY  OF  THE  CRIPPLE  CREEK  DIS- 
TRICT, COLORADO. 
By  Waldemar  Lindgren  and  Frederick  Leslie  Ransome. 
INTRODUCTION. 
The  Cripple  Creek  gold  deposits  were  discovered  in  1801.  Shortly 
afterwards,  in  1894,  an  examination  of  the  new  district  was  under- 
taken by  the  United  States  Geological  Survey,  Mr.  Whitman  Cross 
having  charge  of  geology  and  petrography,  and  Mr.  R.  A.  F.  Penrose, 
jr.,  undertaking  the  examination  of  the  mines.  Their  report,  accom- 
panied by  a  geological  map,  was  published  in  the  Sixteenth  Annual 
Report  of  the  Geological  Survey,  Part  II,  pages  1-207,  and  has  for 
the  last  ten  years  served  as  a  useful  and  accurate  geological  guide  to 
mining  operations. 
W  ith  the  astonishingly  rapid  development  of  the  Cripple  Creek 
nines  the  opportunities  for  geological  study  multiplied,   revealing 
treat  complexity  of  vein  phenomena   and   stimulating  a   desire  for 
further  investigation,  particularly  with  a  view  of  obtaining  some 
Evidence  as  to  the  persistence  of  the   veins  in  depth.     This  desire 
found  expression  in  a  request  by  citizens  of  Colorado  for  a  reexami- 
nation of  the  district  by  the  United  States  Geological  Survey  and  in 
In  offer  of  cooperation,  whereby  the  cost  would  be  equally  divided 
>etween  the  State  of  Colorado  and  the  National  Survey.     The  neces- 
sary  amount   having   been   subscribed    in   Cripple   Creek,   Colorado 
Springs,  and  Denver,  the  State  contribution  was  put  in  the  hands  of 
h\  John  Wellington  Finch,  State  geologist  of  Colorado,  and  by  him 
isbursed.     The  cordial  thanks  of  the  geologists  in  charge  of  the 
work  are  due  to  Mr.  Finch  for  his  hearty  and  efficient  cooperation. 
The  geological  and  mining  work  was  undertaken  jointly  by  the 
uthors  of  the  preliminary  report."     The  examination  began  in  June, 
p03,  and,  with  some  interruptions,  due  to  various  causes,  the  field 
ork   was   concluded   in   April,    1904.     Practically   every   accessible 
line  in  the  district  was  examined  in  greater  or  less  detail.     Mr.  L.  C. 
"Lindgren,  W.,  and  Ransome,  F.  L.,  Report   of  progress  in  the-  geological   resurvey  of 
e  Cripple  Creek  district,  Colorado:    Bull.   U.   S.  Geol.   Survey   No.   254,    U»<i4. 
85 
