802  PRE-CAMBRIAN    GEOLOGY   OF   NORTH   AMERICA. 
strikes  and  dips  of  such  remnants  are  carefully  noted  and  platted 
on  the  map,  they  are  invariably  consistent  among  themselves  in  in- 
dicating a  definite  structure  of  the  whole,  and  accord  with  the  struc- 
ture that  may  be  indicated  by  neighboring  schists  and  other  masses 
of  undoubted  bedded  rocks. 
As  in  the  derived  sedimentaries  is  found  debris  from  the  crystal- 
line rocks,  it  is  concluded  that  the  folding  which  affected  the  meta- 
morphism  is  older  than  that  which  has  upturned  the  sedimentary 
strata.  It  is  not  supposed  that  sufficient  heat  was  necessary  to  cause 
dry  fusion,  but  aqueo-igneous  fusion. 
While  it  is  exceedingly  difficult  to  obtain  structural  results,  a  map 
of  the  eastern  slope  of  the  Front  Range  is  presented.  The  portion  in 
which  the  structure  is  most  clearly  made  out  is  that  south  of  South 
Clear  Creek  and  having  Mount  Evans  as  its  culminating  point.  The 
granite  of  Mount  Evans  occupies  as  low  a  geological  position  as  any 
rocks  in  the  range.  No  special  facts  bearing  on  the  equivalency  of  the 
metamorphic  series  to  any  of  the  divisions  of  the  Archean  of  the 
East  were  observed. 
Peale,03  in  1874,  describes  several  sections  in  the  Front  Range  at 
Pleasant  Park,  Glen  Eyrie,  Bergen  Park,  and  Trout  Creek,  in  all  of 
which  the  granite  underlies  the  fossiliferous  series.  On  the  South 
Platte,  at  the  change  from  the  sandstone  to  the  granite  the  former 
contains  fragments  of  unchanged  granite.  In  other  places  the  sand- 
stone appears  to  pass,  by  gradations,  into  the  granite.  Pikes  Peak 
is  composed  of  fine-grained  reddish  granite,  the  origin  of  which, 
whether  eruptive  or  metamorphic,  is  a  question.  On  the  road  from 
Colorado  Springs  to  South  Park  is  a  granitic  ridge  which  seems  to 
be  thrown  up  through  the  coarse  beds  which  lie  about  it.  In  the 
range  of  the  South  Park  several  sections  of  the  fossiliferous  series 
are  described  which  rest  upon  granite  or  gneiss.  At  Georgia  Pass 
eruptive  granite  forms  the  peak,  while  black  micaceous  gneiss  is  at 
the  base  of  the  series,  there  lying  between  the  two  slates  and  quartz- 
ites.  At  several  of  the  sections  given  the  basal  layer  of  the  series  is 
a  quartzite. 
Endlich,04  in  1874,  describes  granite  as  forming  the  heaviest  mass 
of  rock  north  and  east  of  the  Arkansas  and  south  of  a  line  running 
east  and  west  G  miles  south  of  Pikes  Peak.  On  Cottonwood  Creek  the 
rock  resembles  a  gneiss.  Resting  immediately  upon  the  granite  are 
the  Silurian,  characterized  by  but  a  few  fossils,  and  the  well-known 
quartzitic  formations.  The  granite  of  this  area  is  the  oldest  found 
in  the  region. 
Stevenson,65  in  1875,  states  that  metamorphic  rocks  occur  in  the 
Front  Range.  On  the  North  Fork  of  the  South  Platte  the  schists  are 
much  contorted.  The  schists  near  Bailey's  ranch  contain  rudely  oval 
nodules  of  quartz  and  feldspathic  granite,  which  in  several  localities 
