﻿lOi 
  C. 
  L. 
  Baker 
  — 
  Contributions 
  to 
  the 
  

  

  section 
  of 
  earlier 
  Paleozoic 
  strata 
  overlies 
  unconform- 
  

   ably 
  the 
  Basement 
  Complex 
  of 
  various 
  crystalline 
  rocks. 
  

   Proceeding 
  northward 
  in 
  the 
  San 
  Andreas 
  Mountains, 
  

   the 
  earlier 
  Paleozoic 
  formations 
  are 
  cut 
  out 
  one 
  by 
  one 
  

   in 
  descending 
  order 
  by 
  pre-Pennsylvanian 
  erosion 
  until 
  

   the 
  basal 
  strata 
  of 
  the 
  Magdalena 
  group 
  of 
  the 
  Pennsyl- 
  

   vanian 
  rest 
  directly 
  upon 
  the 
  Basement 
  Complex 
  of 
  the 
  

   north 
  end 
  of 
  the 
  San 
  Andreas 
  Range. 
  

  

  Anthracolithic 
  Sedimentary 
  Rocks. 
  — 
  The 
  anthracolith- 
  

   ic 
  strata 
  of 
  eastern 
  New 
  Mexico 
  are 
  divided 
  into 
  four 
  dis- 
  

   tinct 
  depositional 
  assemblages, 
  separated 
  each 
  from 
  the 
  

   other 
  and 
  from 
  the 
  rocks 
  below 
  and 
  above 
  by 
  well-marked 
  

   unconformities. 
  Although 
  the 
  continuity 
  is 
  intercepted 
  

   by 
  these 
  epochs 
  of 
  erosion, 
  during 
  which 
  the 
  total 
  origi- 
  

   nal 
  thicknesses 
  were 
  greatly 
  reduced, 
  there 
  yet 
  remains 
  

   a 
  maximum 
  thickness 
  of 
  *over 
  11,000 
  feet 
  of 
  anthracolithic 
  

   sediments. 
  The 
  Mississippian 
  of 
  Kinderhook 
  and 
  possi- 
  

   bly 
  of 
  Burlington 
  age 
  lies 
  at 
  the 
  base, 
  followed 
  by 
  the 
  

   great 
  depositional 
  groups 
  of 
  the 
  Magdalena, 
  Manzano, 
  

   and 
  the 
  Guadalupian-Pecos 
  Valley 
  red 
  beds, 
  in 
  upward 
  

   succession. 
  During 
  the 
  time 
  of 
  deposition 
  of 
  all 
  three 
  of 
  

   the 
  later 
  anthracolithic 
  groups, 
  seas 
  of 
  clearer 
  water 
  lay 
  

   to 
  the 
  south 
  and 
  the 
  west, 
  in 
  which 
  directions 
  limestones 
  

   very 
  largely 
  replace 
  terrigenous 
  sediments 
  of 
  the 
  north 
  

   and 
  the 
  east. 
  

  

  Mississippian. 
  — 
  The 
  following 
  section 
  of 
  strata 
  of 
  Mis- 
  

   sissippian 
  age 
  was 
  measured 
  in 
  the 
  vicinity 
  of 
  Little 
  

   Agua 
  Chiquita 
  Creek 
  in 
  the 
  southern 
  Sacramento 
  Moun- 
  

   tains 
  : 
  

  

  Base, 
  resting 
  on 
  Upper 
  Devonian 
  strata. 
  

  

  1. 
  Blackish 
  brown 
  crystalline 
  limestone, 
  either 
  phos- 
  

  

  phatic 
  or 
  bituminous, 
  with 
  dark 
  brown 
  chert 
  in 
  

   lenticular 
  layers 
  forming 
  about 
  one 
  half 
  of 
  the 
  

   member. 
  Limestone 
  full 
  of 
  crinoicl 
  stems 
  14' 
  

  

  2. 
  Covered 
  6' 
  

  

  3. 
  Thin-bedded, 
  fine-grained, 
  gray, 
  argillaceous 
  lime- 
  

  

  stone, 
  with 
  nodular 
  chert. 
  Small 
  complete 
  crinoid 
  

   found 
  23 
  feet 
  above 
  base 
  50' 
  

  

  4. 
  Fossiliferous 
  dark 
  blue-gray 
  limestone, 
  with 
  chert 
  

  

  nodules. 
  Some 
  of 
  the 
  fossils 
  silicified; 
  fossils 
  

   mainly 
  brachiopods. 
  The 
  beds 
  average 
  about 
  9 
  

   inches 
  thick. 
  This 
  member 
  forms 
  a 
  conspicuous 
  

   cliff 
  in 
  the 
  San 
  Andreas 
  Mountains 
  further 
  west. 
  

   Member 
  about 
  one 
  half 
  chert 
  100' 
  

  

  