﻿Stratigraphy 
  of 
  Eastern 
  New 
  Mexico. 
  107 
  

  

  probably 
  limited 
  on 
  the 
  west 
  near 
  the 
  summit 
  divide 
  of 
  

   the 
  Santa 
  Fe 
  Range, 
  east 
  of 
  the 
  town 
  of 
  Santa 
  Fe, 
  by 
  a 
  

   great 
  fault, 
  doubtless 
  the 
  northern 
  continuation 
  of 
  the 
  

   Apache 
  Canon 
  fault. 
  The 
  thick 
  series 
  of 
  Magdalena 
  at 
  

   the 
  headwaters 
  of 
  the 
  Pecos 
  River 
  dips 
  westward, 
  while 
  

   the 
  summit 
  divide 
  and 
  most 
  of 
  the 
  western 
  flanks 
  of 
  the 
  

   Santa 
  Fe 
  Range 
  are 
  composed 
  of 
  crystallines. 
  In 
  the 
  Los 
  

   Pinos 
  and 
  southern 
  Manzano 
  ranges 
  the 
  Magdalena 
  is 
  

   about 
  1850 
  feet 
  thick, 
  consisting 
  mainly 
  of 
  limestones 
  

   with 
  some 
  sandstones. 
  There 
  are 
  beds 
  of 
  arkose 
  in 
  the 
  

   lower 
  part 
  of 
  the 
  section 
  there. 
  The 
  actual 
  base 
  was 
  not 
  

   found, 
  because 
  of 
  faulting. 
  In 
  the 
  San 
  Andreas 
  and 
  

   Sacramento 
  mountains 
  of 
  the 
  southern 
  region, 
  the 
  Mag- 
  

   dalena, 
  about 
  1250 
  feet 
  thick, 
  is 
  almost 
  entirely 
  thick- 
  

   bedded 
  limestones, 
  but 
  some 
  clays 
  and 
  sandstones 
  are 
  

   found 
  near 
  the 
  top, 
  being 
  apparently 
  thicker 
  towards 
  the 
  

   north. 
  

  

  The 
  fauna 
  of 
  the 
  Magdalena, 
  so 
  far 
  as 
  known, 
  is 
  in 
  the 
  

   main 
  composed 
  of 
  brachiopods 
  belonging 
  to 
  the 
  common 
  

   later 
  anthracolithic 
  genera. 
  Crinoid 
  stems 
  are 
  numerous, 
  

   Fusulina, 
  surprisingly 
  rare, 
  is 
  found 
  near 
  the 
  top 
  and 
  

   bottom. 
  Bryozoa 
  and 
  a 
  few 
  genera 
  of 
  corals 
  are 
  rela- 
  

   tively 
  abundant. 
  Several 
  species 
  of 
  trilobites 
  were 
  

   found. 
  Molluscs 
  are 
  apparently 
  not 
  very 
  abundant, 
  be- 
  

   ing 
  represented 
  principally 
  by 
  pelecypods. 
  No 
  ammo- 
  

   noids 
  were 
  found, 
  but 
  quite 
  a 
  number 
  of 
  nautiloids. 
  

   Cochliodonts 
  alone 
  represent 
  the 
  vertebrates. 
  Lepido- 
  

   dendron 
  is 
  found 
  in 
  the 
  lower 
  beds. 
  Although 
  a 
  fauna 
  

   of 
  perhaps 
  150 
  species 
  was 
  collected, 
  it 
  has 
  not 
  yet 
  been 
  

   studied. 
  As 
  Chonetes 
  mesolobus 
  was 
  discovered 
  near 
  

   the 
  base 
  and 
  a 
  large 
  Pseudomonotis 
  near 
  the 
  top, 
  the 
  

   time 
  represented 
  by 
  the 
  deposits 
  includes 
  the 
  upper 
  part 
  

   of 
  the 
  Lower 
  Coal 
  Measures 
  and 
  at 
  least 
  the 
  lower 
  part 
  

   of 
  the 
  Upper 
  Coal 
  Measures. 
  Neither 
  the 
  earliest 
  nor 
  

   the 
  uppermost 
  Pennsylvanian 
  appears 
  to 
  be 
  represented 
  

   in 
  the 
  Magdalena. 
  

  

  Manzano 
  Group. 
  — 
  This 
  group 
  of 
  rocks 
  has 
  been 
  named, 
  

   subdivided, 
  and 
  described 
  by 
  Willis 
  T. 
  Lee 
  1 
  and 
  the 
  dis- 
  

   cussion 
  here 
  will 
  be 
  almost 
  altogether 
  limited 
  to 
  the 
  

   regions 
  not 
  visited 
  by 
  him. 
  The 
  group 
  was 
  divided 
  by 
  

   Lee 
  into 
  three 
  formations 
  : 
  the 
  Abo 
  red 
  beds, 
  mainly 
  of 
  

   sandstone, 
  but 
  with 
  considerable 
  shales 
  and 
  clays 
  and 
  a 
  

  

  ^ee, 
  Willis 
  T.: 
  The 
  Manzano 
  Group 
  of 
  the 
  Rio 
  Grande 
  Valley, 
  New 
  

   Mexico. 
  U. 
  S. 
  Geol. 
  Surv., 
  Bull. 
  389, 
  1909. 
  

  

  