﻿72 
  Scientific 
  Intelligence. 
  

  

  Connecticut 
  to 
  New 
  York 
  island, 
  that 
  it 
  was 
  accepted 
  as 
  evi- 
  

   dence 
  of 
  Archaean 
  age. 
  Superposition 
  of 
  the 
  later 
  limestone 
  on 
  

   the 
  earlier 
  and 
  subsequent 
  changes 
  may 
  account 
  for 
  the 
  cases 
  of 
  

   apparent 
  passage. 
  Limestone 
  belts 
  have 
  determined 
  the 
  positions 
  

   of 
  the 
  chief 
  valleys 
  of 
  Berkshire 
  ; 
  and 
  in 
  some 
  cases 
  Archaean 
  

   limestone 
  was 
  first 
  in 
  the 
  work. 
  

  

  One 
  of 
  the 
  most 
  comprehensive 
  facts 
  in 
  the 
  geology 
  of 
  Eastern 
  

   America 
  is' 
  the 
  general 
  identity 
  of 
  strike 
  and 
  dip, 
  in 
  associated 
  

   metamorphic 
  or 
  crystalline 
  rocks 
  of 
  Archaean 
  and 
  later 
  time. 
  In 
  

   eastern 
  Berkshire 
  the 
  writer 
  failed 
  to 
  detect 
  the 
  limit 
  between 
  

   the 
  Taconic 
  schists 
  and 
  the 
  Archaean, 
  after 
  several 
  trials 
  ; 
  and 
  the 
  

   same 
  was 
  true 
  for 
  the 
  ridge 
  southwest 
  of 
  Cornwall, 
  Conn., 
  where 
  

   chondroditic 
  limestone 
  occurs 
  ; 
  and 
  also 
  in 
  Putnam 
  County, 
  

   N. 
  Y., 
  where 
  there 
  are 
  Archaean 
  iron 
  ores. 
  In 
  each 
  case 
  the 
  

   quartzyte 
  of 
  the 
  Taconic 
  series 
  was 
  followed 
  by 
  gneiss 
  of 
  like 
  

   dip 
  and 
  this 
  by 
  other 
  gneisses, 
  and 
  the 
  Archaean 
  limit 
  was 
  not 
  dis- 
  

   covered. 
  The 
  question 
  was 
  left 
  for 
  a 
  later 
  and 
  more 
  thorough 
  

   investigation, 
  which 
  has 
  not 
  been 
  made. 
  It 
  is 
  now 
  in 
  other 
  

   hands, 
  with 
  a 
  promise 
  of 
  success. 
  Taking 
  the 
  evidence 
  which 
  

   strike 
  and 
  dip 
  afford 
  as 
  of 
  itself 
  conclusive, 
  it 
  is 
  probable 
  that 
  

   nearly 
  all 
  the 
  so-called 
  Archaean 
  rocks 
  of 
  the 
  Appalachian 
  Pro- 
  

   taxis 
  could 
  be 
  proved 
  to 
  be 
  Paleozoic. 
  The 
  problem 
  which 
  Mr. 
  

   Nason 
  has 
  investigated 
  in 
  Northern 
  New 
  Jersey 
  is 
  one 
  of 
  great 
  

   importance 
  and 
  difficulty. 
  It 
  is 
  a 
  part 
  of 
  a 
  wider 
  problem 
  — 
  that 
  

   embracing 
  all 
  the 
  Archaean 
  schists 
  and 
  ore-beds 
  of 
  New 
  Jersey. 
  

  

  J. 
  D. 
  D. 
  

  

  2. 
  Two 
  belts 
  of 
  fossiliferous 
  black 
  shale 
  in 
  the 
  Triassic 
  for) 
  na- 
  

   tion 
  of 
  Connecticut, 
  by 
  W. 
  M. 
  Davis 
  and 
  S. 
  Ward 
  Lopek. 
  

   16 
  pp. 
  8vo. 
  (Bull. 
  Geol. 
  Soc. 
  America, 
  vol. 
  ii, 
  April, 
  1391.) 
  — 
  

   Professor 
  Davis 
  commences 
  his 
  paper 
  with 
  a 
  summary 
  of 
  his 
  

   conclusions 
  respecting 
  the 
  Triassic 
  formation 
  in 
  the 
  vicinity 
  of 
  

   Meriden, 
  Conn., 
  and 
  its 
  associated 
  trap. 
  His 
  list 
  of 
  papers 
  

   mentions 
  five 
  subsequent 
  to 
  the 
  one 
  published 
  in 
  this 
  Journal 
  in 
  

   1886, 
  with 
  the 
  title 
  "Triassic 
  formation 
  of 
  the 
  Connecticut 
  

   Valley." 
  Under 
  the 
  same 
  title, 
  he 
  published 
  a 
  fuller 
  paper 
  in 
  

   the 
  Report 
  of 
  the 
  U. 
  S. 
  Geological 
  Survey 
  for 
  1888. 
  Since 
  then 
  

   the 
  following 
  have 
  appeared 
  : 
  " 
  The 
  ash-bed 
  at 
  Meriden 
  and 
  its 
  

   structural 
  relations," 
  in 
  the 
  Proceedings 
  of 
  the 
  Meriden 
  Scientific 
  

   Association 
  for 
  1889 
  ; 
  "On 
  the 
  Topographic 
  development 
  of 
  the 
  

   Triassic 
  formation 
  of 
  the 
  Connecticut 
  Valley," 
  in 
  vol. 
  xxxvii 
  of 
  

   this 
  Journal, 
  1889; 
  ''On 
  the 
  faults 
  near 
  Meriden, 
  and 
  on 
  the 
  

   intrusive 
  and 
  extrusive 
  trap 
  sheets 
  of 
  the 
  Connecticut 
  Valley," 
  in 
  

   the 
  Bulletin 
  of 
  the 
  Museum 
  of 
  Comparative 
  Zoology 
  for 
  1889. 
  

   In 
  the 
  present 
  paper 
  the 
  following 
  general 
  conclusions 
  are 
  stated. 
  

  

  Three 
  overflow 
  trap-sheets 
  in 
  the 
  vicinity 
  of 
  Meriden 
  are 
  now 
  

   well 
  made 
  out 
  ; 
  the 
  first, 
  thin 
  and 
  amygdaloidal, 
  the 
  second, 
  

   thick 
  and 
  massive 
  and 
  sometimes 
  a 
  double 
  flow, 
  the 
  third, 
  thin 
  

   like 
  the 
  first. 
  Beside 
  these 
  overflows 
  one 
  great 
  intrusive 
  sheet, 
  

   exists, 
  and 
  apparently 
  several 
  smaller 
  ones. 
  The 
  great 
  sheet, 
  as 
  

   implied 
  in 
  a 
  note, 
  is 
  that 
  of 
  West 
  Rock, 
  of 
  the 
  New 
  Haven 
  re- 
  

  

  