ENGLISH AND AMERICAN SILURIC EQUIVALENTS 



251 







Siluric or Ontario. 





e 



CD 

 < 

 O 



a 







Lower Silurian. 



Upper Silurian. 



O 



CD 



CO 

 P 



P. 



CO 







CD 



Wales and Shroi'Shire. 



Upper Silurian, Murchison, 

 1854. 



(Siluria, 1854, page 102.) 



Pentamerixs limestone on 

 the summit of the Cara- 

 doc sandstone. 



Wenlock limestone. 



Wenlock shale. 



Wenlock shale, with lower, 

 . or Woolhope limestone. 



Upper Ludlow, including 

 Tilestones. 



Middle Ludlow or Aymes- 

 try limestone. 



Lower Ludlow. 



o 



CD 

 CO 



P 

 3 



o 



O 

 i-t 



p , 



o 

 < 

 o' 



Tarannon shales, 1,000 to' 

 1,500 feet. 



Upper Llandovery rocks 

 and May Hill sandstone, 

 800 feet. 



Lower Llandovery rocks, 

 600 to 1,500 feet. 



Wenlock, or Dudley lime-" 

 stone, 300 feet. 



Wenlock shale, up to 2,300 

 feet. 



Woolhope, or Barr, lime- 

 stone and shale, 150 feet. 



f Tilestones, 300 feet. 



| Downton Castle sandstone, 



-j 90 feet. 



1 Ledbury shales, 270 feet. 



[, Upper Ludlow rock, 140 feet. 



Aymestry limestone, up to 

 40 feet. 



Lower Ludlow rock, 350 to 

 700 feet. 



S3 

 p 

 a) 



CD 

 O 



O 



CD 

 P 



CO 

 P 



P, 



CO 

 ct- 







3 

 CD 



Wales and Shropshire. 



Upper Silurian, Geikie, 1893. 



(Text-book of Geology, page 753.) 



Llandoveiy group. 



Wenlock group. 



Ludlow group. 





Llandovery 

 or Valentian. 



Wenlock or 

 Salopian. 



Ludlow or Clunian 

 (Downtonian). 



O 



K 

 Pi 



CD 



CO 



P 



CO 







CD 



Wales. 



Upper Silurian, Kayser, 1893. 



(Text-book of Comparative Geology, 

 page 64.) 



'Tarannon shales. 



May Hill sandstone = Upper 

 Llandovery. 



Lower Llandovery beds. 



'Lower Ludlow beds. 



Wenlock limestone. 



Wenlock shale and Woolhope 

 limestone. 



'Ledbury shales. "j Passage 

 \ beds or 

 Downton sandstone, j Tilestones. 



Upper Ludlow beds, including 

 the bone bed. 



.Aymestry limestone. 



P 3" 

 «'P 



Paleontaric or 

 Oswegan. 



Mesontaric or 

 Niagaran. 



Neontaric or 

 Cayugan. 



b 



CD 

 < 

 O 



3 

 0" 





9> 

 pg 

 2.p 

 3 £ 



p CD 



3 ^ 



£p 

 |~j 



3 s! 



2c 



^0 



CO 

 CD O 

 O.C 

 CO »-j 

 v_-CO 



3* 



CD 

 CD 



Medina sandstone. "1 300 



I to 

 Oneida conglomerate (includes [1,800 

 Shawangunk). J feet. . 



Manlius, or "Tentaculite limestone,"" 

 50 to probably 300 feet or more. 



Rondout, or " Waterlime." "] 



| 300 



Salina beds. Shales and marlites I to 

 (Salina group), with Water- f 1,600 

 lime zones generally near the | feet, 

 top (" Waterlime group"). i^- j 



^^-^—~""' Gnelph limestone, 160" 

 feet (probably in part is the 

 marine facies of the Salina shales). 



Waldron shale, 4 to 20 feet. 



Lockport limestone, 4 to 300 feet (in- 

 cludes the " Coralline limestone") 



Rochester shale, 80 feet. 



Clinton beds, 50 to 1,000 feet. 



O 

 O 



CD 



v; 

 3 



p 



CO 







hH 



O 



O CD 



CD 



CD 

 3 



P 



3 



CD 



in 



3 



CD 



North America. 

 Siluric or Ontario equivalents, Schuchert. 



Anticosti divif 



dons, 1 to 4, 1,350 feet. 



A typical marine 

 fauna is gener- 

 ally absent. 



to 



Q 

 05 



