Periods 



Strata 



Organic History 



Long period of disturbance during which the Appalachian and other regions were elevated, largel 

 denuded and some of them sunk again to receive the Mesozoic deposits. 



Permian 



Carboniferous 



End of Trilohites, Gonia 

 tites, Eurypterids and Pro 



cluctus 

 Proterosaurus. 



1000 Feet Denudation 



5,000,000 Years 



Labyrinthodonts Limuloid 

 Sauroid Fishes Macrou- 

 Scaled Amphib- rans 



ians Insects 



Hybodont Sharks Ortliop- 

 Snails ters and 



Myriapods Arachnid 



Ferns Conifers Lycopodii 

 Unconformability 



Sub-Carboniferous 



Cestraciont Sharks (Clado 



clus, Ac.) 



Reptile Tracks (Amphibian 

 End of all the old genera o 



Trilobites 



1,000 Feet Denudation 



.5,000,000 Years 



Catskill 



Chemung 



Hamilton 



Corniferous 



Oriskany 



Helderberg 



Salina 



Niagara 



Holoptychius (Ganoid) 

 Telerpeton 

 Salamandroid Amphibian 



No Vertebrates 

 Few New Shell Fish 

 Noeggerathia (Sea Weed) 



Calumites ___ 



Insects (Neuropters), Gonia 

 tites (Ammonites), (No Ver- 

 tebrates), Lepidodendroii 

 and Sigillaria 



Ptericthys (Ganoid), Sela 

 chians, Ganoids, Pentremites 

 (Crinoids), Productus, Cauda 

 Galli (Sea Weeds) Desmids 



New Species 

 End of Cystids 



Eurypterus remipes (Crus- 

 tacean) 

 Tentaculites 



Few New Species 



Brachiopod Pentamerus (Or- 

 moceras ends), New Fucoid 

 Rusophycus Bilobatus 



Period of elevation and denudation to the amount of 2,000 feet, requiring 10,000,000 years. 



2,250 species become extinct. 



Hudson 



Trenton 



Potsdam 



New Species of Those Below 



Nautilus, Cryptoceras, Star- 

 fish, Ormoceras, Cyrtoceras, 

 Cystids, Corals, Maclurea 



Bryozoans, Conchifers, Os- 

 tracoids, Orthis, Rhynconel- 

 la, Lituites, OrLhoceras, Tri- 

 lobite, Marine Gasteropod, 

 Lingula Pteropods, Worms, 

 Discina, Crinids, Graptolites 

 Sponges and Rhizopods 

 Fucoid Sea Weed 



iterval, iu which the Eozoic rocks were raised slowly out of the water, planed off 6.000 feet, and 

 sunk again to receive the Silurian deposits. (6,000x5,000) 30,000,000 years. 



Huronian 



Laurentian 





V >VMC- ' ^ V V< A >LJ ^\ 



/* VN /^ > c^ t ^x^ ,'Y *' 



Graphite 

 Eozoon 



Iron Ore Deposits 

 Algae 



FlGUKK 70. 



