684 



REPORT OF NATIONAL MUSEUM, 1904. 

 Development of Geological Column — Continued. 



Phillips, 1855. 



Dana, 1862. 



. N 



OS O 



"2'S 



■3| 



-■; 





Post-Glacial. 



Glacial. 



Pre-Glacial. 



Crag. 



Fluvio-Marine. 



London clay. 



Plastic clay. 



Chalk. 

 Greensand. 



Wealden. 

 Upper Oolite. 

 Middle Oolite. 

 Lower Oolite. 

 Lias. 

 Poikilitic series. 



Permian. 

 Coal series. 

 Mountain limestone. 



Old Red, or Devonian 

 series. 



Ludlow. 



Wenlock. 



Caradoc. 



Llandeilo. 



Festiniog. 



Bangor. 



Hypozoic series. 



Mica schist, including chlorite 

 schist, talc schist, quartz roc k , 

 granular limestone, etc. 



Gneiss, including limestone, 

 hornblende schist, etc. 



Granitic rocks which are not 

 stratified usually form the 

 basis of the strata, and are 

 frequently, but not by any 

 means universally, followed 

 by the gneiss and mica slate. 



Age of Man. 



Post-Tertiary 



Tertiary 



Wealden 



Oolitic epoch. 



Liassic epoch. 



Permian. 



Carboniferous . 



Subcarboniferous 



Catskill 



Chemung 



Hamilton 



Upper Helderberg. 

 Oriskany 



Lower Helderburg ... 



Salina . 



Niagara 



Hudson 



Trenton 



Potsdam . 



Azoic . 



Pleistocene or Post-Tertiary. 



Pliocene. 



Miocene. 



Eocene. 



Upper Cretaceous. 



Middle Cretaceous. 



Lower Cretaceous. 



Wealden. 



(Purbeck, Portland, 

 Upper Oolitic. i and Kimmeridge 



[ clays. 

 Middle OoliUcterafrag. ay 



[LowerOoliticJfX^'oolite. 

 Upper Lias. 

 Middle Lias. 

 Lower Lias. 

 Keuper. 

 Muschelkalk. 

 Buntersandstone. 



f 14c 



14/) 



I 14a 



f 136 

 t 13<( 



12 



lib 

 11a 

 10c 

 10b 

 10a 

 9c 

 9b 

 9a 



Permian. 



Upper Coal Measures. 

 Lower Coal Measures. 

 Millstone grit. 



Upper. 

 Lower. 



Chemung. 



Portage. 



Genesee. 



Hamilton. 



Marcellus. 



Upper Helderberg. 



Schoharie. 



Cauda-galli. 



Oriskany. 



Lower Helderberg. 



Saliferous. 



Niagara. 

 Clinton. 

 Medina. 

 Oneida. 



Hudson River. 

 Utica. 



(Trenton. 

 i Black River. 

 [Birdseye. 

 Chazy. 



Calciferous. 

 Potsdam. 



