WHOLE VOL. SKELETAL REMAINS OF EARLY MAN HRDLICKA 5 



ERAS OF GEOLOGIC TIME 



WITH CHARACTERISTIC LIFE 



PSYCHOZOIC ERA 



(Recent) 

 Acre of man 



DIAGRAMMATIC SECTION OF EARTH'S CRUST 



(1^._5._Tbass_fc'i.) 



CENOZOIC EKA 



(Modem lilc) 

 i of mammala aud modern plants 



MESOZOIC ERA 



(Medieval life) 

 Age of reptiles 



PALEOZOIC ERA 



(Ancient life) 

 Age of higher invertebrate animals 



CHARACTERISTIC ROCKS 



WITH MAXIMUM THICKNESS 



Alluvial deposits in rivers, etc. 



Shale, sand, and gravel 



5 "00 feet clay, shale, gravel, and sandstone 



14,000 feet shales, sandstones, and lime- 

 stone 



6,000 feet shales, sandstone, and lime- 

 stone 



8,000 feet limestone, sandstone, and coal 



20,000 feet sandstone, shale, limestone, 

 and coal beds 



20,000 feet limestone, shale, and sandstone 



10,000 feet sandstone and shale 



15,000 feet sandstone, shale, and coal beds 



-is^s? 7,000 feet sandstone and shale 



^ 10,000 feet sandstone, shalo, and coal beds 

 4,500 feet shale and limestone 



3=^~^-^^7= 12,000 feet limestone, sandstone, and shale 



_^ [ I ^ 6,000 feet sandstone, shale, and limestone 



6,000 feet sandfltone, limestone, and shale 



4,000 feet limestone and shale 



6,500 feel massive limestone 



18,000 feet quartzite, sandstone, shale, 

 and limestone 



30,000 feet conglomerate and sandstone 

 with lava flows 



S 14,000 feet handed slates and cherts with iron ore 



20,000 feet of white quartzite 



100,000 feet sedimentary schist and gneiss 

 with lava flows; slates, conglomerates, 

 and limestone 



Granite and other igneous rocks 



Fig. X. 



