DECIMAL CLASSIFICATION 
550 Geology 
350.1 08) theories, geologic time .2 Compends .3 Dictionaries .4 Essays, 
papers, tracts, letters .5 Periodicals .6 Societies .7 Study and teaching, 
museums .8 Collectiv works .9 History 
Physical and dynamic geology 
Including geophysics (physiografy, physical geografy) and geochemistry broadly 
treated; see also 551.94. For Cosmic geografy, see 523 
Structure of earth as a whole 
Interior of earth 
Internal heat 
Earth's crust 
Conductivity of rocks 
Seismology 
Volcanoes 
Earthquakes 
Hot springs, geysers 
Oscillations of the earth’s crust 
Erosion and deposition 
Glaciers and glacial phenomena 
Moraines 
Transported materials, till 
[cebergs 
Aqueous erosion 
Coast changes 
Aerial erosion 
Surface features of the earth 
Physical geografy 
Continents 
Ilands 
Mountains Valleys Orology 
Caves 
Plains 
Oceans 
Ocean currents 
Rivers Lakes 
Springs Wells Ground water 
Meteorology Climate 
Atmosferic currents Winds 
Thermometry, heat 
For other relations see Heat, Temperature, in Relativ index following Tables 
Hypsometry, elevations See 526.368 for methods 
Barometry, pressure 
Storms 
See also 537.4 Atmosferic electricity 
Moisture: rainfall, flow of streams, floods 
Prairies. forests. and deserts 
I 
Division of Oceans for use under .46 
and .47 
1 Atlantic North sea Baltic 
2 Mediterranean Black sea 
3 Gulf of Mexico Caribbean 
4 Southern Atlantic 
5 Pacific 
6 Eastern Pacific or American coast 
7 Indian Bay of Bengal Red sea 
8 Arctic 
0 Antarctic