36 National Geographic Magazine. 



Representative Geographic Forms as classified by Genesis. 



Genetic Processes. 

 Category. Class. 



Deformation 



Gradation 



{Elevation 

 Depression 



f Deposition 

 I Degradation 



' Extravasation 



VULCANISM 



(Antithesis of do.) 



' LiTHIFACTION 



Alteration 



i 



Glaciation 



Wind Action 



Vital Action 



Delithipaction 



f Glacial construc- 

 tion 



I Glacial destruc- 

 l^ tion 



rWiND CONSTRUCTION 



i^ Wind destruction 

 I (Not discriminated) 



Geogbaphic Forms. 



Continents, great islands, most 

 mountain ranges, etc., not 

 classified in detail. 



Oceans, great seas and bays, 

 some inland valleys and lake- 

 basins, etc., not classified in 

 detail. 



Newly emerged ocean-bottoms 

 (e. g. , portions of the Coastal 

 plain), play as and mountain- 

 bound deserts, many flood- 

 plains, marshes, etc., not 

 classified in detail. 



Drainage-systems and result- 

 ing topographic elements 

 which are — 



1 — Autogenous (not classi- 

 fied in detail) ; and 

 2 — Tectonic — 

 Consequent, upon Displace- 

 ment before emergence, 

 and Sudden displacement 

 after emergence; 

 Antecedent; and 

 Superimposed, through 

 Sedimentation, 

 Alluviation, and 

 Planation. 



Volcanic peaks, craters, lava- 

 fields, tufa-crags, sinter- 

 cones, volcanic necks, mesas, 

 dykes, some mineral veins, 

 etc., not classified in detail. 



Sinks, caverns, some fissures, 

 etc. , not classified in detail. 



Minor features of certain topo- 

 graphic forms, e. g., reefs, 

 crags, pinnacles, salients, 

 out-cropping veins, some 

 cataracts, etc., not classified 

 in detail. 



Minor features of certain topo- 

 graphic forms, e. g., pools 

 and basins, reentrants, some 

 fissures and caverns, etc., 

 not classified in detail. 



Drift-plains, moraines of what- 

 ever character, drumlins, 

 kames. aasar, drift-dammed 

 lakes, loss-plains and ridges; 

 etc. , not classified in detail. 



Rock-basins. U-caiions, roches 

 de moutonnees, etc., not 

 here classified in detail. 



Dunes, sand-ridges, bars, spits, 

 etc., not here classified in 

 detail. 



Ponds associated with dunes, 

 "blow-outs," " purgatories," 

 etc., not classified in detail. 



