GEOLOGIC PROCESSES OF THE ARID REGION 



571 



Relation of New Mexico to adjacent Arid Regions 



All of New Mexico is coiuiiiouly regarded as forming a part of the South- 

 west desert. It is, however, peculiarly situated in that it lies at the meeting 

 point of four great physiographic provinces of our continent. Their bounda- 

 ries in New Mexico are outlined in the accompanying sketch-map (figure 1). 

 These provinces are the Great plains, occupying the eastern part of the terri- 

 tory east of the Pecos river; (2) the Rocky mountains, reaching southward 



109* 108* 



\07' 



106* 



105* 



J 04' 105' 



109* 



108* 



(07- 



106" 



Scale 



U ' ti 90 



105° 



104.' 



I OS- 



Figure 1. — Sketch Map of Keio Mc.rico, shoiriiiy Physiographic Provinces 



from Colorado in a long narrow tongue to the (Jlorietta pass; (3) the Mex- 

 ican tableland, hi the south-central part; and (4) the High Plateau province, 

 including all of the northwest. 



These four geographic provinces as represented in New Mexico differ so 

 widely from one another in general surface relief, geologic formation, geotec- 

 tonic arrangement, drainage features, climatic conditions, soil character, plant 

 growth, economic resources, and harmonious environment for human habita- 



