198 



-K. Bryan — Rock Tanks and Charcos. 



water falls of the new canyon working headward in an 

 old valley with gentle slopes, which was formed at the 

 same time as, and forms part of, the neighboring sloping 

 plains or mountain pediment. Baker Tanks (p. 3) and 

 many others belong to this type. 



Falls due to renewed uplift. 



Most of the mountains of southwest Arizona are nar- 

 row, uplifted strips of the earth's crust bounded by faults 



Cemented 

 gravel 



MagoeHc 

 Norl-b 



SecHor? along \\r?e A-B 

 Scale lir7Cb»2oof € eh 

 Trail 



'^Smiiiwijimj 





Rock. 



/> N High RocKy V \ *?*<&$$ 



- Rock V«4>*»^ .o?» 



*te* %ftfini\^ 



Cbaooel 



HigK> Roclcy 

 Hills 



SCALE OF MAP IS I INCH TO 622 FEET. 



Fig. 6. Sketch map of Black Tanks. 



on one or both sides. After uplift streams cut canyons 

 and established smooth grades from the crest of the 

 mountains to the adjacent valleys. In certain ranges re- 

 newed uplift took place on one side of the mountains only, 

 probably along the same fault-plane on which the original 

 uplift occurred. This uplift resulted in flattening the old 

 stream grades in the higher part of the mountain and 

 producing a cliff or fault scarp across the stream chan- 



