X BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Black welder: Page 



Figure 1 — A diagrammatic sketch of tlie valley of Lake Creek as 

 it is supposed to have been before landslide action 



began 488 



" 2 — A diagrammatic sketch of Lake Creek Valley in 1911. . . 488 

 Hershey : 



Figure 1 — Geological map of the Pis-Pis district, Nicaragua 494 



Keyes : 



Figure 1 — Passing of arid youth : rim of a desert basin 558 



" 2 — Approach of arid maturity : last of a desert range 558 



Smith : 



Figure 1 — Explanatory map of part of northwestern Alaska 564 



Lee: 



Figure 1 — Map of part of New Mexico, showing location of coal 



fields 573 



" 2 — Correlation of formations in New Mexico coal fields .... 597 

 " 3 — Sketch section through the Raton Mesa and San Juan 



River regions 614 



" 4 — Map of Tijeras coal field, New Mexico 628 



" 5 — Geeologic sections and drill records in the Cerrillos coal 



field, New Mexico 644 



Shimek : 



Figure 1 — Section at heating plant of east Des Moines High School . 711 



(43 plates; 44 figures.) 



