Smith, Robert L. <br/><br/>
Zones and zonal variations in welded ash flows / 
by Robert L. Smith. 
 - Washington:   U. S. Government Printing Office,   1960.  
 - iii, 149-159 p. ;  29 cm.  + 1 diagr. 
 -  354 Shorter contributions to general geology .
<br/><br/> Conduct diagram: Diagrams showing the zones of some ash-flow cooling units. 
<br/><br/>Includes bibliographical references (p. 158-159). 
<br/><br/> A concept of zonation in ash flows based on degree of welding and type of crystallization. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ignimbrite<br/>Volcanic ash, tuff, etc
<br/><br/><label>Dewey Class. No.: </label>551