SPRAY AND SPLASH IMPRESSIONS 



365 



pressions do not appear to be different from those made by rain-drops, so 

 far as shapes are concerned, but there is great variation in diameter. 



If drip, rain, hail, and spray and splash impressions be made in ex- 

 tremely soft mud, the result will be fiowage of mud into the depressions, 

 and they may be obliterated or greatly reduced in depth. 









^ 



■'V . 



X: 



-*.S» 



Figure 5. — Impressions nicule by stranded Bubbles 



Impressions made by anchored Bubbles 



Bubble impressions are made by bubbles floating and becoming an- 

 chored to the bottom through sediment becoming attached to the films 

 or stranding in shallow water. In the experiments of the writer the im- 

 pressions so made varied in diameter from very small to about 7 milli- 

 meters. The depressions are sections of spheres made by passing a hori- 

 zontal plane through the spheres, the segments remaining in the mud 



