SECT. 2] 



MICROTOPOGRAPHY 



453 



Fig. 22. 35° 12'N, 15° 18'W. Depth 1293 m. Seamount northeast of Madeira. Area of 

 picture 1| by U m. (Photo by L.G.O.) 



Symmetrical ripple marks in Globigerina sand (wave-length 25 cm). 



Fig. 23. 35° 12' N, 15° 18'W. Depth 1317 m. Seamount northeast of Madeira. Area of 

 picture U by 2i m. (Photo by L.G.O.) 



Strongly asymmetrical ripple marks at same station as Fig. 22. Note very long and 

 sharp crests, and coarse material in troughs (wave-length 30 cm). 



