l-i THE SAND STKAND FLOBA 



With a few interruptions by rocky points the sand dune belt con- 

 tinues to Carmel Bay. Here it is, however, quite narrow. 



An analysis of the sand at Point Pinos gave the following result: 



Quartz 61.2% 



Felspar 37.6% 



Hornblende 1.2% 



100% 



This constitutes a fair sample of the sand in the district. The 

 . average size of the grains of 16 samples was 0.35 mm., half of the sam- 

 ples having been secured from the middle of the windward and the other 

 half from the leeward side of dunes. 



The prevailing, winds at Point Pinos are those from W. and con- 

 sequently the dunes wander in an easterly direction. It holds true that 

 wherever winds blow in many different directions, as is the case at this 

 place, the arrangement of the dunes is very irregular. Near the light- 

 house, situated at the point, the dunes do not have any regular position, 

 but turn in all directions. Only one kilometer further south, where the 

 coast line is straight, the sand ridges are almost parallel to the shore. 

 In cases where the wind has been able to break through these ridges, 

 the central part of the dune has traveled forward more rapidly than 

 the sides, thus leaving ridges transverse to the dunes parallel to the 

 coast. I was here able to observe that similar results to these mentioned 

 were obtained by the wind working through an opening between two 

 advancing dunes, thus pushing the sand forward in the depression, and 

 forming low ridges or cusps to leeward of the dunes. When this work 

 has gone on for some time, the result will be exactly the same as when 

 the wind is cutting through the central part of the dune by pushing the 

 concavity forward until an opening is effected, that is, longitudinal 

 ridges are formed. Fig. 11 illustrates both these modes of work of the 

 wind. We thus find that in some cases the dune apparently travels 

 with its convex side turned towards the wind, and I am inclined to the 

 opinion that the formation of "barkhanes" in Sahara and other deserts, 

 as described by several authors, takes place in this way rather than in 

 that suggested by Cornish. 



SOUTHFRN CALIFORNIA. 



At Santa Barbara in Southern California sandy beaches are common. 

 They are, however, rather narrow, and have a steep slope. The sand is 

 coarse, of a light yellow color. Quite extensive sand deposits are found 



