The -cope of this report includes only sandy beaches in which sand 

 is defined as ranging in size from 0,05 mm. to 1,0 mm (U„ S, Bureau of 

 Soils classification). Although there are a few pebbles, gravel, and 

 cobble beaches on the coast studied 5 the largest material found on 

 extensive beaches subjected to systematic sampling was 0,8 mm sand,, It 

 seems reasonable to believe that the curves can be extended smoothly 

 upward when data on beaches composed of coarse material are available. 



The importance of using standardized measurements can scarcely 

 be overstated and other researchers are urged to consider the use of the 

 "■reference point 1 * discussed below in future beach examinations so that 



data will be comparable. This report is concerned with comparing 

 western U, So Beaches on the basis of median sand size and beach-face 

 slope and shows the probable limits of each. The beach face in this 

 instance is synonomous with shore face or foreshore,, The importance of 

 surf action in changing slopes from a profile of deposition to one of 

 erosion is showi as are the variations in slope with exposure „ 



Reference Point - The necessity for standardizing beach sampling 

 and measurement procedures became increasingly evident as data were 

 reduced from widely separated beaches between which it was desirable 

 to make comparisons. The apparently simple job of determining the 

 slope of a. beach from, a plotted profile raised perplexing questions 

 of how and where to make the measurement. Sand samples from a single 

 beach differed so much in median diameter (because of different sample 

 locations) that first attempts at. correlation were failures. Eventual- 

 ly however, by plotting the mass of data in various ways, patterns 

 began to take shape. This work ultimately led to a decision to 

 standardise on a specific location so that valid comparisons could be 

 made across time and distance. The point selected was the part of the 

 beach face subject to wave action at mid-tide elevation— now known as 

 the reference point. All slope measurements and sand samples referred 

 to in this report were taken at that point. The several illustrations 

 discussed below develop the reasons for its selection and indicate the 

 results that may be obtained by its use. Certain advantages are claimed 

 for this techniques (1) a line investigator with simple equipment can 

 take measurements rapidly and easily (2) the variables being samples 

 are those of the present time (the existing waves placed the sand 

 sampled at the slope measured) (3) the inter-tidal beach face slope seems 

 to be a major criterion for the potential, use of the beach (4-) some pre- 

 vious investigators have used this location and their data are usable 

 for comparison. The reference zone may be fairly wide 3 it is delibrate- 

 ly described somewhat loosely as being the part of the beach subject to 

 wave action at mid-tide stage since the technique would be highly im- 

 practicable if it were necessary to locate some exact elevation. Any 

 reference point in this zone is presumed to have approximately the same 

 characteristics. Since the backrush is only slightly below, and the 

 uprush may be considerably above the average sea level, these measure- 

 ments will be somewhat above the mid-tide level. This part of the 

 beach seems to be the most stable and consistent results usually can 

 be obtained there. Mid-tide refers to a level half -way between the 



