EXPLANATION OF TABLE C-7 



CONVERSION CHART FOR PHI VALUES TO DIAMETERS IN MILLIMETERS 



Table C-7 was reproduced from the Journal of Sedimentary Petrology 

 with the permission of the author and publisher. It was taken from the 

 Harry G. Page, "Phi-Millimeter Conversion Table," published in Volume 25, 

 pp. 285-292, 1955. Includes that part of the table from -5.99 (about 

 63 ram) to +5.99 (about 0.016 mm) which provides a sufficient range for 

 beach. deposits. The complete table extends from about -6.65 (about 

 100 mm) to +10.00 (about 0.001 mm). 



The first column of the table shows the absolute value of phi. If 

 it is positive, the corresponding diameter value is shown in the second 

 column. If phi is negative, the corresponding diamter is shown in the 

 third column of the table. In converting diameter values in millimeters 

 to their phi equivalents, the closest phi value to the given diameter may 

 be selected. It is seldom necessary to express phi to more than two 

 decimal places. 



The conversion table is technically a table of negative logarithms 

 to the base 2, from the defining equation of phi: <(> = - log2 d, where 

 d is the diameter in millimeters. 



C-45 



