180 



PROCEEDINGS OP THE AMERICAN ACADEMY. 



direction the dominant movement has taken place. The dominant move- 

 ment may not always correspond to the prevailing movement alongshore. 



A few severe storms causing a strong 

 current from the right during one 

 month might determine forms, which 

 a weak current from the left prevail- 

 ing for eleven months of the year 

 would not be able to efface. 



Current Cuspate Forelands: Type, 

 Figure 9.* — In adolescence, w'hen the 

 currents have more load than they can 

 carry, it is deposited in forelands of 

 various forms. A characteristic one 

 is the cuspate, of which a typical draw- 

 ing is given. In it are combined those 

 features of the three Carolina capes f 

 and cape Canaveral (Figure 10) which 

 the author deems important to show 

 the method of growth. Former posi- 

 tions of the shorelines are indicated 

 by the ridges of dunes built by the 

 wind along the shore. 



Such former positions are beautifully 

 Figure 9. Typical Current Cus- indicated in Canaveral (C. S., 160, 161), 

 pate Foreland. wiiere three or four successive positions of 



tlie outline of the cusp, each farther to tlie 

 left than the preceding, are delineated, besides many lines of aggradation in each 

 position (Fig. 10). Simihir lines of grovvtli are seen at cape Fear, where the present 

 right slioreline cuts off tlie eastern ends of the four dune ridges extending cast- 

 southeast from tlie lighthouse and curving sympathetically with the left shoreline. 



Cape San Bias, on the west coast of Florida (C. S., 183, 184), shows four stages 

 on the right side and nine successive stages of aggradation on the left side. 



A more striking example of aggradation lines is seen in the cusp of Dars cape 

 in the Baltic (Germ., 61, 62, 63), where thirty-eight systematic and successive 

 shorelines are indicated by dune ridges (Fig. 11). The dominant current is from 

 the right, according to the offsets and hook at the point of the cusp; but the 

 thirty-eight successive shorelines suggest a gradual aggradation of strips, and a 

 change from an earlier condition when the current was from the left. The tidal 

 flats, east of Zingst, point to present transportation and growth toward the left. 



* For fuller account see Bull. G. S. A., 1896, VII. 399-411 ; also see references 

 for papers by Abbe and Tarr. 

 t See p. 242. 



