THE BEACH AND BAND DUNES. 



383 



branches. It varies in width from a mere strip 2 or 3 meters wide 

 (as along the estuaries) to nearly 1 kilometer (over -.V mile) at (-ape 

 Henry. Its surface everywhere consists of finely divided, wave- 

 deposited, and often wind-blown whitish sand. 



In the more sheltered coves and along the rivers and bayous the 

 beach is ordinarily smooth and gently sloping, with a contour 

 unbroken by abrupt elevations. The sands of the more exposed por- 

 tions of the coast, on the other hand, are piled up by the wind so as to 

 form dunes which are sometimes much the highest land of the region. 



Pio. 51.— Inner slope of high duties at Cape Henry, Va., showing advance on The Desert. 



This area of sand hills reaches its culmination at Cape Henry, where 

 the summit of the highest dune is roughly estimated to be 25 meters 

 (80 feet) above mean tide level.' Thence along the south shore of 

 Chesapeake Bay west to Willoughby Spit and along the Atlantic strand 

 to a point 24 kilometers (lo miles) southeast of Capo Henry Ihe dunes 

 gradually decrease in size and finally disappear. Whether sand hills 

 of any size occur between the Virginia-North Carolina boundary and 

 Cape ITatteras was not ascertained. 



1 The highe t contour noted on the Norfolk folio of the Geological Atlas of the 

 United States is 50 feet, but higher contours lying inside this are indicated. A 

 century ago B. H. Latrobe (see be 1 ow) estimated the height of the highest dune to be 

 not " less than 100 feet above high-water mark." 



