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PRICE 



Most of the shoreline types of the Gulf belong to the inner lagoons and bays. However, 

 we are studying at present only the marine shoreline. I find that the significant factor for the 

 outer coast is the degree of smoothing . 



Smoothing is significant from the geological as well as the energy relations standpoint. 

 It is very significant with respect to landings and all kinds of shore operations. Smoothing is 

 primarily accomplished by wave energy, which grades the shoreline and shelf bottoms. It is 

 well known that progressive modification of the shoreline by the ocean brings about simplifica- 

 tion and smoothing. A smooth coast should be considered in a mature condition. 



The heavy black lines in Fig. 13 indicate the coasts which are well smoothed. On a 

 drowned river-valley coast, numerous in this area, shorelines may be smoothed by sandy bar- 

 rier islands built across the river mouths. Thus a smooth coast is found wherever such bar- 

 rier islands are formed. 



The barrier islands are built of sand. Proved sources of this sand are dominantly river 

 and bay sediment in Texas, southwestern Louisiana and central Florida, bottom sands in the 

 Chandeleur Islands of Louisiana, and shell sand on the north shore of the Yucatan peninsula. 

 Pocket beaches on the west coast of this peninsula have limestone cobble eroded from up- 

 faulted limestone hills. The limestone coast of the Champoton-Campeche fault-block is 

 smoothed by erosion of the rock and building of pocket beaches. 



In the Gulf all the smoothed coasts show high to medium energy inshore. The completely 

 unmodified, unsmoothed shorelines are where the energy is very low. Along the northern third 

 of the Florida peninsula there are numerous areas, each several miles long, having almost 

 completely unsmoothed shorelines. These unsmoothed shores are found on the drowned karst 

 with practically zero energy. There we find innumerable small peninsulas and islets with 

 small bays and channels. The low elevations are occupied by palms and other trees. There 

 are archipelagoes of islets extending four or five miles from the shoreline. I described this 

 type of coast in a manuscript which will be published in about a year (Communications of IV 

 Congress, INQUA, Rome and Pisa, Italy). 



Figure 14. 



