GULLIVER. — SHORELINE TOPOGRAPHY. 185 



the State is little filled, indicating an earlier stage. In tlie northern portion of the 

 State the offshore bar merges into the southern wing of the Long Branch behead- 

 land (page 213). 



Upon the south side of Long island the sea has devoured the land to an appre- 

 ciable extent during the historical period. Meadows and cultivated lands have 

 been covered with sand, wagon tracks in peat have been found on the ocean side 

 of the dunes, wliile peat, cedar stumps, and tangled roots occur to-day between the 

 sand hills and the sea. These traces of land life seaward of the dunes indicate a 

 march of the dunes landward,* and a general pushing of the offshore bar inland. 



7. Dissected Coastal Plain. 



Surface Form. — On page 155 it was shown that the stage of develop- 

 ment of the surface of a coastal plain may not be the same as that of 

 the coastline of the same region. This subject comes more properly 

 under the cycles of development of land forms ; but, since the coastal 

 plain is one of the main criteria of uplift, the sequential forms will be 

 briefly sketched. 



Mr. W. Lindgren shows a characteristic section of a Quaternary coastal 

 plain lying on a granite oldland,t but he does not use its stage of dis- 

 section to show the time since the elevation of the region around San 

 Diego. 



Youthful Dissection : Ogunquit, Maine. — In southern Maine the forms indicate that 

 there has been a recent episode of uplift revealing a narrow coastal plain, which 

 fills in the irregularities of the coast made by a previous depression. The streams 

 have only begun to intrench themselves upon this late deposit. 



The Monopoli coastal plain on the " heel " of the Italian boot shows youthful 

 dissection of a marine plain (Ital., 190, 191). The Pliocene strata t present a 

 surface gently rising from the sealevel to heights of from 100 to 200 meters at tlie 

 foot of an abrupt slope of Jurassic and Cretaceous rock. This slope rises from 75 

 to 250 meters above the plain, and has the form of an elevated former sea cliff now 

 slightly dissected. A problem for field study is the cause of the minutely ragged 

 outline of the present shoreline. § There is no ofTshore bar shown with this coastal 

 plain, which may be accounted for by the fact that the slope of the surface of the 

 coastal plain is considerable, 100 meters in 5 kilometers, and therefore it is probably 

 steep enough for the direct attack of the sea. The coastal plain character of the 

 heel of Italy is well shown on the topographic sheets by the radial arrangement of 

 roads (Ital., 202, 203, 204, 213, 214, 215, 223). The towns are like the hubs of 

 wheels, the spokes of which are the highways. The distribution of infaces, 

 streams, and outcrops suggests that the area has been developed in several cycles, 

 a study of which in the field would be most attractive. 



* A. G. Pendleton, U. S. C. G. S., 18-50, Appen. 8, 80, 81. 



t Proc. Cal. Acad. Sci., 1888, L., PI. III. 



J Carta Geologica d' Italia, 1 : 1,000,000, Roma, 1889. 



§ See page 239. 



