IN THE DEGRADATION OF THE LITHOSPHERE. 387 



land Harbor, the present distribution of islands and reefs shows 

 the same general lines of direction and the same construction as 

 the lines of distribution in Casco Bay. Indeed they are all parts 

 of the same general structure. Fronts Neck itself I have deter- 

 mined to be a structure composed of a series of parallel reefs cov- 

 ered in part by glacial pebble flats, sand dunes, peat bogs, cedar 

 swamps and contemporary pine wood ; the pine woods are now 

 growing mostly over sand dunes which he across the old lines of 

 parallel reefs. These lines of reefs are shown at certain intervals 

 along the direction of the Neck and are parallel with similar lines 

 of islands and reefs which lie out to seaward from Scarboro Beach, 

 often appearing as isolated masses of rock, in many cases now sur- 

 rounded by bogs or sand dunes. The Neck ends in a mass of rock 

 probably formerly an island in which the same general direction 

 of dip and joint distribution may be seen. The sea encroachment 

 on Fronts Neck itself displays the same joint control of steep cliffs, 

 angular block fragments and contemporary pebble and shingle 

 beaches, such as are common on both sides of the north Atlantic 

 coast. When these lines of Fronts Neck are plotted as to general 

 position and direction they fall into the same scheme as shown in 

 the other structures in Casco Bay. This cannot be regarded in any 

 manner as accidental, but part of the same structure common to this 

 portion of the lithosphere. 



The structures around Bath, Booth Bay Harbor and similar 

 places along the coast of Maine, are usually referred to as indicat- 

 ing processes due to glaciation^' or are regarded as evidence in 

 regard to a displaced coast line, all of which may be perfectly true, 

 but it does not disguise the fact that these structures again may 

 be plotted along a system of lines of jointing. In fact, I regard 

 the entire distribution of islands, reefs, flats, etc., within the Gulf 

 of Maine, not as remnants of the former surface of peneplanation, 

 due to atmospheric erosive agents, but as structures due to the 

 combined action of marine planation and essential lines of weak- 

 ness due to jointing in this portion of the lithosphere, so that the 



3- See Shaler, " Geo. Hist, of Harbors," 13th Ann. Rep., Pt. 2, U. S. G. S., 

 pp. 114-118, 1893. 



