THE 
AMERICAN GEOLOGIST 
Vol. XXII. DECEMBER, 1898. No. 6 
ON THE DIKES IN THE VICINITY OF PORT- 
LAND, MAINE. 
By E. C. E. Lord, Washington, D. C. 
(Plate X.) 
Along the coast of Maine trap dikes are very abundant. 
In his "Geology of Northern New England," professor 
Hitchcock mentions the following localities: Mount Desert, 
Marshall, Little Deer Island, Vinal Haven, Hancock, Ells- 
worth, Bluehill, Brookville, Rockland, Thomaston, Hope, 
Whitehead island, Windham, Limerick, Gorham, Casco bay 
and Portland. 
Professor G. P. Merrill in describing the Maine building 
stones* refers at length to diabase from Addison Pt., Indian 
river and Vinal Haven. Other localities from which similar 
rock has received detailed study are: St. Georget, Seward's 
island in Frenchman's bay,t Kennebunkport,§ Lewiston and 
Auburn ] and the Fox islands.^ 
The region to be described in this paper embraces a part 
^Proceedings of the United States National Museum, Vol. VI., 
No. 12, 1883. 
tQ. E. Dickerman and M. E. Wadsworth: On Olivine Bearing 
Diabase from St. George, Me. Proc. Boston Soc. Nat. Hist., Vol. 
xxni., p. 28. 
fW. O. Corsby: Geology of Frenchman's Bay, Me. Proc. Bost. 
Soc. Nat. Hist., 1880, p. 109. 
§J. E. Kemp: On the Dikes near Kennebunkport, Me. Amer. Geo!., 
Vol. v., 1890, p. 129. 
II George P. Merrill: On Some Eruptive Rocks in the Vicinity of 
Lewiston and Auburn, Androscoggin Co., Me. Amer. Geol., Vol. 
X., 1892. 
T[ G. O. Smith: The Geology of the Fox Islands, Me. Dissert. 
Inaug. Johns Hopkins University, 1896. 
