132 
The American Geologist. 
March, 1890 
distances. They are nevertheless well crystallized, and seem 
to exhibit no amorphous structure, indicative of quick solid- 
ification, whatsoever. Prof. Hitchcock refers the coast gran- 
ite of Maine, when found in such situations as this, to an 
aqueo-igneous fusion of the sedimentary rocks, and it is, con- 
sidering their surroundings, a very natural explanation. The 
narrow dikes seem to indicate in instances a very complete 
fluidity and some injective action. No one could be severely 
criticized, perhaps, for considering the parent masses also 
injected, but as the question is largely speculative, it is not 
one on which demonstrated truth can be expected. Judged 
by the latest petrographic light, we must consider the granite 
to have cooled and crystallized slowly, doubtless under great 
pressure, it being so perfectly holo-crystalline. 
Subsequently to the granite the so- 
called trap dykes were intruded. They 
cut both the stratified rocks and the 
granite indiff'erently, and sometimes 
cross one another. From these in- 
ersections Prof. Hitchcock has traced 
at Bald Cliff" three diff"erent intrusions 
in time, to quote his words, — "The 
eldest is a porphyritic trap developed 
in very large dykes in the slates and 
running N. 55 E. The second series 
of dikes cut across the porphyritic 
dikes, and have frequently greatly dis- 
placed them. These run northeasterly 
and are the most common of all the 
dikes in Maine. The third series is a 
brown scoriaceous trap cutting across 
the common trap." Parallelism of 
direction is cited as an indication of 
unity of age, equally with similar 
While this last may be true for Bald 
Cliff, it hardly holds at Kennebunkport, for while in the case 
of the dikes in the stratified rocks there is some parallehsm, 
when in the granite they run in all^directions. Also in the 
former case they branch, fork, and anastomose in great va- 
riety. My own observations at Blad Cliff confirm Prof. 
Hitchcock's three epochs and kinds of intrusion perfectly. At 
mineral composition. 
