Notice of a Scientific Expedition. 331 



by the kindness of Mr. Thayer, the collector of the port, to whom 

 letters had been addressed by John Tappan, Esq. of Boston, to 

 whom also we are indebted for many of the comforts of the voyage, 

 if not for much of its success. 



■ 



Our stay at Lubec was short. We however visited a few inter- 

 esting places. The first is near the plaster mills ; it is a deposit 

 belonging to the newer tertiary. The body of this formation is a 

 stiff marly clay, in which fossils are thickly imbedded ; the remains 

 of molluscous animals are of the same species as those now inhab- 

 iting this sea. The elevation of this bed of marl is about forty feet 

 above high water ; it occupies in part a ravine which extends inland 

 about half a mile. It rests on a porphyritic greenstone. 



A further examination of this coast, and also of the Grand Nas- 

 sau is desirable, and this we propose to make at some future time. 

 Whether similar formations to the above skirt this coast we were un- 

 able to determine. The single instance of a formation of this char- 

 acter, raises the question of the recent elevation of this coast, and 

 • so far as we can judge, settles it ; but the discovery of similar de- 

 posits would remove some objections and add much in establishing 

 its certainty. Connected with this view is the fact of a multitude 

 of islands on the coast, and in Passamaquaddy Bay. It is even as- 

 serted that there are in it no less than 360 islands. Now a slight 

 elevation of the coast, and the bottom of its neighboring sea would 

 convert much of it into dry land. This would give rise to a great 

 Complexity in the geological structure of this coast. It is not our 

 intention to follow out the thoughts which these few facts suggest ; 

 it is sufficient to say that the elevation of extensive territories is not 

 unfrequent in our day, and of course may have occurred here. 



Another place of geological interest is Comstock's Point, four 

 miles from Lubec. Here occurs a junction of greenstone with what 

 appeared to be transition limestone. There is not so much change 

 in the structure of the two rocks at the line of junction as some 

 would wish to see. Neither of them have a vesicular structure : 







but the limestone is lighter colored, much fractured, and more com- 

 pact near the line of junction. That which will excite the attention 

 of the geologist the most is the existence of trap dykes, wherever 

 the limestone is uncovered. 



Fig. 1 is a representation of one of these. The whole width of 

 the main branch is two feet. The curved portions are segments of 

 circles nearly thirty feet in diameter, a is a portion of the dyke 



