﻿A 7 ! S. Shale? 7 — Geology of Cobscook Bay District, Me. 59 



shale it had an extension to the east which must carry it be- 

 neath the Atlantic Ocean. The exact determination of the age 

 of these beds is one of the most interesting matters for future 

 research afforded by the geology of the Cobscook region. 



Besides the above mentioned localities where organic remains 

 have been found there are many others, a score or more in 

 number, scattered along the great length of shore of this region, 

 which to my preliminary study yielded too few and altogether 

 too imperfect fossils to make it profitable to undertake the 

 determination of their age. It seems possible that among these 

 beds there may be found traces of the fauna of the lower 

 Silurian, especially of the Trenton and Hudson River groups. 

 If these faunas are represented at all, it is clear that they are 

 shown in a very imperfect manner, still the search has as yet 

 been so inadequate that much may yet reward the careful ex- 

 plorer. There is reason to believe that these fossil-bearing 

 Cobscook rocks extend much farther to the west than they 

 have yet been followed. It is also probable that they may be 

 found considerably to the north of the points where my ex- 

 plorations were carried. 



From the foregoing summary of my observations in this 

 region it will be seen that it affords a large field for profitable 

 study. It seems likely that at least three hundred species of 

 fossils may be gathered from the localities exposed along the 

 cliffs of the Cobscook fjord system, many of them are unde- 

 scribed forms, and in all cases they depart in an interesting 

 manner from the types found elsewhere. 



The problems now are to compare these species with those 

 from the classical localities of New York and elsewhere, so as 

 to determine how far the horizons accepted in those regions 

 may be recognized in the Cobscook district. This task cannot 

 well be undertaken until the topographic representation of this 

 district is on a satisfactory basis. Such is the complexity of 

 the topography as well as of the geological accidents that noth- 

 ing in the way of final work can be done until a good map is 

 secured. As the parties of the United States Coast Survey 

 expect to be working in this region in 1887 we may hope to 

 have the basis for a good map before 1890, it may be well to 

 postpone the delineation of the geology until that time. In 

 the meanwhile the more important parts of the geological 

 work, all that relates to the assimilation of the deposits to 

 those of other districts, can be carried on. 



It seems to me that it will be well to extend the search for 

 the beds of the Cobscook series to the shore line both to the 

 east and west of the region treated of in this preliminary re- 

 port. It is not likely that they have been preserved on this 

 portion of the shore alone. Their general character shows that 



