﻿60 JY. S. Shale? 7 — Geology of Cobscook Bay District, Me. 



with the exception of the Perry beds they were deep sea 

 deposits and therefore presumably covered all this part of the 

 coast. They may fairly be expected to appear both in the 

 southern part of New Brunswick and along the Maine shore to 

 the westward. 



It is particularly important that they should be sought for 

 elsewhere for the reason that in the Cobscook series it is evi- 

 dent that not one-twentieth part of the total fossiliferous section 

 is revealed. The greater portion is completely covered by the 

 extruded rocks, or is buried beneath the glacial drift, or is hid- 

 den by the waters of the bay. If the beds are found elsewhere 

 there is reason to hope that these hidden portions of the sec- 

 tion may there be exposed to view. In this way we may hope 

 to complete the stratigraphic as well as the paleontological 

 series of the district. 



Nearly every exposure of fossiliferous strata which occurs in 

 this region manifestly owes its preservation from glacial and other 

 wear, which would have eroded the beds to below the sea level 

 or removed them altogether, to the protection afforded by the 

 dense and erosion-resisting covering of lava which lies upon it, 

 or has only recently been worn away. This points to the con- 

 clusion that in searching for these deposits in the neighboring 

 parts of the coast it will be well to examine every point where 

 stratified rocks appear beneath the cliffs of igneous rock ; such 

 being the position in which these relatively soft beds are most 

 likely to have survived the destructive effects of glacial and 

 marine erosion, both of which causes have acted with peculiar 

 energy along this shore. 



It should be borne in mind that these fossiliferous horizons 

 have an especial interest from the light they may throw on the 

 position of the shore line in past times. Therefore not only 

 the organic remains which they contain but also the detrital 

 matter of which the rocks are formed is of much importance. 

 The occurrence of a conglomerate apparently of the Clinton or 

 Niagara age in the section on the western shores of South Bay 

 seems to show that the shore in this district was not far away 

 during a portion of the time when the Cobscook series was 

 forming. The general character of the pebbles in this bed 

 indicates that the ancient shore was composed of the hypogene 

 rocks, syenites, etc., which now constitute the principal mate- 

 rials exposed to erosion in this part of the continent. Again 

 in the age of the Perry section we have evidence that the shore 

 line was near its present position and that the rocks exposed to 

 erosion were principally of Laurentian age. Thus it is evident 

 that we may reasonably hope, from the study of this field, to 

 find our way to conclusions of great value to American geology. 



