58 BAILEY ON GEOLOGY OF 



partial revision ol' the geology of northern Maine was made by Prof. Hitchcock in an 

 article accomj^anying an atlas of Aroostook County ; bnt this was based npon no new 

 examination of the district, and in the main adhered to the views i^rcvionsly expressed in 

 the report of 1862. In ISTS, an Atlas of the Maritime Provinces was also published by 

 Roe Brothers, of St. John, in which the geology of the western frontier of New Bruns- 

 wick, in common with that of the entire Province, was summarized by Prof. J. Fowler, 

 and represented in a new geological map, but like the publications preAàoiisly named, 

 this also was based upon observations previously made by others, and contained no new 

 results of original investigation. More recently, observations of a more or less desultory 

 kind have been made by various observers in and about Passamac^uoddy Bay, by far 

 the most important being those of Prof. N. S. Shaler, who in a preliminary report 

 addressed to the Director of the United States Greological Survey, but piiblished in the 

 ' American Journal of Science ' (July, 1886), details the results of several months' observa- 

 tions about Eastport and the adjoining bays and islands ; such re]Dort, though only tenta- 

 tive, serving to add materially to our knowledge regarding the structure of the latter and 

 the fossiliferous strata which they embrace. In the meantime, and at various periods 

 between the years 18*70 and 188*7, the work of the Greological Survey in New Brunswick 

 has been extended up the valley of the St. John and along the entire length of the Maine 

 frontier, and some of the results and comparisons thus suggested have been made the 

 basis of communications already published in the Transactions of this Society, as they 

 have also been made the basis of a review of New Brunswick geology, by Dr. Ells, in a 

 pamphlet published for private circulation in 1887. In the present year the last report 

 and the last map relating to this region will be published by the Canadian Survey, 

 and hence it would seem a fitting time in which to renew our retrospect, and, as far as 

 possible, to correct or to extend the comparisons of twenty years ago. 



The importance of these comparisons will be better appreciated when we bear in 

 mind the peculiar position which New Brunswick holds, not only as regards the adjacent 

 portions of Maine, but also as regards the entire State and, indeed, a large part of New 

 England. Situated directly to the east and north-east of the State first named, the north- 

 easterly trends, which here as elsewhere characterize most of the formations of the Atlan- 

 tic sea-board, cause these necessarily to pass directly from the one to the other, so that a 

 correct determination of the relations of these formations in either country will go far to 

 make intelligible the structure of that which adjoins it. Moreover, in the case of New 

 Brunswick, it would seem that the disturbances and accompanying metamorphism which 

 have so greatly obscured the geology of much of New England, have been much less 

 severely felt, so that a much greater number of definite fossiliferous horizons may be 

 identified ; and the relations of other non-fossiliferous formations to these being deter- 

 mined, a key is furnished for the elucidation of regions in which the data available are 

 less complete and satisfactory. The fact that, in many of these fossiliferous horizons, 

 features are iiresented, which are widely diflerent from those of the more westerly portions 

 of the continent, and point to a closer afiinity with those of Europe, adds further interest 

 to comparisons of this kind, and suggests many interesting questions regarding the early 

 geographical and physical conditions of eastern America, a few of which it is jiroposed to 

 consider in the present paper. 



The subject may, for the present purpose, be best considered by a review of the 



