126 NEW YORK STATE MUSEUM 



necessary here to restate briefly the interesting geological rela- 

 tions in order to bring out the pertinence of my present remarks. 

 Dalhousie mountain lies a mile or so back from the shore of the 

 Bay of Chaletir at Dalhousie and appears to be a large boss of 

 eruptives from which apophyses extend eastward into the sea, a 

 large arm reaching down through the village and projecting as 

 two points at the waterfront, thence extending continuously to 

 the lighthouse at Inch Arran, covering the Inch Arran beach, in- 

 cluding the islets known as the Bon Ami rocks, and therefrom 

 reaching to the opening of Stewart's cove. This heavy lava mass 

 is interesting for its great inclusions of crystalline blocks which 

 are finely displayed in the bluff below the Inch Arran light. 

 These inclusions are of various composition, pink and gray syen- 

 ites prevailing, and in this much weathered rock face where the 

 decomposition of the lava has spread radially from their surfaces, 

 the cliff looks as though it had been shot full with great missiles 

 whose impact had fractured the matrix. 



At the south end or bottom of this mass begins an exposure of the 

 upper inclined fossil-bearing Dalhousie shales, the contact being 

 buried under the beach sand and the highest beds, which are coral 

 limestones, being exposed only at extremely low water. Continuing 

 several hundred feet along the shore cliff wherein are one or two thin 

 ash beds, the shale series is cut by a second volcanic mass at the 

 mouth of Stewart's brook where the contact is sharply defined 

 and its effects manifest. The front of this second volcanic mass 

 is a fifth of a mile long and near its midlength lies a large but 

 quite clearly embedded mass of the shale, whose precise posi- 

 tion in the series is not entirely certain. At the bottom or south 

 end of this lava mass the lower section of the shale series appears 

 and continues for several hundred feet more. Its base (beds with 

 Gypidula pseudogaleata) lies on a floor of volcanics 

 which, on the shore section, terminates the sedimentaries. The en- 

 tire section of DcA^onic sediments here is measured at about 450 feet, 

 without evidence of repetition in its parts, and it is actually cut but 

 once by the volcanics. These extrusives were contemporary with 

 the deposition of the sediments, and it seems probable that they are 

 actually connected as apophyses with the mass of Dalhousie 

 mountain as represented on the original map of this region by 

 Dr R. W. Ells (1884). Here on the shore front the volcanic 

 masses are very heavy and their contact effects are shown by 

 the induration of the shales, the whitening of the calcareous fos- 



