﻿REPORT OF THE DIRECTOR I9IO 1 47 



canic-gypsum masses. I fancy there is little to militate against the 

 conception that these volcanic lavas with their sulfur and other gases 

 have not only indurated the sands and thus made them more resistant 

 to meteoric downwear, but have decolored them by rendering the 

 iron oxid soluble. On Grosse Isle Head like conditions are exhibited 

 on a small scale, but more effectively on Alright island where all the 

 demoiselles display the hardened gray sandstones. 



Shales and limestones are of the rarest occurrence, but where they 

 have been observed the shales, when calcareous, carry fossils. 

 Where the great gypsum deposit of Grindstone, stretching nearly 

 east and west across the island from north of Cape aux Meules, 

 reaches the vicinity of Cape le Trou, there are fossil-bearing brown 

 bituminous limestones with goniatites and pelecypods, lying close 

 against the white outstanding gypsum cliffs. A few fossils have 

 also been found near House Harbor along the gypsum masses 

 exposed on the property of the Widow Arseneau. At Grand Entry 

 I observed lying among the piles of " killicks " on the beach many 

 blocks of gray calcareous shale with fossils in them and inquiry of 

 the fishermen brought me to the outcrop of this rock at Oyster 

 basin on Coffin island. Air Richardson reported but one locality of 

 fossils, that on the sea face between Cape aux Meules and House 

 Harbor. Those I have obtained at the three localities mentioned, 

 amounting in all to a very considerable quantity of material (10 

 barrels were brought away from the Oyster basin locality) I 

 have placed in the hands of Dr J. W. Beede, who has very kindly 

 undertaken to examine and report upon them. Their evidence is, 

 of course, ultimately essential to the determination of the geological 

 age of these formations. 



Doctor Beede's conclusions indicate that the marine fauna is of 

 early Carbonic age, to be paralleled in horizon with the Mississippic 

 of the interior basin yet with palpable evidence of development in an 

 Atlantic basin isolated from the interior by the appalachian uplift. 

 All the outcrops which have produced this marine fauna lie very 

 clearly at the base of the sedimentary rock series of the islands, 

 beneath the gray and red sandstones. As to the red sandstones 

 there is no reason to assume any lack of continuity with the similar 

 beds of Prince Edward Island. These have commonly passed as 

 " Triassic " rocks and Leidy, Dawson and Dana believed that this 

 age was effectively determined by the discovery in that island of the 

 reptilian remains which were determined as the lower jaw of a 

 dinosaur. 



