﻿REPORT OF THE DIRECTOR I9IO 

 Sands from Magdalen islands 



153 





ANALYSES 



ANALYSES RECOMPUTED 





Red 



White 



Red 



White 



Differ- 

 ence 



Si0 2 



82.15 



91.66 



100.00 



100.00 





Fe 2 3 ... 



1.30 



0.42 



1.58 



0.46 



1. 12 



FeO.... 



0.28 



0.2s 



0.33 



0.27 



0.06 



A1 2 3 ... 



8.84 



4.16 



10.76 



4-54 



6.22 



CaO.... 



0.46 



0.18 









MgO... 



0.49 



0.14 



0.60 



0.15 



0.45 



Ko 0.... 

 S0 3 



3.17 



2.25 



3.86 



2.4S 



' 1. 41 



0.72 



0.22 









Water. . . 



2.51 



0.65 









Ca So 4 . . 







1.42 



0.5S 



0.87 





99.92 



99-93 



118.55 



108.42 



10.13 



Mesh of sieve 



Retained by 20 



40 



60 



80 



100 



Passed by 100 



Red 

 % 



White 

 % 



5.0 

 2.2 

 8.2 

 5-4 

 9.2 

 69.9 



Pressed 



white 



% 



In these analyses it is quite clear that the red sand differs from 

 the white in the loss of nearly everything soluble by organic and 

 meteoric acids and the inference is fair that the latter are the 

 bleached residue of the former. 



Depth of rock decomposition. So profound has been the decay 

 of the red sandstones that it is sometimes difficult to tell where the 

 altered rock ends and the unchanged rock begins. On nearly all sea 

 front exposures, which have naturally not been of long duration, the 

 finger can often penetrate the surface to a considerable depth. On 

 Grosse Isle Head along a new road opened at the side of the lagoon, 

 the red rock has been cut to a depth of several feet from the mold. 

 The red rocks here are interspersed with boulders, some of which 

 are sand-etched (dreikantner). These boulders, when crystaline, 

 hold their substance well, but if of sandstone, as is often the case, 

 they are rotted clear through like their matrix. 



On Grindstone island, and particularly along the banks at Leslie 

 cove, there lies between the deoxidized sand and the red sandstone an 

 irregular layer of small angular diabase pebbles forming a gravel 

 which lies with a conspicuous lack of uniformity and constitutes a 

 component part of the sand rock. This layer may be traced all about 

 the southwest cliffs of the island. The pebbles show no marked 

 decay, and are in places accompanied by large boulders. While this 

 layer of angular diabase pebbles lies directly beneath the soil, yet the 

 parts which descend within the substance of the sand rock have no 

 appearance of entering preexisting crevices but are a contempo- 

 raneous part of the sandstone itself. 1 



1 On the cliffs of Red cape, Grindstone island, lying on this gravel layer and 

 buried under 6 to 12 inches of plant mold and sod we uncovered the bones of 



