ICE-BORNE SEDIMENTS IX MINAS BASIN, N. S. BANCROFT. 159 



stone of Triassic agv. Its chief constituents are rounded grains 

 of white to colorless quartz, decolorized and ahriost lustreless 

 flakes of niuscjviteand biotite, and a few particles of decomposed 

 feldspar, and the whole cemented together by calcite. The calcite 

 tills the interstices of the rock, and forms a thin film about each 

 individual grain of sand. The frozen interstitial water acts as 

 a powerful force in the disintegration of this sandstone, cracking 

 the calcite, and thus loosening the more durable grains of quartz 

 and mica. Another instance may well be cited. Between 

 Avonport and Hantsport, for the greater part of tlie distance, is 

 a continuous cliff of purplish to black, finely laminated shale, 

 with interspersed layers of sandstone and clay ironstone. In 

 some places, the .shale is capped by a thin layer of boulder clay. 

 Water freezes between the laminae of the shale, and breaks it up 

 into thin scale-like fragments. Large cakes of ice are left by 

 the receding tide beneath these cliffs, and on a sunny day, there 

 is a continual shower of this frost-loosened detritus upon their 

 surfaces. Sometimes landslides, on a small scale, of the over- 

 lying boulder clay pour down upon the ice a load of debris. 



(iii.) The ebb tide leaves many cakes of ice stranded on 

 th? area which is left bare between high and low water. Dur- 

 ing the interval of time between ebb and flood tide, they are 

 frozen to the surface of the ground ; but only to be floated again 

 at high water. They then lift a thin layer of detritus from the 

 land area to which tliey have been frozen. One ice crust was 

 noticed floating about with a layer of sod, which, doubtless, had 

 been in this manner removed from the surface of the marsh. 

 Upon being floated, a layer of ice forms upon the loM^er surface 

 of the ice and the debris is thus enclosed. If this action goes on 

 for several days, it gives the ice a viell stratified appearance. 



During the second week in February, 1903, while study ino- 

 at Acadia College, the writer, under the guidance of Professor 

 Ernest Haj^cock, performed a series of experiments, in order to 

 a.scertain the amount of sediment carried by the ice in Minas 

 Basin at that time. The winter was not very severe, and the 



