SOME MODERN ROCK-BUILDING. 43 



tlie fresh water is drained oft" a thickness of from one to two feet of 

 hike deposit is found, but under this several feet of pure ''quick- 

 sand mud." The tide had once flowed freely over this area, but 

 was checked by its own deposits ; leaving a basin above to be- 

 come lake. 



Occasionally on the banks of streams, in the deey)er de})0sits, 

 are to be seen layers of "blue" mud alternating with "red." 

 The blue mud owes its colour and chemical change to the iron 

 compounds of the red alluvium, brought about by the decay of 

 vegetable material in the presence of much moisture. This pro- 

 cess still goes on in places. The commonest vegetation so de- 

 caying are the roots and leaves of a species of sedge which does 

 not flourish on the highest marsh levels. These levels, before be- 

 ing dyked, are usually bald, or covered meagrely with samphire, 

 rosemary, or other scanty vegetation. Sedge makes a more lux- 

 uriant growth on areas more frequenth' overflowed, or in levels 

 slightly basin-like, where the alluvium is always completely sat- 

 urated with tidal waters. It is in such conditions that red allu- 

 vium becomes blue. 



From the alternate red and blue layers outcropping on river 

 banks we are enabled to read the character that each layer bore 

 when it occupied the surface. Thus then during a continuing 

 subsidence have the deeper deposits of alluvium on the lower 

 courses of rivers been made. 



Besides these there are areas, many thousj.nds of acres, about 

 the upper course of the Tantramar, Avhere rock-building, — or more 

 })r()pcrly, as the agriculturist would think, soil-building, — has 

 been and is now going on. Here nature is aided in her efiorts 

 and directed by the hand of man. These areas were originally 

 shallow lake where the Indian and the pioneer hunted the goose 

 and brant, and where later the sportsman sought the haunts of 

 the mallard. 



Early in the present century lived a farmer in the neighbor- 

 hood, Toler Thompson by name, who studied the tides of the 

 Tantramar. As a result of his observations he began to connect 

 these lake areas with the tidal waters. The fresh water flowed 

 out, and the tidal water flowed in at high water, laden with its 

 riches of salt alluvium. The lake vegetation, — moss, etc., — was 

 killed bv the salt and soon settled and became buried under sue- 



