REPORTS ON TORONTO HARBOl R. 



from us now, when those banks were washed directly by the 

 surges of Lake Ontario. It i- abundantly evident that the Don- 

 within the limits of the Christian era, poured its waters directly 

 into the Lake, as the absence of mud, In ml, which alone constitutes 

 .1 delta, well proves, withoul reference to the deep waters of the 



Marsh, ami (lie absence of that evidence of antiquity whicl 



would expect to find, if the Don had for many ages contributed its 

 detritus to fill the space intervening its mouth and the opposite, 

 though somewhat far removed shore of the Luke boundary of the 

 Marsh. 



It ia, however, important to inquire what phenomena exhibit 

 themselves at the mouths of rivers pouring their" waters directly 

 into the Lake, such rivers, for instance, as the Rouge, the Humber, 

 the Mimico, and the Highland Creek, which are severally larger 

 and smaller than the I >.ni, consequently comprehend either extreme 

 in point of dimensions. It is important to know whether it is 

 probable, or even under ordinary circumstances of wind and wea- 

 ther, possible for the Don to have formed a bar (the proper term) as 

 far from its mouth as the south sand beach of Ashbridge's Bay. 



The testimony of Mr. Hall is peculiarly appropriate in the pre- 

 sent instance. Speaking of bars at the mouths of rivers and streams, 

 he says, "The bar is formed by the influence of two forces — the 

 waves washing in, which carry forward the sand and deposit it in 

 long beaches ; and the opposing power of the steady current, which 

 neutralizes that of the waves, and the sand then falls down in 

 a broad curve. The force of the current is principally expended 

 in opposing the waves of the Lake, and becoming diffused, itflow s 

 quietly over the bar. This continues while there is no more than 

 ordinary force in the waves, but on the occurrence of a violent 

 north-east storm (i. e. near Genesee) the whole of this bar and 

 perhaps ten times as great an amount of matter is thrown upon the 

 beach, closing the outlet. This remains so long as the wind con- 

 tinues, but as soon as it subsides an8 the water in the pond is able 

 to force a passage through the beach, the old order of things is re- 

 sumed to be again subverted and again renewed. Such, simply, 

 is the operation of one stream, as it has existed for the last four or 

 five years, and such would be the history of hundreds of large and 

 small streams along the Lake shore." (Geo. of the 4th District, p. 

 356.) The knowledge acquired by the inspection of any stream 

 pouring its waters directly into Lake Ontario, shows that it is im- 

 possible for a small river like the Don, even if it were ten times as 

 large, to form a bar a mile from its mouth and water to the depth 

 of 18 and 20 feet intervene. Nor is there reason to suppose that 

 the Don was ever a stream much larger than it is at present. 

 Those who are familiar with the cutting action of rivers, first 

 attacking one bank, then by landslips or fallen trees, driven to the 

 opposite bank, will feel fully satisfied that the Don in its present 

 development is abundantly sufficient to explain the denuding action 

 it has exercised since it began to flow with the slowly receding 

 waters of a tertiary ocean. 



"We may, however, gain some clue as to the age of the marshes 

 of the Don, and the beaches which confine them, by examining 

 other marshes and beaches which have been long under observa- 

 tion. In geological investigations every thing is to be learnt by 

 comparison, and he who speculates upon an incident without 

 taking cognizance of similar occurrences must expect to be called 

 upon to furnish a separate theory for every phenomenon, differing 

 in externals from the class to which it belongs. 



[n describing the ponds, marshes, and beaches which lie to the 

 west of the Genesee river, Mr. Hall mentions a few facts which 

 will enable us to form some idea of the probable age of the 'Delta' 

 of the Don. 



"The beach before alluded to between the Lake and these 

 ponds, is nearly a mile long (near Genesee, see Lieut Herbert's 

 chart, bi fore coming to the outlet, from fifty to one hundred feet 

 ivide, and generally nol more than ii\ <• or six feel above the Lake. 

 For flu last few years* it has been wearing away (1842) and the 

 roots of large trees growing upon it are becoming exposed, and 

 some of the trees themselves are thrown down." 



" Farther westward the space between the Lake and the marsh 

 is five or six hundred feet wide. This is occupied by three distinct 

 ridges, running parallel with each other, and with the Lake. 

 Near the western extremity these three' ridges divide into four, 

 but continue equally well marked. Their summits are from six 

 to eight or ton feet above the Lake, and the vallics between them 

 arc from four to six feet below the tops of the ridgcf. The 

 materials of which they are composed are similar to the recent 

 lake beaches, consisting of pebbles and sand covered with a light 

 sandy loam. They are over-grown with large trees of oak, elm, 

 beech, and button-wood, which shows their antiquity. Their form 

 is distinct and well marked, while the cause which gave rise to 

 them morn l/tan a hundred years since is --till active, producing 

 other similar ones before our eyes." 



Mr. Hall is contented to limit the duration of the existence of 

 Lake beaches separating marshes from the Lake, and contain- 

 ing far stronger evidence of antiquity in the form of large trees of 

 " oak, elm, beech, and button-wood" than any portion of Toronto 

 Harbour beaches, to a period of " more than one hundred years," 

 — (Geol. of the 4th Dis., page 357.) 



Further on he says, " I might go on to illustrate the condition 

 of the beaches and outlets further to the west, but these few 

 examples are applicable to the whole. The ridge of beach west of 

 Long Pond is undivided, and in many places from ten to twenty 

 feet high, showing that a variation of a few feet in height can be 

 no objection to the mode of formation." 



" For many years previous to 1835 the Lakes were all at a 

 lower elevation, and this alloiced the formation of liars and beaches 

 at the outlet of streams, which before opened by a deep channel 

 into the lake." Mr. Hall here hints at a condition of things which 

 will be shown hereafter to have exercised a remarkable influence 

 upon the conformation and stability of the marshes of the Don 

 and Toronto Harbour. 



One more example will suffice to illustrate the comparatively 

 modern formation of beaches and marshes on the shores of Lake 

 Ontario. " Some of the Bays along Lake Ontario formerly 

 admitted vessels for several miles, while at the present time they 

 are partially or entirely closed. The beach formed at the mouth 

 of Irondequoit bay has a narrow opening of three feet deep, while 

 formerly it was a quarter of a mile further east, and of a depth 

 sufficient to admit sloops which took in freights at the head of the 

 bay three miles distant. The bay is so situated that it receives the 

 abraded materials of the banks of the Lake, both from east and 

 west. It is one mile and a quarter wide, gradually narrowing 

 southward ; and is separated from the Lake by a sand-bar or 



* High water of 1838 equal to that of 1853. 



