552 STEVENSON— FORMATION OF COAL BEDS. [November 3, 



resembling peat, but which still retains more or less of the fibrous structure 

 of the wood, and layers of this often alternate with layers of clay and sand, 

 the whole being penetrated to the depth of four or five yards or more by 

 the long fibrous roots of the willows. A deposition of this kind, with the 

 aid of a little infiltration of bituminous matter, would produce an excellent 

 imitation of coal, with vegetable impressions of the willow roots. The same 

 operation goes on in a much more magnificent scale in the lakes. A shoal of 

 many miles in extent is formed on the south side of Athabasca lake by 

 the drift timber and vegetable debris brought down by the Elk river; and 

 the Slave lake itself must be filled in process of time by the matters daily 

 conveyed into it from Slave river. Vast quantities of drift timber were 

 buried under the sand at the mouth of the river and enormous piles of it 

 are accumulated on the shore of every part of the lake. The waves washing 

 up much disintegrated vegetable matter, fill the interstices of these entangled 

 masses and in process of time a border of spurious peat is formed around 

 the various bays of the lake." 



In a later work,^*' referring to the drift timber of Slave river, 

 he describes the trees as "partially dentided of their branches and 

 whollv of their bark." The absence of all-important details in Rich- 

 ardson's account is dtte to the fact that he was not a geologist, but 

 he was an acute observer, as is evident from the general tenor of 

 his reports. McConnelP' has supplied many of the details omitted 

 by Richardson. The sandy beaches and islands along the lower 

 reaches of Slave river owe their origin to drift timber, which lodges 

 and soon has the growth of willows noted by that author. But those 

 islands cause currents, which either destroy them or move them 

 down stream. Beds of drift timber alternate with clays and sands 

 on many of the islands and in some instances, constitute a consid- 

 erable portion of the whole mass. The east end of Big island in 

 Great Slave lake is fringed by a wide margin of drift timber. When 

 the interstices have been filled by gradual deposition of sand and the 

 decav of the wood, a dense growth of willows covers it. The coves 

 of the main shore show the same features in many places. Atha- 

 basca and Slave lakes are inland seas, larger than Lake Ontario. 



Islands, such as those described by Franklin, are not unusual in 



^'J. Richardson, "Arctic Searching Expedition," London, 1851, Vol. I., 



p. 142. 



''R. G. McConnell, Ann. Rep. Geol. Survey of Canada, N. S., Vol. IV., 



1890, pp. 63, 64, 74 D. 



150 



