388 Rk. BELL—HUDSON BAY MAMMOTH AND MASTODON: REMAINS. 
J. W. Spencer, further up the latter stream. As the age of the deposit 
in which these mastodon remains were found and the nature of the sur- 
rounding country were important in connection with the discovery, I 
quote Dr Spencer’s report to me on these points: * 
“The valley of the Assiniboine adjacent to that of the Shell river is about a mile 
wide and some 200 feet deep. Thealluvial flat at the bottom of the valley is three- 
quarters of a mile wide, and the banks rise steeply on either side. Through this 
Jevel flat the river pursues a meandering course from side to side, occasionally 
leaping a small rapid caused by the obstruction of Laurentian boulders. Twenty 
miles further up, the valley is nearly 3 miles wide, but at this place, in the bottom 
and following the valley longitudinally, there are 4 or 5 series of hills, rising irreg- 
wlarly one above the other, till the highest reaches nearly to the level of the plain 
above. Between -these hills there are smdfl deep valleys. The western bank is 
often strewn with gravel and boulders, while the flats below are nearly free from 
them, excepting in places along the bed of the river. The sides of the valley are 
often deeply gorged, but the ravines do not extend to any great distance back from 
the valley. Many of them appear to have been cut out by the waters from springs. 
_ These springs usually hold a considerable quantity of iron in solution, and I ob- 
served several places where yellow ochre was being deposited around them. In 
several localities on the banks of the Assiniboine extensive landslides are to be 
met with, sometimes showing stratified deposits of clay or sand. The general 
course of the Assiniboine river at the influx of the Shell river is nearly south, but 
above this it has a more westerly direction. 
“‘T explored the Shell River valley upward for 30 miles, and Mr Hagar continued 
the exploration for 10 miles further. Along the upper part of this distance the 
country on either side has usually a rolling prairie character, while in the lower 
portion the river flows in a valley nearly as wide and deep as that of the Assini- 
boine. The general course is nearly from the north. At the bends of the valley 
the river usually winds its way to the outer side, and on the inner side of the curve 
there is left a terrace or series of terraces rising from the alluvial flat to the plain - 
above. The country is generally wooded, except here and there where fires have 
swept over small areas. The Shell river is much more rapid than the Assiniboine, 
and the sides of the valley are much more deeply gorged than those of the latter 
river. At the landslides along the Shell river I observed a few stratified deposits, 
but they generally showed only a heterogeneous mixture of gravelly earth, with 
boulders. 
“Tf the rivers which now flow through them have excavated these valleys, the 
former must be of great antiquity. The valleys are yearly becoming larger by the 
spring floods bearing away great quantities of material. Everywhere along the 
river banks there are evidences of former landslides. . . . The deposits of the 
Shell River valley frequently consist of irregular beds of clay, with boulders, while 
along the alluvial flat of the Assiniboine they consist of regularly stratified clays, 
The summits and sides of the banks of both streams are generally covered with 
boulders. 
“Tn the more recent deposits of the Shell River valley an Indian is said to have 
found, a few years ago, some large bones, which were at the time sent to Fort 
* Report of the Geological Survey of Canada for 187475, pp. 58 and 63. 
