No. L] GEOGNOSTICAL OBSERVATIONS. 501 



lay 



Hill River, the other branch and the one through which 



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In the lower parts of Hill River the banks are composed nearly of the same 

 materials as those in Hayes and Steel Rivers, but they rise more precipitously 

 from the very narrow channel of the river to an elevation of nearly two hun- 

 dred feet. Their outline, too, is more varied, being broken into conical emi- 

 nences by numerous ravines which open into the river at right angles. Many 

 steep cliffs, sections of these eminences, and of course of a conical form, have 

 their bases washed by the streams ; one of the most remarkable is named the 

 Sugar Loaf. The banks being exactly similar in form and constituent parts 

 to those which occur on Lake Winipeg and the Saskatchawan on the confines 

 of the limestone formation there, I am inclined to believe that this part of Hill 

 River cuts the western boundary of the other limestone district, which has been 

 spoken of as running parallel to the coast. We did not observe, however, any 

 of the solid strata in the bed of the river, although the clay on the banks con- 

 tained many imbedded fragments of the stone, as well as 

 matter intimately blended with it. 



much 



About a mile below the Rock Portage, or ninety-nine miles from the sea, 

 (including the windings of the river course) rocks in situ first occur. They 

 consist of gneiss, and rise in the channel of the river from under the lofty clay 

 banks which still continue. 



The gneiss formation appears to extend from this place to Lake Winipeg, 

 and to contain subordinate beds and veins of granite, beds of hornblende, 

 rock, and mica slate, which we shall enumerate in the order in which they 

 occurred on our route. The general direction of the strata appears to be 

 from NE to SW, but our opportunities of observation were too limited to 

 decide this fact. 



At the Rock Portage a ridge of gneiss, crossing the stream obliquely, forms 

 a chain of small islands, and produces several cascades. The gneiss at this 



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spot is intersected in every direction by veins of quartz, and there is but 

 little mica disseminated through it, the greatest part of this mineral being 

 confined to kidneys, which are insensibly blended with the enclosing rock. 

 The great number of the veins, their intricate ramifications, and reunions, 

 viewed in conj unction with the different portions of the rock very dissimilar 

 to each other, but uniting together by imperceptible gradations, seem to 



