July-August 1873, Alps and Little Yosemite Image 44

(found with Yosemite sketches) E. [Y.] P. 50 of its moraine in a way that crushes off their angles & give them forms that I never before could account for also gives to the bank thus crushed also a finish that I have often observed without knowing its cause Is similar to the edges of a gorge down wh [which] earthquakes have sent stone avalanches. I have been noting for some time the [curved] dirt lines on the snouts of gls [glaciers]. This is well seen here discovered from sections made by the stream & wh [which] I made with axe that this surface marking is the weathered ends or edges rather of the successive layers of wh [which] the whole gl [glacier] is made up by the seasons snows. Wherever a line with greater quantity of dirt appeared a section of the clean ice beneath would always show that the greater dirtiness was correspondent with seam or layer of harder bluer ice. These layers of ice are curved more or less in a vertical direction some places nearly on edge. This [bending] of the [layers] proves a bending of the whole gl [glacier] always most bent where most opposed in its motion thus. The motion of those small steeply inclined glaciers is not at all in the direction of their surfaces throughout all their thickness but [sketch: ends of [layers] once horizontal] rather in the direction of their bottom curves That is when they occupy basins of this form wh [which] most of them do This upward motion of the lower ends of gls [glaciers] explains not only the vertical stratificat[ion] but the condition of their terminal moraines wh [which] [always] have their slopes exceedingly [steep] as if added to & fed [from] bottom upward with outer face convex. The motion of the ice being greater in middle of gl [glacier] would make the [surface] of the terminal mor [moraine] convex [sketch: A; B; dir [direction] of force]https://scholarlycommons.pacific.edu/jmj-all/1636/thumbnail.jp