Geology . ZTmmmmmz Fig. 573.—The same at an early stage of talus formation. at intervals and develop steep bluffs. When the meanders shift,as they are sure to do, the bluffs inevitably grade down to a slope bythe falling, or sliding, or washing of the top to the bottom, as illus-. MlMtll Fig. 574.—The same at a late stage of gradation, when the slope has become nearly stable. trated in Figs. 572-574. What was in the top portion naturallybecomes part of the base of the talus, and is deeply buried. Similarsecondary burials take place in various kinds of loose material, includ- THE PLEISTOCENE OR
Geology . ZTmmmmmz Fig. 573.—The same at an early stage of talus formation. at intervals and develop steep bluffs. When the meanders shift,as they are sure to do, the bluffs inevitably grade down to a slope bythe falling, or sliding, or washing of the top to the bottom, as illus-. MlMtll Fig. 574.—The same at a late stage of gradation, when the slope has become nearly stable. trated in Figs. 572-574. What was in the top portion naturallybecomes part of the base of the talus, and is deeply buried. Similarsecondary burials take place in various kinds of loose material, includ- THE PLEISTOCENE OR GLACIAL PERIOD. 511 ing loess and fluvial deposits of all sorts. It is to be noted that thisis a prevailing habit, and not an exceptional mode of action. While lateral action of this kind seems to have been the most com-mon mode of burial of artefacs and other superficial material, othersystematic methods are One of the more important arisesfrom the scour-and-fill of streams when they run on beds of gravel,sand, silt, or other loose material. The irregularities of a streamsflow, particularly the swirls and rolls developed by its meanders, giverise to shallows and deeps, and constantly shift them so that in timethey cover nearly, or quite, the whole of the b
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