Smithsonian miscellaneous collections . Valley (pi. i). The alder thickets are interruptedlocally by small parklike areas in which there are dense stands of tallbunchgrass or open stands of dwarf birch, Alaska tea, blueberry, cran-berry, and spirea. Sedges, Equisetum, and scattered small alders, ar-ranged in stripes parallel to the slope, grow on poorly drained, gentlysloping areas on the higher parts of the valley walls (upper left, pi. i).Scattered spruce may grow elsewhere in the Reindeer Hills, but thereare none in lyatayet Valley. The steep slopes of lyatayet Valley are stable and free of
Smithsonian miscellaneous collections . Valley (pi. i). The alder thickets are interruptedlocally by small parklike areas in which there are dense stands of tallbunchgrass or open stands of dwarf birch, Alaska tea, blueberry, cran-berry, and spirea. Sedges, Equisetum, and scattered small alders, ar-ranged in stripes parallel to the slope, grow on poorly drained, gentlysloping areas on the higher parts of the valley walls (upper left, pi. i).Scattered spruce may grow elsewhere in the Reindeer Hills, but thereare none in lyatayet Valley. The steep slopes of lyatayet Valley are stable and free of solifluctionor other types of mass movement today and have been for manycenturies, as indicated by the lack of active soil lobes or other activefrost features, by the wide distribution of an undisturbed soil profileat the surface, and by the continuous cover of large, healthy, unde-formed alders. Solifluction probably is active, however, on higher,gentler slopes where drainage is poorer. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 121. O (J o, NO. II lYATAYET SITE, ALASKA—HOPKINS AND GIDDINGS 7 GEOLOGY AND SOILS OF lYATAYET VALLEY Bedrock of marble lies a few feet beneath the hill slopes above theterraces. It is mantled by residual weathered material consisting of an-gular fragments of marble in a matrix of sandy silt. The fine-grainedmatrix consists chiefly of the least-soluble minerals in the and unidentified alteration minerals predominate in samplesexamined by Hopkins ; fine-grained muscovite is abundant; and quartz,apatite, tremolite, and diopside are present in small quantities. Cal-cite constitutes more than 95 percent of the bedrock but is scarce orlacking in the fine-grained matrix of the weathered mantle. The 40-foot terraces on each side of the mouth of lyatayet Creekare composed of similar weathered marble debris. The terrace fill isvaguely stratified and poorly sorted; individual fragments generallyare subangular. The deposit shows little evidenc
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