Till of Bull Lake age

What the map says

Subangular to subrounded boulders, cobbles, and pebbles in a silty sand matrix. Morainal form subdued in comparison to till of Pinedale age (Qp). Undrained depressions on this till are uncommon and it is more weathered than till of Pinedale age. Soils are 1-2 m thick. Thirty to 70 percent of stones in B horizon of soil are partially to totally rotted. Description from Gable and Madole (1976) and Meierding (1977). Patterned lines within unit indicate trend of moraines. South and southwest of Shadow Mountain Lake, the till is partly mantled by sheet-like deposits of fine sand or silt believed to be of eolian origin (Meierding, 1977, pages 41). Till of Bull Lake age may have been deposited between about 130,000 and 150,000 years ago (Madole and Shroba, 1979, pages 130). GRI Source Map ID 141 (I-1973). Lithology: unconsolidated.

1:100,000 sheet: National Park Service Geologic Resources Evaluation program, 2006, National Park Service (5 crags). A contact line at that scale is about 100 m wide on the ground.

Served by Macrostrat (CC BY 4.0). The wording is the map's own, quoted as a fact about the mapped unit, not about any one wall.