Loaf of Bread & Bun (in the Land of Crank)

Rock, from the geologic map

Young stream-channel and overbank alluvium — alluvium. Holocene, younger than 12,000 years.

Mostly pebbly sand and poorly sorted, clast-supported, pebble, cobble, and, locally, bouldery gravel in a sandy matrix. Unit locally may include thin, organic-rich layers. Clasts commonly are sub- angular and subrounded and consist of Proterozoic igneous and metamorphic rocks, Cretaceous and Tertiary intrusive rocks, and, in Arkansas River channel, Paleozoic sedimentary rocks (mostly Cambrian quartzite). Deposits form streambeds and adjacent flood plains, fill channels, and underlie low terraces less than about 2 m above present stream level. Low-lying areas are prone to periodic erosion and (or) deposition. Locally includes minor amounts of colluvium and small fan deposits; locally may include outwash gravel of Pinedale glaciation (Qgp). Estimated thickness is 5–10 m

This is the map unit under this crag's map point, read from the 1:100,000 sheet (Kellogg and others, 2017, U.S. Geological Survey Scientific Investigations Map 3382). The point can be a few hundred metres from the rock, a cliff often stands on the line between two units, and at that scale a line on the map is about 100 m wide on the ground, so the wall itself may be the neighbouring unit. Every crag on this unit: Young stream-channel and overbank alluvium. Geology data: Macrostrat (CC BY 4.0), serving USGS and Colorado Geological Survey maps.