||Geologic Substrates with less than 50% cover of Rock Substrate. This class uses Folk
(1954) terminology to describe any mix of loose mineral substrate that occurs at any
range of sizes—from Boulders to Clay. This hierarchy and the associated terms are
shown in Figure 7.2. These classifications may be based on percent weight (e.g., for
retrieved samples); percent cover (e.g., for plan-view images); or visual percent
composition (for other approaches). Units with bracketed letters, e.g., [G], [mSG],
correspond to the labeled polygons in Figure 7.2, using conventions from Folk (1954).