Cambic Horizon - Soil Geography of the USA: A Diagnostic-Horizon Approach - page 126

Fig. 13.1 Distribution of soils in the USA with cambic horizons (Prepared by Paul Reich)
the Mississippi River valley (Vertisols), and the Pacific Northwest (Cambids,
Andisols) and northern ID (Andisols). Figure 13.1 includes all Andisols, Cambids,
Inceptisols, and Vertisols. About 46 % of the Mollisols contain a cambic horizon;
however, these are not shown in Fig. 13.1 .
13.5 Soil-Forming Factors Influencing the Formation
of Cambic Horizons
The key factor influencing the development of the cambic horizon is the lack of
“pedogenic inertia” (Bryan and Teakle 1949 ) that contributes to the development
of more strongly developed diagnostic horizons. Cambic horizons are common
in alpine soils and soils derived from limestone, volcanic materials, and clay-
enriched materials subject to vertisolization (Table 13.3 ). The cambic horizon
forms in less than 1,000 yr and has been observed in Mesolithic and Medieval-
aged soils.