Argillic Horizons in Pennsylvania Soils

Clay accumulation and argillic-horizon development as influenced by aeolian deposition vs. local parent material on quartzite and limestone-derived alluvial fans

“…Ciolkosz et al (1996) used calculations of limestone rock dissolution to estimate that 1 m of limestone residual soil with clay contents (similar to the current study) would require 300,000 years to accumulate 1 m of soil (dissolution rate of 30 mm 1000 yrs − 1 ) from limestone bedrock. A dissolution rate more reflective of the current study sites (10 mm 1000 yrs − 1 ) would require 1,000,000 years to accumulate 1 m of soil (Ciolkosz et al, 1996).…”

“…Ciolkosz et al (1996) used calculations of limestone rock dissolution to estimate that 1 m of limestone residual soil with clay contents (similar to the current study) would require 300,000 years to accumulate 1 m of soil (dissolution rate of 30 mm 1000 yrs − 1 ) from limestone bedrock. A dissolution rate more reflective of the current study sites (10 mm 1000 yrs − 1 ) would require 1,000,000 years to accumulate 1 m of soil (Ciolkosz et al, 1996). Given (1) no evidence of limestone residuum at the current study site in association with the Charkiln pedons, (2) a shortage of time since fan deposition for similar amounts of clay accumulation, (3) minimal evidence of limestone alluvium, and (4) insufficient amounts of alluvium to have supplied the necessary weathering products, we conclude that upslope limestone parent materials have likely played a minimal role in development of Bt horizons in the Charkiln series.…”

“…Examining the difference in CEC (Table 1) to exchangeable Ca (Table 2) suggests another source of Ca is being contributed to the Troughspring soils (Ca salts are a potential source). The high Ca content of the Btk horizon in the Troughspring pedon may be inhibiting clay translocation via flocculation and thus the development of argillans (Ciolkosz et al, 1996).…”

Cambic Horizons in Pennsylvania Soils

“…This is the third publication on the subject of subsoil horizons in Pennsylvania soils. The other publications focused on fragipans (Ciolkosz et al, 1995) and on argillic horizons (Ciolkosz et al, 1996).…”

“…The southwest plateau has the lowest percentage of soils with cambic horizons (4%) of any area in Pennsylvania (Table 2). Most soils in this area have argillic horizons (Ciolkosz et al, 1996). The main reason for the lack of cambic horizons is that for the most part the parent material of this area has moderate to high carbonate content and a medium to fine texture.…”