MORPHOLOGICAL AND PHYSICAL-PROPERTIES OF SELECTED FRAGIPAN SOILS IN MASSACHUSETTS

Fragipans are no longer officially recognized in New England. Presentl y all dense layers found in the region arc considered unaltered dense basal tills. Comparisons between morphological and physical properties of five pedons in Massachusetts previously classified as having fragi pans and typical fragipan properties were undertaken to ascertain the possible existence of fragipans. Morphologically, the pans contained t he typical fragipan features outlined in the soil taxonomy including b leached prism faces (BPF), lack of rooting in the pan, and the presenc e of an eluvial horizon just above the pan. Physically, the pans have a high bulk density and sometimes enough increase in clay content to m eet the taxonomic criteria for an argillic horizon. Additionally, the pans show redoximorphic features and indications of lateral water move ment across their upper surface. The argument that the pans that devel oped in dense basal till in Massachusetts are largely geogenic in orig in does not appear valid.